/// <summary>
/// Calculate and write a diff for the file.
/// </summary>
/// <param name="interleaved">Whether to output in SDCH interleaved diff format.</param>
/// <param name="checksumFormat">
/// Whether to include Adler32 checksums for encoded data windows. If interleaved is true, <see cref="ChecksumFormat.Xdelta3"/>
/// is not supported.
/// </param>
/// <returns>
/// <see cref="VCDiffResult.SUCCESS"/> if successful, <see cref="VCDiffResult.ERROR"/> if the sourceStream or target are zero-length.</returns>
/// <exception cref="ArgumentException">If interleaved is true, and <see cref="ChecksumFormat.Xdelta3"/> is chosen.</exception>
public VCDiffResult Encode(bool interleaved = false,
ChecksumFormat checksumFormat = ChecksumFormat.None)
{
if (oldData == null)
{
this.oldData = new ByteBuffer(sourceStream);
}
if (interleaved && checksumFormat == ChecksumFormat.Xdelta3)
{
throw new ArgumentException("Interleaved diffs can not have an xdelta3 checksum!");
}
if (targetData.Length == 0 || oldData.Length == 0)
{
return(VCDiffResult.ERROR);
}
VCDiffResult result = VCDiffResult.SUCCESS;
oldData.Position = 0;
targetData.Position = 0;
// file header
// write magic bytes
if (!interleaved && checksumFormat != ChecksumFormat.SDCH)
{
outputStream.Write(MagicBytes);
}
else
{
outputStream.Write(MagicBytesExtended);
}
//read in all the dictionary it is the only thing that needs to be
BlockHash dictionary = new BlockHash(oldData, 0, hasher, blockSize);
dictionary.AddAllBlocks();
oldData.Position = 0;
ChunkEncoder chunker = new ChunkEncoder(dictionary, oldData, hasher, checksumFormat, interleaved, chunkSize);
while (targetData.CanRead)
{
using ByteBuffer ntarget = new ByteBuffer(targetData.ReadBytesAsBuf(bufferSize));
chunker.EncodeChunk(ntarget, outputStream);
}
return(result);
}