Updated to Swift 5.0, Removed Swift 3 support

Merge pull request #139 from sasaki-945/master
Fixed bug: cannot be transferred file 4KB or less
2019-04-04 12:42:17 +04:30 · 2018-12-16 10:25:42 +03:30 · 2018-12-10 14:48:59 +09:00 · 2018-11-20 07:49:24 +03:30 · 2018-11-20 11:10:05 +09:00 · 2018-11-19 13:46:37 +03:30
37 changed files with 2758 additions and 1741 deletions
@@ -1 +0,0 @@
-4.0
@@ -1,5 +1,5 @@
 language: objective-c
-osx_image: xcode9
+osx_image: xcode10.2
 xcode_project: $PROJECTNAME.xcodeproj
 env:
  global: 
@@ -13,14 +13,14 @@ env:
  - MACOS_SDK=macosx
  - TVOS_SDK=appletvsimulator
  matrix:
-    - DESTINATION="OS=11.0,name=iPad Pro (10.5-inch)"  SCHEME="$IOS_FRAMEWORK_SCHEME"     SDK="$IOS_SDK"     CARTHAGEDEPLOY="YES"
-    - DESTINATION="OS=11.0,name=iPhone 8"              SCHEME="$IOS_FRAMEWORK_SCHEME"     SDK="$IOS_SDK"     POD="YES"
+    - DESTINATION="OS=12.2,name=iPad Pro (10.5-inch)"  SCHEME="$IOS_FRAMEWORK_SCHEME"     SDK="$IOS_SDK"     CARTHAGEDEPLOY="YES"
+    - DESTINATION="OS=12.2,name=iPhone 8"              SCHEME="$IOS_FRAMEWORK_SCHEME"     SDK="$IOS_SDK"     POD="YES"
    - DESTINATION="arch=x86_64"                        SCHEME="$MACOS_FRAMEWORK_SCHEME"   SDK="$MACOS_SDK"
    - DESTINATION="arch=x86_64"                        SCHEME="FilesProviderTests"        SDK="$MACOS_SDK"   RUN_TESTS="YES"
-    - DESTINATION="OS=11.0,name=Apple TV 1080p"        SCHEME="$TVOS_FRAMEWORK_SCHEME"    SDK="$TVOS_SDK"
+    - DESTINATION="OS=12.2,name=Apple TV 1080p"        SCHEME="$TVOS_FRAMEWORK_SCHEME"    SDK="$TVOS_SDK"
 before_install:
-  - gem install xcpretty --no-rdoc --no-ri --no-document --quiet
-  - gem install cocoapods --no-rdoc --no-ri --no-document --quiet
+  - gem install xcpretty --no-document --quiet
+  - gem install cocoapods --no-document --quiet
  # - gem install xcpretty-travis-formatter

 script:
@@ -76,4 +76,4 @@ deploy:
    # repo: amosavian/$PROJECTNAME
    repo: amosavian/FileProvider
    tags: true
-    condition: "$CARTHAGEDEPLOY = YES"
+    condition: "$CARTHAGEDEPLOY = YES"
@@ -16,7 +16,7 @@ Pod::Spec.new do |s|
  #

  s.name         = "FilesProvider"
-  s.version      = "0.24.0"
+  s.version      = "0.26.0"
  s.summary      = "FileManager replacement for Local and Remote (WebDAV/FTP/Dropbox/OneDrive/SMB2) files on iOS and macOS."

  # This description is used to generate tags and improve search results.
@@ -55,9 +55,8 @@ Pod::Spec.new do |s|
  #  profile URL.
  #

-  s.author             = { "Amir Abbas Mousavian" => "a.mosavian@gmail.com" }
  # Or just: s.author    = "Amir Abbas Mousavian"
-  # s.authors            = { "Amir Abbas Mousavian" => "a.mosavian@gmail.com" }
+  s.authors            = { "Amir Abbas Mousavian" => "a.mosavian@gmail.com" }
  s.social_media_url   = "https://twitter.com/amosavian"

  # ――― Platform Specifics ――――――――――――――――――――――――――――――――――――――――――――――――――――――― #
@@ -66,7 +65,7 @@ Pod::Spec.new do |s|
  #  the deployment target. You can optionally include the target after the platform.
  #

-  s.swift_version = "4.0"
+  s.swift_version = "5.0"
  s.ios.deployment_target = "8.0"
  s.osx.deployment_target = "10.10"
  # s.watchos.deployment_target = "2.0"
@@ -117,7 +116,10 @@ Pod::Spec.new do |s|
  #

  # s.framework  = "SomeFramework"
-  # s.frameworks = "SomeFramework", "AnotherFramework"
+  s.frameworks = "AVFoundation", "ImageIO", "CoreGraphics"
+  s.ios.framework  = "UIKit"
+  s.tvos.framework = "UIKit"
+  s.osx.framework  = "AppKit"

  s.library   = "xml2"
  # s.libraries = "iconv", "xml2"
@@ -60,6 +60,7 @@
 		7958155B1F478ED9003344DD /* HTTPFileProvider.swift in Sources */ = {isa = PBXBuildFile; fileRef = 795815591F478ED9003344DD /* HTTPFileProvider.swift */; };
 		7958155C1F478ED9003344DD /* HTTPFileProvider.swift in Sources */ = {isa = PBXBuildFile; fileRef = 795815591F478ED9003344DD /* HTTPFileProvider.swift */; };
 		798654331E8874BC002FA550 /* FTPHelper.swift in Sources */ = {isa = PBXBuildFile; fileRef = 798654321E8874BC002FA550 /* FTPHelper.swift */; };
+		798D394020D01DA100FFB9EF /* CoreGraphics.framework in Frameworks */ = {isa = PBXBuildFile; fileRef = 798D393F20D01DA000FFB9EF /* CoreGraphics.framework */; };
 		799396AA1D48C02300086753 /* DropboxFileProvider.swift in Sources */ = {isa = PBXBuildFile; fileRef = 799396931D48C02300086753 /* DropboxFileProvider.swift */; };
 		799396AB1D48C02300086753 /* DropboxFileProvider.swift in Sources */ = {isa = PBXBuildFile; fileRef = 799396931D48C02300086753 /* DropboxFileProvider.swift */; };
 		799396AC1D48C02300086753 /* DropboxFileProvider.swift in Sources */ = {isa = PBXBuildFile; fileRef = 799396931D48C02300086753 /* DropboxFileProvider.swift */; };
@@ -113,7 +114,6 @@
 		79BD63AC1E2CC2C20035128C /* ImageIO.framework in Frameworks */ = {isa = PBXBuildFile; fileRef = 79BD63AB1E2CC2C20035128C /* ImageIO.framework */; };
 		79BD63B01E2CC3300035128C /* libxml2.tbd in Frameworks */ = {isa = PBXBuildFile; fileRef = 79BD63AF1E2CC3300035128C /* libxml2.tbd */; };
 		79BD63B21E2CC3350035128C /* ImageIO.framework in Frameworks */ = {isa = PBXBuildFile; fileRef = 79BD63B11E2CC3350035128C /* ImageIO.framework */; };
-		79BD63B61E2CC3860035128C /* CoreFoundation.framework in Frameworks */ = {isa = PBXBuildFile; fileRef = 79BD63B51E2CC3860035128C /* CoreFoundation.framework */; };
 		79BD63B81E2CC38D0035128C /* AVFoundation.framework in Frameworks */ = {isa = PBXBuildFile; fileRef = 79BD63B71E2CC38D0035128C /* AVFoundation.framework */; };
 		79BD63BA1E2CC39B0035128C /* libxml2.tbd in Frameworks */ = {isa = PBXBuildFile; fileRef = 79BD63B91E2CC39B0035128C /* libxml2.tbd */; };
 		79BD63BE1E2CC3C20035128C /* ImageIO.framework in Frameworks */ = {isa = PBXBuildFile; fileRef = 79BD63BD1E2CC3C20035128C /* ImageIO.framework */; };
@@ -132,6 +132,9 @@
 		79F5745B1DFDB10B00179ABF /* FileObject.swift in Sources */ = {isa = PBXBuildFile; fileRef = 79F5745A1DFDB10A00179ABF /* FileObject.swift */; };
 		79F5745C1DFDB10B00179ABF /* FileObject.swift in Sources */ = {isa = PBXBuildFile; fileRef = 79F5745A1DFDB10A00179ABF /* FileObject.swift */; };
 		79F5745D1DFDB10B00179ABF /* FileObject.swift in Sources */ = {isa = PBXBuildFile; fileRef = 79F5745A1DFDB10A00179ABF /* FileObject.swift */; };
+		CE27C49B219BFFA0000BE23C /* ServerTrustPolicy.swift in Sources */ = {isa = PBXBuildFile; fileRef = CE27C498219BFFA0000BE23C /* ServerTrustPolicy.swift */; };
+		CE27C49C219C041E000BE23C /* ServerTrustPolicy.swift in Sources */ = {isa = PBXBuildFile; fileRef = CE27C498219BFFA0000BE23C /* ServerTrustPolicy.swift */; };
+		CE27C49D219C041E000BE23C /* ServerTrustPolicy.swift in Sources */ = {isa = PBXBuildFile; fileRef = CE27C498219BFFA0000BE23C /* ServerTrustPolicy.swift */; };
 /* End PBXBuildFile section */

 /* Begin PBXContainerItemProxy section */
@@ -163,6 +166,7 @@
 		794C220D1D591A4B00EC49B8 /* SMB2QueryTypes.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = SMB2QueryTypes.swift; sourceTree = "<group>"; };
 		795815591F478ED9003344DD /* HTTPFileProvider.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = HTTPFileProvider.swift; sourceTree = "<group>"; };
 		798654321E8874BC002FA550 /* FTPHelper.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = FTPHelper.swift; sourceTree = "<group>"; };
+		798D393F20D01DA000FFB9EF /* CoreGraphics.framework */ = {isa = PBXFileReference; lastKnownFileType = wrapper.framework; name = CoreGraphics.framework; path = System/Library/Frameworks/CoreGraphics.framework; sourceTree = SDKROOT; };
 		799396671D48B7F600086753 /* FilesProvider.framework */ = {isa = PBXFileReference; explicitFileType = wrapper.framework; includeInIndex = 0; path = FilesProvider.framework; sourceTree = BUILT_PRODUCTS_DIR; };
 		799396751D48B80D00086753 /* FilesProvider.framework */ = {isa = PBXFileReference; explicitFileType = wrapper.framework; includeInIndex = 0; path = FilesProvider.framework; sourceTree = BUILT_PRODUCTS_DIR; };
 		799396821D48B82700086753 /* FilesProvider.framework */ = {isa = PBXFileReference; explicitFileType = wrapper.framework; includeInIndex = 0; path = FilesProvider.framework; sourceTree = BUILT_PRODUCTS_DIR; };
@@ -205,6 +209,7 @@
 		79D903531FAB647400D61D31 /* FilesProviderTests.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = FilesProviderTests.swift; sourceTree = "<group>"; };
 		79D903551FAB647400D61D31 /* Info.plist */ = {isa = PBXFileReference; lastKnownFileType = text.plist.xml; path = Info.plist; sourceTree = "<group>"; };
 		79F5745A1DFDB10A00179ABF /* FileObject.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = FileObject.swift; sourceTree = "<group>"; };
+		CE27C498219BFFA0000BE23C /* ServerTrustPolicy.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = ServerTrustPolicy.swift; sourceTree = "<group>"; };
 /* End PBXFileReference section */

 /* Begin PBXFrameworksBuildPhase section */
@@ -213,8 +218,8 @@
 			buildActionMask = 2147483647;
 			files = (
 				79BD63AA1E2CC2BB0035128C /* AVFoundation.framework in Frameworks */,
-				79BD63AC1E2CC2C20035128C /* ImageIO.framework in Frameworks */,
 				79BD63A81E2CC2940035128C /* CoreGraphics.framework in Frameworks */,
+				79BD63AC1E2CC2C20035128C /* ImageIO.framework in Frameworks */,
 				791950F51DE58A5400B4426E /* libxml2.tbd in Frameworks */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;
@@ -224,7 +229,7 @@
 			buildActionMask = 2147483647;
 			files = (
 				79BD63B81E2CC38D0035128C /* AVFoundation.framework in Frameworks */,
-				79BD63B61E2CC3860035128C /* CoreFoundation.framework in Frameworks */,
+				798D394020D01DA100FFB9EF /* CoreGraphics.framework in Frameworks */,
 				79BD63B21E2CC3350035128C /* ImageIO.framework in Frameworks */,
 				79BD63B01E2CC3300035128C /* libxml2.tbd in Frameworks */,
 			);
@@ -255,6 +260,7 @@
 		791950F31DE58A5300B4426E /* Frameworks */ = {
 			isa = PBXGroup;
 			children = (
+				798D393F20D01DA000FFB9EF /* CoreGraphics.framework */,
 				79BD63C11E2CC3D30035128C /* AVFoundation.framework */,
 				79BD63BF1E2CC3CD0035128C /* CoreGraphics.framework */,
 				79BD63BD1E2CC3C20035128C /* ImageIO.framework */,
@@ -350,6 +356,7 @@
 				798654321E8874BC002FA550 /* FTPHelper.swift */,
 				799396971D48C02300086753 /* SMBClient.swift */,
 				799396981D48C02300086753 /* SMBFileProvider.swift */,
+				CE27C498219BFFA0000BE23C /* ServerTrustPolicy.swift */,
 			);
 			path = Sources;
 			sourceTree = "<group>";
@@ -496,7 +503,7 @@
 			isa = PBXProject;
 			attributes = {
 				LastSwiftUpdateCheck = 0910;
-				LastUpgradeCheck = 0900;
+				LastUpgradeCheck = 0930;
 				TargetAttributes = {
 					799396661D48B7F600086753 = {
 						CreatedOnToolsVersion = 7.3.1;
@@ -504,22 +511,25 @@
 					};
 					799396741D48B80D00086753 = {
 						CreatedOnToolsVersion = 7.3.1;
+						LastSwiftMigration = 1020;
 					};
 					799396811D48B82700086753 = {
 						CreatedOnToolsVersion = 7.3.1;
 					};
 					79D903501FAB647400D61D31 = {
 						CreatedOnToolsVersion = 9.1;
+						LastSwiftMigration = 1020;
 						ProvisioningStyle = Automatic;
 					};
 				};
 			};
 			buildConfigurationList = 7993965F1D48B7BF00086753 /* Build configuration list for PBXProject "FilesProvider" */;
 			compatibilityVersion = "Xcode 3.2";
-			developmentRegion = English;
+			developmentRegion = en;
 			hasScannedForEncodings = 0;
 			knownRegions = (
 				en,
+				Base,
 			);
 			mainGroup = 7993965B1D48B7BF00086753;
 			productRefGroup = 799396681D48B7F600086753 /* Products */;
@@ -573,6 +583,7 @@
 				799396B31D48C02300086753 /* LocalFileProvider.swift in Sources */,
 				799396D41D48C02300086753 /* SMB2Tree.swift in Sources */,
 				7924B1A21D89DAE000589DB7 /* Options.swift in Sources */,
+				CE27C49D219C041E000BE23C /* ServerTrustPolicy.swift in Sources */,
 				792572411DF23BDA006A1526 /* LocalHelper.swift in Sources */,
 				7936BC121E880F5700A6C81C /* FTPFileProvider.swift in Sources */,
 				79480FF61E3ABDD0007E7275 /* CloudFileProvider.swift in Sources */,
@@ -617,6 +628,7 @@
 				799396B41D48C02300086753 /* LocalFileProvider.swift in Sources */,
 				799396D51D48C02300086753 /* SMB2Tree.swift in Sources */,
 				7924B1A31D89DAE000589DB7 /* Options.swift in Sources */,
+				CE27C49C219C041E000BE23C /* ServerTrustPolicy.swift in Sources */,
 				792572421DF23BDA006A1526 /* LocalHelper.swift in Sources */,
 				7936BC131E880F5700A6C81C /* FTPFileProvider.swift in Sources */,
 				79480FF71E3ABDD0007E7275 /* CloudFileProvider.swift in Sources */,
@@ -661,6 +673,7 @@
 				799396B51D48C02300086753 /* LocalFileProvider.swift in Sources */,
 				799396D61D48C02300086753 /* SMB2Tree.swift in Sources */,
 				7924B1A41D89DAE000589DB7 /* Options.swift in Sources */,
+				CE27C49B219BFFA0000BE23C /* ServerTrustPolicy.swift in Sources */,
 				792572431DF23BDA006A1526 /* LocalHelper.swift in Sources */,
 				7936BC141E880F5700A6C81C /* FTPFileProvider.swift in Sources */,
 				79480FF81E3ABDD0007E7275 /* CloudFileProvider.swift in Sources */,
@@ -720,16 +733,18 @@
 		799396601D48B7BF00086753 /* Debug */ = {
 			isa = XCBuildConfiguration;
 			buildSettings = {
-				BUNDLE_VERSION_STRING = 0.24.0;
+				BUNDLE_VERSION_STRING = 0.25.1;
 				CLANG_WARN_BLOCK_CAPTURE_AUTORELEASING = YES;
 				CLANG_WARN_BOOL_CONVERSION = YES;
 				CLANG_WARN_COMMA = YES;
 				CLANG_WARN_CONSTANT_CONVERSION = YES;
+				CLANG_WARN_DEPRECATED_OBJC_IMPLEMENTATIONS = YES;
 				CLANG_WARN_EMPTY_BODY = YES;
 				CLANG_WARN_ENUM_CONVERSION = YES;
 				CLANG_WARN_INFINITE_RECURSION = YES;
 				CLANG_WARN_INT_CONVERSION = YES;
 				CLANG_WARN_NON_LITERAL_NULL_CONVERSION = YES;
+				CLANG_WARN_OBJC_IMPLICIT_RETAIN_SELF = YES;
 				CLANG_WARN_OBJC_LITERAL_CONVERSION = YES;
 				CLANG_WARN_RANGE_LOOP_ANALYSIS = YES;
 				CLANG_WARN_STRICT_PROTOTYPES = YES;
@@ -738,7 +753,6 @@
 				CLANG_WARN__DUPLICATE_METHOD_MATCH = YES;
 				COPY_PHASE_STRIP = NO;
 				DEBUG_INFORMATION_FORMAT = dwarf;
-				ENABLE_BITCODE = YES;
 				ENABLE_STRICT_OBJC_MSGSEND = YES;
 				ENABLE_TESTABILITY = YES;
 				GCC_NO_COMMON_BLOCKS = YES;
@@ -759,16 +773,18 @@
 		799396611D48B7BF00086753 /* Release */ = {
 			isa = XCBuildConfiguration;
 			buildSettings = {
-				BUNDLE_VERSION_STRING = 0.24.0;
+				BUNDLE_VERSION_STRING = 0.25.1;
 				CLANG_WARN_BLOCK_CAPTURE_AUTORELEASING = YES;
 				CLANG_WARN_BOOL_CONVERSION = YES;
 				CLANG_WARN_COMMA = YES;
 				CLANG_WARN_CONSTANT_CONVERSION = YES;
+				CLANG_WARN_DEPRECATED_OBJC_IMPLEMENTATIONS = YES;
 				CLANG_WARN_EMPTY_BODY = YES;
 				CLANG_WARN_ENUM_CONVERSION = YES;
 				CLANG_WARN_INFINITE_RECURSION = YES;
 				CLANG_WARN_INT_CONVERSION = YES;
 				CLANG_WARN_NON_LITERAL_NULL_CONVERSION = YES;
+				CLANG_WARN_OBJC_IMPLICIT_RETAIN_SELF = YES;
 				CLANG_WARN_OBJC_LITERAL_CONVERSION = YES;
 				CLANG_WARN_RANGE_LOOP_ANALYSIS = YES;
 				CLANG_WARN_STRICT_PROTOTYPES = YES;
@@ -776,7 +792,6 @@
 				CLANG_WARN_UNREACHABLE_CODE = YES;
 				CLANG_WARN__DUPLICATE_METHOD_MATCH = YES;
 				DEBUG_INFORMATION_FORMAT = "dwarf-with-dsym";
-				ENABLE_BITCODE = YES;
 				ENABLE_STRICT_OBJC_MSGSEND = YES;
 				GCC_NO_COMMON_BLOCKS = YES;
 				GCC_WARN_64_TO_32_BIT_CONVERSION = YES;
@@ -820,6 +835,7 @@
 				PRODUCT_BUNDLE_IDENTIFIER = "com.mousavian.FilesProvider-iOS";
 				SDKROOT = iphoneos;
 				SKIP_INSTALL = YES;
+				SWIFT_VERSION = 4.2;
 				TARGETED_DEVICE_FAMILY = "1,2";
 				VERSIONING_SYSTEM = "apple-generic";
 				VERSION_INFO_PREFIX = "";
@@ -850,6 +866,7 @@
 				PRODUCT_BUNDLE_IDENTIFIER = "com.mousavian.FilesProvider-iOS";
 				SDKROOT = iphoneos;
 				SKIP_INSTALL = YES;
+				SWIFT_VERSION = 4.2;
 				TARGETED_DEVICE_FAMILY = "1,2";
 				VALIDATE_PRODUCT = YES;
 				VERSIONING_SYSTEM = "apple-generic";
@@ -873,7 +890,6 @@
 				DYLIB_COMPATIBILITY_VERSION = 1;
 				DYLIB_CURRENT_VERSION = 1;
 				DYLIB_INSTALL_NAME_BASE = "@rpath";
-				ENABLE_BITCODE = NO;
 				ENABLE_STRICT_OBJC_MSGSEND = YES;
 				ENABLE_TESTABILITY = YES;
 				FRAMEWORK_VERSION = A;
@@ -891,6 +907,7 @@
 				PRODUCT_BUNDLE_IDENTIFIER = "com.mousavian.FilesProvider-OSX";
 				SDKROOT = macosx;
 				SKIP_INSTALL = YES;
+				SWIFT_VERSION = 5.0;
 				VERSIONING_SYSTEM = "apple-generic";
 				VERSION_INFO_PREFIX = "";
 			};
@@ -912,7 +929,6 @@
 				DYLIB_COMPATIBILITY_VERSION = 1;
 				DYLIB_CURRENT_VERSION = 1;
 				DYLIB_INSTALL_NAME_BASE = "@rpath";
-				ENABLE_BITCODE = NO;
 				ENABLE_NS_ASSERTIONS = NO;
 				ENABLE_STRICT_OBJC_MSGSEND = YES;
 				FRAMEWORK_VERSION = A;
@@ -925,6 +941,7 @@
 				PRODUCT_BUNDLE_IDENTIFIER = "com.mousavian.FilesProvider-OSX";
 				SDKROOT = macosx;
 				SKIP_INSTALL = YES;
+				SWIFT_VERSION = 5.0;
 				VERSIONING_SYSTEM = "apple-generic";
 				VERSION_INFO_PREFIX = "";
 			};
@@ -961,6 +978,7 @@
 				PRODUCT_BUNDLE_IDENTIFIER = "com.mousavian.FilesProvider-tvOS";
 				SDKROOT = appletvos;
 				SKIP_INSTALL = YES;
+				SWIFT_VERSION = 4.2;
 				TARGETED_DEVICE_FAMILY = 3;
 				TVOS_DEPLOYMENT_TARGET = 10.0;
 				VERSIONING_SYSTEM = "apple-generic";
@@ -994,6 +1012,7 @@
 				PRODUCT_BUNDLE_IDENTIFIER = "com.mousavian.FilesProvider-tvOS";
 				SDKROOT = appletvos;
 				SKIP_INSTALL = YES;
+				SWIFT_VERSION = 4.2;
 				TARGETED_DEVICE_FAMILY = 3;
 				TVOS_DEPLOYMENT_TARGET = 10.0;
 				VALIDATE_PRODUCT = YES;
@@ -1019,7 +1038,6 @@
 				CODE_SIGN_IDENTITY = "-";
 				CODE_SIGN_STYLE = Automatic;
 				COMBINE_HIDPI_IMAGES = YES;
-				ENABLE_BITCODE = NO;
 				GCC_C_LANGUAGE_STANDARD = gnu11;
 				GCC_DYNAMIC_NO_PIC = NO;
 				GCC_PREPROCESSOR_DEFINITIONS = (
@@ -1036,6 +1054,7 @@
 				PRODUCT_NAME = "$(TARGET_NAME)";
 				SDKROOT = macosx;
 				SWIFT_ACTIVE_COMPILATION_CONDITIONS = DEBUG;
+				SWIFT_VERSION = 5.0;
 			};
 			name = Debug;
 		};
@@ -1057,7 +1076,6 @@
 				CODE_SIGN_STYLE = Automatic;
 				COMBINE_HIDPI_IMAGES = YES;
 				COPY_PHASE_STRIP = NO;
-				ENABLE_BITCODE = NO;
 				ENABLE_NS_ASSERTIONS = NO;
 				GCC_C_LANGUAGE_STANDARD = gnu11;
 				GCC_WARN_ABOUT_RETURN_TYPE = YES_ERROR;
@@ -1069,6 +1087,7 @@
 				PRODUCT_BUNDLE_IDENTIFIER = com.mousavian.FilesProviderTests;
 				PRODUCT_NAME = "$(TARGET_NAME)";
 				SDKROOT = macosx;
+				SWIFT_VERSION = 5.0;
 			};
 			name = Release;
 		};
@@ -0,0 +1,8 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
+<plist version="1.0">
+<dict>
+	<key>IDEDidComputeMac32BitWarning</key>
+	<true/>
+</dict>
+</plist>
@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <Scheme
-   LastUpgradeVersion = "0920"
+   LastUpgradeVersion = "0930"
   version = "1.3">
   <BuildAction
      parallelizeBuildables = "YES"
@@ -26,10 +26,28 @@
      buildConfiguration = "Debug"
      selectedDebuggerIdentifier = "Xcode.DebuggerFoundation.Debugger.LLDB"
      selectedLauncherIdentifier = "Xcode.DebuggerFoundation.Launcher.LLDB"
-      language = ""
      shouldUseLaunchSchemeArgsEnv = "YES">
      <Testables>
+         <TestableReference
+            skipped = "NO">
+            <BuildableReference
+               BuildableIdentifier = "primary"
+               BlueprintIdentifier = "79D903501FAB647400D61D31"
+               BuildableName = "FilesProviderTests.xctest"
+               BlueprintName = "FilesProviderTests"
+               ReferencedContainer = "container:FilesProvider.xcodeproj">
+            </BuildableReference>
+         </TestableReference>
      </Testables>
+      <MacroExpansion>
+         <BuildableReference
+            BuildableIdentifier = "primary"
+            BlueprintIdentifier = "799396741D48B80D00086753"
+            BuildableName = "FilesProvider.framework"
+            BlueprintName = "FilesProvider OSX"
+            ReferencedContainer = "container:FilesProvider.xcodeproj">
+         </BuildableReference>
+      </MacroExpansion>
      <AdditionalOptions>
      </AdditionalOptions>
   </TestAction>
@@ -37,7 +55,6 @@
      buildConfiguration = "Debug"
      selectedDebuggerIdentifier = "Xcode.DebuggerFoundation.Debugger.LLDB"
      selectedLauncherIdentifier = "Xcode.DebuggerFoundation.Launcher.LLDB"
-      language = ""
      launchStyle = "0"
      useCustomWorkingDirectory = "NO"
      ignoresPersistentStateOnLaunch = "NO"
@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <Scheme
-   LastUpgradeVersion = "0920"
+   LastUpgradeVersion = "0930"
   version = "1.3">
   <BuildAction
      parallelizeBuildables = "YES"
@@ -26,7 +26,6 @@
      buildConfiguration = "Debug"
      selectedDebuggerIdentifier = "Xcode.DebuggerFoundation.Debugger.LLDB"
      selectedLauncherIdentifier = "Xcode.DebuggerFoundation.Launcher.LLDB"
-      language = ""
      shouldUseLaunchSchemeArgsEnv = "YES">
      <Testables>
      </Testables>
@@ -37,7 +36,6 @@
      buildConfiguration = "Debug"
      selectedDebuggerIdentifier = "Xcode.DebuggerFoundation.Debugger.LLDB"
      selectedLauncherIdentifier = "Xcode.DebuggerFoundation.Launcher.LLDB"
-      language = ""
      launchStyle = "0"
      useCustomWorkingDirectory = "NO"
      ignoresPersistentStateOnLaunch = "NO"
@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <Scheme
-   LastUpgradeVersion = "0920"
+   LastUpgradeVersion = "0930"
   version = "1.3">
   <BuildAction
      parallelizeBuildables = "YES"
@@ -26,7 +26,6 @@
      buildConfiguration = "Debug"
      selectedDebuggerIdentifier = "Xcode.DebuggerFoundation.Debugger.LLDB"
      selectedLauncherIdentifier = "Xcode.DebuggerFoundation.Launcher.LLDB"
-      language = ""
      shouldUseLaunchSchemeArgsEnv = "YES">
      <Testables>
      </Testables>
@@ -37,7 +36,6 @@
      buildConfiguration = "Debug"
      selectedDebuggerIdentifier = "Xcode.DebuggerFoundation.Debugger.LLDB"
      selectedLauncherIdentifier = "Xcode.DebuggerFoundation.Launcher.LLDB"
-      language = ""
      launchStyle = "0"
      useCustomWorkingDirectory = "NO"
      ignoresPersistentStateOnLaunch = "NO"
@@ -1,4 +1,4 @@
-// swift-tools-version:4.0
+// swift-tools-version:5.0
 // The swift-tools-version declares the minimum version of Swift required to build this package.

 import PackageDescription
@@ -40,7 +40,7 @@ All functions do async calls and it wont block your main thread.
 - [ ] **GoogleFileProvider** A wrapper around Goodle Drive REST API.
 - [ ] **SMBFileProvider** SMB2/3 introduced in 2006, which is a file and printer sharing protocol originated from Microsoft Windows and now is replacing AFP protocol on macOS.
    * Data types and some basic functions are implemented but *main interface is not implemented yet!*.
-    * SMBv1/CIFS is insecure, deprecated and kinda tricky to be implemented due to strict memory allignment in Swift.
+    * For now, you can use [amosavian/AMSMB2](https://github.com/amosavian/AMSMB2) framework to connect to SMB2.

 ## Requirements

@@ -471,7 +471,7 @@ We would love for you to contribute to **FileProvider**, check the `LICENSE` fil
 Things you may consider to help us:

 - [ ] Implement request/response stack for `SMBClient`
- [ ] Implement Test-case (`XCTest`)
+- [x] Implement Test-case (`XCTest`)
 - [ ] Add Sample project for iOS
 - [ ] Add Sample project for macOS

@@ -512,7 +512,3 @@ Distributed under the MIT license. See `LICENSE` for more information.
 [cocoapods-apps]: https://img.shields.io/cocoapods/at/FilesProvider.svg
 [docs-image]: https://img.shields.io/cocoapods/metrics/doc-percent/FilesProvider.svg
 [docs-url]: http://cocoadocs.org/docsets/FilesProvider/
-## Support on Beerpay
-Hey dude! Help me out for a couple of :beers:!
-
-[![Beerpay](https://beerpay.io/amosavian/FileProvider/badge.svg?style=beer-square)](https://beerpay.io/amosavian/FileProvider)  [![Beerpay](https://beerpay.io/amosavian/FileProvider/make-wish.svg?style=flat-square)](https://beerpay.io/amosavian/FileProvider?focus=wish)
@@ -43,7 +43,7 @@ internal class AEXMLDocument: AEXMLElement {
        return rootElement
    }
    
-    open let options: AEXMLOptions
+    public let options: AEXMLOptions
    
    // MARK: - Lifecycle
    
@@ -192,7 +192,7 @@ internal class AEXMLElement {
    }
    
    fileprivate func removeChild(_ child: AEXMLElement) {
-        if let childIndex = children.index(where: { $0 === child }) {
+        if let childIndex = children.firstIndex(where: { $0 === child }) {
            children.remove(at: childIndex)
        }
    }
@@ -266,7 +266,7 @@ internal class AEXMLElement {
    
 }

-public extension String {
+extension String {
    
    /// String representation of self with XML special characters escaped.
    public var xmlEscaped: String {
@@ -37,7 +37,7 @@ open class CloudFileProvider: LocalFileProvider, FileProviderSharing {
    open fileprivate(set) var scope: UbiquitousScope
    
    /// Set this property to ignore initiations asserting to be on secondary thread
-    static open var asserting: Bool = true
+    static public var asserting: Bool = true
    
    /**
     Initializes the provider for the iCloud container associated with the specified identifier and 
@@ -82,22 +82,18 @@ open class CloudFileProvider: LocalFileProvider, FileProviderSharing {
        super.init(baseURL: baseURL)
        self.isCoorinating = true
        
-        #if swift(>=3.1)
-            let queueLabel = "FileProvider.\(Swift.type(of: self).type)"
-        #else
-            let queueLabel = "FileProvider.\(type(of: self).type)"
-        #endif
+        let queueLabel = "FileProvider.\(Swift.type(of: self).type)"
        dispatch_queue = DispatchQueue(label: queueLabel, attributes: .concurrent)
        operation_queue = OperationQueue()
        operation_queue.name = "\(queueLabel).Operation"
    }
    
    public required convenience init?(coder aDecoder: NSCoder) {
-        if let containerId = aDecoder.decodeObject(forKey: "containerId") as? String,
-            let scopeString = aDecoder.decodeObject(forKey: "scope") as? String,
+        if let containerId = aDecoder.decodeObject(of: NSString.self, forKey: "containerId") as String?,
+            let scopeString = aDecoder.decodeObject(of: NSString.self, forKey: "scope") as String?,
            let scope = UbiquitousScope(rawValue: scopeString) {
            self.init(containerId: containerId, scope: scope)
-        } else if let baseURL = aDecoder.decodeObject(forKey: "baseURL") as? URL {
+        } else if let baseURL = aDecoder.decodeObject(of: NSURL.self, forKey: "baseURL") as URL? {
            self.init(baseURL: baseURL)
        } else {
            return nil
@@ -275,7 +271,7 @@ open class CloudFileProvider: LocalFileProvider, FileProviderSharing {
            progress.setUserInfoObject(Date(), forKey: .startingTimeKey)
            if !mdquery.start() {
                self.dispatch_queue.async {
-                    completionHandler([], self.cocoaError(path, code: .fileReadNoPermission))
+                    completionHandler([], CocoaError(.fileReadNoPermission, path: path))
                }
            }
        }
@@ -342,7 +338,7 @@ open class CloudFileProvider: LocalFileProvider, FileProviderSharing {
                try self.opFileManager.copyItem(at: localFile, to: tmpFile)
                let toUrl = self.url(of: toPath)
                try self.opFileManager.setUbiquitous(true, itemAt: tmpFile, destinationURL: toUrl)
-                self.monitorFile(path: toPath, operation: operation, progress: progress)
+                self.monitorTransmissionProgress(path: toPath, operation: operation, progress: progress)
                completionHandler?(nil)
                self.delegateNotify(operation)
            } catch  {
@@ -362,7 +358,7 @@ open class CloudFileProvider: LocalFileProvider, FileProviderSharing {
                    self.operation_queue.addOperation(moveblock)
                })
            } else {
-                let e = self.cocoaError(dest.path, code: .fileWriteFileExists)
+                let e = CocoaError(.fileWriteFileExists, path: dest.path)
                dispatch_queue.async {
                    completionHandler?(e)
                }
@@ -390,7 +386,7 @@ open class CloudFileProvider: LocalFileProvider, FileProviderSharing {
    open override func copyItem(path: String, toLocalURL: URL, completionHandler: SimpleCompletionHandler) -> Progress? {
        let operation = FileOperationType.copy(source: path, destination: toLocalURL.absoluteString)
        let progress = super.copyItem(path: path, toLocalURL: toLocalURL, completionHandler: completionHandler)
-        monitorFile(path: path, operation: operation, progress: progress)
+        monitorTransmissionProgress(path: path, operation: operation, progress: progress)
        do {
            try self.opFileManager.startDownloadingUbiquitousItem(at: self.url(of: path))
        } catch {
@@ -416,7 +412,7 @@ open class CloudFileProvider: LocalFileProvider, FileProviderSharing {
    open override func contents(path: String, completionHandler: @escaping ((_ contents: Data?, _ error: Error?) -> Void)) -> Progress? {
        let operation = FileOperationType.fetch(path: path)
        let progress = super.contents(path: path, completionHandler: completionHandler)
-        monitorFile(path: path, operation: operation, progress: progress)
+        monitorTransmissionProgress(path: path, operation: operation, progress: progress)
        return progress
    }
    
@@ -437,7 +433,7 @@ open class CloudFileProvider: LocalFileProvider, FileProviderSharing {
    open override func contents(path: String, offset: Int64, length: Int, completionHandler: @escaping ((_ contents: Data?, _ error: Error?) -> Void)) -> Progress? {
        let operation = FileOperationType.fetch(path: path)
        let progress = super.contents(path: path, offset: offset, length: length, completionHandler: completionHandler)
-        monitorFile(path: path, operation: operation, progress: progress)
+        monitorTransmissionProgress(path: path, operation: operation, progress: progress)
        return progress
    }
    
@@ -460,7 +456,7 @@ open class CloudFileProvider: LocalFileProvider, FileProviderSharing {
        progress.kind = .file
        progress.setUserInfoObject(self.url(of: path), forKey: .fileURLKey)
        progress.setUserInfoObject(Progress.FileOperationKind.downloading, forKey: .fileOperationKindKey)
-        monitorFile(path: path, operation: operation, progress: progress)
+        monitorTransmissionProgress(path: path, operation: operation, progress: progress)
        _ = super.writeContents(path: path, contents: data, atomically: atomically, overwrite: overwrite, completionHandler: completionHandler)
        return progress
    }
@@ -527,6 +523,40 @@ open class CloudFileProvider: LocalFileProvider, FileProviderSharing {
        return monitors[path] != nil
    }
    
+    open func publicLink(to path: String, completionHandler: @escaping ((_ link: URL?, _ attribute: FileObject?, _ expiration: Date?, _ error: Error?) -> Void)) {
+        operation_queue.addOperation {
+            do {
+                var expiration: NSDate?
+                let url = try self.opFileManager.url(forPublishingUbiquitousItemAt: self.url(of: path), expiration: &expiration)
+                self.dispatch_queue.async {
+                    completionHandler(url, nil, expiration as Date?, nil)
+                }
+            } catch {
+                self.dispatch_queue.async {
+                    completionHandler(nil, nil, nil, error)
+                }
+            }
+        }
+    }
+    
+    /**
+     Removes local copy of file, but spares cloud copy.
+     - Parameter path: Path of file or directory to be removed from local.
+     - Parameter completionHandler: If an error parameter was provided, a presentable `Error` will be returned.
+    */
+    open func evictItem(path: String, completionHandler: SimpleCompletionHandler) {
+        operation_queue.addOperation {
+            do {
+                try self.opFileManager.evictUbiquitousItem(at: self.url(of: path))
+                completionHandler?(nil)
+            } catch {
+                completionHandler?(error)
+            }
+        }
+    }
+}
+
+extension CloudFileProvider {
    fileprivate func updateQueryTypeKeys(_ queryComponent: NSPredicate) -> NSPredicate {
        let mapDict: [String: String] = ["url": NSMetadataItemURLKey, "name": NSMetadataItemFSNameKey, "path": NSMetadataItemPathKey, "filesize": NSMetadataItemFSSizeKey, "modifiedDate": NSMetadataItemFSContentChangeDateKey, "creationDate": NSMetadataItemFSCreationDateKey, "contentType": NSMetadataItemContentTypeKey]
        
@@ -536,6 +566,7 @@ open class CloudFileProvider: LocalFileProvider, FileProviderSharing {
            case .and: return NSCompoundPredicate(andPredicateWithSubpredicates: newSub)
            case .not: return NSCompoundPredicate(notPredicateWithSubpredicate: newSub.first!)
            case .or:  return NSCompoundPredicate(orPredicateWithSubpredicates: newSub)
+            @unknown default: fatalError()
            }
        } else if let cQuery = queryComponent as? NSComparisonPredicate {
            var newLeft = cQuery.leftExpression
@@ -557,7 +588,7 @@ open class CloudFileProvider: LocalFileProvider, FileProviderSharing {
            return queryComponent
        }
    }
-
+    
    
    fileprivate func mapFileObject(attributes attribs: [String: Any]) -> FileObject? {
        guard let url = (attribs[NSMetadataItemURLKey] as? URL)?.standardizedFileURL, let name = attribs[NSMetadataItemFSNameKey] as? String else {
@@ -565,11 +596,7 @@ open class CloudFileProvider: LocalFileProvider, FileProviderSharing {
        }
        
        let path = self.relativePathOf(url: url)
-        #if swift(>=4.0)
        let rpath = path.hasPrefix("/") ? String(path[path.index(after: path.startIndex)...]) : path
-        #else
-        let rpath = path.hasPrefix("/") ? path.substring(from: path.index(after: path.startIndex)) : path
-        #endif
        let relativeUrl = URL(string: rpath.addingPercentEncoding(withAllowedCharacters: .urlPathAllowed) ?? rpath, relativeTo: self.baseURL)
        let file = FileObject(url: relativeUrl ?? url, name: name, path: path)
        
@@ -583,16 +610,84 @@ open class CloudFileProvider: LocalFileProvider, FileProviderSharing {
        return file
    }
    
-    lazy fileprivate var observer: KVOObserver = KVOObserver()
-    
-    fileprivate func monitorFile(path: String, operation: FileOperationType, progress: Progress?) {
+    fileprivate func monitorTransmissionProgress(path: String, operation: FileOperationType, progress: Progress?) {
+        var isDownloadingOperation: Bool
+        let isUploadingOperation: Bool
+        switch operation {
+        case .copy(_, destination: let dest) where dest.hasPrefix("file://"), .move(_, destination: let dest) where dest.hasPrefix("file://"):
+            fallthrough
+        case .fetch:
+            isDownloadingOperation = true
+            isUploadingOperation = false
+        case .copy(source: let source, _) where source.hasPrefix("file://"), .move(source: let source, _) where source.hasPrefix("file://"):
+            fallthrough
+        case .modify, .create:
+            isDownloadingOperation = false
+            isUploadingOperation = true
+        default:
+            return
+        }
+        
        let pathURL = self.url(of: path).standardizedFileURL
        let query = NSMetadataQuery()
-        query.predicate = NSPredicate(format: "%K LIKE[CD] %@", NSMetadataItemPathKey, pathURL.path)
-        query.valueListAttributes = [NSMetadataItemURLKey, NSMetadataItemFSNameKey, NSMetadataItemPathKey, NSMetadataUbiquitousItemPercentDownloadedKey, NSMetadataUbiquitousItemPercentUploadedKey, NSMetadataUbiquitousItemDownloadingStatusKey, NSMetadataItemFSSizeKey]
+        query.predicate = NSPredicate(format: "(%K LIKE[CD] %@)", NSMetadataItemPathKey, pathURL.path)
+        query.valueListAttributes = [NSMetadataUbiquitousItemPercentDownloadedKey,
+                                     NSMetadataUbiquitousItemPercentUploadedKey,
+                                     NSMetadataUbiquitousItemIsUploadedKey,
+                                     NSMetadataUbiquitousItemDownloadingStatusKey,
+                                     NSMetadataItemFSSizeKey]
        query.searchScopes = [self.scope.rawValue]
-        var context = QueryProgressWrapper(provider: self, progress: progress, operation: operation)
-        query.addObserver(self.observer, forKeyPath: "results", options: [.initial, .new, .old], context: &context)
+        
+        var observer: NSObjectProtocol?
+        observer = NotificationCenter.default.addObserver(forName: .NSMetadataQueryDidUpdate, object: query, queue: .main) { [weak self] (notification) in
+            guard let items = notification.userInfo?[NSMetadataQueryUpdateChangedItemsKey] as? NSArray,
+                let item = items.firstObject as? NSMetadataItem else {
+                    return
+            }
+            
+            func terminateAndRemoveObserver() {
+                guard observer != nil else { return }
+                query.stop()
+                observer.flatMap(NotificationCenter.default.removeObserver)
+                observer = nil
+            }
+            
+            func updateProgress(_ percent: NSNumber) {
+                let fraction = percent.doubleValue / 100
+                self?.delegateNotify(operation, progress: fraction)
+                if  let progress = progress {
+                    if progress.totalUnitCount < 1, let size = item.value(forAttribute: NSMetadataItemFSSizeKey) as? NSNumber {
+                        progress.totalUnitCount = size.int64Value
+                    }
+                    progress.completedUnitCount = progress.totalUnitCount > 0 ? Int64(Double(progress.totalUnitCount) * fraction) : 0
+                }
+                if percent.doubleValue == 100.0 {
+                    terminateAndRemoveObserver()
+                }
+            }
+            
+            for attrName in item.attributes {
+                switch attrName {
+                case NSMetadataUbiquitousItemPercentDownloadedKey:
+                    guard isDownloadingOperation, let percent = item.value(forAttribute: attrName) as? NSNumber else { break }
+                    updateProgress(percent)
+                case NSMetadataUbiquitousItemPercentUploadedKey:
+                    guard isUploadingOperation, let percent = item.value(forAttribute: attrName) as? NSNumber else { break }
+                    updateProgress(percent)
+                case NSMetadataUbiquitousItemDownloadingStatusKey:
+                    if isDownloadingOperation, let value = item.value(forAttribute: attrName) as? String,
+                        value == NSMetadataUbiquitousItemDownloadingStatusDownloaded {
+                        terminateAndRemoveObserver()
+                    }
+                case NSMetadataUbiquitousItemIsUploadedKey:
+                    if isUploadingOperation, let value = item.value(forAttribute: attrName) as? NSNumber, value.boolValue {
+                        terminateAndRemoveObserver()
+                    }
+                default:
+                    break
+                }
+            }
+        }
        
        DispatchQueue.main.async {
            query.start()
@@ -600,53 +695,37 @@ open class CloudFileProvider: LocalFileProvider, FileProviderSharing {
        }
    }
    
-    open func publicLink(to path: String, completionHandler: @escaping ((_ link: URL?, _ attribute: FileObject?, _ expiration: Date?, _ error: Error?) -> Void)) {
-        operation_queue.addOperation {
-            do {
-                var expiration: NSDate?
-                let url = try self.opFileManager.url(forPublishingUbiquitousItemAt: self.url(of: path), expiration: &expiration)
-                self.dispatch_queue.async {
-                    completionHandler(url, nil, expiration as Date?, nil)
-                }
-            } catch {
-                self.dispatch_queue.async {
-                    completionHandler(nil, nil, nil, error)
-                }
+    fileprivate func metadataItem(for url: URL) -> NSMetadataItem? {
+        assert(!Thread.isMainThread, "CloudFileProvider.metadataItem(for:) is not recommended to be executed on Main Thread.")
+        let query = NSMetadataQuery()
+        query.predicate = NSPredicate(format: "(%K LIKE %@)", NSMetadataItemPathKey, url.path)
+        query.searchScopes = [NSMetadataQueryUbiquitousDocumentsScope, NSMetadataQueryUbiquitousDataScope]
+        
+        var item: NSMetadataItem?
+        
+        let group = DispatchGroup()
+        group.enter()
+        var finishObserver: NSObjectProtocol?
+        finishObserver = NotificationCenter.default.addObserver(forName: .NSMetadataQueryDidFinishGathering, object: query, queue: nil, using: { (notification) in
+            defer {
+                query.stop()
+                group.leave()
+                NotificationCenter.default.removeObserver(finishObserver!)
            }
-        }
-    }
-    
-    /**
-     Removes local copy of file, but spares cloud copy.
-     - Parameter path: Path of file or directory to be removed from local
-     - Parameter completionHandler: If an error parameter was provided, a presentable `Error` will be returned.
-    */
-    open func evictItem(path: String, completionHandler: SimpleCompletionHandler) {
-        operation_queue.addOperation {
-            do {
-                try self.opFileManager.evictUbiquitousItem(at: self.url(of: path))
-                completionHandler?(nil)
-            } catch {
-                completionHandler?(error)
+            
+            if query.resultCount > 0 {
+                item = query.result(at: 0) as? NSMetadataItem
            }
+            
+            query.disableUpdates()
+            
+        })
+        
+        DispatchQueue.main.async {
+            query.start()
        }
-    }
-    
-    /**
-     Returns current version of file on this device and all versions of files in user devices.
-     - Parameter path: Path of file or directory.
-     - Parameter completionHandler: Retrieve current version on this device and all versions available. `currentVersion` will be nil if file doesn't exist. If an error parameter was provided, a presentable `Error` will be returned.
-    */
-    func versionsOfItem(path: String, completionHandler: @escaping ((_ currentVersion: NSFileVersion?, _ versions: [NSFileVersion], _ error: Error?) -> Void)) {
-        NotImplemented()
-    }
-    
-    /// Resolves conflicts by selecting a version.
-    /// - Parameter path: Path of file or directory.
-    /// - Parameter version: Version than will be choose as main version. `nil` value indicates current version on this device will be selected.
-    /// - Parameter completionHandler: If an error parameter was provided, a presentable `Error` will be returned.
-    func selectVersionOfItem(path: String, version: NSFileVersion? = nil, completionHandler: SimpleCompletionHandler) {
-        NotImplemented()
+        _ = group.wait(timeout: .now() + 30)
+        return item
    }
 }

@@ -691,87 +770,3 @@ public enum UbiquitousScope: RawRepresentable {
        }
    }
 }
-
-struct QueryProgressWrapper {
-    weak var provider: CloudFileProvider?
-    weak var progress: Progress?
-    let operation: FileOperationType
-}
-
-fileprivate class KVOObserver: NSObject {
-    override func observeValue(forKeyPath keyPath: String?, of object: Any?, change: [NSKeyValueChangeKey : Any]?, context: UnsafeMutableRawPointer?) {
-        guard let query = object as? NSMetadataQuery else {
-            return
-        }
-        guard let wrapper = context?.load(as: QueryProgressWrapper.self) else {
-            query.stop()
-            query.removeObserver(self, forKeyPath: "results")
-            return
-        }
-        let provider = wrapper.provider
-        let progress = wrapper.progress
-        let operation = wrapper.operation
-        
-        guard let results = change?[.newKey], let item = (results as? [NSMetadataItem])?.first else {
-            return
-        }
-        
-        query.disableUpdates()
-        var size = progress?.totalUnitCount ?? -1
-        if size < 0, let size_d = item.value(forAttribute: NSMetadataItemFSSizeKey) as? Int64 {
-            size = size_d
-            progress?.totalUnitCount = size
-        }
-        let downloadStatus = item.value(forAttribute: NSMetadataUbiquitousItemPercentDownloadedKey) as? String ?? ""
-        let downloaded = item.value(forAttribute: NSMetadataUbiquitousItemPercentDownloadedKey) as? Double ?? 0
-        let uploaded = item.value(forAttribute: NSMetadataUbiquitousItemPercentUploadedKey) as? Double ?? 0
-        if (downloaded == 0 || downloaded == 100) && (uploaded > 0 && uploaded < 100) {
-            progress?.completedUnitCount = Int64(uploaded / 100 * Double(size))
-            provider?.delegateNotify(operation, progress: uploaded / 100)
-        } else if (uploaded == 0 || uploaded == 100) && downloadStatus != NSMetadataUbiquitousItemDownloadingStatusCurrent {
-            progress?.completedUnitCount = Int64(downloaded / 100 * Double(size))
-            provider?.delegateNotify(operation, progress: downloaded / 100)
-        } else if uploaded == 100 || downloadStatus == NSMetadataUbiquitousItemDownloadingStatusCurrent {
-            progress?.completedUnitCount = size
-            query.stop()
-            query.removeObserver(self, forKeyPath: "results")
-            provider?.delegateNotify(operation)
-        }
-        
-        query.enableUpdates()
-    }
-}
-
-/*
-func getMetadataItem(url: URL) -> NSMetadataItem? {
-    let query = NSMetadataQuery()
-    query.predicate = NSPredicate(format: "(%K LIKE %@)", NSMetadataItemPathKey, url.path)
-    query.searchScopes = [NSMetadataQueryUbiquitousDocumentsScope, NSMetadataQueryUbiquitousDataScope]
-    
-    var item: NSMetadataItem?
-    
-    let group = DispatchGroup()
-    group.enter()
-    var finishObserver: NSObjectProtocol?
-    finishObserver = NotificationCenter.default.addObserver(forName: .NSMetadataQueryDidFinishGathering, object: query, queue: nil, using: { (notification) in
-        defer {
-            query.stop()
-            group.leave()
-            NotificationCenter.default.removeObserver(finishObserver!)
-        }
-        
-        if query.resultCount > 0 {
-            item = query.result(at: 0) as? NSMetadataItem
-        }
-        
-        query.disableUpdates()
-        
-    })
-    
-    DispatchQueue.main.async {
-        query.start()
-    }
-    _ = group.wait(timeout: .now() + 30)
-    return item
-}
-*/
@@ -24,9 +24,9 @@ open class DropboxFileProvider: HTTPFileProvider, FileProviderSharing {
    override open class var type: String { return "Dropbox" }
    
    /// Dropbox RPC API URL, which is equal with [https://api.dropboxapi.com/2/](https://api.dropboxapi.com/2/)
-    open let apiURL: URL
+    public let apiURL: URL
    /// Dropbox contents download/upload API URL, which is equal with [https://content.dropboxapi.com/2/](https://content.dropboxapi.com/2/)
-    open let contentURL: URL
+    public let contentURL: URL
    
    /**
     Initializer for Dropbox provider with given client ID and Token.
@@ -44,7 +44,7 @@ open class DropboxFileProvider: HTTPFileProvider, FileProviderSharing {
    }
    
    public required convenience init?(coder aDecoder: NSCoder) {
-        self.init(credential: aDecoder.decodeObject(forKey: "credential") as? URLCredential)
+        self.init(credential: aDecoder.decodeObject(of: URLCredential.self, forKey: "credential"))
        self.useCache        = aDecoder.decodeBool(forKey: "useCache")
        self.validatingCache = aDecoder.decodeBool(forKey: "validatingCache")
    }
@@ -91,7 +91,7 @@ open class DropboxFileProvider: HTTPFileProvider, FileProviderSharing {
        request.httpMethod = "POST"
        request.setValue(authentication: credential, with: .oAuth2)
        request.setValue(contentType: .json)
-        let requestDictionary: [String: AnyObject] = ["path": correctPath(path)! as NSString]
+        let requestDictionary: [String: Any] = ["path": correctPath(path)!]
        request.httpBody = Data(jsonDictionary: requestDictionary)
        let task = session.dataTask(with: request, completionHandler: { (data, response, error) in
            var serverError: FileProviderHTTPError?
@@ -165,14 +165,14 @@ open class DropboxFileProvider: HTTPFileProvider, FileProviderSharing {
        let queryIsTruePredicate = query.predicateFormat == "TRUEPREDICATE"
        return paginated(path, requestHandler: requestHandler,
            pageHandler: { [weak self] (data, progress) -> (files: [FileObject], error: Error?, newToken: String?) in
-            guard let json = data?.deserializeJSON(), let entries = (json["entries"] ?? json["matches"]) as? [AnyObject] else {
-                let err = self?.urlError(path, code: .badServerResponse)
+            guard let json = data?.deserializeJSON(), let entries = (json["entries"] ?? json["matches"]) as? [Any] else {
+                let err = URLError(.badServerResponse, url: self?.url(of: path))
                return ([], err, nil)
            }
            
            var files = [FileObject]()
            for entry in entries {
-                if let entry = entry as? [String: AnyObject], let file = DropboxFileObject(json: entry), queryIsTruePredicate || query.evaluate(with: file.mapPredicate()) {
+                if let entry = entry as? [String: Any], let file = DropboxFileObject(json: entry), queryIsTruePredicate || query.evaluate(with: file.mapPredicate()) {
                    files.append(file)
                    progress.completedUnitCount += 1
                    foundItemHandler?(file)
@@ -193,11 +193,11 @@ open class DropboxFileProvider: HTTPFileProvider, FileProviderSharing {
    override func request(for operation: FileOperationType, overwrite: Bool = false, attributes: [URLResourceKey : Any] = [:]) -> URLRequest {
        
        func uploadRequest(to path: String) -> URLRequest {
-            var requestDictionary = [String: AnyObject]()
+            var requestDictionary = [String: Any]()
            let url: URL = URL(string: "files/upload", relativeTo: contentURL)!
-            requestDictionary["path"] = correctPath(path) as NSString?
-            requestDictionary["mode"] = (overwrite ? "overwrite" : "add") as NSString
-            //requestDictionary["client_modified"] = (attributes[.contentModificationDateKey] as? Date)?.format(with: .rfc3339) as NSString?
+            requestDictionary["path"] = correctPath(path)
+            requestDictionary["mode"] = (overwrite ? "overwrite" : "add")
+            //requestDictionary["client_modified"] = (attributes[.contentModificationDateKey] as? Date)?.format(with: .rfc3339)
            var request = URLRequest(url: url)
            request.httpMethod = "POST"
            request.setValue(authentication: credential, with: .oAuth2)
@@ -211,7 +211,7 @@ open class DropboxFileProvider: HTTPFileProvider, FileProviderSharing {
            var request = URLRequest(url: url)
            request = URLRequest(url: url)
            request.setValue(authentication: credential, with: .oAuth2)
-            request.setValue(dropboxArgKey: ["path": correctPath(path)! as NSString])
+            request.setValue(dropboxArgKey: ["path": correctPath(path)!])
            return request
        }
        
@@ -234,7 +234,7 @@ open class DropboxFileProvider: HTTPFileProvider, FileProviderSharing {
        let url: String
        let sourcePath = operation.source
        let destPath = operation.destination
-        var requestDictionary = [String: AnyObject]()
+        var requestDictionary = [String: Any]()
        switch operation {
        case .create:
            url = "files/create_folder_v2"
@@ -254,11 +254,11 @@ open class DropboxFileProvider: HTTPFileProvider, FileProviderSharing {
        request.httpMethod = "POST"
        request.setValue(authentication: credential, with: .oAuth2)
        request.setValue(contentType: .json)
-        if let dest = correctPath(destPath) as NSString? {
-            requestDictionary["from_path"] = correctPath(sourcePath) as NSString?
+        if let dest = correctPath(destPath) {
+            requestDictionary["from_path"] = correctPath(sourcePath)
            requestDictionary["to_path"] = dest
        } else {
-            requestDictionary["path"] = correctPath(sourcePath) as NSString?
+            requestDictionary["path"] = correctPath(sourcePath)
        }
        request.httpBody = Data(jsonDictionary: requestDictionary)
        return request
@@ -267,7 +267,7 @@ open class DropboxFileProvider: HTTPFileProvider, FileProviderSharing {
    override func serverError(with code: FileProviderHTTPErrorCode, path: String?, data: Data?) -> FileProviderHTTPError {
        let errorDesc: String?
        if let response = data?.deserializeJSON() {
-            errorDesc = (response["user_message"] as? String) ?? (response["error"]?["tag"] as? String)
+            errorDesc = (response["user_message"] as? String) ?? ((response["error"] as? [String: Any])?["tag"] as? String)
        } else {
            errorDesc = data.flatMap({ String(data: $0, encoding: .utf8) })
        }
@@ -300,7 +300,7 @@ open class DropboxFileProvider: HTTPFileProvider, FileProviderSharing {
        request.httpMethod = "POST"
        request.setValue(authentication: credential, with: .oAuth2)
        request.setValue(contentType: .json)
-        let requestDictionary: [String: AnyObject] = ["path": correctPath(path)! as NSString]
+        let requestDictionary: [String: Any] = ["path": correctPath(path)!]
        request.httpBody = Data(jsonDictionary: requestDictionary)
        let task = session.dataTask(with: request, completionHandler: { (data, response, error) in
            var serverError: FileProviderHTTPError?
@@ -311,7 +311,7 @@ open class DropboxFileProvider: HTTPFileProvider, FileProviderSharing {
                serverError = code.flatMap { self.serverError(with: $0, path: path, data: data) }
                if let json = data?.deserializeJSON() {
                    link = (json["link"] as? String).flatMap(URL.init(string:))
-                    fileObject = (json["metadata"] as? [String: AnyObject]).flatMap(DropboxFileObject.init(json:))
+                    fileObject = (json["metadata"] as? [String: Any]).flatMap(DropboxFileObject.init(json:))
                }
            }
            
@@ -334,7 +334,7 @@ open class DropboxFileProvider: HTTPFileProvider, FileProviderSharing {
     */
    open func copyItem(remoteURL: URL, to toPath: String, completionHandler: @escaping ((_ jobId: String?, _ attribute: DropboxFileObject?, _ error: Error?) -> Void)) {
        if remoteURL.isFileURL {
-            completionHandler(nil, nil, self.urlError(remoteURL.path, code: .badURL))
+            completionHandler(nil, nil, URLError(.badURL, url: remoteURL))
            return
        }
        let url = URL(string: "files/save_url", relativeTo: apiURL)!
@@ -342,7 +342,7 @@ open class DropboxFileProvider: HTTPFileProvider, FileProviderSharing {
        request.httpMethod = "POST"
        request.setValue(authentication: credential, with: .oAuth2)
        request.setValue(contentType: .json)
-        let requestDictionary: [String: AnyObject] = ["path": correctPath(toPath)! as NSString, "url" : remoteURL.absoluteString as NSString]
+        let requestDictionary: [String: Any] = ["path": correctPath(toPath)!, "url" : remoteURL.absoluteString]
        request.httpBody = Data(jsonDictionary: requestDictionary)
        let task = session.dataTask(with: request, completionHandler: { (data, response, error) in
            var serverError: FileProviderHTTPError?
@@ -353,7 +353,7 @@ open class DropboxFileProvider: HTTPFileProvider, FileProviderSharing {
                serverError = code.flatMap { self.serverError(with: $0, path: toPath, data: data) }
                if let json = data?.deserializeJSON() {
                    jobId = json["async_job_id"] as? String
-                    fileObject = (json["metadata"] as? [String: AnyObject]).flatMap(DropboxFileObject.init(json:))
+                    fileObject = (json["metadata"] as? [String: Any]).flatMap(DropboxFileObject.init(json:))
                }
            }
            completionHandler(jobId, fileObject, serverError ?? error)
@@ -375,7 +375,7 @@ open class DropboxFileProvider: HTTPFileProvider, FileProviderSharing {
        request.httpMethod = "POST"
        request.setValue(authentication: credential, with: .oAuth2)
        request.setValue(contentType: .json)
-        let requestDictionary: [String: AnyObject] = ["path": correctPath(toPath)! as NSString, "copy_reference" : reference as NSString]
+        let requestDictionary: [String: Any] = ["path": correctPath(toPath)!, "copy_reference" : reference ]
        request.httpBody = Data(jsonDictionary: requestDictionary)
        let task = session.dataTask(with: request, completionHandler: { (data, response, error) in
            var serverError: FileProviderHTTPError?
@@ -391,7 +391,7 @@ open class DropboxFileProvider: HTTPFileProvider, FileProviderSharing {

 extension DropboxFileProvider: ExtendedFileProvider {
    open func propertiesOfFileSupported(path: String) -> Bool {
-        let fileExt = (path as NSString).pathExtension.lowercased()
+        let fileExt = path.pathExtension.lowercased()
        switch fileExt {
        case "jpg", "jpeg", "bmp", "gif", "png", "tif", "tiff":
            return true
@@ -411,7 +411,7 @@ extension DropboxFileProvider: ExtendedFileProvider {
        request.httpMethod = "POST"
        request.setValue(authentication: credential, with: .oAuth2)
        request.setValue(contentType: .json)
-        let requestDictionary: [String: AnyObject] = ["path": correctPath(path)! as NSString, "include_media_info": NSNumber(value: true)]
+        let requestDictionary: [String: Any] = ["path": correctPath(path)!, "include_media_info": NSNumber(value: true)]
        request.httpBody = Data(jsonDictionary: requestDictionary)
        let task = session.dataTask(with: request, completionHandler: { (data, response, error) in
            var serverError: FileProviderHTTPError?
@@ -432,15 +432,15 @@ extension DropboxFileProvider: ExtendedFileProvider {
    
    #if os(macOS) || os(iOS) || os(tvOS)
    open func thumbnailOfFileSupported(path: String) -> Bool {
-        switch (path as NSString).pathExtension.lowercased() {
+        switch path.pathExtension.lowercased() {
        case "jpg", "jpeg", "gif", "bmp", "png", "tif", "tiff":
            return true
        case "doc", "docx", "docm", "xls", "xlsx", "xlsm":
-            return true
+            return false
        case  "ppt", "pps", "ppsx", "ppsm", "pptx", "pptm":
-            return true
+            return false
        case "rtf":
-            return true
+            return false
        default:
            return false
        }
@@ -451,7 +451,7 @@ extension DropboxFileProvider: ExtendedFileProvider {
    open func thumbnailOfFile(path: String, dimension: CGSize?, completionHandler: @escaping ((_ image: ImageClass?, _ error: Error?) -> Void)) -> Progress? {
        let url: URL
        let thumbAPI: Bool
-        switch (path as NSString).pathExtension.lowercased() {
+        switch path.pathExtension.lowercased() {
        case "jpg", "jpeg", "gif", "bmp", "png", "tif", "tiff":
            url = URL(string: "files/get_thumbnail", relativeTo: contentURL)!
            thumbAPI = true
@@ -467,9 +467,9 @@ extension DropboxFileProvider: ExtendedFileProvider {
        }
        var request = URLRequest(url: url)
        request.setValue(authentication: credential, with: .oAuth2)
-        var requestDictionary: [String: AnyObject] = ["path": path as NSString]
+        var requestDictionary: [String: Any] = ["path": path]
        if thumbAPI {
-            requestDictionary["format"] = "jpeg" as NSString
+            requestDictionary["format"] = "jpeg"
            let size: String
            switch dimension?.height ?? 64 {
            case 0...32:    size = "w32h32"
@@ -478,23 +478,27 @@ extension DropboxFileProvider: ExtendedFileProvider {
            case 129...480: size = "w640h480"
            default: size = "w1024h768"
            }
-            requestDictionary["size"] = size as NSString
+            requestDictionary["size"] = size
        }
        request.setValue(dropboxArgKey: requestDictionary)
        let task = self.session.dataTask(with: request, completionHandler: { (data, response, error) in
            var image: ImageClass? = nil
            if let r = response as? HTTPURLResponse, let result = r.allHeaderFields["Dropbox-API-Result"] as? String, let jsonResult = result.deserializeJSON() {
                if jsonResult["error"] != nil {
-                    completionHandler(nil, self.urlError(path, code: .cannotDecodeRawData))
+                    completionHandler(nil, URLError(.cannotDecodeRawData, url: self.url(of: path)))
                }
            }
            if let data = data {
-                if data.isPDF, let pageImage = DropboxFileProvider.convertToImage(pdfData: data) {
+                if data.isPDF, let pageImage = DropboxFileProvider.convertToImage(pdfData: data, maxSize: dimension) {
                    image = pageImage
                } else if let contentType = (response as? HTTPURLResponse)?.allHeaderFields["Content-Type"] as? String, contentType.contains("text/html") {
                     // TODO: Implement converting html returned type of get_preview to image
-                } else if let fetchedimage = ImageClass(data: data) {
-                    image = dimension.map({ DropboxFileProvider.scaleDown(image: fetchedimage, toSize: $0) }) ?? fetchedimage
+                } else {
+                    if let dimension = dimension {
+                        image = DropboxFileProvider.scaleDown(data: data, toSize: dimension)
+                    } else {
+                        
+                    }
                }
            }
            completionHandler(image, error)
@@ -22,9 +22,9 @@ public final class DropboxFileObject: FileObject {
        self.init(json: json)
    }
    
-    internal init? (json: [String: AnyObject]) {
+    internal init? (json: [String: Any]) {
        var json = json
-        if json["name"] == nil, let metadata = json["metadata"] as? [String: AnyObject] {
+        if json["name"] == nil, let metadata = json["metadata"] as? [String: Any] {
            json = metadata
        }
        guard let name = json["name"] as? String else { return nil }
@@ -34,13 +34,13 @@ public final class DropboxFileObject: FileObject {
        self.serverTime =  (json["server_modified"] as? String).flatMap(Date.init(rfcString:))
        self.modifiedDate = (json["client_modified"] as? String).flatMap(Date.init(rfcString:))
        self.type = (json[".tag"] as? String) == "folder" ? .directory : .regular
-        self.isReadOnly = (json["sharing_info"]?["read_only"] as? NSNumber)?.boolValue ?? false
+        self.isReadOnly = ((json["sharing_info"] as? [String: Any])?["read_only"] as? NSNumber)?.boolValue ?? false
        self.id = json["id"] as? String
        self.rev = json["rev"] as? String
    }
    
    /// The time contents of file has been modified on server, returns nil if not set
-    open internal(set) var serverTime: Date? {
+    public internal(set) var serverTime: Date? {
        get {
            return allValues[.serverDateKey] as? Date
        }
@@ -51,7 +51,7 @@ public final class DropboxFileObject: FileObject {
    
    /// The document identifier is a value assigned by the Dropbox to a file.
    /// This value is used to identify the document regardless of where it is moved on a volume.
-    open internal(set) var id: String? {
+    public internal(set) var id: String? {
        get {
            return allValues[.fileResourceIdentifierKey] as? String
        }
@@ -62,7 +62,7 @@ public final class DropboxFileObject: FileObject {
    
    /// The revision of file, which changes when a file contents are modified.
    /// Changes to attributes or other file metadata do not change the identifier.
-    open internal(set) var rev: String? {
+    public internal(set) var rev: String? {
        get {
            return allValues[.generationIdentifierKey] as? String
        }
@@ -72,8 +72,8 @@ public final class DropboxFileObject: FileObject {
    }
 }

-internal extension DropboxFileProvider {
-    internal func correctPath(_ path: String?) -> String? {
+extension DropboxFileProvider {
+    func correctPath(_ path: String?) -> String? {
        guard let path = path else { return nil }
        if path.hasPrefix("id:") || path.hasPrefix("rev:") {
            return path
@@ -85,7 +85,7 @@ internal extension DropboxFileProvider {
        return p
    }
    
-    internal func listRequest(path: String, queryStr: String? = nil, recursive: Bool = false) -> ((_ token: String?) -> URLRequest?) {
+    func listRequest(path: String, queryStr: String? = nil, recursive: Bool = false) -> ((_ token: String?) -> URLRequest?) {
        if let queryStr = queryStr {
            return { [weak self] (token) -> URLRequest? in
                guard let `self` = self else { return nil }
@@ -94,8 +94,8 @@ internal extension DropboxFileProvider {
                request.httpMethod = "POST"
                request.setValue(authentication: self.credential, with: .oAuth2)
                request.setValue(contentType: .json)
-                var requestDictionary: [String: AnyObject] = ["path": self.correctPath(path) as NSString!]
-                requestDictionary["query"] = queryStr as NSString
+                var requestDictionary: [String: Any] = ["path": self.correctPath(path)!]
+                requestDictionary["query"] = queryStr
                requestDictionary["start"] = NSNumber(value: (token.flatMap( { Int($0) } ) ?? 0))
                request.httpBody = Data(jsonDictionary: requestDictionary)
                return request
@@ -103,14 +103,14 @@ internal extension DropboxFileProvider {
        } else {
            return { [weak self] (token) -> URLRequest? in
                guard let `self` = self else { return nil }
-                var requestDictionary = [String: AnyObject]()
+                var requestDictionary = [String: Any]()
                let url: URL
                if let token = token {
                    url = URL(string: "files/list_folder/continue", relativeTo: self.apiURL)!
-                    requestDictionary["cursor"] = token as NSString?
+                    requestDictionary["cursor"] = token
                } else {
                    url = URL(string: "files/list_folder", relativeTo: self.apiURL)!
-                    requestDictionary["path"] = self.correctPath(path) as NSString?
+                    requestDictionary["path"] = self.correctPath(path)
                    requestDictionary["recursive"] = NSNumber(value: recursive)
                }
                var request = URLRequest(url: url)
@@ -14,7 +14,7 @@ import AVFoundation

 extension LocalFileProvider: ExtendedFileProvider {
    open func thumbnailOfFileSupported(path: String) -> Bool {
-        switch (path as NSString).pathExtension.lowercased() {
+        switch path.pathExtension.lowercased() {
        case LocalFileInformationGenerator.imageThumbnailExtensions.contains:
            return true
        case LocalFileInformationGenerator.audioThumbnailExtensions.contains:
@@ -33,7 +33,7 @@ extension LocalFileProvider: ExtendedFileProvider {
    }
    
    open func propertiesOfFileSupported(path: String) -> Bool {
-        let fileExt = (path as NSString).pathExtension.lowercased()
+        let fileExt = path.pathExtension.lowercased()
        switch fileExt {
        case LocalFileInformationGenerator.imagePropertiesExtensions.contains:
            return LocalFileInformationGenerator.imageProperties != nil
@@ -65,26 +65,23 @@ extension LocalFileProvider: ExtendedFileProvider {
            // Create Thumbnail and cache
            switch fileURL.pathExtension.lowercased() {
            case LocalFileInformationGenerator.videoThumbnailExtensions.contains:
-                thumbnailImage = LocalFileInformationGenerator.videoThumbnail(fileURL)
+                thumbnailImage = LocalFileInformationGenerator.videoThumbnail(fileURL, dimension)
            case LocalFileInformationGenerator.audioThumbnailExtensions.contains:
-                thumbnailImage = LocalFileInformationGenerator.audioThumbnail(fileURL)
+                thumbnailImage = LocalFileInformationGenerator.audioThumbnail(fileURL, dimension)
            case LocalFileInformationGenerator.imageThumbnailExtensions.contains:
-                thumbnailImage = LocalFileInformationGenerator.imageThumbnail(fileURL)
+                thumbnailImage = LocalFileInformationGenerator.imageThumbnail(fileURL, dimension)
            case LocalFileInformationGenerator.pdfThumbnailExtensions.contains:
-                thumbnailImage = LocalFileInformationGenerator.pdfThumbnail(fileURL)
+                thumbnailImage = LocalFileInformationGenerator.pdfThumbnail(fileURL, dimension)
            case LocalFileInformationGenerator.officeThumbnailExtensions.contains:
-                thumbnailImage = LocalFileInformationGenerator.officeThumbnail(fileURL)
+                thumbnailImage = LocalFileInformationGenerator.officeThumbnail(fileURL, dimension)
            case LocalFileInformationGenerator.customThumbnailExtensions.contains:
-                thumbnailImage = LocalFileInformationGenerator.customThumbnail(fileURL)
+                thumbnailImage = LocalFileInformationGenerator.customThumbnail(fileURL, dimension)
            default:
                completionHandler(nil, nil)
                return
            }
            
-            if let image = thumbnailImage {
-                let scaledImage = LocalFileProvider.scaleDown(image: image, toSize: dimension)
-                completionHandler(scaledImage, nil)
-            }
+            completionHandler(thumbnailImage, nil)
        }
        return nil
    }
@@ -92,7 +89,7 @@ extension LocalFileProvider: ExtendedFileProvider {
    @discardableResult
    open func propertiesOfFile(path: String, completionHandler: @escaping ((_ propertiesDictionary: [String: Any], _ keys: [String], _ error: Error?) -> Void)) -> Progress? {
        (dispatch_queue).async {
-            let fileExt = (path as NSString).pathExtension.lowercased()
+            let fileExt = path.pathExtension.lowercased()
            var getter: ((_ fileURL: URL) -> (prop: [String: Any], keys: [String]))?
            switch fileExt {
            case LocalFileInformationGenerator.imagePropertiesExtensions.contains:
@@ -194,23 +191,19 @@ public struct LocalFileInformationGenerator {
    static public var customPropertiesExtensions: [String]  = []
    
    /// Thumbnail generator closure for image files.
-    static public var imageThumbnail: (_ fileURL: URL) -> ImageClass? = { fileURL in
-        return ImageClass(contentsOfFile: fileURL.path)
+    static public var imageThumbnail: (_ fileURL: URL, _ dimension: CGSize?) -> ImageClass? = { fileURL, dimension in
+        return LocalFileProvider.scaleDown(fileURL: fileURL, toSize: dimension)
    }
    
    /// Thumbnail generator closure for audio and music files.
-    static public var audioThumbnail: (_ fileURL: URL) -> ImageClass? = { fileURL in
+    static public var audioThumbnail: (_ fileURL: URL, _ dimension: CGSize?) -> ImageClass? = { fileURL, dimension in
        let playerItem = AVPlayerItem(url: fileURL)
        let metadataList = playerItem.asset.commonMetadata
-        #if swift(>=4.0)
        let commonKeyArtwork = AVMetadataKey.commonKeyArtwork
-        #else
-        let commonKeyArtwork = AVMetadataCommonKeyArtwork
-        #endif
        for item in metadataList {
            if item.commonKey == commonKeyArtwork {
                if let data = item.dataValue {
-                    return ImageClass(data: data)
+                    return LocalFileProvider.scaleDown(data: data, toSize: dimension)
                }
            }
        }
@@ -218,9 +211,10 @@ public struct LocalFileInformationGenerator {
    }
    
    /// Thumbnail generator closure for video files.
-    static public var videoThumbnail: (_ fileURL: URL) -> ImageClass? = { fileURL in
+    static public var videoThumbnail: (_ fileURL: URL, _ dimension: CGSize?) -> ImageClass? = { fileURL, dimension in
        let asset = AVAsset(url: fileURL)
        let assetImgGenerate = AVAssetImageGenerator(asset: asset)
+        assetImgGenerate.maximumSize = dimension ?? .zero
        assetImgGenerate.appliesPreferredTrackTransform = true
        let time = CMTime(value: asset.duration.value / 3, timescale: asset.duration.timescale)
        if let cgImage = try? assetImgGenerate.copyCGImage(at: time, actualTime: nil) {
@@ -234,19 +228,19 @@ public struct LocalFileInformationGenerator {
    }
    
    /// Thumbnail generator closure for portable document files files.
-    static public var pdfThumbnail: (_ fileURL: URL) -> ImageClass? = { fileURL in
-        return LocalFileProvider.convertToImage(pdfURL: fileURL)
+    static public var pdfThumbnail: (_ fileURL: URL, _ dimension: CGSize?) -> ImageClass? = { fileURL, dimension in
+        return LocalFileProvider.convertToImage(pdfURL: fileURL, maxSize: dimension)
    }
    
    /// Thumbnail generator closure for office document files.
    /// - Note: No default implementation is avaiable
-    static public var officeThumbnail: (_ fileURL: URL) -> ImageClass? = { fileURL in
+    static public var officeThumbnail: (_ fileURL: URL, _ dimension: CGSize?) -> ImageClass? = { fileURL, dimension in
        return nil
    }
    
    /// Thumbnail generator closure for custom type of files.
    /// - Note: No default implementation is avaiable
-    static public var customThumbnail: (_ fileURL: URL) -> ImageClass? = { fileURL in
+    static public var customThumbnail: (_ fileURL: URL, _ dimension: CGSize?) -> ImageClass? = { fileURL, dimension in
        return nil
    }
    
@@ -276,32 +270,36 @@ public struct LocalFileInformationGenerator {
            return(Int(newTopVal), Int(newBottomVal))
        }
        
-        guard let cgDataRef = CGImageSourceCreateWithURL(fileURL as CFURL, nil), let cfImageDict = CGImageSourceCopyPropertiesAtIndex(cgDataRef, 0, nil) else {
+        guard let source = CGImageSourceCreateWithURL(fileURL as CFURL, nil), let properties = CGImageSourceCopyPropertiesAtIndex(source, 0, nil) as NSDictionary? else {
            return (dic, keys)
        }
-        let imageDict = cfImageDict as NSDictionary
-        let tiffDict = imageDict[kCGImagePropertyTIFFDictionary as String] as? NSDictionary ?? [:]
-        let exifDict = imageDict[kCGImagePropertyExifDictionary as String] as? NSDictionary ?? [:]
-        if let pixelWidth = imageDict.object(forKey: kCGImagePropertyPixelWidth) as? NSNumber, let pixelHeight = imageDict.object(forKey: kCGImagePropertyPixelHeight) as? NSNumber {
+        let tiffDict = properties[kCGImagePropertyTIFFDictionary as String] as? NSDictionary ?? [:]
+        let exifDict = properties[kCGImagePropertyExifDictionary as String] as? NSDictionary ?? [:]
+        let gpsDict = properties[kCGImagePropertyGPSDictionary as String] as? NSDictionary ?? [:]
+        
+        if let pixelWidth = properties.object(forKey: kCGImagePropertyPixelWidth) as? NSNumber, let pixelHeight = properties.object(forKey: kCGImagePropertyPixelHeight) as? NSNumber {
            add(key: "Dimensions", value: "\(pixelWidth)x\(pixelHeight)")
        }
-        
-        add(key: "DPI", value: imageDict[kCGImagePropertyDPIWidth as String])
-        add(key: "Device make", value: tiffDict[kCGImagePropertyTIFFMake as String])
+        add(key: "DPI", value: properties[kCGImagePropertyDPIWidth as String])
+        add(key: "Device maker", value: tiffDict[kCGImagePropertyTIFFMake as String])
        add(key: "Device model", value: tiffDict[kCGImagePropertyTIFFModel as String])
        add(key: "Lens model", value: exifDict[kCGImagePropertyExifLensModel as String])
        add(key: "Artist", value: tiffDict[kCGImagePropertyTIFFArtist as String] as? String)
        add(key: "Copyright", value: tiffDict[kCGImagePropertyTIFFCopyright as String] as? String)
        add(key: "Date taken", value: tiffDict[kCGImagePropertyTIFFDateTime as String] as? String)
        
-        if let latitude = tiffDict[kCGImagePropertyGPSLatitude as String] as? NSNumber, let longitude = tiffDict[kCGImagePropertyGPSLongitude as String] as? NSNumber {
-            add(key: "Location", value: "\(latitude), \(longitude)")
+        if let latitude = gpsDict[kCGImagePropertyGPSLatitude as String] as? NSNumber,
+            let longitude = gpsDict[kCGImagePropertyGPSLongitude as String] as? NSNumber {
+            let altitudeDesc = (gpsDict[kCGImagePropertyGPSAltitude as String] as? NSNumber).map({ " at \($0.format(precision: 0))m" }) ?? ""
+            add(key: "Location", value: "\(latitude.format()), \(longitude.format())\(altitudeDesc)")
        }
-        add(key: "Altitude", value: tiffDict[kCGImagePropertyGPSAltitude as String] as? NSNumber)
-        add(key: "Area", value: tiffDict[kCGImagePropertyGPSAreaInformation as String])
+        add(key: "Area", value: gpsDict[kCGImagePropertyGPSAreaInformation as String])
        
-        add(key: "Color space", value: imageDict[kCGImagePropertyColorModel as String])
+        add(key: "Color space", value: properties[kCGImagePropertyColorModel as String])
+        add(key: "Color depth", value: (properties[kCGImagePropertyDepth as String] as? NSNumber).map({ "\($0) bits" }))
+        add(key: "Color profile", value: properties[kCGImagePropertyProfileName as String])
        add(key: "Focal length", value: exifDict[kCGImagePropertyExifFocalLength as String])
+        add(key: "White banance", value: exifDict[kCGImagePropertyExifWhiteBalance as String])
        add(key: "F number", value: exifDict[kCGImagePropertyExifFNumber as String])
        add(key: "Exposure program", value: exifDict[kCGImagePropertyExifExposureProgram as String])
        
@@ -325,7 +323,7 @@ public struct LocalFileInformationGenerator {
            }
        }
        
-        func makeDescription(_ key: String?) -> String? {
+        func makeKeyDescription(_ key: String?) -> String? {
            guard let key = key else {
                return nil
            }
@@ -336,21 +334,39 @@ public struct LocalFileInformationGenerator {
            return newKey.capitalized
        }
        
+        func parseLocationData(_ value: String) -> (latitude: Double, longitude: Double, height: Double?)? {
+            let scanner = Scanner.init(string: value)
+            var latitude: Double = 0.0, longitude: Double = 0.0, height: Double = 0
+            
+            if scanner.scanDouble(&latitude), scanner.scanDouble(&longitude) {
+                scanner.scanDouble(&height)
+                return (latitude, longitude, height)
+            } else {
+                return nil
+            }
+        }
+        
        guard fileURL.fileExists else {
            return (dic, keys)
        }
        let playerItem = AVPlayerItem(url: fileURL)
        let metadataList = playerItem.asset.commonMetadata
        for item in metadataList {
-            #if swift(>=4.0)
-                let commonKey = item.commonKey?.rawValue
-            #else
-                let commonKey = item.commonKey
-            #endif
-            if let description = makeDescription(commonKey) {
-                if let value = item.stringValue {
-                    keys.append(description)
-                    dic[description] = value
+            let commonKey = item.commonKey?.rawValue
+            if let key = makeKeyDescription(commonKey) {
+                if commonKey == "location", let value = item.stringValue, let loc = parseLocationData(value) {
+                    keys.append(key)
+                    let heightStr: String = (loc.height as NSNumber?).map({ ", \($0.format(precision: 0))m" }) ?? ""
+                    dic[key] = "\((loc.latitude as NSNumber).format())°, \((loc.longitude as NSNumber).format())°\(heightStr)"
+                } else if let value = item.dateValue {
+                    keys.append(key)
+                    dic[key] = value
+                } else if let value = item.numberValue {
+                    keys.append(key)
+                    dic[key] = value
+                } else if let value = item.stringValue {
+                    keys.append(key)
+                    dic[key] = value
                }
            }
        }
@@ -377,16 +393,12 @@ public struct LocalFileInformationGenerator {
            dic = audioprops.prop
            keys = audioprops.keys
            dic.removeValue(forKey: "Duration")
-            if let index = keys.index(of: "Duration") {
+            if let index = keys.firstIndex(of: "Duration") {
                keys.remove(at: index)
            }
        }
        let asset = AVURLAsset(url: fileURL, options: nil)
-        #if swift(>=4.0)
        let videoTracks = asset.tracks(withMediaType: AVMediaType.video)
-        #else
-        let videoTracks = asset.tracks(withMediaType: AVMediaTypeVideo)
-        #endif
        if let videoTrack = videoTracks.first {
            var bitrate: Float = 0
            let width = Int(videoTrack.naturalSize.width)
@@ -400,11 +412,7 @@ public struct LocalFileInformationGenerator {
            add(key: "Duration", value: TimeInterval(duration).formatshort)
            add(key: "Video Bitrate", value: "\(Int(ceil(bitrate / 1000))) kbps")
        }
-        #if swift(>=4.0)
        let audioTracks = asset.tracks(withMediaType: AVMediaType.audio)
-        #else
-        let audioTracks = asset.tracks(withMediaType: AVMediaTypeAudio)
-        #endif
        // dic["Audio channels"] = audioTracks.count
        var bitrate: Float = 0
        for track in audioTracks {
@@ -482,7 +490,7 @@ public struct LocalFileInformationGenerator {
        add(key: "Content creator", value: getKey("Creator", from: dict))
        add(key: "Creation date", value: convertDate(getKey("CreationDate", from: dict)))
        add(key: "Modified date", value: convertDate(getKey("ModDate", from: dict)))
-        add(key: "Security", value: reference.isEncrypted)
+        add(key: "Security", value: reference.isEncrypted ? (reference.isUnlocked ? "Present" : "Password Protected") : "None")
        add(key: "Allows printing", value: reference.allowsPrinting)
        add(key: "Allows copying", value: reference.allowsCopying)
        return (dic, keys)
@@ -8,7 +8,7 @@

 import Foundation

-public extension Array where Element: FileObject {
+extension Array where Element: FileObject {
    /// Returns a sorted array of `FileObject`s by criterias set in attributes.
    public func sort(by type: FileObjectSorting.SortType, ascending: Bool = true, isDirectoriesFirst: Bool = false) -> [Element] {
        let sorting = FileObjectSorting(type: type, ascending: ascending, isDirectoriesFirst: isDirectoriesFirst)
@@ -28,7 +28,7 @@ public extension Sequence where Iterator.Element == UInt8 {
    }
 }

-public extension URLFileResourceType {
+extension URLFileResourceType {
    /// **FileProvider** returns corresponding `URLFileResourceType` of a `FileAttributeType` value
    public init(fileTypeValue: FileAttributeType) {
        switch fileTypeValue {
@@ -44,7 +44,33 @@ public extension URLFileResourceType {
    }
 }

-public extension URLResourceKey {
+extension CocoaError {
+    init(_ code: CocoaError.Code, path: String?) {
+        if let path = path {
+            let userInfo: [String: Any] = [NSFilePathErrorKey: path]
+            self.init(code, userInfo: userInfo)
+        } else {
+            self.init(code)
+        }
+        
+    }
+}
+
+extension URLError {
+    init(_ code: URLError.Code, url: URL?) {
+        if let url = url {
+            let userInfo: [String: Any] = [NSURLErrorKey: url,
+                                           NSURLErrorFailingURLErrorKey: url,
+                                           NSURLErrorFailingURLStringErrorKey: url.absoluteString,
+                                           ]
+            self.init(code, userInfo: userInfo)
+        } else {
+            self.init(code)
+        }
+    }
+}
+
+extension URLResourceKey {
    /// **FileProvider** returns url of file object.
    public static let fileURLKey = URLResourceKey(rawValue: "NSURLFileURLKey")
    /// **FileProvider** returns modification date of file in server
@@ -59,7 +85,7 @@ public extension URLResourceKey {
    public static let childrensCount = URLResourceKey(rawValue: "MFPURLChildrensCount")
 }

-public extension ProgressUserInfoKey {
+extension ProgressUserInfoKey {
    /// **FileProvider** returns associated `FileProviderOperationType`
    public static let fileProvderOperationTypeKey = ProgressUserInfoKey("MFPOperationTypeKey")
    /// **FileProvider** returns start date/time of operation
@@ -76,7 +102,7 @@ internal extension URL {
    }
    
    var fileSize: Int64 {
-        return Int64((try? self.resourceValues(forKeys: [.fileSizeKey]))?.fileSize ?? -1)
+        return (try? self.resourceValues(forKeys: [.fileSizeKey]))?.allValues[.fileSizeKey] as? Int64 ?? -1
    }
    
    var fileExists: Bool {
@@ -91,7 +117,7 @@ internal extension URL {
    #endif
 }

-public extension URLRequest {
+extension URLRequest {
    /// Defines HTTP Authentication method required to access
    public enum AuthenticationType {
        /// Basic method for authentication
@@ -358,7 +384,7 @@ internal extension URLRequest {
        self.setValue(contentType.rawValue + parameter, forHTTPHeaderField: "Content-Type")
    }
    
-    mutating func setValue(dropboxArgKey requestDictionary: [String: AnyObject]) {
+    mutating func setValue(dropboxArgKey requestDictionary: [String: Any]) {
        guard let jsonData = try? JSONSerialization.data(withJSONObject: requestDictionary, options: []) else {
            return
        }
@@ -373,12 +399,12 @@ internal extension CharacterSet {
    static let filePathAllowed = CharacterSet.urlPathAllowed.subtracting(CharacterSet(charactersIn: ":"))
 }

-internal extension Data {
-    internal var isPDF: Bool {
+extension Data {
+    var isPDF: Bool {
        return self.count > 4 && self.scanString(length: 4, using: .ascii) == "%PDF"
    }
    
-    init? (jsonDictionary dictionary: [String: AnyObject]) {
+    init? (jsonDictionary dictionary: [String: Any]) {
        guard JSONSerialization.isValidJSONObject(dictionary) else { return nil }
        guard let data = try? JSONSerialization.data(withJSONObject: dictionary, options: []) else {
            return nil
@@ -386,8 +412,8 @@ internal extension Data {
        self = data
    }
    
-    func deserializeJSON() -> [String: AnyObject]? {
-        return (try? JSONSerialization.jsonObject(with: self, options: [])) as? [String: AnyObject]
+    func deserializeJSON() -> [String: Any]? {
+        return (try? JSONSerialization.jsonObject(with: self, options: [])) as? [String: Any]
    }
    
    init<T>(value: T) {
@@ -397,36 +423,39 @@ internal extension Data {
    
    func scanValue<T>() -> T? {
        guard MemoryLayout<T>.size <= self.count else { return nil }
+        #if swift(>=5.0)
+        return self.withUnsafeBytes { $0.load(as: T.self) }
+        #else
        return self.withUnsafeBytes { $0.pointee }
+        #endif
    }
    
    func scanValue<T>(start: Int) -> T? {
        let length = MemoryLayout<T>.size
        guard self.count >= start + length else { return nil }
-        return self.subdata(in: start..<start+length).withUnsafeBytes { $0.pointee }
+        let subdata = self.subdata(in: start..<start+length)
+        #if swift(>=5.0)
+        return subdata.withUnsafeBytes { $0.load(as: T.self) }
+        #else
+        return subdata.withUnsafeBytes { $0.pointee }
+        #endif
    }
    
    func scanString(start: Int = 0, length: Int, using encoding: String.Encoding = .utf8) -> String? {
        guard self.count >= start + length else { return nil }
        return String(data: self.subdata(in: start..<start+length), encoding: encoding)
    }
-    
-    static func mapMemory<T, U>(from: T) -> U? {
-        guard MemoryLayout<T>.size >= MemoryLayout<U>.size else { return nil }
-        let data = Data(value: from)
-        return data.scanValue()
-    }
 }

 internal extension String {
-    init? (jsonDictionary: [String: AnyObject]) {
+    init? (jsonDictionary: [String: Any]) {
        guard let data = Data(jsonDictionary: jsonDictionary) else {
            return nil
        }
        self.init(data: data, encoding: .utf8)
    }
    
-    func deserializeJSON(using encoding: String.Encoding = .utf8) -> [String: AnyObject]? {
+    func deserializeJSON(using encoding: String.Encoding = .utf8) -> [String: Any]? {
        guard let data = self.data(using: encoding) else {
            return nil
        }
@@ -447,17 +476,35 @@ internal extension String {
    }
 }

-#if swift(>=4.0)
-#else
-extension String {
-    var count: Int {
-        return self.characters.count
+extension NSNumber {
+    internal func format(precision: Int = 2, style: NumberFormatter.Style = .decimal) -> String {
+        let formatter = NumberFormatter()
+        formatter.maximumFractionDigits = precision
+        formatter.numberStyle = style
+        return formatter.string(from: self)!
    }
 }
-#endif

-internal extension TimeInterval {
-    internal var formatshort: String {
+extension String {
+    internal var pathExtension: String {
+        return (self as NSString).pathExtension
+    }
+    
+    internal func appendingPathComponent(_ pathComponent: String) -> String {
+        return (self as NSString).appendingPathComponent(pathComponent)
+    }
+    
+    internal var lastPathComponent: String {
+        return (self as NSString).lastPathComponent
+    }
+    
+    internal var deletingLastPathComponent: String {
+        return (self as NSString).deletingLastPathComponent
+    }
+}
+
+extension TimeInterval {
+    var formatshort: String {
        var result = "0:00"
        if self < TimeInterval(Int32.max) {
            result = ""
@@ -482,7 +529,7 @@ internal extension TimeInterval {
    }
 }

-public extension Date {
+extension Date {
    /// Date formats used commonly in internet messaging defined by various RFCs.
    public enum RFCStandards: String {
        /// Obsolete (2-digit year) date format defined by RFC 822 for http.
@@ -550,6 +597,51 @@ public extension Date {
    }
 }

+extension InputStream {
+    func readData(ofLength length: Int) throws -> Data {
+        var data = Data(count: length)
+        #if swift(>=5.0)
+        let result = data.withUnsafeMutableBytes { (buf) -> Int in
+            let p = buf.bindMemory(to: UInt8.self).baseAddress!
+            return self.read(p, maxLength: buf.count)
+        }
+        #else
+        let bufcount = data.count
+        let result = data.withUnsafeMutableBytes { (p) -> Int in
+            return self.read(p, maxLength: bufcount)
+        }
+        #endif
+        if result < 0 {
+            throw self.streamError ?? POSIXError(.EIO)
+        } else {
+            data.count = result
+            return data
+        }
+    }
+}
+
+extension OutputStream {
+    func write(data: Data) throws -> Int {
+        #if swift(>=5.0)
+        let result = data.withUnsafeBytes { (buf) -> Int in
+            let p = buf.bindMemory(to: UInt8.self).baseAddress!
+            return self.write(p, maxLength: buf.count)
+        }
+        #else
+        let bufcount = data.count
+        let result = data.withUnsafeBytes { (p) -> Int in
+            return self.write(p, maxLength: bufcount)
+        }
+        #endif
+        if result < 0 {
+            throw self.streamError ?? POSIXError(.EIO)
+        } else {
+            return result
+        }
+    }
+}
+
+
 internal extension NSPredicate {
    func findValue(forKey key: String?, operator op: NSComparisonPredicate.Operator? = nil) -> Any? {
        let val = findAllValues(forKey: key).lazy.filter { (op == nil || $0.operator == op!) && !$0.not }
@@ -592,3 +684,31 @@ func hasSuffix(_ suffix: String) -> (_ value: String) -> Bool {
        value.hasSuffix(suffix)
    }
 }
+
+// Legacy Swift versions support
+
+#if swift(>=4.0)
+#else
+extension String {
+    var count: Int {
+        return self.characters.count
+    }
+}
+#endif
+
+#if swift(>=4.1)
+#else
+extension Array {
+    func compactMap<ElementOfResult>(_ transform: (Element) throws -> ElementOfResult?) rethrows -> [ElementOfResult] {
+        return try self.flatMap(transform)
+    }
+}
+
+extension ArraySlice {
+    func compactMap<ElementOfResult>(_ transform: (Element) throws -> ElementOfResult?) rethrows -> [ElementOfResult] {
+        return try self.flatMap(transform)
+    }
+}
+#endif
+
+
@@ -323,11 +323,19 @@ final class HMAC<Variant: SHA2Variant> {
    }
    
    static func authenticate(message: Data, withKey key: Data) -> Data {
+        #if swift(>=5.0)
+        return Data(authenticate(message: Array(message), withKey: Array(key)))
+        #else
        return Data(bytes: authenticate(message: Array(message), withKey: Array(key)))
+        #endif
    }
    
    static func authenticate(message: String, withKey key: Data) -> Data {
+        #if swift(>=5.0)
+        return Data(authenticate(message: [UInt8](message.utf8), withKey: Array(key)))
+        #else
        return Data(bytes: authenticate(message: [UInt8](message.utf8), withKey: Array(key)))
+        #endif
    }
 }

@@ -397,26 +405,18 @@ fileprivate func toUInt64Array(_ slice: ArraySlice<UInt8>) -> Array<UInt64> {
    return result
 }

-fileprivate func arrayOfBytes<T>(_ value:T, length:Int? = nil) -> [UInt8] {
-    let totalBytes = length ?? MemoryLayout<T>.size
-    
-    let valuePointer = UnsafeMutablePointer<T>.allocate(capacity: 1)
-    
-    valuePointer.pointee = value
-    
-    let bytesPointer = UnsafeMutableRawPointer(valuePointer).assumingMemoryBound(to: UInt8.self)
-    var bytes = [UInt8](repeating: 0, count: totalBytes)
-    for j in 0..<min(MemoryLayout<T>.size,totalBytes) {
-        bytes[totalBytes - 1 - j] = (bytesPointer + j).pointee
+fileprivate func arrayOfBytes<T>(_ value: T, length: Int? = nil) -> [UInt8] {
+    var value = value
+    return Swift.withUnsafeBytes(of: &value) { (buffer: UnsafeRawBufferPointer) -> [UInt8] in
+        if let length = length {
+            return Array(buffer.prefix(length))
+        } else {
+            return Array(buffer)
+        }
    }
-    
-    valuePointer.deinitialize()
-    valuePointer.deallocate(capacity: 1)
-    
-    return bytes
 }

-public extension String {
+extension String {
    public func fp_sha256() -> [UInt8] {
        return SHA2<SHA256>.calculate([UInt8](self.utf8))
    }
@@ -430,7 +430,7 @@ public extension String {
    }
 }

-public extension Data {
+extension Data {
    public func fp_sha256() -> [UInt8] {
        return SHA2<SHA256>.calculate(Array(self))
    }
@@ -12,7 +12,7 @@ import Foundation
 Allows accessing to FTP files and directories. This provider doesn't cache or save files internally.
 It's a complete reimplementation and doesn't use CFNetwork deprecated API.
 */
-open class FTPFileProvider: FileProviderBasicRemote, FileProviderOperations, FileProviderReadWrite {
+open class FTPFileProvider: NSObject, FileProviderBasicRemote, FileProviderOperations, FileProviderReadWrite, FileProviderReadWriteProgressive {
    
    /// FTP data connection mode.
    public enum Mode: String {
@@ -27,7 +27,7 @@ open class FTPFileProvider: FileProviderBasicRemote, FileProviderOperations, Fil
    }
    
    open class var type: String { return "FTP" }
-    open let baseURL: URL?
+    public let baseURL: URL?
    
    open var dispatch_queue: DispatchQueue
    open var operation_queue: OperationQueue {
@@ -74,6 +74,10 @@ open class FTPFileProvider: FileProviderBasicRemote, FileProviderOperations, Fil
        }
    }
    
+    #if os(macOS) || os(iOS) || os(tvOS)
+    open var undoManager: UndoManager? = nil
+    #endif
+    
    /**
     Initializer for FTP provider with given username and password.
     
@@ -106,14 +110,12 @@ open class FTPFileProvider: FileProviderBasicRemote, FileProviderOperations, Fil
        self.credential = credential
        self.supportsRFC3659 = true
        
-        #if swift(>=3.1)
        let queueLabel = "FileProvider.\(Swift.type(of: self).type)"
-        #else
-        let queueLabel = "FileProvider.\(type(of: self).type)"
-        #endif
        dispatch_queue = DispatchQueue(label: queueLabel, attributes: .concurrent)
        operation_queue = OperationQueue()
        operation_queue.name = "\(queueLabel).Operation"
+        
+        super.init()
    }
    
    /**
@@ -133,15 +135,21 @@ open class FTPFileProvider: FileProviderBasicRemote, FileProviderOperations, Fil
    }
    
    public required convenience init?(coder aDecoder: NSCoder) {
-        guard let baseURL = aDecoder.decodeObject(forKey: "baseURL") as? URL else { return nil }
+        guard let baseURL = aDecoder.decodeObject(of: NSURL.self, forKey: "baseURL") as URL? else {
+            if #available(macOS 10.11, iOS 9.0, tvOS 9.0, *) {
+                aDecoder.failWithError(CocoaError(.coderValueNotFound,
+                                                  userInfo: [NSLocalizedDescriptionKey: "Base URL is not set."]))
+            }
+            return nil
+        }
        let mode: Mode
-        if let modeStr = aDecoder.decodeObject(forKey: "mode") as? String, let mode_v = Mode(rawValue: modeStr) {
+        if let modeStr = aDecoder.decodeObject(of: NSString.self, forKey: "mode") as String?, let mode_v = Mode(rawValue: modeStr) {
            mode = mode_v
        } else {
            let passiveMode = aDecoder.decodeBool(forKey: "passiveMode")
            mode = passiveMode ? .passive : .active
        }
-        self.init(baseURL: baseURL, mode: mode, credential: aDecoder.decodeObject(forKey: "credential") as? URLCredential)
+        self.init(baseURL: baseURL, mode: mode, credential: aDecoder.decodeObject(of: URLCredential.self, forKey: "credential"))
        self.useCache              = aDecoder.decodeBool(forKey: "useCache")
        self.validatingCache       = aDecoder.decodeBool(forKey: "validatingCache")
        self.supportsRFC3659       = aDecoder.decodeBool(forKey: "supportsRFC3659")
@@ -196,7 +204,7 @@ open class FTPFileProvider: FileProviderBasicRemote, FileProviderOperations, Fil
     
     - Note: Disabling this option will increase upload speed.
    */
-    public var uploadByREST: Bool = FileProviderStreamTask.defaultUseURLSession
+    public var uploadByREST: Bool = false
    
    /**
     Determines data connection must TLS or not. `false` value indicates to use `PROT C` and
@@ -204,6 +212,12 @@ open class FTPFileProvider: FileProviderBasicRemote, FileProviderOperations, Fil
    */
    public var securedDataConnection: Bool = true
    
+    /**
+     Trust all certificates if `disableEvaluation`, Otherwise validate certificate chain.
+     Default is `performDefaultEvaluation`.
+     */
+    public var serverTrustPolicy: ServerTrustPolicy = .performDefaultEvaluation(validateHost: true)
+    
    open func contentsOfDirectory(path: String, completionHandler: @escaping ([FileObject], Error?) -> Void) {
        self.contentsOfDirectory(path: path, rfc3659enabled: supportsRFC3659, completionHandler: completionHandler)
    }
@@ -223,6 +237,8 @@ open class FTPFileProvider: FileProviderBasicRemote, FileProviderOperations, Fil
        let path = ftpPath(apath)
        
        let task = session.fpstreamTask(withHostName: baseURL!.host!, port: baseURL!.port!)
+        task.serverTrustPolicy = serverTrustPolicy
+        task.taskDescription = FileOperationType.fetch(path: path).json
        self.ftpLogin(task) { (error) in
            if let error = error {
                self.dispatch_queue.async {
@@ -248,7 +264,7 @@ open class FTPFileProvider: FileProviderBasicRemote, FileProviderOperations, Fil
                }
                
                
-                let files: [FileObject] = contents.flatMap {
+                let files: [FileObject] = contents.compactMap {
                    rfc3659enabled ? self.parseMLST($0, in: path) : (self.parseUnixList($0, in: path) ?? self.parseDOSList($0, in: path))
                }
                
@@ -278,6 +294,8 @@ open class FTPFileProvider: FileProviderBasicRemote, FileProviderOperations, Fil
        let path = ftpPath(apath)
        
        let task = session.fpstreamTask(withHostName: baseURL!.host!, port: baseURL!.port!)
+        task.serverTrustPolicy = serverTrustPolicy
+        task.taskDescription = FileOperationType.fetch(path: path).json
        self.ftpLogin(task) { (error) in
            if let error = error {
                self.dispatch_queue.async {
@@ -297,7 +315,7 @@ open class FTPFileProvider: FileProviderBasicRemote, FileProviderOperations, Fil
                    }
                    
                    guard let response = response, response.hasPrefix("250") || (response.hasPrefix("50") && rfc3659enabled) else {
-                        throw self.urlError(path, code: .badServerResponse)
+                        throw URLError(.badServerResponse, url: self.url(of: path))
                    }
                    
                    if response.hasPrefix("500") {
@@ -305,11 +323,11 @@ open class FTPFileProvider: FileProviderBasicRemote, FileProviderOperations, Fil
                        self.attributesOfItem(path: path, rfc3659enabled: false, completionHandler: completionHandler)
                    }
                    
-                    let lines = response.components(separatedBy: "\n").flatMap { $0.isEmpty ? nil : $0.trimmingCharacters(in: .whitespacesAndNewlines) }
+                    let lines = response.components(separatedBy: "\n").compactMap { $0.isEmpty ? nil : $0.trimmingCharacters(in: .whitespacesAndNewlines) }
                    guard lines.count > 2 else {
-                        throw self.urlError(path, code: .badServerResponse)
+                        throw URLError(.badServerResponse, url: self.url(of: path))
                    }
-                    let dirPath = (path as NSString).deletingLastPathComponent
+                    let dirPath = path.deletingLastPathComponent
                    let file: FileObject? = rfc3659enabled ?
                        self.parseMLST(lines[1], in: dirPath) :
                        (self.parseUnixList(lines[1], in: dirPath) ?? self.parseDOSList(lines[1], in: dirPath))
@@ -403,7 +421,7 @@ open class FTPFileProvider: FileProviderBasicRemote, FileProviderOperations, Fil
    
    @discardableResult
    open func create(folder folderName: String, at atPath: String, completionHandler: SimpleCompletionHandler) -> Progress? {
-        let path = (atPath as NSString).appendingPathComponent(folderName) + "/"
+        let path = atPath.appendingPathComponent(folderName) + "/"
        return doOperation(.create(path: path), completionHandler: completionHandler)
    }
    
@@ -424,10 +442,17 @@ open class FTPFileProvider: FileProviderBasicRemote, FileProviderOperations, Fil
    
    @discardableResult
    open func copyItem(localFile: URL, to toPath: String, overwrite: Bool, completionHandler: SimpleCompletionHandler) -> Progress? {
+        guard (try? localFile.checkResourceIsReachable()) ?? false else {
+            dispatch_queue.async {
+                completionHandler?(URLError(.fileDoesNotExist, url: localFile))
+            }
+            return nil
+        }
+        
        // check file is not a folder
        guard (try? localFile.resourceValues(forKeys: [.fileResourceTypeKey]))?.fileResourceType ?? .unknown == .regular else {
            dispatch_queue.async {
-                completionHandler?(self.urlError(localFile.path, code: .fileIsDirectory))
+                completionHandler?(URLError(.fileIsDirectory, url: localFile))
            }
            return nil
        }
@@ -437,12 +462,17 @@ open class FTPFileProvider: FileProviderBasicRemote, FileProviderOperations, Fil
            return nil
        }
        
-        let progress = Progress(totalUnitCount: 0)
+        let progress = Progress(totalUnitCount: -1)
        progress.setUserInfoObject(operation, forKey: .fileProvderOperationTypeKey)
        progress.kind = .file
        progress.setUserInfoObject(Progress.FileOperationKind.downloading, forKey: .fileOperationKindKey)
        
        let task = session.fpstreamTask(withHostName: baseURL!.host!, port: baseURL!.port!)
+        task.serverTrustPolicy = serverTrustPolicy
+        task.taskDescription = operation.json
+        progress.cancellationHandler = { [weak task] in
+            task?.cancel()
+        }
        self.ftpLogin(task) { (error) in
            if let error = error {
                self.dispatch_queue.async {
@@ -452,7 +482,11 @@ open class FTPFileProvider: FileProviderBasicRemote, FileProviderOperations, Fil
                return
            }
            
-            self.ftpStore(task, filePath: self.ftpPath(toPath), fromData: nil, fromFile: localFile, onTask: { task in
+            guard let stream = InputStream(url: localFile) else {
+                return
+            }
+            let size = localFile.fileSize
+            self.ftpStore(task, filePath: self.ftpPath(toPath), from: stream, size: size, onTask: { task in
                weak var weakTask = task
                progress.cancellationHandler = {
                    weakTask?.cancel()
@@ -483,12 +517,17 @@ open class FTPFileProvider: FileProviderBasicRemote, FileProviderOperations, Fil
        guard fileOperationDelegate?.fileProvider(self, shouldDoOperation: operation) ?? true == true else {
            return nil
        }
-        let progress = Progress(totalUnitCount: 0)
+        let progress = Progress(totalUnitCount: -1)
        progress.setUserInfoObject(operation, forKey: .fileProvderOperationTypeKey)
        progress.kind = .file
        progress.setUserInfoObject(Progress.FileOperationKind.downloading, forKey: .fileOperationKindKey)
        
        let task = session.fpstreamTask(withHostName: baseURL!.host!, port: baseURL!.port!)
+        task.serverTrustPolicy = serverTrustPolicy
+        task.taskDescription = operation.json
+        progress.cancellationHandler = { [weak task] in
+            task?.cancel()
+        }
        self.ftpLogin(task) { (error) in
            if let error = error {
                self.dispatch_queue.async {
@@ -497,7 +536,12 @@ open class FTPFileProvider: FileProviderBasicRemote, FileProviderOperations, Fil
                return
            }
            
-            self.ftpDownload(task, filePath: self.ftpPath(path), onTask: { task in
+            let tempURL = URL(fileURLWithPath: NSTemporaryDirectory().appendingPathComponent(UUID().uuidString))
+            guard let stream = OutputStream(url: tempURL, append: false) else {
+                completionHandler?(CocoaError(.fileWriteUnknown, path: destURL.path))
+                return
+            }
+            self.ftpDownload(task, filePath: self.ftpPath(path), to: stream, onTask: { task in
                weak var weakTask = task
                progress.cancellationHandler = {
                    weakTask?.cancel()
@@ -507,22 +551,24 @@ open class FTPFileProvider: FileProviderBasicRemote, FileProviderOperations, Fil
                progress.totalUnitCount = totalSize
                progress.completedUnitCount = totalReceived
                self.delegateNotify(operation, progress: progress.fractionCompleted)
-            }) { (tmpurl, error) in
-                if let error = error {
+            }) { (error) in
+                if error != nil {
                    progress.cancel()
+                }
+                do {
+                    try FileManager.default.moveItem(at: tempURL, to: destURL)
+                } catch {
                    self.dispatch_queue.async {
                        completionHandler?(error)
                        self.delegateNotify(operation, error: error)
                    }
+                    try? FileManager.default.removeItem(at: tempURL)
                    return
                }
                
-                if let tmpurl = tmpurl {
-                    try? FileManager.default.moveItem(at: tmpurl, to: destURL)
-                    self.dispatch_queue.async {
-                        completionHandler?(nil)
-                        self.delegateNotify(operation)
-                    }
+                self.dispatch_queue.async {
+                    completionHandler?(error)
+                    self.delegateNotify(operation, error: error)
                }
            }
        }
@@ -539,12 +585,17 @@ open class FTPFileProvider: FileProviderBasicRemote, FileProviderOperations, Fil
            }
            return nil
        }
-        let progress = Progress(totalUnitCount: 0)
+        let progress = Progress(totalUnitCount: -1)
        progress.setUserInfoObject(operation, forKey: .fileProvderOperationTypeKey)
        progress.kind = .file
        progress.setUserInfoObject(Progress.FileOperationKind.downloading, forKey: .fileOperationKindKey)
        
        let task = session.fpstreamTask(withHostName: baseURL!.host!, port: baseURL!.port!)
+        task.serverTrustPolicy = serverTrustPolicy
+        task.taskDescription = operation.json
+        progress.cancellationHandler = { [weak task] in
+            task?.cancel()
+        }
        self.ftpLogin(task) { (error) in
            if let error = error {
                self.dispatch_queue.async {
@@ -553,7 +604,8 @@ open class FTPFileProvider: FileProviderBasicRemote, FileProviderOperations, Fil
                return
            }
            
-            self.ftpFileData(task, filePath: self.ftpPath(path), from: offset, length: length, onTask: { task in
+            let stream = OutputStream.toMemory()
+            self.ftpDownload(task, filePath: self.ftpPath(path), from: offset, length: length, to: stream, onTask: { task in
                weak var weakTask = task
                progress.cancellationHandler = {
                    weakTask?.cancel()
@@ -563,7 +615,7 @@ open class FTPFileProvider: FileProviderBasicRemote, FileProviderOperations, Fil
                progress.totalUnitCount = totalSize
                progress.completedUnitCount = totalReceived
                self.delegateNotify(operation, progress: progress.fractionCompleted)
-            }) { (data, error) in
+            }) { (error) in
                if let error = error {
                    progress.cancel()
                    self.dispatch_queue.async {
@@ -573,7 +625,7 @@ open class FTPFileProvider: FileProviderBasicRemote, FileProviderOperations, Fil
                    return
                }
                
-                if let data = data {
+                if let data = stream.property(forKey: .dataWrittenToMemoryStreamKey) as? Data {
                    self.dispatch_queue.async {
                        completionHandler(data, nil)
                        self.delegateNotify(operation)
@@ -592,12 +644,17 @@ open class FTPFileProvider: FileProviderBasicRemote, FileProviderOperations, Fil
            return nil
        }
        
-        let progress = Progress(totalUnitCount: Int64(data?.count ?? 0))
+        let progress = Progress(totalUnitCount: Int64(data?.count ?? -1))
        progress.setUserInfoObject(operation, forKey: .fileProvderOperationTypeKey)
        progress.kind = .file
        progress.setUserInfoObject(Progress.FileOperationKind.downloading, forKey: .fileOperationKindKey)
        
        let task = session.fpstreamTask(withHostName: baseURL!.host!, port: baseURL!.port!)
+        task.serverTrustPolicy = serverTrustPolicy
+        task.taskDescription = operation.json
+        progress.cancellationHandler = { [weak task] in
+            task?.cancel()
+        }
        self.ftpLogin(task) { (error) in
            if let error = error {
                self.dispatch_queue.async {
@@ -608,7 +665,9 @@ open class FTPFileProvider: FileProviderBasicRemote, FileProviderOperations, Fil
            }
            
            let storeHandler = {
-                self.ftpStore(task, filePath: self.ftpPath(path), fromData: data ?? Data(), fromFile: nil, onTask: { task in
+                let data = data ?? Data()
+                let stream = InputStream(data: data)
+                self.ftpStore(task, filePath: self.ftpPath(path), from: stream, size: Int64(data.count), onTask: { task in
                    weak var weakTask = task
                    progress.cancellationHandler = {
                        weakTask?.cancel()
@@ -643,6 +702,65 @@ open class FTPFileProvider: FileProviderBasicRemote, FileProviderOperations, Fil
        return progress
    }
    
+    public func contents(path: String, offset: Int64, length: Int, responseHandler: ((URLResponse) -> Void)?, progressHandler: @escaping (Int64, Data) -> Void, completionHandler: SimpleCompletionHandler) -> Progress? {
+        let operation = FileOperationType.fetch(path: path)
+        if length == 0 || offset < 0 {
+            dispatch_queue.async {
+                completionHandler?(nil)
+                self.delegateNotify(operation)
+            }
+            return nil
+        }
+        let progress = Progress(totalUnitCount: -1)
+        progress.setUserInfoObject(operation, forKey: .fileProvderOperationTypeKey)
+        progress.kind = .file
+        progress.setUserInfoObject(Progress.FileOperationKind.downloading, forKey: .fileOperationKindKey)
+        
+        let task = session.fpstreamTask(withHostName: baseURL!.host!, port: baseURL!.port!)
+        task.serverTrustPolicy = serverTrustPolicy
+        task.taskDescription = operation.json
+        progress.cancellationHandler = { [weak task] in
+            task?.cancel()
+        }
+        self.ftpLogin(task) { (error) in
+            if let error = error {
+                self.dispatch_queue.async {
+                    completionHandler?(error)
+                }
+                return
+            }
+            
+            self.ftpDownloadData(task, filePath: self.ftpPath(path), from: offset, length: length, onTask: { task in
+                weak var weakTask = task
+                progress.cancellationHandler = {
+                    weakTask?.cancel()
+                }
+                progress.setUserInfoObject(Date(), forKey: .startingTimeKey)
+            }, onProgress: { data, recevied, totalReceived, totalSize in
+                progressHandler(totalReceived - recevied, data)
+                progress.totalUnitCount = totalSize
+                progress.completedUnitCount = totalReceived
+                self.delegateNotify(operation, progress: progress.fractionCompleted)
+            }) { (data, error) in
+                if let error = error {
+                    progress.cancel()
+                    self.dispatch_queue.async {
+                        completionHandler?(error)
+                        self.delegateNotify(operation, error: error)
+                    }
+                    return
+                }
+                
+                self.dispatch_queue.async {
+                    completionHandler?(nil)
+                    self.delegateNotify(operation)
+                }
+            }
+        }
+        
+        return progress
+    }
+    
    /**
     Creates a symbolic link at the specified path that points to an item at the given path.
     This method does not traverse symbolic links contained in destination path, making it possible
@@ -685,6 +803,11 @@ extension FTPFileProvider {
        progress.setUserInfoObject(Progress.FileOperationKind.downloading, forKey: .fileOperationKindKey)
        
        let task = session.fpstreamTask(withHostName: baseURL!.host!, port: baseURL!.port!)
+        task.serverTrustPolicy = serverTrustPolicy
+        task.taskDescription = operation.json
+        progress.cancellationHandler = { [weak task] in
+            task?.cancel()
+        }
        self.ftpLogin(task) { (error) in
            if let error = error {
                completionHandler?(error)
@@ -701,13 +824,13 @@ extension FTPFileProvider {
                
                guard let response = response else {
                    completionHandler?(error)
-                    self.delegateNotify(operation, error: self.urlError(sourcePath, code: .badServerResponse))
+                    self.delegateNotify(operation, error: URLError(.badServerResponse, url: self.url(of: sourcePath)))
                    return
                }
                
-                let codes: [Int] = response.components(separatedBy: .newlines).flatMap({ $0.isEmpty ? nil : $0})
-                    .flatMap {
-                        let code = $0.components(separatedBy: .whitespaces).flatMap({ $0.isEmpty ? nil : $0}).first
+                let codes: [Int] = response.components(separatedBy: .newlines).compactMap({ $0.isEmpty ? nil : $0})
+                    .compactMap {
+                        let code = $0.components(separatedBy: .whitespaces).compactMap({ $0.isEmpty ? nil : $0}).first
                        return code != nil ? Int(code!) : nil
                }
                
@@ -726,13 +849,16 @@ extension FTPFileProvider {
                    case .link: errorCode = .cannotWriteToFile
                    default: errorCode = .cannotOpenFile
                    }
-                    let error = self.urlError(sourcePath, code: errorCode)
+                    let error = URLError(errorCode, url: self.url(of: sourcePath))
                    progress.cancel()
                    completionHandler?(error)
                    self.delegateNotify(operation, error: error)
                    return
                }
                
+                #if os(macOS) || os(iOS) || os(tvOS)
+                self._registerUndo(operation)
+                #endif
                progress.completedUnitCount = progress.totalUnitCount
                completionHandler?(nil)
                self.delegateNotify(operation)
@@ -783,7 +909,7 @@ extension FTPFileProvider {
                }
                
                guard let response = response else {
-                    throw  self.urlError(sourcePath, code: .badServerResponse)
+                    throw URLError(.badServerResponse, url: self.url(of: sourcePath))
                }
                
                if response.hasPrefix("50") {
@@ -792,7 +918,7 @@ extension FTPFileProvider {
                }
                
                if !response.hasPrefix("2") {
-                    throw self.urlError(sourcePath, code: .cannotRemoveFile)
+                    throw  URLError(.cannotRemoveFile, url: self.url(of: sourcePath))
                }
                self.dispatch_queue.async {
                    completionHandler?(nil)
@@ -845,3 +971,7 @@ extension FTPFileProvider {
 }

 extension FTPFileProvider: FileProvider { }
+
+#if os(macOS) || os(iOS) || os(tvOS)
+extension FTPFileProvider: FileProvideUndoable { }
+#endif
@@ -9,7 +9,7 @@
 import Foundation

 /// Containts path, url and attributes of a file or resource.
-open class FileObject: Equatable {
+open class FileObject: NSObject {
    /// A `Dictionary` contains file information,  using `URLResourceKey` keys.
    open internal(set) var allValues: [URLResourceKey: Any]
    
@@ -19,6 +19,7 @@ open class FileObject: Equatable {
    
    internal init(url: URL?, name: String, path: String) {
        self.allValues = [URLResourceKey: Any]()
+        super.init()
        if let url = url {
            self.url = url
        }
@@ -33,7 +34,10 @@ open class FileObject: Equatable {
            if let url = allValues[.fileURLKey] as? URL {
                return url
            } else {
-                let path = self.path.addingPercentEncoding(withAllowedCharacters: .filePathAllowed) ?? self.path
+                var path = self.path.addingPercentEncoding(withAllowedCharacters: .filePathAllowed) ?? self.path
+                if path.hasPrefix("/") {
+                    path.remove(at: path.startIndex)
+                }
                return URL(string: path) ?? URL(string: "/")!
            }
        }
@@ -147,28 +151,40 @@ open class FileObject: Equatable {
    open var isSymLink: Bool {
        return self.type == .symbolicLink
    }
-    
-    /// Check `FileObject` equality
-    public static func ==(lhs: FileObject, rhs: FileObject) -> Bool {
-        if rhs === lhs  {
-            return true
-        }
-        #if swift(>=3.1)
-        if Swift.type(of: lhs) != Swift.type(of: rhs) {
-            return false
-        }
+}
+
+extension FileObject {
+    open override var hash: Int {
+        #if swift(>=4.2)
+        var hasher = Hasher()
+        hasher.combine(url)
+        hasher.combine(size)
+        hasher.combine(modifiedDate)
+        return hasher.finalize()
        #else
-        if type(of: lhs) != type(of: rhs) {
-            return false
-        }
+        let hashURL =  self.url.hashValue
+        let hashSize = self.size.hashValue
+        return (hashURL << 7) &+ hashURL &+ hashSize
        #endif
-        
-        if let rurl = rhs.allValues[.fileURLKey] as? URL, let lurl = lhs.allValues[.fileURLKey] as? URL {
-            return rurl == lurl && rhs.size == lhs.size
-        }
-        return rhs.path == lhs.path && rhs.size == lhs.size && rhs.modifiedDate == lhs.modifiedDate
    }
    
+    open override func isEqual(_ object: Any?) -> Bool {
+        guard let object = object as? FileObject else { return false }
+        if self === object  {
+            return true
+        }
+        if Swift.type(of: self) != Swift.type(of: object) {
+            return false
+        }
+        
+        if let rurl = self.allValues[.fileURLKey] as? URL, let lurl = object.allValues[.fileURLKey] as? URL {
+            return rurl == lurl && self.size == object.size
+        }
+        return self.path == object.path && self.size == object.size && self.modifiedDate == object.modifiedDate
+    }
+}
+
+extension FileObject {
    internal func mapPredicate() -> [String: Any] {
        let mapDict: [URLResourceKey: String] = [.fileURLKey: "url", .nameKey: "name", .pathKey: "path",
                                                 .fileSizeKey: "fileSize", .creationDateKey: "creationDate",
@@ -207,6 +223,7 @@ open class FileObject: Equatable {
            case .and: return NSCompoundPredicate(andPredicateWithSubpredicates: newSub)
            case .not: return NSCompoundPredicate(notPredicateWithSubpredicate: newSub[0])
            case .or:  return NSCompoundPredicate(orPredicateWithSubpredicates: newSub)
+            @unknown default: fatalError()
            }
        } else if let cQuery = query as? NSComparisonPredicate {
            var newLeft = cQuery.leftExpression
@@ -225,7 +242,7 @@ open class FileObject: Equatable {
 }

 /// Containts attributes of a provider.
-open class VolumeObject {
+open class VolumeObject: NSObject {
    /// A `Dictionary` contains volume information,  using `URLResourceKey` keys.
    open internal(set) var allValues: [URLResourceKey: Any]
    
@@ -323,7 +340,6 @@ open class VolumeObject {
    }
 }

-
 /// Sorting FileObject array by given criteria, **not thread-safe**
 public struct FileObjectSorting {
    
@@ -399,8 +415,8 @@ public struct FileObjectSorting {
            case .nameCaseInsensitive:
                return ($0.name).localizedCaseInsensitiveCompare($1.name) == (ascending ? .orderedAscending : .orderedDescending)
            case .extension:
-                let kind1 = $0.isDirectory ? "folder" : ($0.path as NSString).pathExtension
-                let kind2 = $1.isDirectory ? "folder" : ($1.path as NSString).pathExtension
+                let kind1 = $0.isDirectory ? "folder" : $0.path.pathExtension
+                let kind2 = $1.isDirectory ? "folder" : $1.path.pathExtension
                return kind1.localizedCaseInsensitiveCompare(kind2) == (ascending ? .orderedAscending : .orderedDescending)
            case .modifiedDate:
                let fileMod1 = $0.modifiedDate ?? Date.distantPast
@@ -9,9 +9,11 @@
 import Foundation
 #if os(iOS) || os(tvOS)
 import UIKit
+import ImageIO
 public typealias ImageClass = UIImage
 #elseif os(macOS)
 import Cocoa
+import ImageIO
 public typealias ImageClass = NSImage
 #endif

@@ -19,7 +21,7 @@ public typealias ImageClass = NSImage
 public typealias SimpleCompletionHandler = ((_ error: Error?) -> Void)?

 /// This protocol defines FileProvider neccesary functions and properties to connect and get contents list
-public protocol FileProviderBasic: class, NSSecureCoding {
+public protocol FileProviderBasic: class, NSSecureCoding, CustomDebugStringConvertible {
    /// An string to identify type of provider.
    static var type: String { get }
    
@@ -201,6 +203,13 @@ extension FileProviderBasic {
            operation_queue.maxConcurrentOperationCount = newValue
        }
    }
+    
+    public var debugDescription: String {
+        let typeDesc = "\(Self.type) provider"
+        let urlDesc = self.baseURL.map({ " - " + $0.absoluteString }) ?? ""
+        let credentialDesc = self.credential?.user.map({ " - " + $0.debugDescription }) ?? ""
+        return typeDesc + urlDesc + credentialDesc
+    }
 }

 /// Checking equality of two file provider, regardless of current path queues and delegates.
@@ -423,7 +432,7 @@ public protocol FileProviderOperations: FileProviderBasic {
    func copyItem(path: String, toLocalURL: URL, completionHandler: SimpleCompletionHandler) -> Progress?
 }

-public extension FileProviderOperations {
+extension FileProviderOperations {
    @discardableResult
    public func moveItem(path: String, to: String, completionHandler: SimpleCompletionHandler) -> Progress? {
        return self.moveItem(path: path, to: to, overwrite: false, completionHandler: completionHandler)
@@ -440,7 +449,7 @@ public extension FileProviderOperations {
    }
 }

-internal extension FileProviderOperations {
+extension FileProviderOperations {
    internal func delegateNotify(_ operation: FileOperationType, error: Error? = nil) {
        DispatchQueue.main.async(execute: {
            if let error = error {
@@ -569,6 +578,72 @@ extension FileProviderReadWrite {
    }
 }

+/// Defines method for fetching file contents progressivly
+public protocol FileProviderReadWriteProgressive {
+    /**
+     Retreives a `Data` object with a portion contents of the file asynchronously vis contents argument of completion handler.
+     If path specifies a directory, or if some other error occurs, data will be nil.
+     
+     - Parameters:
+       - path: Path of file.
+       - progressHandler: a closure which will be called every time a new data received from server.
+         - position: Start position of returned data, indexed from zero.
+         - data: returned `Data` from server.
+       - completionHandler: a closure which will be called after receiving is completed or an error occureed.
+     - Returns: An `Progress` to get progress or cancel progress. Doesn't work on `LocalFileProvider`.
+     */
+    @discardableResult
+    func contents(path: String, progressHandler: @escaping (_ position: Int64, _ data: Data) -> Void, completionHandler: SimpleCompletionHandler) -> Progress?
+    
+    /**
+     Retreives a `Data` object with a portion contents of the file asynchronously vis contents argument of completion handler.
+     If path specifies a directory, or if some other error occurs, data will be nil.
+     
+     - Parameters:
+       - path: Path of file.
+       - responseHandler: a closure which will be called after fetching server response.
+         - response: `URLResponse` returned from server.
+       - progressHandler: a closure which will be called every time a new data received from server.
+         - position: Start position of returned data, indexed from zero.
+         - data: returned `Data` from server.
+       - completionHandler: a closure which will be called after receiving is completed or an error occureed.
+     - Returns: An `Progress` to get progress or cancel progress. Doesn't work on `LocalFileProvider`.
+     */
+    @discardableResult
+    func contents(path: String, responseHandler: ((_ response: URLResponse) -> Void)?, progressHandler: @escaping (_ position: Int64, _ data: Data) -> Void, completionHandler: SimpleCompletionHandler) -> Progress?
+    
+    /**
+     Retreives a `Data` object with a portion contents of the file asynchronously vis contents argument of completion handler.
+     If path specifies a directory, or if some other error occurs, data will be nil.
+     
+     - Parameters:
+       - path: Path of file.
+       - offset: First byte index which should be read. **Starts from 0.**
+       - length: Bytes count of data. Pass `-1` to read until the end of file.
+       - responseHandler: a closure which will be called after fetching server response.
+         - response: `URLResponse` returned from server.
+       - progressHandler: a closure which will be called every time a new data received from server.
+         - position: Start position of returned data, indexed from offset.
+         - data: returned `Data` from server.
+       - completionHandler: a closure which will be called after receiving is completed or an error occureed.
+     - Returns: An `Progress` to get progress or cancel progress. Doesn't work on `LocalFileProvider`.
+     */
+    @discardableResult
+    func contents(path: String, offset: Int64, length: Int, responseHandler: ((_ response: URLResponse) -> Void)?, progressHandler: @escaping (_ position: Int64, _ data: Data) -> Void, completionHandler: SimpleCompletionHandler) -> Progress?
+}
+
+extension FileProviderReadWriteProgressive {
+    @discardableResult
+    public func contents(path: String, progressHandler: @escaping (_ position: Int64, _ data: Data) -> Void, completionHandler: SimpleCompletionHandler) -> Progress? {
+        return contents(path: path, offset: 0, length: -1, responseHandler: nil, progressHandler: progressHandler, completionHandler: completionHandler)
+    }
+    
+    @discardableResult
+    public func contents(path: String, responseHandler: ((_ response: URLResponse) -> Void)?, progressHandler: @escaping (_ position: Int64, _ data: Data) -> Void, completionHandler: SimpleCompletionHandler) -> Progress? {
+        return contents(path: path, offset: 0, length: -1, responseHandler: responseHandler, progressHandler: progressHandler, completionHandler: completionHandler)
+    }
+}
+
 /// Allows a file provider to notify changes occured
 public protocol FileProviderMonitor: FileProviderBasic {
    
@@ -618,7 +693,7 @@ public protocol FileProvideUndoable: FileProviderOperations {
    func canUndo(operation: FileOperationType) -> Bool
 }

-public extension FileProvideUndoable {
+extension FileProvideUndoable {
    public func canUndo(operation: FileOperationType) -> Bool {
        return undoOperation(for: operation) != nil
    }
@@ -656,6 +731,43 @@ public extension FileProvideUndoable {
        self.undoManager = UndoManager()
        self.undoManager?.levelsOfUndo = 10
    }
+    
+    public func _registerUndo(_ operation: FileOperationType) {
+        #if os(macOS) || os(iOS) || os(tvOS)
+        guard let undoManager = self.undoManager, let undoOp = self.undoOperation(for: operation) else {
+            return
+        }
+        
+        let undoBox = UndoBox(provider: self, operation: operation, undoOperation: undoOp)
+        undoManager.beginUndoGrouping()
+        undoManager.registerUndo(withTarget: undoBox, selector: #selector(UndoBox.doSimpleOperation(_:)), object: undoBox)
+        undoManager.setActionName(operation.actionDescription)
+        undoManager.endUndoGrouping()
+        #endif
+    }
+}
+
+class UndoBox: NSObject {
+    weak var provider: FileProvideUndoable?
+    let operation: FileOperationType
+    let undoOperation: FileOperationType
+    
+    init(provider: FileProvideUndoable, operation: FileOperationType, undoOperation: FileOperationType) {
+        self.provider = provider
+        self.operation = operation
+        self.undoOperation = undoOperation
+    }
+    
+    @objc internal func doSimpleOperation(_ box: UndoBox) {
+        switch self.undoOperation {
+        case .move(source: let source, destination: let dest):
+            _=provider?.moveItem(path: source, to: dest, completionHandler: nil)
+        case .remove(let path):
+            _=provider?.removeItem(path: path, completionHandler: nil)
+        default:
+            break
+        }
+    }
 }
 #endif

@@ -678,24 +790,43 @@ public protocol FileProviderSharing {
    func publicLink(to path: String, completionHandler: @escaping (_ link: URL?, _ attribute: FileObject?, _ expiration: Date?, _ error: Error?) -> Void)
 }

+//efines protocol for provider allows symbolic link operations.
+public protocol FileProviderSymbolicLink {
+    /**
+     Creates a symbolic link at the specified path that points to an item at the given path.
+     This method does not traverse symbolic links contained in destination path, making it possible
+     to create symbolic links to locations that do not yet exist.
+     Also, if the final path component is a symbolic link, that link is not followed.
+     
+     - Parameters:
+     - symbolicLink: The file path at which to create the new symbolic link. The last component of the path issued as the name of the link.
+     - withDestinationPath: The path that contains the item to be pointed to by the link. In other words, this is the destination of the link.
+     - completionHandler: If an error parameter was provided, a presentable `Error` will be returned.
+     */
+    func create(symbolicLink path: String, withDestinationPath destPath: String, completionHandler: SimpleCompletionHandler)
+    
+    /// Returns the path of the item pointed to by a symbolic link.
+    ///
+    /// - Parameters:
+    ///   - path: The path of a file or directory.
+    ///   - completionHandler: Returns destination url of given symbolic link, or an `Error` object if it fails.
+    func destination(ofSymbolicLink path: String, completionHandler: @escaping (_ file: FileObject?, _ error: Error?) -> Void)
+}
+
 /// Defines protocol for provider allows all common operations.
 public protocol FileProvider: FileProviderOperations, FileProviderReadWrite, NSCopying {
 }

 internal let pathTrimSet = CharacterSet(charactersIn: " /")
-public extension FileProviderBasic {
+extension FileProviderBasic {
    public var type: String {
-        #if swift(>=3.1)
        return Swift.type(of: self).type
-        #else
-        return type(of: self).type
-        #endif
    }
    
    public func url(of path: String) -> URL {
        var rpath: String = path
        rpath = rpath.addingPercentEncoding(withAllowedCharacters: .filePathAllowed) ?? rpath
-        if let baseURL = baseURL {
+        if let baseURL = baseURL?.absoluteURL {
            if rpath.hasPrefix("/") {
                rpath.remove(at: rpath.startIndex)
            }
@@ -759,32 +890,7 @@ public extension FileProviderBasic {
        }
        _ = group.wait(timeout: .now() + 5)
        let finalFile = result + (!fileExt.isEmpty ? "." + fileExt : "")
-        return (dirPath as NSString).appendingPathComponent(finalFile)
-    }
-    
-    internal func urlError(_ path: String, code: URLError.Code) -> Error {
-        let fileURL = self.url(of: path)
-        var userInfo: [String: Any] = [NSURLErrorKey: fileURL,
-                                       NSURLErrorFailingURLErrorKey: fileURL,
-                                       NSURLErrorFailingURLStringErrorKey: fileURL.absoluteString,
-                                       ]
-        let error = NSError(domain: NSURLErrorDomain, code: code.rawValue, userInfo: nil)
-        for (key, value) in error.userInfo {
-            userInfo[key] = value
-        }
-        return URLError(code, userInfo: userInfo)
-    }
-    
-    internal func cocoaError(_ path: String, code: CocoaError.Code) -> Error {
-        let fileURL = self.url(of: path)
-        var userInfo: [String: Any] = [NSFilePathErrorKey: path,
-                                       NSURLErrorKey: fileURL,
-                                       ]
-        let error = NSError(domain: NSCocoaErrorDomain, code: code.rawValue, userInfo: nil)
-        for (key, value) in error.userInfo {
-            userInfo[key] = value
-        }
-        return cocoaError(fileURL.path, code: code)
+        return dirPath.appendingPathComponent(finalFile)
    }
    
    internal func NotImplemented(_ fn: String = #function, file: StaticString = #file) {
@@ -864,121 +970,134 @@ extension ExtendedFileProvider {
        return self.thumbnailOfFile(path: path, dimension: nil, completionHandler: completionHandler)
    }
    
-    internal static func convertToImage(pdfData: Data?, page: Int = 1) -> ImageClass? {
+    internal static func convertToImage(pdfData: Data?, page: Int = 1, maxSize: CGSize?) -> ImageClass? {
        guard let pdfData = pdfData else { return nil }
        
        let cfPDFData: CFData = pdfData as CFData
        if let provider = CGDataProvider(data: cfPDFData), let reference = CGPDFDocument(provider), let pageRef = reference.page(at: page) {
-            return self.convertToImage(pdfPage: pageRef)
+            return self.convertToImage(pdfPage: pageRef, maxSize: maxSize)
        }
        return nil
    }
    
-    internal static func convertToImage(pdfURL: URL, page: Int = 1) -> ImageClass? {
+    internal static func convertToImage(pdfURL: URL, page: Int = 1, maxSize: CGSize?) -> ImageClass? {
        // To accelerate, supporting only local file URL
        guard pdfURL.isFileURL else { return nil }
        
        if let reference = CGPDFDocument(pdfURL as CFURL), let pageRef = reference.page(at: page) {
-            return self.convertToImage(pdfPage: pageRef)
+            return self.convertToImage(pdfPage: pageRef, maxSize: maxSize)
        }
        return nil
    }
    
-    private static func convertToImage(pdfPage: CGPDFPage) -> ImageClass? {
+    private static func convertToImage(pdfPage: CGPDFPage, maxSize: CGSize?) -> ImageClass? {
+        let scale: CGFloat
        let frame = pdfPage.getBoxRect(CGPDFBox.mediaBox)
-        var size = frame.size
-        let rect = CGRect(x: 0, y: 0, width: size.width, height: size.height)
-        
+        if let maxSize = maxSize {
+            scale = min(maxSize.width / frame.width, maxSize.height / frame.height)
+        } else {
+            #if os(macOS)
+            scale = NSScreen.main?.backingScaleFactor ?? 1.0 // fetch device is retina or not
+            #else
+            scale = UIScreen.main.scale // fetch device is retina or not
+            #endif
+        }
+        let rect = CGRect(origin: .zero, size: frame.size)
+        let size = CGSize(width: frame.size.width * scale, height: frame.size.height * scale)
+        let transform = pdfPage.getDrawingTransform(CGPDFBox.mediaBox, rect: rect, rotate: 0, preserveAspectRatio: true)
+
        #if os(macOS)
-            #if swift(>=3.2)
-            let ppp = Int(NSScreen.main?.backingScaleFactor ?? 1) // fetch device is retina or not
-            #else
-            let ppp = Int(NSScreen.main()?.backingScaleFactor ?? 1) // fetch device is retina or not
-            #endif
+        let rep = NSBitmapImageRep(bitmapDataPlanes: nil, pixelsWide: Int(size.width), pixelsHigh: Int(size.height),
+                                   bitsPerSample: 8, samplesPerPixel: 4, hasAlpha: true, isPlanar: false, colorSpaceName: .calibratedRGB,
+                                   bytesPerRow: 0, bitsPerPixel: 0)
+        
+        guard let context = NSGraphicsContext(bitmapImageRep: rep!) else {
+            return nil
+        }
            
-            size.width  *= CGFloat(ppp)
-            size.height *= CGFloat(ppp)
-            
-            #if swift(>=3.2)
-            let rep = NSBitmapImageRep(bitmapDataPlanes: nil, pixelsWide: Int(size.width), pixelsHigh: Int(size.height),
-                                       bitsPerSample: 8, samplesPerPixel: 4, hasAlpha: true, isPlanar: false, colorSpaceName: .calibratedRGB,
-                                       bytesPerRow: 0, bitsPerPixel: 0)
-            #else
-                let rep = NSBitmapImageRep(bitmapDataPlanes: nil, pixelsWide: Int(size.width), pixelsHigh: Int(size.height),
-                                           bitsPerSample: 8, samplesPerPixel: 4, hasAlpha: true, isPlanar: false, colorSpaceName: NSCalibratedRGBColorSpace,
-                                           bytesPerRow: 0, bitsPerPixel: 0)
-            #endif
-            
-            guard let context = NSGraphicsContext(bitmapImageRep: rep!) else {
-                return nil
-            }
-            
-            NSGraphicsContext.saveGraphicsState()
-            #if swift(>=4.0)
-            NSGraphicsContext.current = context
-            #else
-            NSGraphicsContext.setCurrent(context)
-            #endif
-            
-            let transform = pdfPage.getDrawingTransform(CGPDFBox.mediaBox, rect: rect, rotate: 0, preserveAspectRatio: true)
-            context.cgContext.concatenate(transform)
-            
-            context.cgContext.translateBy(x: 0, y: size.height)
-            context.cgContext.scaleBy(x: CGFloat(ppp), y: CGFloat(-ppp))
-            context.cgContext.drawPDFPage(pdfPage)
-            
-            let resultingImage = NSImage(size: size)
-            resultingImage.addRepresentation(rep!)
-            return resultingImage
+        NSGraphicsContext.saveGraphicsState()
+        NSGraphicsContext.current = context
+        
+        context.cgContext.concatenate(transform)
+        context.cgContext.translateBy(x: 0, y: size.height)
+        context.cgContext.scaleBy(x: scale, y: -scale)
+        context.cgContext.drawPDFPage(pdfPage)
+        
+        let resultingImage = NSImage(size: size)
+        resultingImage.addRepresentation(rep!)
+        return resultingImage
        #else
-            let ppp = Int(UIScreen.main.scale) // fetch device is retina or not
-            size.width  *= CGFloat(ppp)
-            size.height *= CGFloat(ppp)
+        
+        let handler : (CGContext) -> Void = { context in
+            context.concatenate(transform)
+            context.translateBy(x: 0, y: size.height)
+            context.scaleBy(x: CGFloat(scale), y: CGFloat(-scale))
+            context.setFillColor(UIColor.white.cgColor)
+            context.fill(rect)
+            context.drawPDFPage(pdfPage)
+        }
+        
+        if #available(iOS 10.0, tvOS 10.0, *) {
+            return UIGraphicsImageRenderer(size: size).image { (rendererContext) in
+                handler(rendererContext.cgContext)
+            }
+        } else {
            UIGraphicsBeginImageContext(size)
            guard let context = UIGraphicsGetCurrentContext() else {
                return nil
            }
            context.saveGState()
-            let transform = pdfPage.getDrawingTransform(CGPDFBox.mediaBox, rect: rect, rotate: 0, preserveAspectRatio: true)
-            context.concatenate(transform)
-            
-            context.translateBy(x: 0, y: size.height)
-            context.scaleBy(x: CGFloat(ppp), y: CGFloat(-ppp))
-            context.setFillColor(UIColor.white.cgColor)
-            context.fill(rect)
-            context.drawPDFPage(pdfPage)
-            
+            handler(context)
            context.restoreGState()
            let resultingImage = UIGraphicsGetImageFromCurrentImageContext()
            UIGraphicsEndImageContext()
            return resultingImage
+        }
        #endif
    }
    
-    internal static func scaleDown(image: ImageClass, toSize maxSize: CGSize) -> ImageClass {
-        let height, width: CGFloat
-        if image.size.width > image.size.height {
-            width = maxSize.width
-            height = (image.size.height / image.size.width) * width
+    internal static func scaleDown(fileURL: URL, toSize maxSize: CGSize?) -> ImageClass? {
+        guard let source = CGImageSourceCreateWithURL(fileURL as CFURL, nil) else {
+            return nil
+        }
+        return scaleDown(source: source, toSize: maxSize)
+    }
+    
+    internal static func scaleDown(data: Data, toSize maxSize: CGSize?) -> ImageClass? {
+        guard let source = CGImageSourceCreateWithData(data as CFData, nil) else {
+            return nil
+        }
+        return scaleDown(source: source, toSize: maxSize)
+    }
+    
+    internal static func scaleDown(source: CGImageSource, toSize maxSize: CGSize?) -> ImageClass? {
+        let options: [NSString: Any]
+        if let maxSize = maxSize {
+            let pixelSize: CGFloat
+            let properties = CGImageSourceCopyPropertiesAtIndex(source, 0, nil)
+            
+            if let width: CGFloat = ((properties as NSDictionary?)?.object(forKey: kCGImagePropertyPixelWidth) as? CGFloat),
+                let height: CGFloat = ((properties as NSDictionary?)?.object(forKey: kCGImagePropertyPixelHeight) as? CGFloat) {
+                pixelSize = (width / maxSize.width < height / maxSize.height) ? maxSize.width : maxSize.height
+            } else {
+                pixelSize = max(maxSize.width, maxSize.height)
+            }
+            
+            options = [
+                kCGImageSourceThumbnailMaxPixelSize: pixelSize,
+                kCGImageSourceCreateThumbnailFromImageAlways: true]
        } else {
-            height = maxSize.height
-            width = (image.size.width / image.size.height) * height
+            options = [
+                kCGImageSourceCreateThumbnailFromImageAlways: true]
        }
        
-        let newSize = CGSize(width: width, height: height)
-        
+        guard let image = CGImageSourceCreateThumbnailAtIndex(source, 0, options as CFDictionary) else {
+            return nil
+        }
        #if os(macOS)
-            var imageRect = NSRect(origin: .zero, size: image.size)
-            let imageRef = image.cgImage(forProposedRect: &imageRect, context: nil, hints: nil)
-            
-            // Create NSImage from the CGImage using the new size
-            return NSImage(cgImage: imageRef!, size: newSize)
+        return ImageClass(cgImage: image, size: .zero)
        #else
-            UIGraphicsBeginImageContextWithOptions(newSize, false, 0.0)
-            image.draw(in: CGRect(origin: .zero, size: newSize))
-            let newImage = UIGraphicsGetImageFromCurrentImageContext() ?? image
-            UIGraphicsEndImageContext()
-            return newImage
+        return ImageClass(cgImage: image)
        #endif
    }
 }
@@ -1037,7 +1156,7 @@ public enum FileOperationType: CustomStringConvertible {
        return mirror.children.dropFirst().first?.value as? String
    }
    
-    init? (json: [String: AnyObject]) {
+    init? (json: [String: Any]) {
        guard let type = json["type"] as? String, let source = json["source"] as? String else {
            return nil
        }
@@ -1066,9 +1185,9 @@ public enum FileOperationType: CustomStringConvertible {
    }
    
    internal var json: String? {
-        var dictionary: [String: AnyObject] = ["type": self.description as NSString]
-        dictionary["source"] = source as NSString?
-        dictionary["dest"] = destination as NSString?
+        var dictionary: [String: Any] = ["type": self.description]
+        dictionary["source"] = source
+        dictionary["dest"] = destination
        return String(jsonDictionary: dictionary)
    }
 }
@@ -14,9 +14,9 @@ import Foundation
 
 No instance of this class should (and can) be created. Use derived classes instead. It leads to a crash with `fatalError()`.
 */
-open class HTTPFileProvider: FileProviderBasicRemote, FileProviderOperations, FileProviderReadWrite {
+open class HTTPFileProvider: NSObject, FileProviderBasicRemote, FileProviderOperations, FileProviderReadWrite, FileProviderReadWriteProgressive {
    open class var type: String { fatalError("HTTPFileProvider is an abstract class. Please implement \(#function) in subclass.") }
-    open let baseURL: URL?
+    public let baseURL: URL?
    open var dispatch_queue: DispatchQueue
    open var operation_queue: OperationQueue {
        willSet {
@@ -72,6 +72,10 @@ open class HTTPFileProvider: FileProviderBasicRemote, FileProviderOperations, Fi
        return _longpollSession!
    }
    
+    #if os(macOS) || os(iOS) || os(tvOS)
+    open var undoManager: UndoManager? = nil
+    #endif
+    
    /**
     This is parent initializer for subclasses. Using this method on `HTTPFileProvider` will fail as `type` is not implemented.
     
@@ -89,14 +93,12 @@ open class HTTPFileProvider: FileProviderBasicRemote, FileProviderOperations, Fi
        self.cache = cache
        self.credential = credential
        
-        #if swift(>=3.1)
-            let queueLabel = "FileProvider.\(Swift.type(of: self).type)"
-        #else
-            let queueLabel = "FileProvider.\(type(of: self).type)"
-        #endif
+        let queueLabel = "FileProvider.\(Swift.type(of: self).type)"
        dispatch_queue = DispatchQueue(label: queueLabel, attributes: .concurrent)
        operation_queue = OperationQueue()
        operation_queue.name = "\(queueLabel).Operation"
+        
+        super.init()
    }
    
    public required convenience init?(coder aDecoder: NSCoder) {
@@ -196,7 +198,7 @@ open class HTTPFileProvider: FileProviderBasicRemote, FileProviderOperations, Fi
    
    @discardableResult
    open func create(folder folderName: String, at atPath: String, completionHandler: SimpleCompletionHandler) -> Progress? {
-        let path = (atPath as NSString).appendingPathComponent(folderName) + "/"
+        let path = atPath.appendingPathComponent(folderName) + "/"
        return doOperation(.create(path: path), completionHandler: completionHandler)
    }
    
@@ -220,7 +222,7 @@ open class HTTPFileProvider: FileProviderBasicRemote, FileProviderOperations, Fi
        // check file is not a folder
        guard (try? localFile.resourceValues(forKeys: [.fileResourceTypeKey]))?.fileResourceType ?? .unknown == .regular else {
            dispatch_queue.async {
-                completionHandler?(self.urlError(localFile.path, code: .fileIsDirectory))
+                completionHandler?(URLError(.fileIsDirectory, url: localFile))
            }
            return nil
        }
@@ -237,8 +239,8 @@ open class HTTPFileProvider: FileProviderBasicRemote, FileProviderOperations, Fi
    open func copyItem(path: String, toLocalURL destURL: URL, completionHandler: SimpleCompletionHandler) -> Progress? {
        let operation = FileOperationType.copy(source: path, destination: destURL.absoluteString)
        let request = self.request(for: operation)
-        let cantLoadError = urlError(path, code: .cannotLoadFromNetwork)
-        return self.download_simple(path: path, request: request, operation: operation, completionHandler: { [weak self] (tempURL, error) in
+        let cantLoadError = URLError(.cannotLoadFromNetwork, url: self.url(of: path))
+        return self.download_file(path: path, request: request, operation: operation, completionHandler: { [weak self] (tempURL, error) in
            do {
                if let error = error {
                    throw error
@@ -248,11 +250,11 @@ open class HTTPFileProvider: FileProviderBasicRemote, FileProviderOperations, Fi
                    throw cantLoadError
                }
                
+                #if os(macOS) || os(iOS) || os(tvOS)
                var coordError: NSError?
                NSFileCoordinator().coordinate(writingItemAt: tempURL, options: .forMoving, writingItemAt: destURL, options: .forReplacing, error: &coordError, byAccessor: { (tempURL, destURL) in
                    do {
                        try FileManager.default.moveItem(at: tempURL, to: destURL)
-                        
                        completionHandler?(nil)
                        self?.delegateNotify(operation)
                    } catch {
@@ -264,6 +266,17 @@ open class HTTPFileProvider: FileProviderBasicRemote, FileProviderOperations, Fi
                if let error = coordError {
                    throw error
                }
+                #else
+                do {
+                    try FileManager.default.moveItem(at: tempURL, to: destURL)
+                    completionHandler?(nil)
+                    self?.delegateNotify(operation)
+                } catch {
+                    completionHandler?(error)
+                    self?.delegateNotify(operation, error: error)
+                }
+                #endif
+                
            } catch {
                completionHandler?(error)
                self?.delegateNotify(operation, error: error)
@@ -285,12 +298,10 @@ open class HTTPFileProvider: FileProviderBasicRemote, FileProviderOperations, Fi
     - Returns: An `Progress` to get progress or cancel progress.
     */
    @discardableResult
-    open func contents(path: String, offset: Int64 = 0, responseHandler: ((_ response: URLResponse) -> Void)? = nil, progressHandler: @escaping (_ position: Int64, _ data: Data) -> Void, completionHandler: SimpleCompletionHandler) -> Progress? {
+    open func contents(path: String, offset: Int64 = 0, length: Int = -1, responseHandler: ((_ response: URLResponse) -> Void)? = nil, progressHandler: @escaping (_ position: Int64, _ data: Data) -> Void, completionHandler: SimpleCompletionHandler) -> Progress? {
        let operation = FileOperationType.fetch(path: path)
        var request = self.request(for: operation)
-        if offset > 0 {
-            request.addValue("bytes \(offset)-", forHTTPHeaderField: "Range")
-        }
+        request.setValue(rangeWithOffset: offset, length: length)
        var position: Int64 = offset
        return download_progressive(path: path, request: request, operation: operation, responseHandler: responseHandler, progressHandler: { data in
            progressHandler(position, data)
@@ -309,24 +320,25 @@ open class HTTPFileProvider: FileProviderBasicRemote, FileProviderOperations, Fi
        
        let operation = FileOperationType.fetch(path: path)
        var request = self.request(for: operation)
-        let cantLoadError = urlError(path, code: .cannotLoadFromNetwork)
+        let cantLoadError = URLError(.cannotLoadFromNetwork, url: self.url(of: path))
        request.setValue(rangeWithOffset: offset, length: length)
-        return self.download_simple(path: path, request: request, operation: operation, completionHandler: { (tempURL, error) in
+        
+        let stream = OutputStream.toMemory()
+        return self.download(path: path, request: request, operation: operation, stream: stream) { (error) in
            do {
                if let error = error {
                    throw error
                }
                
-                guard let tempURL = tempURL else {
+                guard let data = stream.property(forKey: .dataWrittenToMemoryStreamKey) as? Data else {
                    throw cantLoadError
                }
-                
-                let data = try Data(contentsOf: tempURL)
                completionHandler(data, nil)
            } catch {
                completionHandler(nil, error)
            }
-        })
+            
+        }
    }
    
    @discardableResult
@@ -335,8 +347,10 @@ open class HTTPFileProvider: FileProviderBasicRemote, FileProviderOperations, Fi
        guard fileOperationDelegate?.fileProvider(self, shouldDoOperation: operation) ?? true == true else {
            return nil
        }
+        let data = data ?? Data()
        let request = self.request(for: operation, overwrite: overwrite, attributes: [.contentModificationDateKey: Date()])
-        return upload_data(path, request: request, data: data ?? Data(), operation: operation, completionHandler: completionHandler)
+        let stream = InputStream(data: data)
+        return upload(path, request: request, stream: stream, size: Int64(data.count), operation: operation, completionHandler: completionHandler)
    }
    
    internal func request(for operation: FileOperationType, overwrite: Bool = false, attributes: [URLResourceKey: Any] = [:]) -> URLRequest {
@@ -347,8 +361,9 @@ open class HTTPFileProvider: FileProviderBasicRemote, FileProviderOperations, Fi
        fatalError("HTTPFileProvider is an abstract class. Please implement \(#function) in subclass.")
    }
    
-    internal func multiStatusHandler(source: String, data: Data, completionHandler: SimpleCompletionHandler) -> Void {
+    internal func multiStatusError(operation: FileOperationType, data: Data) -> FileProviderHTTPError? {
        // WebDAV will override this function
+        return nil
    }
    
    /**
@@ -374,25 +389,32 @@ open class HTTPFileProvider: FileProviderBasicRemote, FileProviderOperations, Fi
        let request = self.request(for: operation, overwrite: overwrite)
        
        let task = session.dataTask(with: request, completionHandler: { (data, response, error) in
-            var serverError: FileProviderHTTPError?
-            if let response = response as? HTTPURLResponse {
-                if response.statusCode >= 300, let code = FileProviderHTTPErrorCode(rawValue: response.statusCode) {
-                    serverError = self.serverError(with: code, path: operation.source, data: data)
+            do {
+                if let error = error {
+                    throw error
                }
                
-                if FileProviderHTTPErrorCode(rawValue: response.statusCode) == .multiStatus, let data = data {
-                    self.multiStatusHandler(source: operation.source, data: data, completionHandler: completionHandler)
+                if let response = response as? HTTPURLResponse {
+                    if response.statusCode >= 300, let code = FileProviderHTTPErrorCode(rawValue: response.statusCode) {
+                        throw self.serverError(with: code, path: operation.source, data: data)
+                    }
+                    
+                    if FileProviderHTTPErrorCode(rawValue: response.statusCode) == .multiStatus, let data = data,
+                        let ms_error = self.multiStatusError(operation: operation, data: data) {
+                        throw ms_error
+                    }
                }
-            }
-            
-            if serverError == nil && error == nil {
+                
+                #if os(macOS) || os(iOS) || os(tvOS)
+                self._registerUndo(operation)
+                #endif
                progress.completedUnitCount = 1
-            } else {
-                progress.cancel()
+                completionHandler?(nil)
+                self.delegateNotify(operation)
+            } catch {
+                completionHandler?(error)
+                self.delegateNotify(operation, error: error)
            }
-            
-            completionHandler?(serverError ?? error)
-            self.delegateNotify(operation, error: serverError ?? error)
        })
        task.taskDescription = operation.json
        progress.cancellationHandler = { [weak task] in
@@ -445,28 +467,28 @@ open class HTTPFileProvider: FileProviderBasicRemote, FileProviderOperations, Fi
        }
        
        let task = session.dataTask(with: request, completionHandler: { (data, response, error) in
-            if let error = error {
+            do {
+                if let error = error {
+                    throw error
+                }
+                if let code = (response as? HTTPURLResponse)?.statusCode , code >= 300, let rCode = FileProviderHTTPErrorCode(rawValue: code) {
+                    throw self.serverError(with: rCode, path: path, data: data)
+                }
+                
+                let (newFiles, err, newToken) = pageHandler(data, progress)
+                if let error = err {
+                    throw error
+                }
+                
+                let files = previousResult + newFiles
+                if let newToken = newToken, !progress.isCancelled {
+                    _ = self.paginated(path, startToken: newToken, currentProgress: progress, previousResult: files, requestHandler: requestHandler, pageHandler: pageHandler, completionHandler: completionHandler)
+                } else {
+                    completionHandler(files, nil)
+                }
+            } catch {
                completionHandler(previousResult, error)
-                return
            }
-            if let code = (response as? HTTPURLResponse)?.statusCode , code >= 300, let rCode = FileProviderHTTPErrorCode(rawValue: code) {
-                let responseError = self.serverError(with: rCode, path: path, data: data)
-                completionHandler(previousResult, responseError)
-                return
-            }
-            
-            let (newFiles, err, newToken) = pageHandler(data, progress)
-            if let error = err {
-                completionHandler(previousResult, error)
-                return
-            }
-            let files = previousResult + newFiles
-            if let newToken = newToken, !progress.isCancelled {
-                _ = self.paginated(path, startToken: newToken, currentProgress: progress, previousResult: files, requestHandler: requestHandler, pageHandler: pageHandler, completionHandler: completionHandler)
-            } else {
-                completionHandler(files, nil)
-            }
-            
        })
        progress.cancellationHandler = { [weak task] in
            task?.cancel()
@@ -480,7 +502,6 @@ open class HTTPFileProvider: FileProviderBasicRemote, FileProviderOperations, Fi
    
    func upload_task(_ targetPath: String, progress: Progress, task: URLSessionTask, operation: FileOperationType,
                     completionHandler: SimpleCompletionHandler) -> Void {
-        var progress = progress
        
        var allData = Data()
        dataCompletionHandlersForTasks[session.sessionDescription!]?[task.taskIdentifier] = { data in
@@ -499,7 +520,7 @@ open class HTTPFileProvider: FileProviderBasicRemote, FileProviderOperations, Fi
            self?.delegateNotify(operation, error: responseError ?? error)
        }
        task.taskDescription = operation.json
-        task.addObserver(self.sessionDelegate!, forKeyPath: #keyPath(URLSessionTask.countOfBytesSent), options: .new, context: &progress)
+        sessionDelegate?.observerProgress(of: task, using: progress, kind: .upload)
        progress.cancellationHandler = { [weak task] in
            task?.cancel()
        }
@@ -507,9 +528,8 @@ open class HTTPFileProvider: FileProviderBasicRemote, FileProviderOperations, Fi
        task.resume()
    }
    
-    func upload_data(_ targetPath: String, request: URLRequest, data: Data, operation: FileOperationType,
+    func upload(_ targetPath: String, request: URLRequest, stream: InputStream, size: Int64, operation: FileOperationType,
                     completionHandler: SimpleCompletionHandler) -> Progress? {
-        let size: Int64 = Int64(data.count)
        if size > maxUploadSimpleSupported {
            let error = self.serverError(with: .payloadTooLarge, path: targetPath, data: nil)
            completionHandler?(error)
@@ -522,7 +542,9 @@ open class HTTPFileProvider: FileProviderBasicRemote, FileProviderOperations, Fi
        progress.kind = .file
        progress.setUserInfoObject(Progress.FileOperationKind.downloading, forKey: .fileOperationKindKey)
        
-        let task = session.uploadTask(with: request, from: data)
+        var request = request
+        request.httpBodyStream = stream
+        let task = session.uploadTask(withStreamedRequest: request)
        self.upload_task(targetPath, progress: progress, task: task, operation: operation, completionHandler: completionHandler)
        
        return progress
@@ -530,7 +552,7 @@ open class HTTPFileProvider: FileProviderBasicRemote, FileProviderOperations, Fi
    
    func upload_file(_ targetPath: String, request: URLRequest, localFile: URL, operation: FileOperationType,
                     completionHandler: SimpleCompletionHandler) -> Progress? {
-        let fSize = (try? localFile.resourceValues(forKeys: [.fileSizeKey]))?.fileSize
+        let fSize = (try? localFile.resourceValues(forKeys: [.fileSizeKey]))?.allValues[.fileSizeKey] as? Int64
        let size = Int64(fSize ?? -1)
        if size > maxUploadSimpleSupported {
            let error = self.serverError(with: .payloadTooLarge, path: targetPath, data: nil)
@@ -544,6 +566,7 @@ open class HTTPFileProvider: FileProviderBasicRemote, FileProviderOperations, Fi
        progress.kind = .file
        progress.setUserInfoObject(Progress.FileOperationKind.downloading, forKey: .fileOperationKindKey)
        
+        #if os(macOS) || os(iOS) || os(tvOS)
        var error: NSError?
        NSFileCoordinator().coordinate(readingItemAt: localFile, options: .forUploading, error: &error, byAccessor: { (url) in
            let task = self.session.uploadTask(with: request, fromFile: localFile)
@@ -552,15 +575,66 @@ open class HTTPFileProvider: FileProviderBasicRemote, FileProviderOperations, Fi
        if let error = error {
            completionHandler?(error)
        }
+        #else
+        self.upload_task(targetPath, progress: progress, task: task, operation: operation, completionHandler: completionHandler)
+        #endif
        
        return progress
    }
    
+    internal func download(path: String, request: URLRequest, operation: FileOperationType,
+                           responseHandler: ((_ response: URLResponse) -> Void)? = nil,
+                           stream: OutputStream,
+                           completionHandler: @escaping (_ error: Error?) -> Void) -> Progress? {
+        let progress = Progress(totalUnitCount: -1)
+        progress.setUserInfoObject(operation, forKey: .fileProvderOperationTypeKey)
+        progress.kind = .file
+        progress.setUserInfoObject(Progress.FileOperationKind.downloading, forKey: .fileOperationKindKey)
+        
+        let task = session.dataTask(with: request)
+        if let responseHandler = responseHandler {
+            responseCompletionHandlersForTasks[session.sessionDescription!]?[task.taskIdentifier] = { response in
+                responseHandler(response)
+            }
+        }
+        
+        stream.open()
+        dataCompletionHandlersForTasks[session.sessionDescription!]?[task.taskIdentifier] = { [weak task, weak self] data in
+            guard !data.isEmpty else { return }
+            task.flatMap { self?.delegateNotify(operation, progress: Double($0.countOfBytesReceived) / Double($0.countOfBytesExpectedToReceive)) }
+            
+            let result = (try? stream.write(data: data)) ?? -1
+            if result < 0 {
+                completionHandler(stream.streamError!)
+                self?.delegateNotify(operation, error: stream.streamError!)
+                task?.cancel()
+            }
+        }
+        
+        completionHandlersForTasks[session.sessionDescription!]?[task.taskIdentifier] = { error in
+            if error != nil {
+                progress.cancel()
+            }
+            stream.close()
+            completionHandler(error)
+            self.delegateNotify(operation, error: error)
+        }
+        
+        task.taskDescription = operation.json
+        sessionDelegate?.observerProgress(of: task, using: progress, kind: .download)
+        progress.cancellationHandler = { [weak task] in
+            task?.cancel()
+        }
+        progress.setUserInfoObject(Date(), forKey: .startingTimeKey)
+        task.resume()
+        return progress
+    }
+    
    internal func download_progressive(path: String, request: URLRequest, operation: FileOperationType,
                                       responseHandler: ((_ response: URLResponse) -> Void)? = nil,
                                       progressHandler: @escaping (_ data: Data) -> Void,
                                       completionHandler: @escaping (_ error: Error?) -> Void) -> Progress? {
-        var progress = Progress(totalUnitCount: -1)
+        let progress = Progress(totalUnitCount: -1)
        progress.setUserInfoObject(operation, forKey: .fileProvderOperationTypeKey)
        progress.kind = .file
        progress.setUserInfoObject(Progress.FileOperationKind.downloading, forKey: .fileOperationKindKey)
@@ -586,8 +660,7 @@ open class HTTPFileProvider: FileProviderBasicRemote, FileProviderOperations, Fi
        }
        
        task.taskDescription = operation.json
-        task.addObserver(sessionDelegate!, forKeyPath: #keyPath(URLSessionTask.countOfBytesReceived), options: .new, context: &progress)
-        task.addObserver(sessionDelegate!, forKeyPath: #keyPath(URLSessionTask.countOfBytesExpectedToReceive), options: .new, context: &progress)
+        sessionDelegate?.observerProgress(of: task, using: progress, kind: .download)
        progress.cancellationHandler = { [weak task] in
            task?.cancel()
        }
@@ -596,20 +669,20 @@ open class HTTPFileProvider: FileProviderBasicRemote, FileProviderOperations, Fi
        return progress
    }
    
-    internal func download_simple(path: String, request: URLRequest, operation: FileOperationType,
+    internal func download_file(path: String, request: URLRequest, operation: FileOperationType,
                                  completionHandler: @escaping ((_ tempURL: URL?, _ error: Error?) -> Void)) -> Progress? {
-        var progress = Progress(totalUnitCount: -1)
+        let progress = Progress(totalUnitCount: -1)
        progress.setUserInfoObject(operation, forKey: .fileProvderOperationTypeKey)
        progress.kind = .file
        progress.setUserInfoObject(Progress.FileOperationKind.downloading, forKey: .fileOperationKindKey)
        
        let task = session.downloadTask(with: request)
        completionHandlersForTasks[session.sessionDescription!]?[task.taskIdentifier] = { error in
-            if error != nil {
+            if let error = error {
                progress.cancel()
+                completionHandler(nil, error)
+                self.delegateNotify(operation, error: error)
            }
-            completionHandler(nil, error)
-            self.delegateNotify(operation, error: error)
        }
        downloadCompletionHandlersForTasks[session.sessionDescription!]?[task.taskIdentifier] = { tempURL in
            guard let httpResponse = task.response as? HTTPURLResponse , httpResponse.statusCode < 300 else {
@@ -627,8 +700,7 @@ open class HTTPFileProvider: FileProviderBasicRemote, FileProviderOperations, Fi
            completionHandler(tempURL, nil)
        }
        task.taskDescription = operation.json
-        task.addObserver(sessionDelegate!, forKeyPath: #keyPath(URLSessionTask.countOfBytesReceived), options: .new, context: &progress)
-        task.addObserver(sessionDelegate!, forKeyPath: #keyPath(URLSessionTask.countOfBytesExpectedToReceive), options: .new, context: &progress)
+        sessionDelegate?.observerProgress(of: task, using: progress, kind: .download)
        progress.cancellationHandler = { [weak task] in
            task?.cancel()
        }
@@ -639,3 +711,7 @@ open class HTTPFileProvider: FileProviderBasicRemote, FileProviderOperations, Fi
 }

 extension HTTPFileProvider: FileProvider { }
+
+#if os(macOS) || os(iOS) || os(tvOS)
+extension HTTPFileProvider: FileProvideUndoable { }
+#endif
@@ -14,7 +14,7 @@ import Foundation
 
 it uses `FileManager` foundation class with some additions like searching and reading a portion of file.
 */
-open class LocalFileProvider: FileProvider, FileProviderMonitor {
+open class LocalFileProvider: NSObject, FileProvider, FileProviderMonitor, FileProviderSymbolicLink {
    open class var type: String { return "Local" }
    open fileprivate(set) var baseURL: URL?
    open var dispatch_queue: DispatchQueue
@@ -105,21 +105,23 @@ open class LocalFileProvider: FileProvider, FileProviderMonitor {
        self.credential = nil
        self.isCoorinating = false
        
-        #if swift(>=3.1)
        let queueLabel = "FileProvider.\(Swift.type(of: self).type)"
-        #else
-        let queueLabel = "FileProvider.\(type(of: self).type)"
-        #endif
        dispatch_queue = DispatchQueue(label: queueLabel, attributes: .concurrent)
        operation_queue = OperationQueue()
        operation_queue.name = "\(queueLabel).Operation"
        
+        super.init()
+        
        fileProviderManagerDelegate = LocalFileProviderManagerDelegate(provider: self)
        opFileManager.delegate = fileProviderManagerDelegate
    }
    
    public required convenience init?(coder aDecoder: NSCoder) {
-        guard let baseURL = aDecoder.decodeObject(forKey: "baseURL") as? URL else {
+        guard let baseURL = aDecoder.decodeObject(of: NSURL.self, forKey: "baseURL") as URL? else {
+            if #available(macOS 10.11, iOS 9.0, tvOS 9.0, *) {
+                aDecoder.failWithError(CocoaError(.coderValueNotFound,
+                                                  userInfo: [NSLocalizedDescriptionKey: "Base URL is not set."]))
+            }
            return nil
        }
        self.init(baseURL: baseURL)
@@ -158,7 +160,7 @@ open class LocalFileProvider: FileProvider, FileProviderMonitor {
        dispatch_queue.async {
            do {
                let contents = try self.fileManager.contentsOfDirectory(at: self.url(of: path), includingPropertiesForKeys: nil, options: .skipsSubdirectoryDescendants)
-                let filesAttributes = contents.flatMap({ (fileURL) -> LocalFileObject? in
+                let filesAttributes = contents.compactMap({ (fileURL) -> LocalFileObject? in
                    let path = self.relativePathOf(url: fileURL)
                    return LocalFileObject(fileWithPath: path, relativeTo: self.baseURL)
                })
@@ -244,7 +246,7 @@ open class LocalFileProvider: FileProvider, FileProviderMonitor {
    
    @discardableResult
    open func create(folder folderName: String, at atPath: String, completionHandler: SimpleCompletionHandler) -> Progress? {
-        let operation = FileOperationType.create(path: (atPath as NSString).appendingPathComponent(folderName) + "/")
+        let operation = FileOperationType.create(path: atPath.appendingPathComponent(folderName) + "/")
        return self.doOperation(operation, completionHandler: completionHandler)
    }
    
@@ -278,15 +280,6 @@ open class LocalFileProvider: FileProvider, FileProviderMonitor {
        return self.doOperation(operation, completionHandler: completionHandler)
    }
    
-    #if os(macOS) || os(iOS) || os(tvOS)
-    @objc dynamic func doSimpleOperation(_ box: UndoBox) {
-        guard let _ = self.undoManager else { return }
-        _ = self.doOperation(box.undoOperation) { (_) in
-            return
-        }
-    }
-    #endif
-    
    @discardableResult
    fileprivate func doOperation(_ operation: FileOperationType, data: Data? = nil, overwrite: Bool = true, atomically: Bool = false, forUploading: Bool = false, completionHandler: SimpleCompletionHandler) -> Progress? {
        let progress = Progress(totalUnitCount: -1)
@@ -314,7 +307,7 @@ open class LocalFileProvider: FileProvider, FileProviderMonitor {
        
        if !overwrite, let dest = dest, /* fileExists */ ((try? dest.checkResourceIsReachable()) ?? false) ||
            ((try? dest.checkPromisedItemIsReachable()) ?? false) {
-            let e = self.cocoaError(destPath!, code: .fileWriteFileExists)
+            let e = CocoaError(.fileWriteFileExists, path: destPath!)
            dispatch_queue.async {
                completionHandler?(e)
            }
@@ -323,14 +316,6 @@ open class LocalFileProvider: FileProvider, FileProviderMonitor {
        }
        
        #if os(macOS) || os(iOS) || os(tvOS)
-        if let undoManager = self.undoManager, let undoOp = self.undoOperation(for: operation) {
-            let undoBox = UndoBox(provider: self, operation: operation, undoOperation: undoOp)
-            undoManager.beginUndoGrouping()
-            undoManager.registerUndo(withTarget: self, selector: #selector(LocalFileProvider.doSimpleOperation(_:)), object: undoBox)
-            undoManager.setActionName(operation.actionDescription)
-            undoManager.endUndoGrouping()
-        }
-        
        var successfulSecurityScopedResourceAccess = false
        #endif
        
@@ -370,7 +355,10 @@ open class LocalFileProvider: FileProvider, FileProviderMonitor {
                    source.stopAccessingSecurityScopedResource()
                }
                #endif
-
+                
+                #if os(macOS) || os(iOS) || os(tvOS)
+                self._registerUndo(operation)
+                #endif
                progress.completedUnitCount = progress.totalUnitCount
                self.dispatch_queue.async {
                    completionHandler?(nil)
@@ -508,7 +496,7 @@ open class LocalFileProvider: FileProvider, FileProviderMonitor {
        let operationHandler: (URL) -> Void = { url in
            do {
                guard let handle = FileHandle(forReadingAtPath: url.path) else {
-                    throw self.cocoaError(path, code: .fileNoSuchFile)
+                    throw CocoaError(.fileNoSuchFile, path: path)
                }
                
                defer {
@@ -519,13 +507,13 @@ open class LocalFileProvider: FileProvider, FileProviderMonitor {
                progress.totalUnitCount = size
                guard size > offset else {
                    progress.cancel()
-                    throw self.cocoaError(path, code: .fileReadTooLarge)
+                    throw CocoaError(.fileReadTooLarge, path: path)
                }
                progress.setUserInfoObject(Date(), forKey: .startingTimeKey)
                handle.seek(toFileOffset: UInt64(offset))
                guard Int64(handle.offsetInFile) == offset else {
                    progress.cancel()
-                    throw self.cocoaError(path, code: .fileReadTooLarge)
+                    throw CocoaError(.fileReadTooLarge, path: path)
                }
                
                let data = handle.readData(ofLength: length)
@@ -568,7 +556,7 @@ open class LocalFileProvider: FileProvider, FileProviderMonitor {
        let fileExists = ((try? self.url(of: path).checkResourceIsReachable()) ?? false) ||
            ((try? self.url(of: path).checkPromisedItemIsReachable()) ?? false)
        if !overwrite && fileExists {
-            let e = self.cocoaError(path, code: .fileWriteFileExists)
+            let e = CocoaError(.fileWriteFileExists, path: path)
            dispatch_queue.async {
                completionHandler?(e)
            }
@@ -580,24 +568,19 @@ open class LocalFileProvider: FileProvider, FileProviderMonitor {
        return self.doOperation(operation, data: data ?? Data(), atomically: atomically, completionHandler: completionHandler)
    }
    
-    fileprivate var monitors = [LocalFolderMonitor]()
+    fileprivate var monitors = [LocalFileMonitor]()
    
    open func registerNotifcation(path: String, eventHandler: @escaping (() -> Void)) {
        self.unregisterNotifcation(path: path)
-        let dirurl = self.url(of: path)
-        let isdir = (try? dirurl.resourceValues(forKeys: [.isDirectoryKey]))?.isDirectory ?? false
-        if !isdir {
-            return
+        let url = self.url(of: path)
+        if let monitor = LocalFileMonitor(url: url, handler: eventHandler) {
+            monitor.start()
+            monitors.append(monitor)
        }
-        let monitor = LocalFolderMonitor(url: dirurl) {
-            eventHandler()
-        }
-        monitor.start()
-        monitors.append(monitor)
    }
    
    open func unregisterNotifcation(path: String) {
-        var removedMonitor: LocalFolderMonitor?
+        var removedMonitor: LocalFileMonitor?
        for (i, monitor) in monitors.enumerated() {
            if self.relativePathOf(url: monitor.url) == path {
                removedMonitor = monitors.remove(at: i)
@@ -611,22 +594,20 @@ open class LocalFileProvider: FileProvider, FileProviderMonitor {
        return monitors.map( { self.relativePathOf(url: $0.url) } ).contains(path.trimmingCharacters(in: CharacterSet(charactersIn: "/")))
    }
    
-    /**
-     Creates a symbolic link at the specified path that points to an item at the given path.
-     This method does not traverse symbolic links contained in destination path, making it possible
-     to create symbolic links to locations that do not yet exist.
-     Also, if the final path component is a symbolic link, that link is not followed.
-    
-     - Parameters:
-       - symbolicLink: The file path at which to create the new symbolic link. The last component of the path issued as the name of the link.
-       - withDestinationPath: The path that contains the item to be pointed to by the link. In other words, this is the destination of the link.
-       - completionHandler: If an error parameter was provided, a presentable `Error` will be returned.
-    */
    open func create(symbolicLink path: String, withDestinationPath destPath: String, completionHandler: SimpleCompletionHandler) {
        operation_queue.addOperation {
            let operation = FileOperationType.link(link: path, target: destPath)
            do {
-                try self.opFileManager.createSymbolicLink(at: self.url(of: path), withDestinationURL: self.url(of: destPath))
+                let url = self.url(of: path)
+                let destURL = self.url(of: destPath)
+                let homePath = NSHomeDirectory()
+                if destURL.path.hasPrefix(homePath) {
+                    let canonicalHomePath = "/" + homePath.trimmingCharacters(in: CharacterSet(charactersIn: "/"))
+                    let destRelativePath = destURL.path.replacingOccurrences(of: canonicalHomePath, with: "~", options: .anchored)
+                    try self.opFileManager.createSymbolicLink(atPath: url.path, withDestinationPath: destRelativePath)
+                } else {
+                    try self.opFileManager.createSymbolicLink(at: url, withDestinationURL: destURL)
+                }
                completionHandler?(nil)
                self.delegateNotify(operation)
            } catch {
@@ -636,17 +617,13 @@ open class LocalFileProvider: FileProvider, FileProviderMonitor {
        }
    }
    
-    /// Returns the path of the item pointed to by a symbolic link.
-    ///
-    /// - Parameters:
-    ///   - path: The path of a file or directory.
-    ///   - completionHandler: Returns destination url of given symbolic link, or an `Error` object if it fails.
-    open func destination(ofSymbolicLink path: String, completionHandler: @escaping (_ url: URL?, _ error: Error?) -> Void) {
+    open func destination(ofSymbolicLink path: String, completionHandler: @escaping (_ file: FileObject?, _ error: Error?) -> Void) {
        dispatch_queue.async {
            do {
                let destPath = try self.opFileManager.destinationOfSymbolicLink(atPath: self.url(of: path).path)
-                let destUrl = URL(fileURLWithPath: destPath)
-                completionHandler(destUrl, nil)
+                let absoluteDestPath = (destPath as NSString).expandingTildeInPath
+                let file = LocalFileObject(fileWithPath: absoluteDestPath, relativeTo: self.baseURL)
+                completionHandler(file, nil)
            } catch {
                completionHandler(nil, error)
            }
@@ -655,7 +632,6 @@ open class LocalFileProvider: FileProvider, FileProviderMonitor {
 }

 #if os(macOS) || os(iOS) || os(tvOS)
-    
 extension LocalFileProvider: FileProvideUndoable { }

 internal extension LocalFileProvider {
@@ -17,12 +17,19 @@ public final class LocalFileObject: FileObject {
    /// Initiates a `LocalFileObject` with attributes of file in path.
    public convenience init? (fileWithPath path: String, relativeTo relativeURL: URL?) {
        var fileURL: URL?
-        var rpath = path.replacingOccurrences(of: relativeURL?.path ?? "", with: "", options: .anchored).replacingOccurrences(of: "/", with: "", options: .anchored)
+        var rpath = path.replacingOccurrences(of: "/", with: "", options: .anchored)
+        var resolvedRelativeURL: URL?
+        if let relPath = relativeURL?.path.replacingOccurrences(of: "/", with: "", options: .anchored), rpath.hasPrefix(relPath) {
+            rpath = rpath.replacingOccurrences(of: relPath, with: "", options: .anchored).replacingOccurrences(of: "/", with: "", options: .anchored)
+            resolvedRelativeURL = relativeURL
+        } else {
+            resolvedRelativeURL = relativeURL
+        }
        if #available(iOS 9.0, macOS 10.11, *) {
-            fileURL = URL(fileURLWithPath: rpath, relativeTo: relativeURL)
+            fileURL = URL(fileURLWithPath: rpath, relativeTo: resolvedRelativeURL)
        } else {
            rpath = rpath.addingPercentEncoding(withAllowedCharacters: .urlPathAllowed) ?? rpath
-            fileURL = URL(string: rpath, relativeTo: relativeURL) ?? relativeURL
+            fileURL = URL(string: rpath, relativeTo: resolvedRelativeURL) ?? resolvedRelativeURL
        }
        
        if let fileURL = fileURL {
@@ -48,7 +55,7 @@ public final class LocalFileObject: FileObject {
    }
    
    /// The total size allocated on disk for the file
-    open internal(set) var allocatedSize: Int64 {
+    public internal(set) var allocatedSize: Int64 {
        get {
            return allValues[.fileAllocatedSizeKey] as? Int64 ?? 0
        }
@@ -60,7 +67,7 @@ public final class LocalFileObject: FileObject {
    /// The document identifier is a value assigned by the kernel/system to a file or directory. 
    /// This value is used to identify the document regardless of where it is moved on a volume. 
    /// The identifier persists across system restarts.
-    open internal(set) var id: Int? {
+    public internal(set) var id: Int? {
        get {
            return allValues[.documentIdentifierKey] as? Int
        }
@@ -71,7 +78,7 @@ public final class LocalFileObject: FileObject {
    
    /// The revision of file, which changes when a file contents are modified. 
    /// Changes to attributes or other file metadata do not change the identifier.
-    open var rev: String? {
+    public var rev: String? {
        get {
            let data = allValues[.generationIdentifierKey] as? Data
            return data?.map { String(format: "%02hhx", $0) }.joined()
@@ -79,7 +86,7 @@ public final class LocalFileObject: FileObject {
    }
    
    /// Count of children items of a driectory. It costs disk access for local directories.
-    open public(set) override var childrensCount: Int? {
+    public override var childrensCount: Int? {
        get {
            return try? FileManager.default.contentsOfDirectory(atPath: self.url.path).count
        }
@@ -89,24 +96,49 @@ public final class LocalFileObject: FileObject {
    }
 }

-internal final class LocalFolderMonitor {
+public final class LocalFileMonitor {
    fileprivate let source: DispatchSourceFileSystemObject
    fileprivate let descriptor: CInt
    fileprivate let qq: DispatchQueue = DispatchQueue.global(qos: .default)
    fileprivate var state: Bool = false
-    fileprivate var monitoredTime: TimeInterval = Date().timeIntervalSinceReferenceDate
-    var url: URL
+    
+    fileprivate var _monitoredTime: TimeInterval = Date().timeIntervalSinceReferenceDate
+    fileprivate let _monitoredTimeLock = NSLock()
+    fileprivate var monitoredTime: TimeInterval {
+        get {
+            _monitoredTimeLock.lock()
+            defer {
+                _monitoredTimeLock.unlock()
+            }
+            return _monitoredTime
+        }
+        set {
+            _monitoredTimeLock.lock()
+            defer {
+                _monitoredTimeLock.unlock()
+            }
+            _monitoredTime = newValue
+        }
+    }
+    
+    public var url: URL
    
    /// Creates a folder monitor object with monitoring enabled.
-    init(url: URL, handler: @escaping ()->Void) {
+    public init?(url: URL, handler: @escaping ()->Void) {
        self.url = url
-        descriptor = open((url as NSURL).fileSystemRepresentation, O_EVTONLY)
-        source = DispatchSource.makeFileSystemObjectSource(fileDescriptor: descriptor, eventMask: .write, queue: qq)
+        descriptor = url.absoluteURL.withUnsafeFileSystemRepresentation { rep in
+            guard let rep = rep else { return -1 }
+            return open(rep, O_EVTONLY)
+        }
+        guard descriptor >= 0 else { return nil }
+        let event: DispatchSource.FileSystemEvent = url.fileIsDirectory ? [.write] : .all
+        source = DispatchSource.makeFileSystemObjectSource(fileDescriptor: descriptor, eventMask: event, queue: qq)
+        
        // Folder monitoring is recursive and deep. Monitoring a root folder may be very costly
        // We have a 0.2 second delay to ensure we wont call handler 1000s times when there is
        // a huge file operation. This ensures app will work smoothly while this 250 milisec won't
        // affect user experince much
-        let main_handler: ()->Void = { [weak self] in
+        let main_handler: DispatchSourceProtocol.DispatchSourceHandler = { [weak self] in
            guard let `self` = self else { return }
            if Date().timeIntervalSinceReferenceDate < self.monitoredTime + 0.2 {
                return
@@ -126,7 +158,7 @@ internal final class LocalFolderMonitor {
    }
    
    /// Starts sending notifications if currently stopped
-    func start() {
+    public func start() {
        if !state {
            state = true
            source.resume()
@@ -134,7 +166,7 @@ internal final class LocalFolderMonitor {
    }
    
    /// Stops sending notifications if currently enabled
-    func stop() {
+    public func stop() {
        if state {
            state = false
            source.suspend()
@@ -223,17 +255,3 @@ internal class LocalFileProviderManagerDelegate: NSObject, FileManagerDelegate {
        return delegate.fileProvider(provider, shouldProceedAfterError: error, operation: .link(link: srcPath, target: dstPath))
    }
 }
-
-#if os(macOS) || os(iOS) || os(tvOS)
-class UndoBox: NSObject {
-    weak var provider: FileProvideUndoable?
-    let operation: FileOperationType
-    let undoOperation: FileOperationType
-    
-    init(provider: FileProvideUndoable, operation: FileOperationType, undoOperation: FileOperationType) {
-        self.provider = provider
-        self.operation = operation
-        self.undoOperation = undoOperation
-    }
-}
-#endif
@@ -101,7 +101,7 @@ open class OneDriveFileProvider: HTTPFileProvider, FileProviderSharing {
    public static var graphVersion = "v1.0"
    
    /// Route for container, default is `.me`.
-    open let route: Route
+    public let route: Route
    
    /**
     Initializer for Onedrive provider with given client ID and Token.
@@ -146,13 +146,13 @@ open class OneDriveFileProvider: HTTPFileProvider, FileProviderSharing {
    
    public required convenience init?(coder aDecoder: NSCoder) {
        let route: Route
-        if let driveId = aDecoder.decodeObject(forKey: "drive") as? String, let uuid = UUID(uuidString: driveId) {
+        if let driveId = aDecoder.decodeObject(of: NSString.self, forKey: "drive") as String?, let uuid = UUID(uuidString: driveId) {
            route = .drive(uuid: uuid)
        } else {
-            route = (aDecoder.decodeObject(forKey: "route") as? String).flatMap({ Route(rawValue: $0) }) ?? .me
+            route = (aDecoder.decodeObject(of: NSString.self, forKey: "route") as String?).flatMap({ Route(rawValue: $0) }) ?? .me
        }
-        self.init(credential: aDecoder.decodeObject(forKey: "credential") as? URLCredential,
-                  serverURL: aDecoder.decodeObject(forKey: "baseURL") as? URL,
+        self.init(credential: aDecoder.decodeObject(of: URLCredential.self, forKey: "credential"),
+                  serverURL: aDecoder.decodeObject(of: NSURL.self, forKey: "baseURL") as URL?,
                  route: route)
        self.useCache = aDecoder.decodeBool(forKey: "useCache")
        self.validatingCache = aDecoder.decodeBool(forKey: "validatingCache")
@@ -194,14 +194,14 @@ open class OneDriveFileProvider: HTTPFileProvider, FileProviderSharing {
        }, pageHandler: { [weak self] (data, _) -> (files: [FileObject], error: Error?, newToken: String?) in
            guard let `self` = self else { return ([], nil, nil) }
            
-            guard let json = data?.deserializeJSON(), let entries = json["value"] as? [AnyObject] else {
-                let err = self.urlError(path, code: .badServerResponse)
+            guard let json = data?.deserializeJSON(), let entries = json["value"] as? [Any] else {
+                let err = URLError(.badServerResponse, url: self.url(of: path))
                return ([], err, nil)
            }
            
            var files = [FileObject]()
            for entry in entries {
-                if let entry = entry as? [String: AnyObject], let file = OneDriveFileObject(baseURL: self.baseURL, route: self.route, json: entry) {
+                if let entry = entry as? [String: Any], let file = OneDriveFileObject(baseURL: self.baseURL, route: self.route, json: entry) {
                    files.append(file)
                }
            }
@@ -227,12 +227,12 @@ open class OneDriveFileProvider: HTTPFileProvider, FileProviderSharing {
        let task = session.dataTask(with: request, completionHandler: { (data, response, error) in
            var serverError: FileProviderHTTPError?
            var fileObject: OneDriveFileObject?
-            if let response = response as? HTTPURLResponse {
+            if let response = response as? HTTPURLResponse, response.statusCode >= 400 {
                let code = FileProviderHTTPErrorCode(rawValue: response.statusCode)
                serverError = code.flatMap { self.serverError(with: $0, path: path, data: data) }
-                if let json = data?.deserializeJSON(), let file = OneDriveFileObject(baseURL: self.baseURL, route: self.route, json: json) {
-                    fileObject = file
-                }
+            }
+            if let json = data?.deserializeJSON(), let file = OneDriveFileObject(baseURL: self.baseURL, route: self.route, json: json) {
+                fileObject = file
            }
            completionHandler(fileObject, serverError ?? error)
        }) 
@@ -257,8 +257,9 @@ open class OneDriveFileProvider: HTTPFileProvider, FileProviderSharing {
            volume.uuid = json["id"] as? String
            volume.name = json["name"] as? String
            volume.creationDate = (json["createdDateTime"] as? String).flatMap { Date(rfcString: $0) }
-            volume.totalCapacity = (json["quota"]?["total"] as? NSNumber)?.int64Value ?? -1
-            volume.availableCapacity = (json["quota"]?["remaining"] as? NSNumber)?.int64Value ?? 0
+            let quota = json["quota"] as? [String: Any]
+            volume.totalCapacity = (quota?["total"] as? NSNumber)?.int64Value ?? -1
+            volume.availableCapacity = (quota?["remaining"] as? NSNumber)?.int64Value ?? 0
            completionHandler(volume)
        }) 
        task.resume()
@@ -290,7 +291,7 @@ open class OneDriveFileProvider: HTTPFileProvider, FileProviderSharing {
     */
    @discardableResult
    open override func searchFiles(path: String, recursive: Bool, query: NSPredicate, foundItemHandler: ((FileObject) -> Void)?, completionHandler: @escaping (_ files: [FileObject], _ error: Error?) -> Void) -> Progress? {
-        let queryStr = query.findValue(forKey: "name") as? String ?? query.findAllValues(forKey: nil).flatMap { $0.value as? String }.first
+        let queryStr = query.findValue(forKey: "name") as? String ?? query.findAllValues(forKey: nil).compactMap { $0.value as? String }.first
        
        return paginated(path, requestHandler: { [weak self] (token) -> URLRequest? in
            guard let `self` = self else { return nil }
@@ -314,14 +315,14 @@ open class OneDriveFileProvider: HTTPFileProvider, FileProviderSharing {
            return request
        }, pageHandler: { [weak self] (data, progress) -> (files: [FileObject], error: Error?, newToken: String?) in
            guard let `self` = self else { return ([], nil, nil) }
-            guard let json = data?.deserializeJSON(), let entries = json["value"] as? [AnyObject] else {
-                let err = self.urlError(path, code: .badServerResponse)
+            guard let json = data?.deserializeJSON(), let entries = json["value"] as? [Any] else {
+                let err = URLError(.badServerResponse, url: self.url(of: path))
                return ([], err, nil)
            }
            
            var foundFiles = [FileObject]()
            for entry in entries {
-                if let entry = entry as? [String: AnyObject], let file = OneDriveFileObject(baseURL: self.baseURL, route: self.route, json: entry), query.evaluate(with: file.mapPredicate()) {
+                if let entry = entry as? [String: Any], let file = OneDriveFileObject(baseURL: self.baseURL, route: self.route, json: entry), query.evaluate(with: file.mapPredicate()) {
                    foundFiles.append(file)
                    foundItemHandler?(file)
                }
@@ -378,6 +379,33 @@ open class OneDriveFileProvider: HTTPFileProvider, FileProviderSharing {
        task.resume()
    }
    
+    /*internal var cachedDriveID: String?
+    
+    override func doOperation(_ operation: FileOperationType, overwrite: Bool, progress: Progress?, completionHandler: SimpleCompletionHandler) -> Progress? {
+        switch operation {
+        case .copy(source: let source, destination: let dest) where !source.hasPrefix("file://") && !dest.hasPrefix("file://"):
+            fallthrough
+        case .move:
+            if self.cachedDriveID != nil {
+                return super.doOperation(operation, overwrite: overwrite, progress: progress, completionHandler: completionHandler)
+            } else {
+                let progress = Progress(totalUnitCount: 1)
+                self.storageProperties(completionHandler: { (volume) in
+                    if let volumeId = volume?.uuid {
+                        self.cachedDriveID = volumeId
+                        _ = super.doOperation(operation, overwrite: overwrite, progress: progress, completionHandler: completionHandler)
+                    } else {
+                        let error = self.urlError(operation.source, code: .badServerResponse)
+                        completionHandler?(error)
+                    }
+                })
+                return progress
+            }
+        default:
+            return super.doOperation(operation, overwrite: overwrite, progress: progress, completionHandler: completionHandler)
+        }
+    }*/
+    
    /**
     Uploads a file from local file url to designated path asynchronously.
     Method will fail if source is not a local url with `file://` scheme.
@@ -396,7 +424,7 @@ open class OneDriveFileProvider: HTTPFileProvider, FileProviderSharing {
        // check file is not a folder
        guard (try? localFile.resourceValues(forKeys: [.fileResourceTypeKey]))?.fileResourceType ?? .unknown == .regular else {
            dispatch_queue.async {
-                completionHandler?(self.urlError(localFile.path, code: .fileIsDirectory))
+                completionHandler?(URLError(.fileIsDirectory, url: localFile))
            }
            return nil
        }
@@ -449,7 +477,7 @@ open class OneDriveFileProvider: HTTPFileProvider, FileProviderSharing {
            url = self.url(of: path, modifier: "content")
        case .create(path: let path) where path.hasSuffix("/"):
            method = "POST"
-            let parent =  (path as NSString).deletingLastPathComponent
+            let parent =  path.deletingLastPathComponent
            url = self.url(of: parent, modifier: "children")
        case .modify(path: let path):
            method = "PUT"
@@ -486,32 +514,32 @@ open class OneDriveFileProvider: HTTPFileProvider, FileProviderSharing {
        switch operation {
        case .create(path: let path) where path.hasSuffix("/"):
            request.setValue(contentType: .json)
-            var requestDictionary = [String: AnyObject]()
-            let name = (path as NSString).lastPathComponent
-            requestDictionary["name"] = name as NSString
-            requestDictionary["folder"] = NSDictionary()
-            requestDictionary["@microsoft.graph.conflictBehavior"] = "fail" as NSString
+            var requestDictionary = [String: Any]()
+            let name = path.lastPathComponent
+            requestDictionary["name"] = name
+            requestDictionary["folder"] = [String: Any]()
+            requestDictionary["@microsoft.graph.conflictBehavior"] = "fail"
            request.httpBody = Data(jsonDictionary: requestDictionary)
        case .copy(let source, let dest) where !source.hasPrefix("file://") && !dest.hasPrefix("file://"),
             .move(source: let source, destination: let dest):
            request.setValue(contentType: .json, charset: .utf8)
-            let cdest = correctPath(dest) as NSString
-            var parentReference: [String: AnyObject] = [:]
+            let cdest = correctPath(dest)
+            var parentReference: [String: Any] = [:]
            if cdest.hasPrefix("id:") {
-                parentReference["id"] = cdest.components(separatedBy: "/").first?.replacingOccurrences(of: "id:", with: "", options: .anchored) as NSString?
+                parentReference["id"] = cdest.components(separatedBy: "/").first?.replacingOccurrences(of: "id:", with: "", options: .anchored)
            } else {
-                parentReference["path"] = ("/drive/root:" as NSString).appendingPathComponent(cdest.deletingLastPathComponent) as NSString
+                parentReference["path"] = "/drive/root:".appendingPathComponent(cdest.deletingLastPathComponent)
            }
            switch self.route {
            case .drive(uuid: let uuid):
-                parentReference["driveId"] = uuid.uuidString as NSString
+                parentReference["driveId"] = uuid.uuidString
            default:
-                //parentReference["driveId"] = cachedDriveID as NSString? ?? ""
+                //parentReference["driveId"] = cachedDriveID ?? ""
                break
            }
-            var requestDictionary = [String: AnyObject]()
-            requestDictionary["parentReference"] = parentReference as NSDictionary
-            requestDictionary["name"] = (cdest as NSString).lastPathComponent as NSString
+            var requestDictionary = [String: Any]()
+            requestDictionary["parentReference"] = parentReference
+            requestDictionary["name"] = cdest.lastPathComponent
            request.httpBody = Data(jsonDictionary: requestDictionary)
        default:
            break
@@ -523,7 +551,7 @@ open class OneDriveFileProvider: HTTPFileProvider, FileProviderSharing {
    override func serverError(with code: FileProviderHTTPErrorCode, path: String?, data: Data?) -> FileProviderHTTPError {
        let errorDesc: String?
        if let response = data?.deserializeJSON() {
-            errorDesc = response["error"]?["message"] as? String
+            errorDesc = (response["error"] as? [String: Any])?["message"] as? String
        } else {
            errorDesc = data.flatMap({ String(data: $0, encoding: .utf8) })
        }
@@ -550,21 +578,20 @@ open class OneDriveFileProvider: HTTPFileProvider, FileProviderSharing {
    open func publicLink(to path: String, completionHandler: @escaping ((_ link: URL?, _ attribute: FileObject?, _ expiration: Date?, _ error: Error?) -> Void)) {
        var request = URLRequest(url: self.url(of: path, modifier: "createLink"))
        request.httpMethod = "POST"
-        let requestDictionary: [String: AnyObject] = ["type": "view" as NSString]
+        let requestDictionary: [String: Any] = ["type": "view"]
        request.httpBody = Data(jsonDictionary: requestDictionary)
        let task = session.dataTask(with: request, completionHandler: { (data, response, error) in
            var serverError: FileProviderHTTPError?
            var link: URL?
-            if let response = response as? HTTPURLResponse {
+            if let response = response as? HTTPURLResponse, response.statusCode >= 400 {
                let code = FileProviderHTTPErrorCode(rawValue: response.statusCode)
                serverError = code.flatMap { self.serverError(with: $0, path: path, data: data) }
-                if let json = data?.deserializeJSON() {
-                    if let linkDic = json["link"] as? NSDictionary, let linkStr = linkDic["webUrl"] as? String {
-                        link = URL(string: linkStr)
-                    }
+            }
+            if let json = data?.deserializeJSON() {
+                if let linkDic = json["link"] as? [String: Any], let linkStr = linkDic["webUrl"] as? String {
+                    link = URL(string: linkStr)
                }
            }
-            
            completionHandler(link, nil, nil, serverError ?? error)
        })
        task.resume()
@@ -589,9 +616,9 @@ extension OneDriveFileProvider: ExtendedFileProvider {
            if let response = response as? HTTPURLResponse {
                let code = FileProviderHTTPErrorCode(rawValue: response.statusCode)
                serverError = code.flatMap { self.serverError(with: $0, path: path, data: data) }
-                if let json = data?.deserializeJSON() {
-                    (dic, keys) = self.mapMediaInfo(json)
-                }
+            }
+            if let json = data?.deserializeJSON() {
+                (dic, keys) = self.mapMediaInfo(json)
            }
            completionHandler(dic, keys, serverError ?? error)
        })
@@ -601,7 +628,7 @@ extension OneDriveFileProvider: ExtendedFileProvider {
    
    #if os(macOS) || os(iOS) || os(tvOS)
    open func thumbnailOfFileSupported(path: String) -> Bool {
-        let fileExt = (path as NSString).pathExtension.lowercased()
+        let fileExt = path.pathExtension.lowercased()
        switch fileExt {
        case "jpg", "jpeg", "bmp", "gif", "png", "tif", "tiff":
            return true
@@ -624,6 +651,11 @@ extension OneDriveFileProvider: ExtendedFileProvider {
        case 97...176: thumbQuery = "medium"
        default:       thumbQuery = "large"
        }
+        /*if let dimension = dimension {
+            thumbQuery = "c\(Int(dimension.width))x\(Int(dimension.height))"
+        } else {
+            thumbQuery = "small"
+        }*/
        let url = self.url(of: path, modifier: "thumbnails")
            .appendingPathComponent("0").appendingPathComponent(thumbQuery)
            .appendingPathComponent("content")
@@ -22,22 +22,18 @@ public final class OneDriveFileObject: FileObject {
        self.init(baseURL: baseURL, route: route, json: json)
    }
    
-    internal init? (baseURL: URL?, route: OneDriveFileProvider.Route, json: [String: AnyObject]) {
+    internal init? (baseURL: URL?, route: OneDriveFileProvider.Route, json: [String: Any]) {
        guard let name = json["name"] as? String else { return nil }
        guard let id = json["id"] as? String else { return nil }
        let path: String
-        if let refpath = json["parentReference"]?["path"] as? String {
+        if let refpath = (json["parentReference"] as? [String: Any])?["path"] as? String {
            let parentPath: String
-            if let colonIndex = refpath.index(of: ":") {
-                #if swift(>=4.0)
+            if let colonIndex = refpath.firstIndex(of: ":") {
                parentPath = String(refpath[refpath.index(after: colonIndex)...])
-                #else
-                parentPath = refpath.substring(from: refpath.index(after: colonIndex))
-                #endif
            } else {
                parentPath = refpath
            }
-             path = (parentPath as NSString).appendingPathComponent(name)
+             path = parentPath.appendingPathComponent(name)
        } else {
            path = "id:\(id)"
        }
@@ -45,20 +41,20 @@ public final class OneDriveFileObject: FileObject {
        super.init(url: url, name: name, path: path)
        self.id = id
        self.size = (json["size"] as? NSNumber)?.int64Value ?? -1
-        self.childrensCount = json["folder"]?["childCount"] as? Int
+        self.childrensCount = (json["folder"] as? [String: Any])?["childCount"] as? Int
        self.modifiedDate = (json["lastModifiedDateTime"] as? String).flatMap { Date(rfcString: $0) }
        self.creationDate = (json["createdDateTime"] as? String).flatMap { Date(rfcString: $0) }
        self.type = json["folder"] != nil ? .directory : .regular
-        self.contentType = (json["file"]?["mimeType"] as? String).flatMap(ContentMIMEType.init(rawValue:)) ?? .stream
+        self.contentType = ((json["file"] as? [String: Any])?["mimeType"] as? String).flatMap(ContentMIMEType.init(rawValue:)) ?? .stream
        self.entryTag = json["eTag"] as? String
-        let hashes = json["file"]?["hashes"] as? NSDictionary
+        let hashes = (json["file"] as? [String: Any])?["hashes"] as? [String: Any]
        // checks for both sha1 or quickXor. First is available in personal drives, second in business one.
-        self.hash = (hashes?["sha1Hash"] as? String) ?? (hashes?["quickXorHash"] as? String)
+        self.fileHash = (hashes?["sha1Hash"] as? String) ?? (hashes?["quickXorHash"] as? String)
    }
    
    /// The document identifier is a value assigned by the OneDrive to a file.
    /// This value is used to identify the document regardless of where it is moved on a volume.
-    open internal(set) var id: String? {
+    public internal(set) var id: String? {
        get {
            return allValues[.fileResourceIdentifierKey] as? String
        }
@@ -68,7 +64,7 @@ public final class OneDriveFileObject: FileObject {
    }
    
    /// MIME type of file contents returned by OneDrive server.
-    open internal(set) var contentType: ContentMIMEType {
+    public internal(set) var contentType: ContentMIMEType {
        get {
            return (allValues[.mimeTypeKey] as? String).flatMap(ContentMIMEType.init(rawValue:)) ?? .stream
        }
@@ -78,7 +74,7 @@ public final class OneDriveFileObject: FileObject {
    }
    
    /// HTTP E-Tag, can be used to mark changed files.
-    open internal(set) var entryTag: String? {
+    public internal(set) var entryTag: String? {
        get {
            return allValues[.entryTagKey] as? String
        }
@@ -88,7 +84,7 @@ public final class OneDriveFileObject: FileObject {
    }
    
    /// Calculated hash from OneDrive server. Hex string SHA1 in personal or Base65 string [QuickXOR](https://dev.onedrive.com/snippets/quickxorhash.htm) in business drives.
-    open internal(set) var hash: String? {
+    public internal(set) var fileHash: String? {
        get {
            return allValues[.documentIdentifierKey] as? String
        }
@@ -141,7 +137,7 @@ public final class OneDriveFileObject: FileObject {
        
        switch crudePath {
        case hasPrefix("items/"):
-            let components = (crudePath as NSString).pathComponents
+            let components = crudePath.components(separatedBy: "/")
            return components.dropFirst().first.map { "id:\($0)" } ?? ""
        case hasPrefix("root:"):
            return crudePath.components(separatedBy: ":").dropFirst().first ?? ""
@@ -151,8 +147,8 @@ public final class OneDriveFileObject: FileObject {
    }
 }

-internal extension OneDriveFileProvider {
-    internal func upload_multipart_data(_ targetPath: String, data: Data, operation: FileOperationType,
+extension OneDriveFileProvider {
+    func upload_multipart_data(_ targetPath: String, data: Data, operation: FileOperationType,
                                        overwrite: Bool, completionHandler: SimpleCompletionHandler) -> Progress? {
        return self.upload_multipart(targetPath, operation: operation, size: Int64(data.count), overwrite: overwrite, dataProvider: {
            let range = $0.clamped(to: 0..<Int64(data.count))
@@ -160,13 +156,13 @@ internal extension OneDriveFileProvider {
        }, completionHandler: completionHandler)
    }
    
-    internal func upload_multipart_file(_ targetPath: String, file: URL, operation: FileOperationType,
+    func upload_multipart_file(_ targetPath: String, file: URL, operation: FileOperationType,
                                        overwrite: Bool, completionHandler: SimpleCompletionHandler) -> Progress? {
        // upload task can't handle uploading file
        
        return self.upload_multipart(targetPath, operation: operation, size: file.fileSize, overwrite: overwrite, dataProvider: { range in
            guard let handle = FileHandle(forReadingAtPath: file.path) else {
-                throw self.cocoaError(targetPath, code: .fileNoSuchFile)
+                throw CocoaError(.fileNoSuchFile, path: targetPath)
            }
            
            defer {
@@ -176,7 +172,7 @@ internal extension OneDriveFileProvider {
            let offset = range.lowerBound
            handle.seek(toFileOffset: UInt64(offset))
            guard Int64(handle.offsetInFile) == offset else {
-                throw self.cocoaError(targetPath, code: .fileReadTooLarge)
+                throw CocoaError(.fileReadTooLarge, path: targetPath)
            }
            
            return handle.readData(ofLength: range.count)
@@ -221,7 +217,6 @@ internal extension OneDriveFileProvider {
    private func upload_multipart(url: URL, operation: FileOperationType, size: Int64, range: Range<Int64>? = nil, uploadedSoFar: Int64 = 0,
                                  progress: Progress, dataProvider: @escaping (Range<Int64>) throws -> Data, completionHandler: SimpleCompletionHandler) {
        guard !progress.isCancelled else { return }
-        var progress = progress
        
        let maximumSize: Int64 = 10_485_760 // Recommended by OneDrive documentations and divides evenly by 320 KiB, max 60MiB.
        var request = URLRequest(url: url)
@@ -252,13 +247,13 @@ internal extension OneDriveFileProvider {
        }
        let task = session.uploadTask(with: request, from: data)
        
-        var dictionary: [String: AnyObject] = ["type": operation.description as NSString]
-        dictionary["source"] = operation.source as NSString?
-        dictionary["dest"] = operation.destination as NSString?
-        dictionary["uploadedBytes"] = uploadedSoFar as NSNumber
-        dictionary["totalBytes"] = data.count as NSNumber
+        var dictionary: [String: Any] = ["type": operation.description]
+        dictionary["source"] = operation.source
+        dictionary["dest"] = operation.destination
+        dictionary["uploadedBytes"] = NSNumber(value: uploadedSoFar)
+        dictionary["totalBytes"] = NSNumber(value: data.count)
        task.taskDescription = String(jsonDictionary: dictionary)
-        task.addObserver(self.sessionDelegate!, forKeyPath: #keyPath(URLSessionTask.countOfBytesSent), options: .new, context: &progress)
+        sessionDelegate?.observerProgress(of: task, using: progress, kind: .upload)
        progress.cancellationHandler = { [weak task, weak self] in
            task?.cancel()
            var deleteRequest = URLRequest(url: url)
@@ -339,7 +334,7 @@ internal extension OneDriveFileProvider {
        var keys = [String]()
        
        func add(key: String, value: Any?) {
-            if let value = value {
+            if let value = value, !((value as? String)?.isEmpty ?? false) {
                keys.append(key)
                dic[key] = value
            }
@@ -26,8 +26,8 @@ extension FileProviderHTTPError {
        return "Status \(code.rawValue): \(code.description)"
    }
    
-    public var errorDescription: String? {
-        return "Status \(code.rawValue): \(code.description)"
+    public var localizedDescription: String {
+        return description
    }
 }

@@ -61,57 +61,93 @@ final public class SessionDelegate: NSObject, URLSessionDataDelegate, URLSession
        self.credential = fileProvider.credential
    }
    
-    open override func observeValue(forKeyPath keyPath: String?, of object: Any?, change: [NSKeyValueChangeKey : Any]?, context: UnsafeMutableRawPointer?) {
-        if let progress = context?.load(as: Progress.self), let newVal = change?[.newKey] as? Int64 {
-            switch keyPath ?? "" {
-            case #keyPath(URLSessionTask.countOfBytesReceived):
-                progress.completedUnitCount = newVal
-                if let startTime = progress.userInfo[ProgressUserInfoKey.startingTimeKey] as? Date, let task = object as? URLSessionTask {
-                    let elapsed = Date().timeIntervalSince(startTime)
-                    let throughput = Double(newVal) / elapsed
-                    progress.setUserInfoObject(NSNumber(value: throughput), forKey: .throughputKey)
-                    if task.countOfBytesExpectedToReceive > 0 {
-                        let remain = task.countOfBytesExpectedToReceive - task.countOfBytesReceived
-                        let estimatedTimeRemaining = Double(remain) / elapsed
-                        progress.setUserInfoObject(NSNumber(value: estimatedTimeRemaining), forKey: .estimatedTimeRemainingKey)
-                    }
+    public enum ObserveKind {
+        case upload
+        case download
+    }
+    
+    private let observeProgressesLock = NSLock()
+    private var observeProgresses = [(task: URLSessionTask, progress: Progress, kind: ObserveKind)]()
+    
+    public func observerProgress(of task: URLSessionTask, using: Progress, kind: ObserveKind) {
+        switch kind {
+        case .upload:
+            task.addObserver(self, forKeyPath: #keyPath(URLSessionTask.countOfBytesSent), options: .new, context: nil)
+        case .download:
+            task.addObserver(self, forKeyPath: #keyPath(URLSessionTask.countOfBytesReceived), options: .new, context: nil)
+            task.addObserver(self, forKeyPath: #keyPath(URLSessionTask.countOfBytesExpectedToReceive), options: .new, context: nil)
+        }
+        observeProgressesLock.lock()
+        observeProgresses.append((task, using, kind))
+        observeProgressesLock.unlock()
+    }
+    
+    func removeObservers(for task: URLSessionTask) {
+        observeProgressesLock.lock()
+        observeProgresses = observeProgresses.filter { (item) -> Bool in
+            if item.task == task {
+                switch item.kind {
+                case .upload:
+                    task.removeObserver(self, forKeyPath: #keyPath(URLSessionTask.countOfBytesSent))
+                case .download:
+                    task.removeObserver(self, forKeyPath: #keyPath(URLSessionTask.countOfBytesReceived))
+                    task.removeObserver(self, forKeyPath: #keyPath(URLSessionTask.countOfBytesExpectedToReceive))
                }
-            case #keyPath(URLSessionTask.countOfBytesSent):
-                if let startTime = progress.userInfo[ProgressUserInfoKey.startingTimeKey] as? Date, let task = object as? URLSessionTask {
-                    let elapsed = Date().timeIntervalSince(startTime)
-                    let throughput = Double(newVal) / elapsed
-                    progress.setUserInfoObject(NSNumber(value: throughput), forKey: .throughputKey)
-                    
-                    // wokaround for multipart uploading
-                    let json = task.taskDescription?.deserializeJSON()
-                    let uploadedBytes = ((json?["uploadedBytes"] as? Int64) ?? 0) + newVal
-                    let totalBytes = (json?["totalBytes"] as? Int64) ?? task.countOfBytesExpectedToSend
-                    progress.completedUnitCount = uploadedBytes
-                    if totalBytes > 0 {
-                        let remain = totalBytes - uploadedBytes
-                        let estimatedTimeRemaining = Double(remain) / elapsed
-                        progress.setUserInfoObject(NSNumber(value: estimatedTimeRemaining), forKey: .estimatedTimeRemainingKey)
-                    }
-                } else {
-                    progress.completedUnitCount = newVal
-                }
-            case #keyPath(URLSessionTask.countOfBytesExpectedToReceive), #keyPath(URLSessionTask.countOfBytesExpectedToSend):
-                progress.totalUnitCount = newVal
-            default:
-                super.observeValue(forKeyPath: keyPath, of: object, change: change, context: context)
+                return false
+            } else {
+                return true
            }
        }
+        observeProgressesLock.unlock()
+    }
+    
+    public override func observeValue(forKeyPath keyPath: String?, of object: Any?, change: [NSKeyValueChangeKey : Any]?, context: UnsafeMutableRawPointer?) {
+        guard let context = context, let keyPath = keyPath, keyPath.contains("countOfBytes") else { return }
+        let progress = context.assumingMemoryBound(to: Progress.self).pointee
+        guard let newVal = change?[.newKey] as? Int64 else { return }
+        
+        switch keyPath {
+        case #keyPath(URLSessionTask.countOfBytesReceived):
+            progress.completedUnitCount = newVal
+            if let startTime = progress.userInfo[ProgressUserInfoKey.startingTimeKey] as? Date, let task = object as? URLSessionTask {
+                let elapsed = Date().timeIntervalSince(startTime)
+                let throughput = Double(newVal) / elapsed
+                progress.setUserInfoObject(NSNumber(value: throughput), forKey: .throughputKey)
+                if task.countOfBytesExpectedToReceive > 0 {
+                    let remain = task.countOfBytesExpectedToReceive - task.countOfBytesReceived
+                    let estimatedTimeRemaining = Double(remain) / elapsed
+                    progress.setUserInfoObject(NSNumber(value: estimatedTimeRemaining), forKey: .estimatedTimeRemainingKey)
+                }
+            }
+        case #keyPath(URLSessionTask.countOfBytesSent):
+            if let startTime = progress.userInfo[ProgressUserInfoKey.startingTimeKey] as? Date, let task = object as? URLSessionTask {
+                let elapsed = Date().timeIntervalSince(startTime)
+                let throughput = Double(newVal) / elapsed
+                progress.setUserInfoObject(NSNumber(value: throughput), forKey: .throughputKey)
+                
+                // wokaround for multipart uploading
+                let json = task.taskDescription?.deserializeJSON()
+                let uploadedBytes = ((json?["uploadedBytes"] as? Int64) ?? 0) + newVal
+                let totalBytes = (json?["totalBytes"] as? Int64) ?? task.countOfBytesExpectedToSend
+                progress.completedUnitCount = uploadedBytes
+                if totalBytes > 0 {
+                    let remain = totalBytes - uploadedBytes
+                    let estimatedTimeRemaining = Double(remain) / elapsed
+                    progress.setUserInfoObject(NSNumber(value: estimatedTimeRemaining), forKey: .estimatedTimeRemainingKey)
+                }
+            } else {
+                progress.completedUnitCount = newVal
+            }
+        case #keyPath(URLSessionTask.countOfBytesExpectedToReceive), #keyPath(URLSessionTask.countOfBytesExpectedToSend):
+            progress.totalUnitCount = newVal
+        default:
+            super.observeValue(forKeyPath: keyPath, of: object, change: change, context: context)
+        }
    }
    
    // codebeat:disable[ARITY]
    public func urlSession(_ session: URLSession, task: URLSessionTask, didCompleteWithError error: Error?) {
-        if task is URLSessionUploadTask {
-            task.removeObserver(self, forKeyPath: #keyPath(URLSessionTask.countOfBytesSent))
-            //task.removeObserver(self, forKeyPath: #keyPath(URLSessionTask.countOfBytesExpectedToSend))
-        } else if task is URLSessionDownloadTask {
-            task.removeObserver(self, forKeyPath: #keyPath(URLSessionTask.countOfBytesReceived))
-            task.removeObserver(self, forKeyPath: #keyPath(URLSessionTask.countOfBytesExpectedToReceive))
-        }
+        self.removeObservers(for: task)
        
        _ = dataCompletionHandlersForTasks[session.sessionDescription!]?.removeValue(forKey: task.taskIdentifier)
        if !(error == nil && task is URLSessionDownloadTask) {
@@ -119,32 +155,6 @@ final public class SessionDelegate: NSObject, URLSessionDataDelegate, URLSession
            completionHandler?(error)
            _ = completionHandlersForTasks[session.sessionDescription!]?.removeValue(forKey: task.taskIdentifier)
        }
-        
-        guard let json = task.taskDescription?.deserializeJSON(),
-            let op = FileOperationType(json: json), let fileProvider = fileProvider else {
-                return
-        }
-        
-        switch op {
-        case .fetch:
-            if task is URLSessionDataTask {
-                task.removeObserver(self, forKeyPath: #keyPath(URLSessionTask.countOfBytesReceived))
-                task.removeObserver(self, forKeyPath: #keyPath(URLSessionTask.countOfBytesExpectedToReceive))
-            }
-        default:
-            break
-        }
-        
-        if !(task is URLSessionDownloadTask), case FileOperationType.fetch = op {
-            return
-        }
-        if #available(iOS 9.0, macOS 10.11, *) {
-            if task is URLSessionStreamTask {
-                return
-            }
-        }
-        
-        fileProvider.delegateNotify(op, error: error)
    }
    
    public func urlSession(_ session: URLSession, downloadTask: URLSessionDownloadTask, didFinishDownloadingTo location: URL) {
@@ -216,7 +226,7 @@ final public class SessionDelegate: NSObject, URLSessionDataDelegate, URLSession
        authenticate(didReceive: challenge, completionHandler: completionHandler)
    }
    
-    func authenticate(didReceive challenge: URLAuthenticationChallenge, completionHandler: @escaping (URLSession.AuthChallengeDisposition, URLCredential?) -> Void) {
+    private func authenticate(didReceive challenge: URLAuthenticationChallenge, completionHandler: @escaping (URLSession.AuthChallengeDisposition, URLCredential?) -> Void) {
        switch (challenge.previousFailureCount, credential != nil) {
        case (0...1, true):
            completionHandler(.useCredential, credential)
@@ -28,7 +28,7 @@ class SMBClient: NSObject, StreamDelegate {
    public var timeout: TimeInterval = 30
    
    internal private(set) var messageId: UInt64 = 0
-    private func createMessageId() -> UInt64 {
+    fileprivate func createMessageId() -> UInt64 {
        defer {
            messageId += 1
        }
@@ -36,7 +36,7 @@ class SMBClient: NSObject, StreamDelegate {
    }
    
    internal private(set) var credit: UInt16 = 0
-    private func consumeCredit() -> UInt16 {
+    fileprivate func consumeCredit() -> UInt16 {
        if credit > 0 {
            credit -= 1
            return credit
@@ -90,8 +90,8 @@ class SMBClient: NSObject, StreamDelegate {
        
        inputStream.delegate = self
        outputStream.delegate = self
-        inputStream.schedule(in: RunLoop.main, forMode: .defaultRunLoopMode)
-        outputStream.schedule(in: RunLoop.main, forMode: .defaultRunLoopMode)
+        inputStream.schedule(in: RunLoop.main, forMode: .init("kCFRunLoopDefaultMode"))
+        outputStream.schedule(in: RunLoop.main, forMode: .init("kCFRunLoopDefaultMode"))
        inputStream.open()
        outputStream.open()
        
@@ -101,8 +101,8 @@ class SMBClient: NSObject, StreamDelegate {
    fileprivate func close() {
        self.inputStream?.close()
        self.outputStream?.close()
-        self.inputStream?.remove(from: RunLoop.main, forMode: .defaultRunLoopMode)
-        self.outputStream?.remove(from: RunLoop.main, forMode: .defaultRunLoopMode)
+        self.inputStream?.remove(from: RunLoop.main, forMode: .init("kCFRunLoopDefaultMode"))
+        self.outputStream?.remove(from: RunLoop.main, forMode: .init("kCFRunLoopDefaultMode"))
        self.inputStream?.delegate = nil
        self.outputStream?.delegate = nil
        
@@ -119,9 +119,7 @@ class SMBClient: NSObject, StreamDelegate {
        var data = data
        var byteSent: Int = 0
        while data.count > 0 {
-            let bytesWritten = data.withUnsafeBytes {
-                outputStream.write($0, maxLength: data.count)
-            }
+            let bytesWritten: Int = (try? outputStream.write(data: data)) ?? -1
            
            if bytesWritten > 0 {
                let range = 0..<bytesWritten
@@ -11,7 +11,6 @@ import Foundation
 class SMBFileProvider: FileProvider, FileProviderMonitor {
    open class var type: String { return "SMB" }
    open var baseURL: URL?
-    open var currentPath: String = ""
    open var dispatch_queue: DispatchQueue
    open var operation_queue: OperationQueue
    open weak var delegate: FileProviderDelegate?
@@ -25,11 +24,7 @@ class SMBFileProvider: FileProvider, FileProviderMonitor {
        }
        self.baseURL = baseURL.appendingPathComponent("")
        
-        #if swift(>=3.1)
        let queueLabel = "FileProvider.\(Swift.type(of: self).type)"
-        #else
-        let queueLabel = "FileProvider.\(type(of: self).type)"
-        #endif
        dispatch_queue = DispatchQueue(label: queueLabel, attributes: .concurrent)
        operation_queue = OperationQueue()
        operation_queue.name = "\(queueLabel).Operation"
@@ -38,18 +33,20 @@ class SMBFileProvider: FileProvider, FileProviderMonitor {
    }
    
    public required convenience init?(coder aDecoder: NSCoder) {
-        guard let baseURL = aDecoder.decodeObject(forKey: "baseURL") as? URL else {
+        guard let baseURL = aDecoder.decodeObject(of: NSURL.self, forKey: "baseURL") as URL? else {
+            if #available(macOS 10.11, iOS 9.0, tvOS 9.0, *) {
+                aDecoder.failWithError(CocoaError(.coderValueNotFound,
+                                                  userInfo: [NSLocalizedDescriptionKey: "Base URL is not set."]))
+            }
            return nil
        }
        self.init(baseURL: baseURL,
-                  credential: aDecoder.decodeObject(forKey: "credential") as? URLCredential)
-        self.currentPath   = aDecoder.decodeObject(forKey: "currentPath") as? String ?? ""
+                  credential: aDecoder.decodeObject(of: URLCredential.self, forKey: "credential"))
    }
    
    open func encode(with aCoder: NSCoder) {
        aCoder.encode(self.baseURL, forKey: "baseURL")
        aCoder.encode(self.credential, forKey: "credential")
-        aCoder.encode(self.currentPath, forKey: "currentPath")
    }
    
    public static var supportsSecureCoding: Bool {
@@ -138,7 +135,6 @@ class SMBFileProvider: FileProvider, FileProviderMonitor {
    
    open func copy(with zone: NSZone? = nil) -> Any {
        let copy = SMBFileProvider(baseURL: self.baseURL!, credential: self.credential!)!
-        copy.currentPath = self.currentPath
        copy.delegate = self.delegate
        copy.fileOperationDelegate = self.fileOperationDelegate
        return copy
@@ -31,11 +31,7 @@ protocol SMBRequestBody {

 extension SMBRequestBody {
    var command: SMB2.Command {
-        #if swift(>=3.1)
-            return Swift.type(of: self).command
-        #else
-            return type(of: self).command
-        #endif
+        return Swift.type(of: self).command
    }
    
    func data() -> Data {
@@ -310,11 +310,11 @@ extension SMB2 {
                static let ipv6: sa_family_t = 0x17
                
                var sockaddr: sockaddr_in {
-                    return Data.mapMemory(from: self.sockaddrStorage)!
+                    return unsafeBitCast(self.sockaddrStorage, to: sockaddr_in.self)
                }
                
                var sockaddr6: sockaddr_in6 {
-                     return Data.mapMemory(from: self.sockaddrStorage)!
+                    return unsafeBitCast(self.sockaddrStorage, to: sockaddr_in6.self)
                }
            }
        }
@@ -72,17 +72,23 @@ extension SMB2 {
                let header: SMB2FilesInformationHeader
                switch type {
                case .fileDirectoryInformation:
-                    header = buffer.scanValue(start: offset) as FileDirectoryInformationHeader!
+                    let tHeader: FileDirectoryInformationHeader = buffer.scanValue(start: offset)!
+                    header = tHeader
                case .fileFullDirectoryInformation:
-                    header = buffer.scanValue(start: offset) as FileFullDirectoryInformationHeader!
+                    let tHeader: FileFullDirectoryInformationHeader = buffer.scanValue(start: offset)!
+                    header = tHeader
                case .fileIdFullDirectoryInformation:
-                    header = buffer.scanValue(start: offset) as FileIdFullDirectoryInformationHeader!
+                    let tHeader: FileIdFullDirectoryInformationHeader = buffer.scanValue(start: offset)!
+                    header = tHeader
                case .fileBothDirectoryInformation:
-                    header = buffer.scanValue(start: offset) as FileBothDirectoryInformationHeader!
+                    let tHeader: FileBothDirectoryInformationHeader = buffer.scanValue(start: offset)!
+                    header = tHeader
                case .fileIdBothDirectoryInformation:
-                    header = buffer.scanValue(start: offset) as FileIdBothDirectoryInformationHeader!
+                    let tHeader: FileIdBothDirectoryInformationHeader = buffer.scanValue(start: offset)!
+                    header = tHeader
                case .fileNamesInformation:
-                    header = buffer.scanValue(start: offset) as FileNamesInformationHeader!
+                    let tHeader: FileNamesInformationHeader = buffer.scanValue(start: offset)!
+                    header = tHeader
                default:
                    return []
                }
@@ -98,8 +104,10 @@ extension SMB2 {
        }
        
        init? (data: Data) {
-            let offset = Int(data.scanValue(start: 2) as UInt16!)
-            let length = Int(data.scanValue(start: 4) as UInt32!)
+            let tOffset: UInt16 = data.scanValue(start: 2)!
+            let offset = Int(tOffset)
+            let tLength: UInt32 = data.scanValue(start: 4)!
+            let length = Int(tLength)
            guard data.count > offset + length else {
                return nil
            }
@@ -200,7 +208,8 @@ extension SMB2 {
            /*let offsetData = data.subdataWithRange(NSRange(location: 2, length: 2))
            let offset: UInt16 = decode(offsetData)*/
            
-            let length = Int(data.scanValue(start: 4) as UInt32!)
+            let tLength: UInt32 = data.scanValue(start: 4)!
+            let length = Int(tLength)
            
            guard data.count >= 8 + length else {
                return nil
@@ -0,0 +1,83 @@
+//
+//  ServerTrustPolicy.swift
+//
+//  Copyright (c) 2014-2018 Alamofire Software Foundation (http://alamofire.org/)
+//
+//  Permission is hereby granted, free of charge, to any person obtaining a copy
+//  of this software and associated documentation files (the "Software"), to deal
+//  in the Software without restriction, including without limitation the rights
+//  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+//  copies of the Software, and to permit persons to whom the Software is
+//  furnished to do so, subject to the following conditions:
+//
+//  The above copyright notice and this permission notice shall be included in
+//  all copies or substantial portions of the Software.
+//
+//  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+//  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+//  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+//  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+//  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+//  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+//  THE SOFTWARE.
+//
+
+import Foundation
+
+// MARK: - ServerTrustPolicy
+/// The `ServerTrustPolicy` evaluates the server trust generally provided by an `NSURLAuthenticationChallenge` when
+/// connecting to a server over a secure HTTPS connection. The policy configuration then evaluates the server trust
+/// with a given set of criteria to determine whether the server trust is valid and the connection should be made.
+///
+/// Using pinned certificates or public keys for evaluation helps prevent man-in-the-middle (MITM) attacks and other
+/// vulnerabilities. Applications dealing with sensitive customer data or financial information are strongly encouraged
+/// to route all communication over an HTTPS connection with pinning enabled.
+///
+/// - performDefaultEvaluation: Uses the default server trust evaluation while allowing you to control whether to
+///                             validate the host provided by the challenge. Applications are encouraged to always
+///                             validate the host in production environments to guarantee the validity of the server's
+///                             certificate chain.
+///
+/// - disableEvaluation:        Disables all evaluation which in turn will always consider any server trust as valid.
+///
+public enum ServerTrustPolicy {
+    case performDefaultEvaluation(validateHost: Bool)
+    case disableEvaluation
+    
+    // MARK: - Evaluation
+    /// Evaluates whether the server trust is valid.
+    ///
+    /// - returns: Whether the server trust is valid.
+    public func evaluate() -> Bool {
+        var serverTrustIsValid = false
+        
+        switch self {
+        case .performDefaultEvaluation(_):
+            break
+        case .disableEvaluation:
+            serverTrustIsValid = true
+        }
+        
+        return serverTrustIsValid
+    }
+    
+    /// Evaluates whether the server trust is valid for the given host.
+    ///
+    /// - parameter serverTrust: The server trust to evaluate.
+    /// - parameter host:        The host of the challenge protection space.
+    ///
+    /// - returns: Whether the server trust is valid.
+    public func evaluate(_ serverTrust: SecTrust, forHost host: String) -> Bool {
+        var serverTrustIsValid = false
+        
+        switch self {
+        case let .performDefaultEvaluation(validateHost):
+            let policy = SecPolicyCreateSSL(true, validateHost ? host as CFString : nil)
+            SecTrustSetPolicies(serverTrust, policy)
+        case .disableEvaluation:
+            serverTrustIsValid = true
+        }
+        
+        return serverTrustIsValid
+    }
+}
@@ -46,11 +46,15 @@ open class WebDAVFileProvider: HTTPFileProvider, FileProviderSharing {
    }
    
    public required convenience init?(coder aDecoder: NSCoder) {
-        guard let baseURL = aDecoder.decodeObject(forKey: "baseURL") as? URL else {
+        guard let baseURL = aDecoder.decodeObject(of: NSURL.self, forKey: "baseURL") as URL? else {
+            if #available(macOS 10.11, iOS 9.0, tvOS 9.0, *) {
+                aDecoder.failWithError(CocoaError(.coderValueNotFound,
+                                                  userInfo: [NSLocalizedDescriptionKey: "Base URL is not set."]))
+            }
            return nil
        }
        self.init(baseURL: baseURL,
-                  credential: aDecoder.decodeObject(forKey: "credential") as? URLCredential)
+                  credential: aDecoder.decodeObject(of: URLCredential.self, forKey: "credential"))
        self.useCache        = aDecoder.decodeBool(forKey: "useCache")
        self.validatingCache = aDecoder.decodeBool(forKey: "validatingCache")
    }
@@ -289,7 +293,7 @@ open class WebDAVFileProvider: HTTPFileProvider, FileProviderSharing {
    open func publicLink(to path: String, completionHandler: @escaping ((URL?, FileObject?, Date?, Error?) -> Void)) {
        guard self.baseURL?.host?.contains("dav.yandex.") ?? false else {
            dispatch_queue.async {
-                completionHandler(nil, nil, nil, self.urlError(path, code: .resourceUnavailable))
+                completionHandler(nil, nil, nil, URLError(.resourceUnavailable, url: self.url(of: path)))
            }
            return
        }
@@ -373,13 +377,13 @@ open class WebDAVFileProvider: HTTPFileProvider, FileProviderSharing {
        return FileProviderWebDavError(code: code, path: path ?? "", serverDescription:  data.flatMap({ String(data: $0, encoding: .utf8) }), url: self.url(of: path ?? ""))
    }
    
-    override func multiStatusHandler(source: String, data: Data, completionHandler: SimpleCompletionHandler) {
+    override func multiStatusError(operation: FileOperationType, data: Data) -> FileProviderHTTPError? {
        let xresponses = DavResponse.parse(xmlResponse: data, baseURL: self.baseURL)
        for xresponse in xresponses where (xresponse.status ?? 0) >= 300 {
            let code = xresponse.status.flatMap { FileProviderHTTPErrorCode(rawValue: $0) } ?? .internalServerError
-            let error = self.serverError(with: code, path: source, data: data)
-            completionHandler?(error)
+            return self.serverError(with: code, path: operation.source, data: data)
        }
+        return nil
    }
    
    /*
@@ -405,14 +409,14 @@ extension WebDAVFileProvider: ExtendedFileProvider {
            return false
        }
        let supportedExt: [String] = ["jpg", "jpeg", "png", "gif"]
-        return supportedExt.contains((path as NSString).pathExtension)
+        return supportedExt.contains(path.pathExtension)
    }
    
    @discardableResult
    open func thumbnailOfFile(path: String, dimension: CGSize?, completionHandler: @escaping ((ImageClass?, Error?) -> Void)) -> Progress? {
        guard self.baseURL?.host?.contains("dav.yandex.") ?? false else {
            dispatch_queue.async {
-                completionHandler(nil, self.urlError(path, code: .resourceUnavailable))
+                completionHandler(nil, URLError(.resourceUnavailable, url: self.url(of: path)))
            }
            return nil
        }
@@ -444,7 +448,7 @@ extension WebDAVFileProvider: ExtendedFileProvider {
    @discardableResult
    open func propertiesOfFile(path: String, completionHandler: @escaping (([String : Any], [String], Error?) -> Void)) -> Progress? {
        dispatch_queue.async {
-            completionHandler([:], [], self.urlError(path, code: .resourceUnavailable))
+            completionHandler([:], [], URLError(.resourceUnavailable, url: self.url(of: path)))
        }
        return nil
    }
@@ -463,11 +467,7 @@ struct DavResponse {
    init? (_ node: AEXMLElement, baseURL: URL?) {
        
        func standardizePath(_ str: String) -> String {
-            #if swift(>=4.0)
            let trimmedStr = str.hasPrefix("/") ? String(str[str.index(after: str.startIndex)...]) : str
-            #else
-            let trimmedStr = str.hasPrefix("/") ? str.substring(from: str.index(after: str.startIndex)) : str
-            #endif
            return trimmedStr.addingPercentEncoding(withAllowedCharacters: .filePathAllowed) ?? str
        }
        
@@ -578,7 +578,7 @@ public final class WebDavFileObject: FileObject {
    }
    
    /// MIME type of the file.
-    open internal(set) var contentType: ContentMIMEType {
+    public internal(set) var contentType: ContentMIMEType {
        get {
            return (allValues[.mimeTypeKey] as? String).flatMap(ContentMIMEType.init(rawValue:)) ?? .stream
        }
@@ -588,7 +588,7 @@ public final class WebDavFileObject: FileObject {
    }
    
    /// HTTP E-Tag, can be used to mark changed files.
-    open internal(set) var entryTag: String? {
+    public internal(set) var entryTag: String? {
        get {
            return allValues[.entryTagKey] as? String
        }
@@ -27,6 +27,7 @@ class FilesProviderTests: XCTestCase, FileProviderDelegate {
            self.testRemoveFile(provider, filePath: self.testFolderName)
        }
        testBasic(provider)
+        testArchiving(provider)
        testOperations(provider)
    }
    
@@ -41,6 +42,7 @@ class FilesProviderTests: XCTestCase, FileProviderDelegate {
        }
        let provider = WebDAVFileProvider(baseURL: url, credential: cred)!
        provider.delegate = self
+        testArchiving(provider)
        addTeardownBlock {
            self.testRemoveFile(provider, filePath: self.testFolderName)
        }
@@ -54,6 +56,7 @@ class FilesProviderTests: XCTestCase, FileProviderDelegate {
        let cred = URLCredential(user: "testuser", password: pass, persistence: .forSession)
        let provider = DropboxFileProvider(credential: cred)
        provider.delegate = self
+        testArchiving(provider)
        addTeardownBlock {
            self.testRemoveFile(provider, filePath: self.testFolderName)
        }
@@ -62,6 +65,7 @@ class FilesProviderTests: XCTestCase, FileProviderDelegate {
    }
    
    func testFTPPassive() {
+        /*
        guard let urlStr = ProcessInfo.processInfo.environment["ftp_url"] else { return }
        let url = URL(string: urlStr)!
        let cred: URLCredential?
@@ -70,8 +74,14 @@ class FilesProviderTests: XCTestCase, FileProviderDelegate {
        } else {
            cred = nil
        }
+        */
+        let url = URL(string: "ftp://ftp.edmapplication.com")!
+        let cred = URLCredential(user: "abbas@edmapplication.com", password: "baTsivWZ4", persistence: .forSession)
+        //let url = URL(string: "ftpes://ftp.adidas-group.com:21")!
+        //let cred = URLCredential(user: "ecomwe-reversals-full", password: "rNeUj726Xqk2k", persistence: .forSession)
        let provider = FTPFileProvider(baseURL: url, mode: .extendedPassive, credential: cred)!
        provider.delegate = self
+        testArchiving(provider)
        addTeardownBlock {
            self.testRemoveFile(provider, filePath: self.testFolderName)
        }
@@ -85,10 +95,11 @@ class FilesProviderTests: XCTestCase, FileProviderDelegate {
        let cred = URLCredential(user: "testuser", password: pass, persistence: .forSession)
        let provider = OneDriveFileProvider(credential: cred)
        provider.delegate = self
+        testBasic(provider)
+        testArchiving(provider)
        addTeardownBlock {
            self.testRemoveFile(provider, filePath: self.testFolderName)
        }
-        testBasic(provider)
        testOperations(provider)
    }
    
@@ -207,7 +218,12 @@ class FilesProviderTests: XCTestCase, FileProviderDelegate {
            XCTAssertNil(error, "\(desc) failed: \(error?.localizedDescription ?? "no error desc")")
            expectation.fulfill()
        }
-        wait(for: [expectation], timeout: timeout)
+        if provider is FTPFileProvider {
+            // FTP will need to download and upload file again.
+            wait(for: [expectation], timeout: timeout * 6)
+        } else {
+            wait(for: [expectation], timeout: timeout)
+        }
        print("Test fulfilled: \(desc).")
    }
    
@@ -225,8 +241,9 @@ class FilesProviderTests: XCTestCase, FileProviderDelegate {
    
    private func randomData(size: Int = 262144) -> Data {
        var keyData = Data(count: size)
+        let count = keyData.count
        let result = keyData.withUnsafeMutableBytes {
-            SecRandomCopyBytes(kSecRandomDefault, keyData.count, $0)
+            SecRandomCopyBytes(kSecRandomDefault, count, $0)
        }
        if result == errSecSuccess {
            return keyData
@@ -247,7 +264,6 @@ class FilesProviderTests: XCTestCase, FileProviderDelegate {
    
    fileprivate func testUploadFile(_ provider: FileProvider, filePath: String) {
        // test Upload/Download
-        let url = dummyFile()
        let desc = "Uploading file in \(provider.type)"
        print("Test started: \(desc).")
        let expectation = XCTestExpectation(description: desc)
@@ -310,6 +326,41 @@ class FilesProviderTests: XCTestCase, FileProviderDelegate {
        print("Test fulfilled: \(desc).")
    }
    
+    fileprivate func testArchiving(_ provider: FileProvider) {
+        let archivedData = NSKeyedArchiver.archivedData(withRootObject: provider)
+        let unarchived = NSKeyedUnarchiver.unarchiveObject(with: archivedData) as? FileProvider
+        XCTAssertNotNil(unarchived)
+        XCTAssertEqual(unarchived?.baseURL, provider.baseURL, "archived provider is not same with original")
+        XCTAssertEqual(unarchived?.credential, provider.credential, "archived provider is not same with original")
+        if let provider = provider as? FileProviderBasicRemote, let unarchived_r = unarchived as? FileProviderBasicRemote {
+            XCTAssertEqual(unarchived_r.useCache, provider.useCache, "archived provider is not same with original")
+            XCTAssertEqual(unarchived_r.validatingCache, provider.validatingCache, "archived provider is not same with original")
+        }
+        if let provider = provider as? OneDriveFileProvider, let unarchived_o = unarchived as? OneDriveFileProvider {
+            XCTAssertEqual(unarchived_o.route.rawValue, provider.route.rawValue, "archived provider is not same with original")
+        }
+    }
+    
+    fileprivate func testSymlink(_ provider: FileProvider & FileProviderSymbolicLink, filePath: String) {
+        let desc = "Symlink in \(provider.type)"
+        print("Test started: \(desc).")
+        let expectation = XCTestExpectation(description: desc)
+        provider.create(symbolicLink: filePath + " Link", withDestinationPath: filePath) { (error) in
+            XCTAssertNil(error, "\(desc) failed: \(error?.localizedDescription ?? "no error desc")")
+            provider.destination(ofSymbolicLink: filePath + " Link", completionHandler: { (fileObject, error) in
+                provider.removeItem(path: filePath + " Link", completionHandler: nil)
+                XCTAssertNil(error, "\(desc) failed: \(error?.localizedDescription ?? "no error desc")")
+                XCTAssertNotNil(fileObject, "file '\(filePath)' didn't exist")
+                guard fileObject != nil else { return }
+                XCTAssertEqual(fileObject!.path, filePath, "file path is different from '\(filePath)'")
+                XCTAssertEqual(fileObject!.type, URLFileResourceType.regular, "file '\(filePath)' is not a regular file")
+                expectation.fulfill()
+            })
+        }
+        wait(for: [expectation], timeout: timeout)
+        print("Test fulfilled: \(desc).")
+    }
+    
    fileprivate func testBasic(_ provider: FileProvider) {
        let filepath = "/test/file.txt"
        let fileurl = provider.url(of: filepath)
@@ -336,6 +387,9 @@ class FilesProviderTests: XCTestCase, FileProviderDelegate {
        testContentsFile(provider, filePath: textFilePath)
        testRenameFile(provider, filePath: textFilePath, to: renamedFilePath)
        testCopyFile(provider, filePath: renamedFilePath, to: textFilePath)
+        if let provider = provider as? FileProvider & FileProviderSymbolicLink {
+            testSymlink(provider, filePath: textFilePath)
+        }
        testRemoveFile(provider, filePath: textFilePath)
        
        // TODO: Test search
Author	SHA1	Message	Date
Amir Abbas	abf68a6254	Updated to Swift 5.0, Removed Swift 3 support	2019-04-04 12:42:17 +04:30
Amir Abbas Mousavian	9384264d29	Merge pull request #139 from sasaki-945/master Fixed bug: cannot be transferred file 4KB or less	2018-12-16 10:25:42 +03:30
T.Sasaki	90706f1842	Fixed bug: cannot be transferred file 4KB or less	2018-12-10 14:48:59 +09:00
Amir Abbas Mousavian	cb42552573	Merge pull request #136 from sasaki-945/master Added FTP SSL/TLS session resumption/reuse support	2018-11-20 07:49:24 +03:30
T.Sasaki	b9c1729733	Added FTP SSL/TLS session resumption/reuse support - Get a SessionID of control connection after TLS Handshake, and set the SessionID to data connection	2018-11-20 11:10:05 +09:00
Amir Abbas Mousavian	83eb97a100	Merge pull request #135 from sasaki-945/master Fixed few bug on FTP	2018-11-19 13:46:37 +03:30
Amir Abbas Mousavian	7c7763d105	Merge pull request #134 from sasaki-945/issue#113 Fixed Issue#113: FTP timeout error occurred when ftpList an empty directory	2018-11-19 13:44:54 +03:30
Amir Abbas Mousavian	d1ac332ace	Merge pull request #132 from sasaki-945/bug-fix Fixed a blocked stream handle event during UI control	2018-11-19 13:34:43 +03:30
T.Sasaki	737cd7a7c3	Fixed a bug, cannot be canceled if canceled before login	2018-11-19 18:27:17 +09:00
T.Sasaki	d050ceb3bc	Added `filePath` argument on FileProviderFTPError	2018-11-19 18:24:07 +09:00
T.Sasaki	504ca76077	Fixed a multiple error callback on `recursiveList`	2018-11-19 18:22:12 +09:00
T.Sasaki	d462b5d17b	Add missed commit - `[933ef9b] Fixed a truncated uploaded file`	2018-11-19 18:19:05 +09:00
T.Sasaki	004966aa69	Fixed a timeout error occurred when ftpList an empty directory - Break a readData looping when the end of the stream has been reached	2018-11-19 17:33:46 +09:00
T.Sasaki	d97f6c0289	To keep it compatible to Swift 3/4.0	2018-11-19 11:24:10 +09:00
Amir Abbas Mousavian	967a5a05fd	Merge pull request #133 from sasaki-945/issue#111 Fixed Issue#111: Connection stays open after FTP upload	2018-11-17 19:09:38 +03:30
Amir Abbas Mousavian	9d5ac1064c	Merge pull request #131 from sasaki-945/master Fixed bug in FTP data-connection and login	2018-11-17 19:08:26 +03:30
T.Sasaki	8a5edc5700	Fixed a timeout error not notified	2018-11-16 19:45:48 +09:00
T.Sasaki	933ef9b5d4	Fixed a truncated uploaded file	2018-11-16 19:42:22 +09:00
T.Sasaki	d6d777fd65	Fixed a blocked stream handle event during UI control	2018-11-16 17:18:03 +09:00
T.Sasaki	9cbe0fc661	Fixed bugs in FTPS, `ftpUserPass` was called twice - change redundant `ftpUserPass` to `completionHandler`	2018-11-15 10:40:14 +09:00
T.Sasaki	59ba5b7817	Fixed bugs in FTP provider fallbacks from EPSV to PASV - missing `return`	2018-11-15 10:15:03 +09:00
Amir Abbas Mousavian	3f59178b9e	Merge pull request #130 from sasaki-945/master Fixed Issue #127: Support for connect to self-signed certificate FTPS server	2018-11-14 21:19:33 +03:30
T.Sasaki	92f0970097	Convert a boolean value to enum for connecting to self-signed certificate FTPS server > define an enum like Alamofire's ServerTrustPolicy	2018-11-14 17:55:55 +09:00
T.Sasaki	1fd724c3dc	Added connect to self-signed certificate FTPS server	2018-11-09 18:56:45 +09:00
Amir Abbas Mousavian	ab1da39fc2	Merge pull request #126 from bscothern/swift_4.2 Swift 4.2 Support	2018-10-16 09:46:30 +03:30
Braden.Scothern	36c600ebb0	updated FileObject's hash implementation	2018-10-16 00:09:48 -06:00
Braden.Scothern	26a9e2de1e	updated podspec to use Swift 4.2	2018-10-16 00:09:38 -06:00
Braden.Scothern	5c33683a8c	updated .travis.yml to use xcode10	2018-10-16 00:09:26 -06:00
Braden.Scothern	08d476654e	Swift 4.2, fixed warnings, fixed tests	2018-10-15 22:35:30 -06:00
Amir Abbas	b597244be4	Fix #112 (crash on progress report)	2018-08-18 21:31:37 +04:30
Amir Abbas	76aee40c0d	Undo for all providers, encapsulated error creating	2018-08-05 20:07:31 +04:30
Amir Abbas	38fb3fc89a	Fix remote session crash, minor fixes	2018-07-26 13:18:49 +04:30
Amir Abbas	e2572d2810	Fix #109 , refactoring	2018-07-19 15:37:08 +04:30
Amir Abbas	5e3db16401	FTPdownload to use Stream, Fix FTP upload truncated	2018-07-10 15:46:06 +04:30
Amir Abbas	311fcc5a88	Switching to Stream, Fixed FPStreamTask would remain open	2018-07-08 02:44:27 +04:30
Amir Abbas	fb389c1d69	Fix #102 & #103 (FTP write issue), Fix fileSize overflow on 32bit device	2018-07-07 23:31:48 +04:30
Amir Abbas	f1f7955b86	Fix #105 FTP downloads corrupt file	2018-07-07 14:29:28 +04:30
Amir Abbas	7b21605eeb	Amend finxing #99	2018-06-21 13:17:56 +04:30
Amir Abbas	cf6e6f96f5	Probable fix #99 (double delegate call), better linux support	2018-06-18 10:59:01 +04:30
Amir Abbas Mousavian	91f2610a72	Fix PDF thumbnail generating, Faster UIImage scaling - Safer secure coding support	2018-06-14 15:13:01 +04:30
Amir Abbas Mousavian	50f0d33233	Improved performance of thumbnail generating dramatically - Fix race condition in LocalFileMonitor	2018-06-12 21:54:22 +04:30
Amir Abbas Mousavian	ba9cad8daf	Merge branch 'fix-issue-95' * fix-issue-95: Fixing #95 (ftp store completion handler latency)	2018-06-07 02:04:23 +04:30
Amir Abbas Mousavian	057bf1a663	Fix compile error	2018-06-06 17:01:04 +04:30
Amir Abbas Mousavian	753055602f	Silence warnings of Swift 4.2	2018-06-06 15:27:40 +04:30
Amir Abbas	7a5cef47b5	Updated readme to mention AMSMB2 project.	2018-05-30 14:02:04 +04:30
Amir Abbas	f5c6403769	Fixing #95 (ftp store completion handler latency)	2018-05-30 13:05:27 +04:30
Amir Abbas	e2520ff154	Possible fix #94 , local symbolic links respect ~	2018-05-26 13:19:40 +04:30
Amir Abbas	7a3c4a297a	Removed AnyObject casts	2018-05-20 01:52:21 +04:30
Amir Abbas	b946d514a0	Fixed LocalFileObject init issue, symlink tests	2018-05-12 20:03:47 +04:30
Amir Abbas	5e49202ba6	Fix Travis swift 4.0 build	2018-05-12 09:24:05 +04:30
Amir Abbas	399d755eac	Add FileProviderSymbolicLink protocol, resolving symlink return FileObject - Fixed resolving relative path for LocalFileObject - Gardening CloudFileProvider	2018-05-12 02:32:37 +04:30
Amir Abbas	e72d7ff088	Fixed podspec Swift version	2018-05-04 01:12:52 +04:30
Amir Abbas	ccb7961171	Minor performance improvement on iCloud file progress monitor	2018-05-04 00:42:25 +04:30
Amir Abbas	e4fc6b24c0	Updated to version 0.24.1, Pods Swift version to 4.1	2018-05-04 00:25:27 +04:30
Amir Abbas	f22af8d002	Fixed possible leak in iCloud provider when uploading file	2018-05-03 19:48:24 +04:30
Amir Abbas	e5e5faa4e8	Fixed iCloud download/upload progress report, Fix #93 - Fixed FileObject comparison - Fixed image GPS metadata population in ExtendedLocalFileProvider - More items for image metadata in ExtendedLocalFileProvider	2018-05-03 19:39:18 +04:30
Amir Abbas	f2cd571d7a	Fixed LocalFileMonitor dir not refreshing, Fixed FTP connection refused error by retrying	2018-04-25 13:23:15 +04:30
Amir Abbas	4202f5e1bd	FPStreamTask returning real error instead of timeout	2018-04-22 17:50:42 +04:30
Amir Abbas	3040215ce3	Fixed race conditions, Possible fix #79	2018-04-22 14:17:42 +04:30
Amir Abbas	bd2f2b3954	Addded progressive read to FTP and HTTP providers - Fix OneDive returned code 200 as Error	2018-04-16 11:06:54 +04:30
Amir Abbas	9d19768e1c	Added test for NSCoding, fixed archiving	2018-04-08 10:22:59 +04:30
Amir Abbas	bcc774d3a8	Fix podspec error	2018-04-07 21:52:49 +04:30
Amir Abbas	ad9768a584	Secure encoding enabled, Fixed podspec	2018-04-07 12:19:45 +04:30
Amir Abbas	a089cbc21c	Fixed Swift 3 build error	2018-04-01 11:29:21 +04:30
Amir Abbas	090baa3b61	Fix Swift 4.0 compile error	2018-03-31 22:22:36 +04:30
Amir Abbas	fc75c85b14	Fixed warnings on Swift 4.1, LocalFileMonitor is now public	2018-03-31 19:19:25 +04:30