1 files changed, 87 insertions, 0 deletions
diff --git a/ios/MullvadLogging/TextFileOutputStream.swift b/ios/MullvadLogging/TextFileOutputStream.swift
new file mode 100644
index 0000000000..95387b53ec
--- /dev/null
+++ b/ios/MullvadLogging/TextFileOutputStream.swift
@@ -0,0 +1,87 @@
+//
+//  TextFileOutputStream.swift
+//  MullvadVPN
+//
+//  Created by pronebird on 02/08/2020.
+//  Copyright © 2020 Mullvad VPN AB. All rights reserved.
+//
+
+import Foundation
+
+class TextFileOutputStream: TextOutputStream {
+    private let writer: DispatchIO
+    private let encoding: String.Encoding
+    private let queue = DispatchQueue.global(qos: .utility)
+
+    class func standardOutputStream(encoding: String.Encoding = .utf8) -> TextFileOutputStream {
+        return TextFileOutputStream(
+            fileDescriptor: FileHandle.standardOutput.fileDescriptor,
+            encoding: encoding
+        )
+    }
+
+    init(fileDescriptor: Int32, encoding: String.Encoding = .utf8) {
+        self.encoding = encoding
+        writer = DispatchIO(type: .stream, fileDescriptor: fileDescriptor, queue: queue) { errno in
+            if errno != 0 {
+                print("TextFileOutputStream: closed channel with error: \(errno)")
+            }
+        }
+    }
+
+    init?(
+        fileURL: URL,
+        createFile: Bool,
+        filePermissions: mode_t = S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH,
+        encoding: String.Encoding = .utf8
+    ) {
+        var oflag: Int32 = O_WRONLY
+        var mode: mode_t = .zero
+        if createFile {
+            oflag |= O_CREAT
+            mode = filePermissions
+        }
+
+        let queue = queue
+        let writer = fileURL.path.withCString { filePathPointer -> DispatchIO? in
+            return DispatchIO(
+                type: .stream,
+                path: filePathPointer,
+                oflag: oflag,
+                mode: mode,
+                queue: queue,
+                cleanupHandler: { errno in
+                    if errno != 0 {
+                        print("TextFileOutputStream: closed channel with error: \(errno)")
+                    }
+                }
+            )
+        }
+
+        if let writer = writer {
+            self.writer = writer
+            self.encoding = encoding
+        } else {
+            return nil
+        }
+    }
+
+    deinit {
+        writer.close()
+    }
+
+    func write(_ string: String) {
+        string.data(using: encoding)?.withUnsafeBytes { bytes in
+            writer
+                .write(
+                    offset: .zero,
+                    data: DispatchData(bytes: bytes),
+                    queue: queue
+                ) { done, data, errno in
+                    if errno != 0 {
+                        print("TextFileOutputStream: write error: \(errno)")
+                    }
+                }
+        }
+    }
+}