C#

Streaming Compression

See more Compression Examples

Compress and decompress using a stream. C#

bool success = false;

//  This example assumes the Chilkat API to have been previously unlocked.
//  See Global Unlock Sample for sample code.

Chilkat.FileAccess fac = new Chilkat.FileAccess();
Chilkat.Compression compress = new Chilkat.Compression();
compress.Algorithm = "deflate";

Chilkat.Stream streamC = new Chilkat.Stream();

//  This example sets the source and sink of the stream to files.
//  A stream can have use other streams as a source or sink,
//  or the application can itself be the source/sink by directly
//  reading or writing a stream.  (See below for an example of this..)
streamC.SourceFile = "qa_data/hamlet.xml";
streamC.SinkFile = "qa_output/hamlet_compressed.dat";

//  Compress from source to sink.
success = compress.CompressStream(streamC);
if (success != true) {
    Debug.WriteLine(compress.LastErrorText);
    return;
}

Debug.WriteLine("File-to-file deflate compression successful.");
//  Note: The FileSize method returns a signed 32-bit integer.  If the file is potentially larger than 2GB, call FileSizeStr instead to return
//  the size of the file as a string, then convert to an integer value.
Debug.WriteLine("Original size = " + Convert.ToString(fac.FileSize(streamC.SourceFile)));
Debug.WriteLine("Compressed size = " + Convert.ToString(fac.FileSize(streamC.SinkFile)));

//  Now do file-to-file decompression
Chilkat.Stream streamD = new Chilkat.Stream();
streamD.SourceFile = "qa_output/hamlet_compressed.dat";
streamD.SinkFile = "qa_output/hamlet_restored.xml";

//  Decompress from source to sink.
success = compress.DecompressStream(streamD);
if (success != true) {
    Debug.WriteLine(compress.LastErrorText);
    return;
}

Debug.WriteLine("File-to-file deflate decompression successful.");

//  Let's double-check to see that the files are equal in size and content:

bool bFilesEqual = fac.FileContentsEqual(streamC.SourceFile,streamD.SinkFile);
if (bFilesEqual != true) {
    Debug.WriteLine("The output file is not equal to the input file!");
}
else {
    Debug.WriteLine("The file was successfully compressed and decompressed.");
}

//  ---------------------------------------------------------------------
//  Now let's decompress again, but this time w/ the application reading
//  the decompressed data directly from a stream.
Chilkat.Stream streamA = new Chilkat.Stream();

streamA.SourceFile = "qa_output/hamlet_compressed.dat";

//  Start decompressing in a background thread.
Chilkat.Task task = compress.DecompressStreamAsync(streamA);
success = task.Run();

//  Read decompressed data from streamA:
string decompressedText;
while ((streamA.EndOfStream != true)) {
    if (streamA.DataAvailable == true) {
        decompressedText = streamA.ReadString();
        Debug.WriteLine(decompressedText);
    }

}

//  Let's make sure the background task finished and that the decompress was successful.
//  It should already be the case that the task is finished.
while ((task.Finished != true)) {
    task.SleepMs(20);
}

//  The decompressor may have finished, but it is possible that data
//  remains to be flushed.  
if (streamA.DataAvailable == true) {
    decompressedText = streamA.ReadString();
    Debug.WriteLine(decompressedText);
}

//  Did streamA succeed in reading the entire file?
if (task.TaskSuccess != true) {
    Debug.WriteLine("async decompress failed:");
    Debug.WriteLine(task.ResultErrorText);
    success = false;
}

Debug.WriteLine("The async decompress was successful.");