public void GetBlock(DeflateInput input, OutputBuffer output, bool isFinal)
{
Debug.Assert(output != null);
Debug.Assert(output.FreeBytes >= 5);
int num = 0;
if (input != null)
{
num = Math.Min(input.Count, output.FreeBytes - 5 - output.BitsInBuffer);
if (num > 65531)
{
num = 65531;
}
}
if (isFinal)
{
output.WriteBits(3, 1U);
}
else
{
output.WriteBits(3, 0U);
}
output.FlushBits();
this.WriteLenNLen((ushort)num, output);
if (input == null || num <= 0)
{
return;
}
output.WriteBytes(input.Buffer, input.StartIndex, num);
input.ConsumeBytes(num);
}
internal static void WriteMatch(int matchLen, int matchPos, OutputBuffer output)
{
Debug.Assert(matchLen >= 3 && matchLen <= 258, "Illegal currentMatch length!");
uint num1 = FastEncoderStatics.FastEncoderLiteralCodeInfo[254 + matchLen];
int n1 = (int)num1 & 31;
Debug.Assert((uint)n1 > 0U, "Invalid Match Length!");
if (n1 <= 16)
{
output.WriteBits(n1, num1 >> 5);
}
else
{
output.WriteBits(16, num1 >> 5 & (uint)ushort.MaxValue);
output.WriteBits(n1 - 16, num1 >> 21);
}
uint num2 = FastEncoderStatics.FastEncoderDistanceCodeInfo[FastEncoderStatics.GetSlot(matchPos)];
output.WriteBits((int)num2 & 15, num2 >> 8);
int n2 = (int)(num2 >> 4) & 15;
if ((uint)n2 <= 0U)
{
return;
}
output.WriteBits(n2, (uint)matchPos & FastEncoderStatics.BitMask[n2]);
}
private void GetCompressedOutput(DeflateInput input, OutputBuffer output, int maxBytesToCopy)
{
int bytesWritten = output.BytesWritten;
int num1 = 0;
int num2 = this.BytesInHistory + input.Count;
do
{
int num3 = input.Count < this.inputWindow.FreeWindowSpace ? input.Count : this.inputWindow.FreeWindowSpace;
if (maxBytesToCopy >= 1)
{
num3 = Math.Min(num3, maxBytesToCopy - num1);
}
if (num3 > 0)
{
this.inputWindow.CopyBytes(input.Buffer, input.StartIndex, num3);
input.ConsumeBytes(num3);
num1 += num3;
}
this.GetCompressedOutput(output);
}while (this.SafeToWriteTo(output) && this.InputAvailable(input) && (maxBytesToCopy < 1 || num1 < maxBytesToCopy));
int num4 = output.BytesWritten - bytesWritten;
int num5 = this.BytesInHistory + input.Count;
int num6 = num2 - num5;
if ((uint)num4 <= 0U)
{
return;
}
this.lastCompressionRatio = (double)num4 / (double)num6;
}
internal void GetBlock(DeflateInput input, OutputBuffer output, int maxBytesToCopy)
{
Debug.Assert(this.InputAvailable(input), "call SetInput before trying to compress!");
FastEncoder.WriteDeflatePreamble(output);
this.GetCompressedOutput(input, output, maxBytesToCopy);
this.WriteEndOfBlock(output);
}
private void WriteEndOfBlock(OutputBuffer output)
{
uint num = FastEncoderStatics.FastEncoderLiteralCodeInfo[256];
int n = (int)num & 31;
output.WriteBits(n, num >> 5);
}
internal DeflaterManaged()
{
this.deflateEncoder = new FastEncoder();
this.copyEncoder = new CopyEncoder();
this.input = new DeflateInput();
this.output = new OutputBuffer();
this.processingState = DeflaterManaged.DeflaterState.NotStarted;
}
private void GetCompressedOutput(OutputBuffer output)
{
while (this.inputWindow.BytesAvailable > 0 && this.SafeToWriteTo(output))
{
this.inputWindow.GetNextSymbolOrMatch(this.currentMatch);
if (this.currentMatch.State == MatchState.HasSymbol)
{
FastEncoder.WriteChar(this.currentMatch.Symbol, output);
}
else if (this.currentMatch.State == MatchState.HasMatch)
{
FastEncoder.WriteMatch(this.currentMatch.Length, this.currentMatch.Position, output);
}
else
{
FastEncoder.WriteChar(this.currentMatch.Symbol, output);
FastEncoder.WriteMatch(this.currentMatch.Length, this.currentMatch.Position, output);
}
}
}
internal void GetBlockFooter(OutputBuffer output)
{
this.WriteEndOfBlock(output);
}
internal void GetBlockHeader(OutputBuffer output)
{
FastEncoder.WriteDeflatePreamble(output);
}
internal void GetCompressedData(DeflateInput input, OutputBuffer output)
{
this.GetCompressedOutput(input, output, -1);
}
internal static void WriteDeflatePreamble(OutputBuffer output)
{
output.WriteBytes(FastEncoderStatics.FastEncoderTreeStructureData, 0, FastEncoderStatics.FastEncoderTreeStructureData.Length);
output.WriteBits(9, 34U);
}
internal static void WriteChar(byte b, OutputBuffer output)
{
uint num = FastEncoderStatics.FastEncoderLiteralCodeInfo[(int)b];
output.WriteBits((int)num & 31, num >> 5);
}
private bool SafeToWriteTo(OutputBuffer output)
{
return(output.FreeBytes > 16);
}