private static int[] DecompressTagSlow(byte[] input, int inputIndex, byte[] output, int outputLimit, int outputOffset, int outputIndex)
{
int opCode = DataHelper.LoadByte(input, inputIndex++);
int entry = DataHelper.LookupShort(_opLookupTable, opCode);
int trailerBytes = Extensions.BitwiseUnsignedRightShift(entry, 11);
int trailer = 0;
switch (trailerBytes)
{
case 4:
trailer = (input[inputIndex + 3] & 0xff) << 24;
break;
case 3:
trailer |= (input[inputIndex + 2] & 0xff) << 16;
break;
case 2:
trailer |= (input[inputIndex + 1] & 0xff) << 8;
break;
case 1:
trailer |= (input[inputIndex] & 0xff);
break;
}
inputIndex += trailerBytes;
int length = entry & 0xff;
if ((opCode & 0x3) == LITERAL)
{
int literalLength = length + trailer;
CopyLiteral(input, inputIndex, output, outputIndex, literalLength);
inputIndex += literalLength;
outputIndex += literalLength;
}
else
{
int copyOffset = entry & 0x700;
copyOffset += trailer;
int spaceLeft = outputLimit - outputIndex;
int srcIndex = outputIndex - copyOffset;
if (srcIndex < outputOffset)
{
throw new CorruptionException("Invalid copy offset for opcode starting at " + (inputIndex - trailerBytes - 1));
}
if (length <= 16 && copyOffset >= 8 && spaceLeft >= 16)
{
DataHelper.CopyLong(output, srcIndex, output, outputIndex);
DataHelper.CopyLong(output, srcIndex + 8, output, outputIndex + 8);
}
else if (spaceLeft >= length + MAX_INCREMENT_COPY_OVERFLOW)
{
IncrementalCopyFastPath(output, srcIndex, outputIndex, length);
}
else
{
IncrementalCopy(output, srcIndex, output, outputIndex, length);
}
outputIndex += length;
}
return(new int[] { inputIndex, outputIndex });
}
private static int DecompressAllTags(byte[] input, int inputOffset, int inputSize, byte[] output, int outputOffset)
{
int outputLimit = output.Length;
int inputLimit = inputOffset + inputSize;
int outputIndex = outputOffset;
int inputIndex = inputOffset;
while (inputIndex < inputLimit - 5)
{
int opCode = DataHelper.LoadByte(input, inputIndex++);
int entry = DataHelper.LookupShort(_opLookupTable, opCode);
int trailerBytes = Extensions.BitwiseUnsignedRightShift(entry, 11);
int trailer = ReadTrailer(input, inputIndex, trailerBytes);
inputIndex += Extensions.BitwiseUnsignedRightShift(entry, 11);
int length = entry & 0xff;
if ((opCode & 0x3) == LITERAL)
{
int literalLength = length + trailer;
CopyLiteral(input, inputIndex, output, outputIndex, literalLength);
inputIndex += literalLength;
outputIndex += literalLength;
}
else
{
int copyOffset = entry & 0x700;
copyOffset += trailer;
int spaceLeft = outputLimit - outputIndex;
int srcIndex = outputIndex - copyOffset;
if (srcIndex < outputOffset)
{
throw new CorruptionException("Invalid copy offset for opcode starting at " + (inputIndex - trailerBytes - 1));
}
if (length <= 16 && copyOffset >= 8 && spaceLeft >= 16)
{
DataHelper.CopyLong(output, srcIndex, output, outputIndex);
DataHelper.CopyLong(output, srcIndex + 8, output, outputIndex + 8);
}
else if (spaceLeft >= length + MAX_INCREMENT_COPY_OVERFLOW)
{
IncrementalCopyFastPath(output, srcIndex, outputIndex, length);
}
else
{
IncrementalCopy(output, srcIndex, output, outputIndex, length);
}
outputIndex += length;
}
}
while (inputIndex < inputLimit)
{
int[] result = DecompressTagSlow(input, inputIndex, output, outputLimit, outputOffset, outputIndex);
inputIndex = result[0];
outputIndex = result[1];
}
return(outputIndex - outputOffset);
}
