From 80be740493c000b8318824022ca3ee68d765abdd Mon Sep 17 00:00:00 2001
From: Ihar Katkavets <job4ihar@gmail.com>
Date: Sat, 26 Aug 2023 14:09:04 +0200
Subject: [PATCH] Create FileStream.md

---
 FileStream.md | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)
 create mode 100644 FileStream.md

diff --git a/FileStream.md b/FileStream.md
new file mode 100644
index 0000000..99fac62
--- /dev/null
+++ b/FileStream.md
@@ -0,0 +1,22 @@
+# File Input Stream
+
+`FileInputStream` is used for reading data from a file. It can be added to a ciphers chain
+```swift
+let inputFileStream = FileInputStream(with: try! FileHandle(forReadingFrom: originalFileURL))
+try inputFileStream.open()
+```
+```swift
+guard let inputFileStream = FileInputStream(with: originalFileURL) else {
+  // file not exist
+  return
+}
+try inputFileStream.open()
+```
+```swift
+let tmpBufferLen = 1<<16 // 65KB buffer
+var tmpBuffer = Array<UInt8>(repeating: 0, count: tmpBufferLen)
+while inputFileStream.hasBytesAvailable {
+  let readLen = inputFileStream.read(&tmpBuffer, maxLength: tmpBufferLen)
+  try compressingStream.write(tmpBuffer, length: readLen)
+}
+```