From 097aaf7b24c239f031eaafcba188bbadf7c49ca0 Mon Sep 17 00:00:00 2001
From: Timofey Solomko <tsolomko@gmail.com>
Date: Tue, 25 Jul 2017 00:35:57 +0300
Subject: [PATCH] Complete 7zip structures implementations

Though some questions, problems and opportunities for improvements are remaining.
---
 Sources/7zCodec.swift         | 13 +++---
 Sources/7zCoderInfo.swift     | 47 +++++++++++++------
 Sources/7zFileInfo.swift      | 86 +++--------------------------------
 Sources/7zFolder.swift        |  4 +-
 Sources/7zPackInfo.swift      | 32 +++++++++----
 Sources/7zSubstreamInfo.swift | 49 +++++++++++---------
 6 files changed, 98 insertions(+), 133 deletions(-)

diff --git a/Sources/7zCodec.swift b/Sources/7zCodec.swift
index d986a773..eacc4416 100644
--- a/Sources/7zCodec.swift
+++ b/Sources/7zCodec.swift
@@ -13,8 +13,8 @@ struct SevenZipCodec {
 
     let id: [UInt8]
 
-    var numInStreams: Int?
-    var numOutStreams: Int?
+    let numInStreams: Int
+    let numOutStreams: Int
 
     var propertiesSize: Int?
     var properties: [UInt8]?
@@ -29,10 +29,11 @@ struct SevenZipCodec {
 
         id = pointerData.bytes(count: idSize)
 
-        if isComplex {
-            numInStreams = try pointerData.multiByteDecode(SevenZipError.multiByteIntegerError).multiByteInteger
-            numOutStreams = try pointerData.multiByteDecode(SevenZipError.multiByteIntegerError).multiByteInteger
-        }
+        // TODO: Introduce typealias for SevenZipError.multiByteIntegerError.
+        numInStreams = isComplex ? try pointerData
+            .multiByteDecode(SevenZipError.multiByteIntegerError).multiByteInteger : 1
+        numOutStreams = isComplex ? try pointerData
+            .multiByteDecode(SevenZipError.multiByteIntegerError).multiByteInteger : 1
 
         if attributesExist {
             propertiesSize = try pointerData.multiByteDecode(SevenZipError.multiByteIntegerError).multiByteInteger
diff --git a/Sources/7zCoderInfo.swift b/Sources/7zCoderInfo.swift
index 8ffbba5d..fccfbd1d 100644
--- a/Sources/7zCoderInfo.swift
+++ b/Sources/7zCoderInfo.swift
@@ -10,10 +10,10 @@ struct SevenZipCoderInfo {
     let numFolders: Int
 
     let external: UInt8
-    var folders: [SevenZipFolder]?
+    var folders = [SevenZipFolder]()
     var dataStreamIndex: Int?
-
     let unpackSizes: [Int]
+    var digests = [UInt32?]()
 
     init(_ pointerData: DataWithPointer) throws {
         guard pointerData.byte() == 0x0B
@@ -22,9 +22,8 @@ struct SevenZipCoderInfo {
         external = pointerData.byte()
         switch external {
         case 0:
-            folders = []
             for _ in 0..<numFolders {
-                folders?.append(try SevenZipFolder(pointerData))
+                folders.append(try SevenZipFolder(pointerData))
             }
         case 1:
             dataStreamIndex = try pointerData.multiByteDecode(SevenZipError.multiByteIntegerError).multiByteInteger
@@ -36,7 +35,7 @@ struct SevenZipCoderInfo {
             else { throw SevenZipError.wrongPropertyID }
         var sizes = [Int]()
         if external == 0 {
-            for folder in folders! {
+            for folder in folders {
                 for _ in 0..<folder.numPackedStreams { // TODO: ???
                     sizes.append(try pointerData.multiByteDecode(SevenZipError.multiByteIntegerError).multiByteInteger)
                 }
@@ -44,15 +43,33 @@ struct SevenZipCoderInfo {
         }
         unpackSizes = sizes
 
-        // TODO:
-        //
-        //    []
-        //    BYTE NID::kCRC   (0x0A)
-        //    UnPackDigests[NumFolders]
-        //    []
-        //
-
-        guard pointerData.byte() == 0x00
-            else { throw SevenZipError.wrongPropertyID }
+        switch pointerData.byte() {
+        case 0x0A:
+            // TODO: Extract digests code.
+            let allDefined = pointerData.byte()
+            let definedBits: [UInt8]
+            if allDefined == 0 {
+                let bitReader = BitReader(data: pointerData.data, bitOrder: .reversed) // TODO: Bit order???
+                bitReader.index = pointerData.index
+                definedBits = bitReader.bits(count: numFolders)
+                bitReader.skipUntilNextByte()
+                pointerData.index = bitReader.index
+            } else {
+                definedBits = Array(repeating: 1, count: numFolders)
+            }
+            for bit in definedBits {
+                if bit == 1 {
+                    digests.append(pointerData.uint32())
+                } else {
+                    digests.append(nil)
+                }
+            }
+            guard pointerData.byte() == 0x00
+                else { throw SevenZipError.wrongPropertyID }
+        case 0x00:
+            break
+        default:
+            throw SevenZipError.wrongPropertyID
+        }
     }
 }
diff --git a/Sources/7zFileInfo.swift b/Sources/7zFileInfo.swift
index 7c1223c8..caa1ec14 100644
--- a/Sources/7zFileInfo.swift
+++ b/Sources/7zFileInfo.swift
@@ -16,95 +16,23 @@ struct SevenZipFileInfo {
     let numFiles: Int
     var files = [File]()
 
+    var properties = [(Int, [UInt8])]()
+
     init(_ pointerData: DataWithPointer) throws {
         numFiles = try pointerData.multiByteDecode(SevenZipError.multiByteIntegerError).multiByteInteger
         for _ in 0..<numFiles {
             files.append(File())
         }
-        let bitReader = BitReader(data: pointerData.data, bitOrder: .reversed) // TODO: bitOrder ???
-        var totalEmptyStreams = 0
         while true {
             let propertyType = pointerData.byte()
             if propertyType == 0 {
                 break
             }
-            switch propertyType {
-            case 0x0E: // Empty stream
-                for i in 0..<numFiles {
-                    let isEmptyStream = bitReader.bit() != 0
-                    files[i].isEmptyStream = isEmptyStream
-                    totalEmptyStreams += isEmptyStream ? 1 : 0 // TODO: Should we skipUntilNextByte() ???
-                }
-            case 0x0F: // Empty file
-                break
-            default:
-                break // TODO: Should we throw error?
-            }
+            let size = try pointerData.multiByteDecode(SevenZipError.multiByteIntegerError).multiByteInteger
+            properties.append((propertyType.toInt(), pointerData.bytes(count: size)))
+
+            // TODO: Add properties parsing.
         }
     }
-//
-//    for (;;)
-//    {
-//    BYTE PropertyType;
-//    if (aType == 0)
-//    break;
-//
-//    UINT64 Size;
-//
-//    switch(PropertyType)
-//    {
-//
-//    kEmptyFile:     (0x0F)
-//    for(EmptyStreams)
-//    BIT IsEmptyFile
-//
-//    kAnti:          (0x10)
-//    for(EmptyStreams)
-//    BIT IsAntiFile
-//
-//    case kCTime: (0x12)
-//    case kATime: (0x13)
-//    case kMTime: (0x14)
-//    BYTE AllAreDefined
-//    if (AllAreDefined == 0)
-//    {
-//    for(NumFiles)
-//    BIT TimeDefined
-//    }
-//    BYTE External;
-//    if(External != 0)
-//    UINT64 DataIndex
-//    []
-//    for(Definded Items)
-//    UINT64 Time
-//    []
-//
-//    kNames:     (0x11)
-//    BYTE External;
-//    if(External != 0)
-//    UINT64 DataIndex
-//    []
-//    for(Files)
-//    {
-//    wchar_t Names[NameSize];
-//    wchar_t 0;
-//    }
-//    []
-//
-//    kAttributes:  (0x15)
-//    BYTE AllAreDefined
-//    if (AllAreDefined == 0)
-//    {
-//    for(NumFiles)
-//    BIT AttributesAreDefined
-//    }
-//    BYTE External;
-//    if(External != 0)
-//    UINT64 DataIndex
-//    []
-//    for(Definded Attributes)
-//    UINT32 Attributes
-//    []
-//    }
-//    }
+
 }
diff --git a/Sources/7zFolder.swift b/Sources/7zFolder.swift
index 21e9fa65..a9fc72f5 100644
--- a/Sources/7zFolder.swift
+++ b/Sources/7zFolder.swift
@@ -37,8 +37,8 @@ struct SevenZipFolder {
         for _ in 0..<numCodecs {
             let codec = try SevenZipCodec(pointerData)
             codecs.append(codec)
-            outStreamsTotal += codec.numOutStreams ?? 0
-            inStreamsTotal += codec.numInStreams ?? 0
+            outStreamsTotal += codec.numOutStreams
+            inStreamsTotal += codec.numInStreams
         }
         self.codecs = codecs
         numBindPairs = outStreamsTotal - 1
diff --git a/Sources/7zPackInfo.swift b/Sources/7zPackInfo.swift
index 699cb65d..9224cc1e 100644
--- a/Sources/7zPackInfo.swift
+++ b/Sources/7zPackInfo.swift
@@ -9,8 +9,8 @@ struct SevenZipPackInfo {
 
     let packPosition: Int
     let numPackStreams: Int
-
-    var packSizes: [Int]?
+    var packSizes = [Int]()
+    var digests = [UInt32?]()
 
     init(_ pointerData: DataWithPointer) throws {
         packPosition = try pointerData.multiByteDecode(SevenZipError.multiByteIntegerError).multiByteInteger
@@ -22,17 +22,29 @@ struct SevenZipPackInfo {
             }
             switch structureType {
             case 0x09: // **PackInfo - PackSizes**
-                packSizes = []
                 for _ in 0..<numPackStreams {
-                    packSizes?.append(try pointerData.multiByteDecode(SevenZipError.multiByteIntegerError).multiByteInteger)
+                    packSizes.append(try pointerData.multiByteDecode(SevenZipError.multiByteIntegerError).multiByteInteger)
                 }
             case 0x0A: // **PackInfo - PackStreamDigests**
-                // TODO:
-                //    []
-                //    BYTE NID::kCRC      (0x0A)
-                //    PackStreamDigests[NumPackStreams]
-                //    []
-                break
+                let allDefined = pointerData.byte()
+                let definedBits: [UInt8]
+                let numStreams = numPackStreams
+                if allDefined == 0 {
+                    let bitReader = BitReader(data: pointerData.data, bitOrder: .reversed) // TODO: Bit order???
+                    bitReader.index = pointerData.index
+                    definedBits = bitReader.bits(count: numStreams)
+                    bitReader.skipUntilNextByte()
+                    pointerData.index = bitReader.index
+                } else {
+                    definedBits = Array(repeating: 1, count: numStreams)
+                }
+                for bit in definedBits {
+                    if bit == 1 {
+                        digests.append(pointerData.uint32())
+                    } else {
+                        digests.append(nil)
+                    }
+                }
             default:
                 throw SevenZipError.wrongPropertyID
             }
diff --git a/Sources/7zSubstreamInfo.swift b/Sources/7zSubstreamInfo.swift
index 330a1319..2476d571 100644
--- a/Sources/7zSubstreamInfo.swift
+++ b/Sources/7zSubstreamInfo.swift
@@ -7,8 +7,9 @@ import Foundation
 
 struct SevenZipSubstreamInfo {
 
-    var numUnpackStreamsInFolders: [Int]?
-    var unpackSizes: [Int]?
+    var numUnpackStreamsInFolders = [Int]()
+    var unpackSizes = [Int]()
+    var digests = [UInt32?]()
 
     init(_ pointerData: DataWithPointer, _ numFolders: Int) throws {
         while true {
@@ -18,29 +19,35 @@ struct SevenZipSubstreamInfo {
             }
             switch structureType {
             case 0x0D: // **SubstreamsInfo - NumUnpackStreamsInFolders**
-                numUnpackStreamsInFolders = []
                 for _ in 0..<numFolders {
-                    numUnpackStreamsInFolders?
+                    numUnpackStreamsInFolders
                         .append(try pointerData.multiByteDecode(SevenZipError.multiByteIntegerError).multiByteInteger)
                 }
             case 0x09: // **SubstreamsInfo - Size**
-                // TODO: How many sizes?
-                //
-                //    []
-                //    BYTE NID::kSize  (0x09)
-                //    UINT64 UnPackSizes[]
-                //    []
-                //
-                break
-            case 0x0A: // **SubstreamsInfo - CRC**
-                // TODO:
-                //
-                //    []
-                //    BYTE NID::kCRC  (0x0A)
-                //    Digests[Number of streams with unknown CRC]
-                //    []
-                //
-                break
+                let numStreams = numUnpackStreamsInFolders.reduce(0, { $0 + $1 })
+                for _ in 0..<numStreams {
+                    unpackSizes.append(try pointerData.multiByteDecode(SevenZipError.multiByteIntegerError).multiByteInteger)
+                }
+            case 0x0A: // **SubstreamsInfo - CRC** // TODO: Unknown numStreams???
+                let allDefined = pointerData.byte()
+                let definedBits: [UInt8]
+                let numStreams = numUnpackStreamsInFolders.reduce(0, { $0 + $1 })
+                if allDefined == 0 {
+                    let bitReader = BitReader(data: pointerData.data, bitOrder: .reversed) // TODO: Bit order???
+                    bitReader.index = pointerData.index
+                    definedBits = bitReader.bits(count: numStreams)
+                    bitReader.skipUntilNextByte()
+                    pointerData.index = bitReader.index
+                } else {
+                    definedBits = Array(repeating: 1, count: numStreams)
+                }
+                for bit in definedBits {
+                    if bit == 1 {
+                        digests.append(pointerData.uint32())
+                    } else {
+                        digests.append(nil)
+                    }
+                }
             default:
                 throw SevenZipError.wrongPropertyID
             }