/// <summary>
/// Initializes a new instance of the <see cref="BrotliStream"/> class using the specified stream and
/// compression mode, and optionally leaves the stream open.
/// </summary>
/// <param name="stream">The stream to compress or decompress.</param>
/// <param name="mode">One of the enumeration values that indicates whether to compress or decompress the stream.</param>
/// <param name="leaveOpen"><c>true</c> to leave the stream open after disposing the <see cref="BrotliStream"/> object; otherwise, <c>false</c>.</param>
public BrotliStream(Stream stream, CompressionMode mode, bool leaveOpen) {
if (stream == null)
throw new ArgumentNullException(nameof(stream));
if (CompressionMode.Compress != mode && CompressionMode.Decompress != mode)
throw new ArgumentOutOfRangeException(nameof(mode));
_stream = stream;
_mode = mode;
_leaveOpen = leaveOpen;
switch (_mode) {
case CompressionMode.Decompress:
if (!_stream.CanRead)
throw new ArgumentException("Stream does not support read", nameof(stream));
_decoderState = Brotli.BrotliCreateDecoderState();
Brotli.BrotliDecoderStateInit(ref _decoderState);
_buffer = new byte[0xfff0];
break;
case CompressionMode.Compress:
if (!_stream.CanWrite)
throw new ArgumentException("Stream does not support write", nameof(stream));
_encoderState = Brotli.BrotliEncoderCreateInstance(null, null, null);
SetQuality(1);
break;
}
}
/// <summary>
/// Releases the unmanaged resources used by the <see cref="BrotliStream"/> and optionally releases the managed resources.
/// </summary>
/// <param name="disposing"></param>
protected override void Dispose(bool disposing)
{
if (!_disposed)
{
FlushCompress(true);
if (_mode == CompressionMode.Compress)
{
Brotli.BrotliEncoderDestroyInstance(ref _encoderState);
}
else
{
Brotli.BrotliDecoderStateCleanup(ref _decoderState);
}
if (_customDictionary != IntPtr.Zero)
{
Marshal.FreeHGlobal(_customDictionary);
_customDictionary = IntPtr.Zero;
}
_disposed = true;
}
if (disposing && !_leaveOpen && _stream != null)
{
_stream.Dispose();
_stream = null;
}
base.Dispose(disposing);
}
private void WriteCore(byte[] buffer, int offset, int count, Brotli.BrotliEncoderOperation operation) {
bool flush = operation == Brotli.BrotliEncoderOperation.BROTLI_OPERATION_FLUSH ||
operation == Brotli.BrotliEncoderOperation.BROTLI_OPERATION_FINISH;
byte[] out_buf = new byte[0x1FFFE];
size_t available_in = count, available_out = out_buf.Length;
fixed (byte* out_buf_ptr = out_buf)
fixed (byte* buf_ptr = buffer) {
byte* next_in = buf_ptr + offset;
byte* next_out = out_buf_ptr;
while ((!flush && available_in > 0) || flush) {
if (!Brotli.BrotliEncoderCompressStream(ref _encoderState,
operation, &available_in, &next_in,
&available_out, &next_out, null)) {
throw new InvalidDataException("Compression failed");
}
bool hasData = available_out != out_buf.Length;
if (hasData) {
int out_size = (int)(out_buf.Length - available_out);
_stream.Write(out_buf, 0, out_size);
available_out = out_buf.Length;
next_out = out_buf_ptr;
}
if (Brotli.BrotliEncoderIsFinished(ref _encoderState))
break;
if (!hasData && flush)
break;
}
}
}
/// <summary>
/// Sets the dictionary for compression and decompression.
/// </summary>
/// <param name="dictionary">The dictionary as a byte array.</param>
public void SetCustomDictionary(byte[] dictionary)
{
if (dictionary == null)
{
throw new ArgumentNullException(nameof(dictionary));
}
EnsureNotDisposed();
if (_customDictionary != IntPtr.Zero)
{
Marshal.FreeHGlobal(_customDictionary);
}
_customDictionary = Marshal.AllocHGlobal(dictionary.Length);
Marshal.Copy(dictionary, 0, _customDictionary, dictionary.Length);
if (_mode == CompressionMode.Compress)
{
Brotli.BrotliEncoderSetCustomDictionary(ref _encoderState, dictionary.Length,
(byte *)_customDictionary);
}
else
{
Brotli.BrotliDecoderSetCustomDictionary(ref _decoderState, dictionary.Length,
(byte *)_customDictionary);
}
}
/// <summary>
/// Reads a number of decompressed bytes into the specified byte array.
/// </summary>
/// <param name="buffer">The array to store decompressed bytes.</param>
/// <param name="offset">The byte offset in <paramref name="buffer"/> at which the read bytes will be placed.</param>
/// <param name="count">The maximum number of decompressed bytes to read.</param>
/// <returns>The number of bytes that were read into the byte array.</returns>
public override int Read(byte[] buffer, int offset, int count) {
if (_mode != CompressionMode.Decompress)
throw new InvalidOperationException("Read is only supported in Decompress mode");
EnsureNotDisposed();
ValidateParameters(buffer, offset, count);
int totalWritten = 0;
while (offset < buffer.Length && _lastDecoderState != Brotli.BrotliDecoderResult.BROTLI_DECODER_RESULT_SUCCESS) {
if (_lastDecoderState == Brotli.BrotliDecoderResult.BROTLI_DECODER_RESULT_NEEDS_MORE_INPUT) {
if (_bufferCount > 0 && _bufferOffset != 0) {
Array.Copy(_buffer, _bufferOffset, _buffer, 0, _bufferCount);
}
_bufferOffset = 0;
int numRead = 0;
while (_bufferCount < _buffer.Length && ((numRead = _stream.Read(_buffer, _bufferCount, _buffer.Length - _bufferCount)) > 0)) {
_bufferCount += numRead;
if (_bufferCount > _buffer.Length)
throw new InvalidDataException("Invalid input stream detected, more bytes supplied than expected.");
}
if (_bufferCount <= 0)
break;
}
size_t available_in = _bufferCount;
size_t available_in_old = available_in;
size_t available_out = count;
size_t available_out_old = available_out;
fixed (byte* out_buf_ptr = buffer)
fixed (byte* in_buf_ptr = _buffer) {
byte* in_buf = in_buf_ptr + _bufferOffset;
byte* out_buf = out_buf_ptr + offset;
_lastDecoderState = Brotli.BrotliDecoderDecompressStream(ref _decoderState, &available_in, &in_buf,
&available_out, &out_buf, null);
}
if (_lastDecoderState == Brotli.BrotliDecoderResult.BROTLI_DECODER_RESULT_ERROR)
throw new InvalidDataException("Decompression failed with error code: " + _decoderState.error_code);
size_t bytesConsumed = available_in_old - available_in;
size_t bytesWritten = available_out_old - available_out;
if (bytesConsumed > 0) {
_bufferOffset += (int) bytesConsumed;
_bufferCount -= (int) bytesConsumed;
}
if (bytesWritten > 0) {
totalWritten += (int)bytesWritten;
offset += (int)bytesWritten;
count -= (int)bytesWritten;
}
}
return totalWritten;
}
/// <summary>
/// Sets the quality for compression.
/// </summary>
/// <param name="quality">The quality value (a value from 0-11).</param>
public void SetQuality(int quality) {
if (_mode != CompressionMode.Compress)
throw new InvalidOperationException("SetQuality is only valid for compress");
if (quality < Brotli.BROTLI_MIN_QUALITY || quality > Brotli.BROTLI_MAX_QUALITY)
throw new ArgumentOutOfRangeException(nameof(quality), "Quality should be a value between " +
Brotli.BROTLI_MIN_QUALITY + "-" + Brotli
.BROTLI_MAX_QUALITY);
EnsureNotDisposed();
Brotli.BrotliEncoderSetParameter(ref _encoderState, Brotli.BrotliEncoderParameter.BROTLI_PARAM_QUALITY,
(uint) quality);
}
private void FlushCompress(bool finish) {
if (_mode != CompressionMode.Compress)
return;
if (Brotli.BrotliEncoderIsFinished(ref _encoderState))
return;
var op = finish
? Brotli.BrotliEncoderOperation.BROTLI_OPERATION_FINISH
: Brotli.BrotliEncoderOperation.BROTLI_OPERATION_FLUSH;
byte[] buffer = new byte[0];
WriteCore(buffer, 0, 0, op);
}
/// <summary>
/// Sets the window size for the encoder
/// </summary>
/// <param name="windowSize">The window size in bits (a value from 10-24)</param>
public void SetWindow(int windowSize) {
if (_mode != CompressionMode.Compress)
throw new InvalidOperationException("SetWindow is only valid for compress");
if (windowSize < Brotli.BROTLI_MIN_WINDOW_BITS || windowSize > Brotli.BROTLI_MAX_WINDOW_BITS)
throw new ArgumentOutOfRangeException(nameof(windowSize), "Window size should be a value between " +
Brotli.BROTLI_MIN_WINDOW_BITS + "-" + Brotli
.BROTLI_MAX_WINDOW_BITS);
EnsureNotDisposed();
Brotli.BrotliEncoderSetParameter(ref _encoderState, Brotli.BrotliEncoderParameter.BROTLI_PARAM_LGWIN,
(uint) windowSize);
}
public override unsafe void PrepareDistanceCache(HasherHandle handle, int *distance_cache)
{
Brotli.PrepareDistanceCache(distance_cache,
GetHasherCommon(handle)->params_.num_last_distances_to_check);
}
/// <summary>
/// Reads a number of decompressed bytes into the specified byte array.
/// </summary>
/// <param name="buffer">The array to store decompressed bytes.</param>
/// <param name="offset">The byte offset in <paramref name="buffer"/> at which the read bytes will be placed.</param>
/// <param name="count">The maximum number of decompressed bytes to read.</param>
/// <returns>The number of bytes that were read into the byte array.</returns>
public override int Read(byte[] buffer, int offset, int count)
{
if (_mode != CompressionMode.Decompress)
{
throw new InvalidOperationException("Read is only supported in Decompress mode");
}
EnsureNotDisposed();
ValidateParameters(buffer, offset, count);
bool endOfStream = false;
byte[] in_buf = new byte[0xffff];
size_t available_in = 0, available_out = count;
fixed(byte *in_buf_ptr = in_buf)
fixed(byte *buf_ptr = buffer)
{
byte *next_in = in_buf_ptr;
byte *next_out = buf_ptr + offset;
int total = 0;
while (true)
{
if (_lastDecoderState == Brotli.BrotliDecoderResult.BROTLI_DECODER_RESULT_NEEDS_MORE_INPUT)
{
int len = _stream.Read(in_buf, 0, in_buf.Length);
if (len <= 0)
{
endOfStream = true;
break;
}
available_in = len;
next_in = in_buf_ptr;
}
else if (_lastDecoderState == Brotli.BrotliDecoderResult.BROTLI_DECODER_RESULT_NEEDS_MORE_OUTPUT)
{
/* Ignore */
}
else
{
endOfStream = true;
break;
}
size_t available_out_old = available_out;
_lastDecoderState = Brotli.BrotliDecoderDecompressStream(ref _decoderState, &available_in,
&next_in, &available_out, &next_out, null);
total += (int)(available_out_old - available_out);
if (total >= count)
{
break;
}
}
if (endOfStream && _lastDecoderState != Brotli.BrotliDecoderResult.BROTLI_DECODER_RESULT_SUCCESS)
{
throw new InvalidDataException("Decompression failed with error code: " + _decoderState.error_code);
}
return(total);
}
}
