(Swift 2) Unzip Binary File to Stream

Demonstrates how to unzip a large binary file to a stream to allow the application to process the uncompressed bytes chunk by chunk.

Note: This example requires Chilkat v9.5.0.67 or greater.

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func chilkatTest() {
    // This requires the Chilkat Zip API to have been previously unlocked.
    // See Unlock Chilkat Zip for sample code.

    let zip = CkoZip()

    // First open a .zip.
    var success: Bool = zip.OpenZip("qa_data/zips/big.zip")
    if success != true {
        print("\(zip.LastErrorText)")
        return
    }

    // Get the entry to be unzipped to a stream..
    var entry: CkoZipEntry? = zip.GetEntryByIndex(0)
    if zip.LastMethodSuccess != true {
        print("\(zip.LastErrorText)")
        return
    }

    let dataStream = CkoStream()

    var unzipTask: CkoTask? = entry!.UnzipToStreamAsync(dataStream)
    if entry!.LastMethodSuccess != true {
        print("\(entry!.LastErrorText)")
        entry = nil
        return
    }

    // Start the background unzip thread.
    unzipTask!.Run()

    // We'll read the uncompressed data chunk-by-chunk and write to an output file.
    let fac = CkoFileAccess()
    success = fac.OpenForWrite("qa_output/out.dat")
    if success != true {
        print("\(fac.LastErrorText)")
        entry = nil
        return
    }

    // Read the stream.  (this is reading the unzipped file data)
    let bd = CkoBinData()
    while dataStream.EndOfStream != true {
        // Get the next chunk of decompressed bytes.
        dataStream.ReadBd(bd)
        // Do something with it..
        // In this simple example, we'll just write to the file.
        fac.FileWriteBd(bd, offset: 0, numBytes: 0)
        // Clear for the next read.
        bd.Clear()
    }

    fac.FileClose()

    entry = nil
    unzipTask = nil
    print("Success.")

}