/// <summary>
/// buffstate的状态重置
/// </summary>
/// <param name="state"></param>
internal void RestoreState(OutputBuffer.BufferState state)
{
this.pos = state.pos;
this.bitBuf = state.bitBuf;
this.bitCount = state.bitCount;
}
int IDeflater.GetDeflateOutput(byte[] outputBuffer)
{
Debug.Assert(outputBuffer != null, "Can't pass in a null output buffer!");
Debug.Assert(!this.NeedsInput(), "GetDeflateOutput should only be called after providing input");
this.output.UpdateBuffer(outputBuffer);
switch (this.processingState)
{
case DeflaterManaged.DeflaterState.NotStarted:
Debug.Assert(this.deflateEncoder.BytesInHistory == 0, "have leftover bytes in window");
DeflateInput.InputState state1 = this.input.DumpState();
OutputBuffer.BufferState state2 = this.output.DumpState();
this.deflateEncoder.GetBlockHeader(this.output);
this.deflateEncoder.GetCompressedData(this.input, this.output);
if (!this.UseCompressed(this.deflateEncoder.LastCompressionRatio))
{
this.input.RestoreState(state1);
this.output.RestoreState(state2);
this.copyEncoder.GetBlock(this.input, this.output, false);
this.FlushInputWindows();
this.processingState = DeflaterManaged.DeflaterState.CheckingForIncompressible;
break;
}
this.processingState = DeflaterManaged.DeflaterState.CompressThenCheck;
break;
case DeflaterManaged.DeflaterState.SlowDownForIncompressible1:
this.deflateEncoder.GetBlockFooter(this.output);
this.processingState = DeflaterManaged.DeflaterState.SlowDownForIncompressible2;
goto case DeflaterManaged.DeflaterState.SlowDownForIncompressible2;
case DeflaterManaged.DeflaterState.SlowDownForIncompressible2:
if (this.inputFromHistory.Count > 0)
{
this.copyEncoder.GetBlock(this.inputFromHistory, this.output, false);
}
if (this.inputFromHistory.Count == 0)
{
this.deflateEncoder.FlushInput();
this.processingState = DeflaterManaged.DeflaterState.CheckingForIncompressible;
break;
}
break;
case DeflaterManaged.DeflaterState.StartingSmallData:
this.deflateEncoder.GetBlockHeader(this.output);
this.processingState = DeflaterManaged.DeflaterState.HandlingSmallData;
goto case DeflaterManaged.DeflaterState.HandlingSmallData;
case DeflaterManaged.DeflaterState.CompressThenCheck:
this.deflateEncoder.GetCompressedData(this.input, this.output);
if (!this.UseCompressed(this.deflateEncoder.LastCompressionRatio))
{
this.processingState = DeflaterManaged.DeflaterState.SlowDownForIncompressible1;
this.inputFromHistory = this.deflateEncoder.UnprocessedInput;
break;
}
break;
case DeflaterManaged.DeflaterState.CheckingForIncompressible:
Debug.Assert(this.deflateEncoder.BytesInHistory == 0, "have leftover bytes in window");
DeflateInput.InputState state3 = this.input.DumpState();
OutputBuffer.BufferState state4 = this.output.DumpState();
this.deflateEncoder.GetBlock(this.input, this.output, 8072);
if (!this.UseCompressed(this.deflateEncoder.LastCompressionRatio))
{
this.input.RestoreState(state3);
this.output.RestoreState(state4);
this.copyEncoder.GetBlock(this.input, this.output, false);
this.FlushInputWindows();
break;
}
break;
case DeflaterManaged.DeflaterState.HandlingSmallData:
this.deflateEncoder.GetCompressedData(this.input, this.output);
break;
}
return(this.output.BytesWritten);
}
