LZMA unarchiving

LempelZivMarkovUnarchiver.swift

protocol LempelZivMarkovUnarchiver {
    func unarchive(url: URL) throws -> URL
}

class StandartLZMUnarchiver: LempelZivMarkovUnarchiver {

    func unarchive(url: URL) throws -> URL {

        let algorithm: Algorithm = .lzma
        let fileManager = FileManager.default

        // Declare destinationURL outside of the autoreleasepool
        let destinationFileName = url.deletingPathExtension().lastPathComponent
        let destinationURL = fileManager.temporaryDirectory.appendingPathComponent(destinationFileName)

        try autoreleasepool {

            let sourceFile = try FileHandle(forReadingFrom: url)
            defer { sourceFile.closeFile() }

            // Use FileManager's createFile method to create the destination file
            fileManager.createFile(atPath: destinationURL.path, contents: nil)
            let destinationFile = try FileHandle(forWritingTo: destinationURL)
            defer { destinationFile.closeFile() }

            let bufferSize = 32_768

            let coder = try OutputFilter(.decompress, using: algorithm, bufferCapacity: bufferSize) { data in
                guard let chunk = data else { return }
                try destinationFile.write(contentsOf: chunk)
            }

            while true {
                let chunk = sourceFile.readData(ofLength: bufferSize)
                try coder.write(chunk)
                if chunk.count < bufferSize {
                    break
                }
            }
        }

        return destinationURL
    }

}