ChunkDecoder

ChunkDecoder is useful to help decode chunk-transfer-encoded data, particularly from HTTP.

New in v1.0.4

• XML documentation

Usage

using ChunkDecoder;

public Decoder decoder = new Decoder();

// process a byte array
if (decoder.Decode(data, out outData))
{
  // success
}

// process a stream
long outLength = 0;
MemoryStream outStream = null;
if (decoder.Decode(stream, out outLength, out outStream))
{
  // success
}

Functionality

Chunk-transfer-encoded data is sent in segments, where each segment is comprised of a line containing the length (in hexadecimal) and the subsequent line containing the payload. Each line ends with a carriage return and line feed .

The final line ends with 0<crlf><crlf> indicating the end of the stream.

For instance:

6<crlf>        // 6 bytes of data will follow.
Hello_<crlf>   // data.  The value is 'Hello_' where _ is actually a space.
5<crlf>        // 5 bytes of data will follow.
World<crlf>    // data.  The value is 'World'.
0<crlf><crlf>  // end of stream.

Results in:

Hello world

For more information, please see:

• https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Transfer-Encoding
• https://en.wikipedia.org/wiki/Chunked_transfer_encoding

Callbacks

In cases where the supplied data has signatures, i.e.

6;chunk-signature=foo<crlf>  // 6 bytes of data will follow, and the signature of the chunk is foo.
Hello_<crlf>                 // data.  The value is 'Hello ' and _ is actually a space.
5;chunk-signature:bar<crlf>  // 5 bytes of data will follow, and the signature of the chunk is bar.
World<crlf>                  // data.  The value is 'World'.
0;<crlf><crlf>               // end of stream.

You can assigned the Decoder.ProcessSignature callback, which has the following signature:

using System.Collections.Generic;

static bool ProcessSignature(KeyValuePair<string, string>, byte[] data)
{
	return true;
}

This method should return true, otherwise ChunkDecoder will assume there is an error and terminate.

If you wish to process each chunk as it is read, set the Decoder.ProcessChunk callback, which has the followning signature:

static bool ProcessChunk(byte[] data)
{
	return true;
}

This method should also return true, for the same reason. ProcessChunk is always called after ProcessSignature.

Version History

Refer to CHANGELOG.md