Add text file streamer

2 files changed, 121 insertions, 0 deletions

diff --git a/ios/MullvadVPN.xcodeproj/project.pbxproj b/ios/MullvadVPN.xcodeproj/project.pbxproj
index de3226aa5d..6ce6bcc2c7 100644
--- a/ios/MullvadVPN.xcodeproj/project.pbxproj
+++ b/ios/MullvadVPN.xcodeproj/project.pbxproj
@@ -39,6 +39,7 @@
 		580EE22824B3289300F9D8A1 /* AssociatedValue.swift in Sources */ = {isa = PBXBuildFile; fileRef = 580EE22724B3289300F9D8A1 /* AssociatedValue.swift */; };
 		580EE22924B3289300F9D8A1 /* AssociatedValue.swift in Sources */ = {isa = PBXBuildFile; fileRef = 580EE22724B3289300F9D8A1 /* AssociatedValue.swift */; };
 		5811DE50239014550011EB53 /* NEVPNStatus+Debug.swift in Sources */ = {isa = PBXBuildFile; fileRef = 5811DE4F239014550011EB53 /* NEVPNStatus+Debug.swift */; };
+		58141EC924DAC0ED0013F79C /* TextFileStream.swift in Sources */ = {isa = PBXBuildFile; fileRef = 58141EC824DAC0ED0013F79C /* TextFileStream.swift */; };
 		5815039724D6ECAE00C9C50E /* CustomFormatLogHandler.swift in Sources */ = {isa = PBXBuildFile; fileRef = 5815039624D6ECAE00C9C50E /* CustomFormatLogHandler.swift */; };
 		5815039824D6ECAE00C9C50E /* CustomFormatLogHandler.swift in Sources */ = {isa = PBXBuildFile; fileRef = 5815039624D6ECAE00C9C50E /* CustomFormatLogHandler.swift */; };
 		5815039D24D6ECE600C9C50E /* TextFileOutputStream.swift in Sources */ = {isa = PBXBuildFile; fileRef = 5815039C24D6ECE600C9C50E /* TextFileOutputStream.swift */; };
@@ -268,6 +269,7 @@
 		580EE22324B3243100F9D8A1 /* AsyncBlockOperation.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = AsyncBlockOperation.swift; sourceTree = "<group>"; };
 		580EE22724B3289300F9D8A1 /* AssociatedValue.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = AssociatedValue.swift; sourceTree = "<group>"; };
 		5811DE4F239014550011EB53 /* NEVPNStatus+Debug.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = "NEVPNStatus+Debug.swift"; sourceTree = "<group>"; };
+		58141EC824DAC0ED0013F79C /* TextFileStream.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = TextFileStream.swift; sourceTree = "<group>"; };
 		5815039324D6EB7200C9C50E /* LogRotation.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = LogRotation.swift; sourceTree = "<group>"; };
 		5815039624D6ECAE00C9C50E /* CustomFormatLogHandler.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = CustomFormatLogHandler.swift; sourceTree = "<group>"; };
 		5815039C24D6ECE600C9C50E /* TextFileOutputStream.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = TextFileOutputStream.swift; sourceTree = "<group>"; };
@@ -465,6 +467,7 @@
 				5815039C24D6ECE600C9C50E /* TextFileOutputStream.swift */,
 				581503A524D6F4AE00C9C50E /* Logging.swift */,
 				5815039324D6EB7200C9C50E /* LogRotation.swift */,
+				58141EC824DAC0ED0013F79C /* TextFileStream.swift */,
 			);
 			path = Logging;
 			sourceTree = "<group>";
@@ -1032,6 +1035,7 @@
 				58561C99239A5D1500BD6B5E /* IPEndpoint.swift in Sources */,
 				58FD5BF22424F7D700112C88 /* UserInterfaceInteractionRestriction.swift in Sources */,
 				5811DE50239014550011EB53 /* NEVPNStatus+Debug.swift in Sources */,
+				58141EC924DAC0ED0013F79C /* TextFileStream.swift in Sources */,
 				58C3A4B222456F1B00340BDB /* AccountInputGroupView.swift in Sources */,
 				58F840B22464491D0044E708 /* ChainedError.swift in Sources */,
 				58FAEDFF24533A7000CB0F5B /* KeychainReturn.swift in Sources */,
diff --git a/ios/MullvadVPN/Logging/TextFileStream.swift b/ios/MullvadVPN/Logging/TextFileStream.swift
new file mode 100644
index 0000000000..2ae9b3e82f
--- /dev/null
+++ b/ios/MullvadVPN/Logging/TextFileStream.swift
@@ -0,0 +1,117 @@
+//
+//  TextFileStream.swift
+//  MullvadVPN
+//
+//  Created by pronebird on 05/08/2020.
+//  Copyright © 2020 Mullvad VPN AB. All rights reserved.
+//
+
+import Foundation
+import Darwin
+
+class TextFileStream<Codec> where Codec: UnicodeCodec {
+    private let readSource: DispatchSourceRead
+    private let fileDescriptor: Int32
+    private let queue = DispatchQueue(label: "net.mullvad.MullvadVPN.TextFileStream<\(Codec.self)>")
+    private let stringStream: StringStreamIterator<Codec>
+
+    init?(fileURL: URL, separator: Character, encoding: String.Encoding = .utf8) {
+        let filePath = fileURL.path.utf8CString.map { $0 }
+
+        let fileDescriptor = open(filePath, O_RDONLY)
+        if (fileDescriptor == -1) {
+            return nil
+        }
+
+        // Avoid blocking the read operation
+        _ = fcntl(fileDescriptor, F_SETFL, O_NONBLOCK);
+
+        let readSource = DispatchSource.makeReadSource(fileDescriptor: fileDescriptor, queue: queue)
+        readSource.setCancelHandler {
+            close(fileDescriptor)
+        }
+
+        stringStream = StringStreamIterator(separator: separator)
+
+        self.readSource = readSource
+        self.fileDescriptor = fileDescriptor
+    }
+
+    deinit {
+        readSource.cancel()
+    }
+
+    func read(_ handler: @escaping (String) -> Void) {
+        readSource.setEventHandler { [weak self] in
+            guard let self = self else { return }
+
+            let estimated = Int(self.readSource.data + 1)
+            var buffer = [Codec.CodeUnit](repeating: 0, count: estimated)
+            let actual = Darwin.read(self.fileDescriptor, &buffer, estimated)
+
+            if actual == -1 {
+                print("TextFileInputStream: read error: \(errno)")
+            }
+
+            if actual > 0 {
+                let bytes = buffer[..<actual]
+                self.stringStream.append(bytes: bytes)
+
+                while let s = self.stringStream.next() {
+                    handler(s)
+                }
+            }
+        }
+        readSource.activate()
+    }
+
+    func cancel() {
+        readSource.cancel()
+    }
+
+}
+
+class StringStreamIterator<Codec>: IteratorProtocol where Codec: UnicodeCodec {
+    let separator: Character
+
+    private var string = ""
+    private var data = [Codec.CodeUnit]()
+    private var parser = Codec.ForwardParser()
+
+    init(separator: Character) {
+        self.separator = separator
+    }
+
+    func append<S>(bytes: S) where S: Sequence, S.Element == Codec.CodeUnit {
+        data.append(contentsOf: bytes)
+    }
+
+    func next() -> String? {
+        var dataIterator = data.makeIterator()
+        var bytesRead = 0
+
+        defer {
+            if bytesRead > 0 {
+                data.removeSubrange(..<bytesRead)
+            }
+        }
+
+        while case .valid(let encodedScalar) = parser.parseScalar(from: &dataIterator) {
+            let unicodeScalar = Codec.decode(encodedScalar)
+            let character = Character(unicodeScalar)
+
+            bytesRead += encodedScalar.count
+
+            if character == separator {
+                let returnString = string
+                string = ""
+
+                return returnString
+            } else {
+                string.append(character)
+            }
+        }
+
+        return nil
+    }
+}