internal int Inflate()
{
if (this.codec.InputBuffer == null)
{
throw new ZlibException("InputBuffer is null. ");
}
// int f = (flush == FlushType.Finish) ? ZlibConstants.Z_BUF_ERROR : ZlibConstants.Z_OK;
// workitem 8870
const int f = ZlibConstants.Zok;
int r = ZlibConstants.ZBufError;
while (true)
{
switch (this.mode)
{
case InflateManagerMode.Method:
if (this.codec.AvailableBytesIn == 0)
{
return r;
}
r = f;
this.codec.AvailableBytesIn--;
this.codec.TotalBytesIn++;
if (((this.method = this.codec.InputBuffer[this.codec.NextIn++]) & 0xf) != ZDeflated)
{
this.mode = InflateManagerMode.Bad;
this.codec.Message = string.Format(
CultureInfo.CurrentCulture, "unknown compression method (0x{0:X2})", this.method);
break;
}
if ((this.method >> 4) + 8 > this.wbits)
{
this.mode = InflateManagerMode.Bad;
this.codec.Message = string.Format(
CultureInfo.CurrentCulture, "invalid window size ({0})", (this.method >> 4) + 8);
break;
}
this.mode = InflateManagerMode.Flag;
break;
case InflateManagerMode.Flag:
if (this.codec.AvailableBytesIn == 0)
{
return r;
}
r = f;
this.codec.AvailableBytesIn--;
this.codec.TotalBytesIn++;
int b = this.codec.InputBuffer[this.codec.NextIn++] & 0xff;
if ((((this.method << 8) + b) % 31) != 0)
{
this.mode = InflateManagerMode.Bad;
this.codec.Message = "incorrect header check";
break;
}
this.mode = ((b & PresetDict) == 0) ? InflateManagerMode.Blocks : InflateManagerMode.DicT4;
break;
case InflateManagerMode.DicT4:
if (this.codec.AvailableBytesIn == 0)
{
return r;
}
r = f;
this.codec.AvailableBytesIn--;
this.codec.TotalBytesIn++;
this.expectedCheck = (uint)((this.codec.InputBuffer[this.codec.NextIn++] << 24) & 0xff000000);
this.mode = InflateManagerMode.DicT3;
break;
case InflateManagerMode.DicT3:
if (this.codec.AvailableBytesIn == 0)
{
return r;
}
r = f;
this.codec.AvailableBytesIn--;
this.codec.TotalBytesIn++;
this.expectedCheck += (uint)((this.codec.InputBuffer[this.codec.NextIn++] << 16) & 0x00ff0000);
this.mode = InflateManagerMode.DicT2;
break;
case InflateManagerMode.DicT2:
if (this.codec.AvailableBytesIn == 0)
{
return r;
}
r = f;
this.codec.AvailableBytesIn--;
this.codec.TotalBytesIn++;
this.expectedCheck += (uint)((this.codec.InputBuffer[this.codec.NextIn++] << 8) & 0x0000ff00);
this.mode = InflateManagerMode.DicT1;
break;
case InflateManagerMode.DicT1:
if (this.codec.AvailableBytesIn == 0)
{
return r;
}
this.codec.AvailableBytesIn--;
this.codec.TotalBytesIn++;
this.expectedCheck += (uint)(this.codec.InputBuffer[this.codec.NextIn++] & 0x000000ff);
this.codec.Adler32 = this.expectedCheck;
this.mode = InflateManagerMode.DicT0;
return ZlibConstants.ZNeedDict;
case InflateManagerMode.DicT0:
this.mode = InflateManagerMode.Bad;
this.codec.Message = "need dictionary";
return ZlibConstants.ZStreamError;
case InflateManagerMode.Blocks:
r = this.blocks.Process(r);
if (r == ZlibConstants.ZDataError)
{
this.mode = InflateManagerMode.Bad;
break;
}
if (r == ZlibConstants.Zok)
{
r = f;
}
if (r != ZlibConstants.ZStreamEnd)
{
return r;
}
r = f;
this.computedCheck = this.blocks.Reset();
if (!this.HandleRfc1950HeaderBytes)
{
this.mode = InflateManagerMode.Done;
return ZlibConstants.ZStreamEnd;
}
this.mode = InflateManagerMode.ChecK4;
break;
case InflateManagerMode.ChecK4:
if (this.codec.AvailableBytesIn == 0)
{
return r;
}
r = f;
this.codec.AvailableBytesIn--;
this.codec.TotalBytesIn++;
this.expectedCheck = (uint)((this.codec.InputBuffer[this.codec.NextIn++] << 24) & 0xff000000);
this.mode = InflateManagerMode.ChecK3;
break;
case InflateManagerMode.ChecK3:
if (this.codec.AvailableBytesIn == 0)
{
return r;
}
r = f;
this.codec.AvailableBytesIn--;
this.codec.TotalBytesIn++;
this.expectedCheck += (uint)((this.codec.InputBuffer[this.codec.NextIn++] << 16) & 0x00ff0000);
this.mode = InflateManagerMode.ChecK2;
break;
case InflateManagerMode.ChecK2:
if (this.codec.AvailableBytesIn == 0)
{
return r;
}
r = f;
this.codec.AvailableBytesIn--;
this.codec.TotalBytesIn++;
this.expectedCheck += (uint)((this.codec.InputBuffer[this.codec.NextIn++] << 8) & 0x0000ff00);
this.mode = InflateManagerMode.ChecK1;
break;
case InflateManagerMode.ChecK1:
if (this.codec.AvailableBytesIn == 0)
{
return r;
}
r = f;
this.codec.AvailableBytesIn--;
this.codec.TotalBytesIn++;
this.expectedCheck += (uint)(this.codec.InputBuffer[this.codec.NextIn++] & 0x000000ff);
if (this.computedCheck != this.expectedCheck)
{
this.mode = InflateManagerMode.Bad;
this.codec.Message = "incorrect data check";
break;
}
this.mode = InflateManagerMode.Done;
return ZlibConstants.ZStreamEnd;
case InflateManagerMode.Done:
return ZlibConstants.ZStreamEnd;
case InflateManagerMode.Bad:
throw new ZlibException(
string.Format(CultureInfo.CurrentCulture, "Bad state ({0})", this.codec.Message));
default:
throw new ZlibException("Stream error.");
}
}
}
/// <summary>
/// Inflate the data in the InputBuffer, placing the result in the OutputBuffer.
/// </summary>
/// <remarks>
/// You must have set InputBuffer and OutputBuffer, NextIn and NextOut, and AvailableBytesIn and
/// AvailableBytesOut before calling this method.
/// </remarks>
/// <example>
/// <code>
/// private void InflateBuffer()
/// {
/// int bufferSize = 1024;
/// byte[] buffer = new byte[bufferSize];
/// ZlibCodec decompressor = new ZlibCodec();
///
/// Console.WriteLine("\n============================================");
/// Console.WriteLine("Size of Buffer to Inflate: {0} bytes.", CompressedBytes.Length);
/// MemoryStream ms = new MemoryStream(DecompressedBytes);
///
/// int rc = decompressor.InitializeInflate();
///
/// decompressor.InputBuffer = CompressedBytes;
/// decompressor.NextIn = 0;
/// decompressor.AvailableBytesIn = CompressedBytes.Length;
///
/// decompressor.OutputBuffer = buffer;
///
/// // pass 1: inflate
/// do
/// {
/// decompressor.NextOut = 0;
/// decompressor.AvailableBytesOut = buffer.Length;
/// rc = decompressor.Inflate(FlushType.None);
///
/// if (rc != ZlibConstants.Z_OK && rc != ZlibConstants.Z_STREAM_END)
/// throw new Exception("inflating: " + decompressor.Message);
///
/// ms.Write(decompressor.OutputBuffer, 0, buffer.Length - decompressor.AvailableBytesOut);
/// }
/// while (decompressor.AvailableBytesIn > 0 || decompressor.AvailableBytesOut == 0);
///
/// // pass 2: finish and flush
/// do
/// {
/// decompressor.NextOut = 0;
/// decompressor.AvailableBytesOut = buffer.Length;
/// rc = decompressor.Inflate(FlushType.Finish);
///
/// if (rc != ZlibConstants.Z_STREAM_END && rc != ZlibConstants.Z_OK)
/// throw new Exception("inflating: " + decompressor.Message);
///
/// if (buffer.Length - decompressor.AvailableBytesOut > 0)
/// ms.Write(buffer, 0, buffer.Length - decompressor.AvailableBytesOut);
/// }
/// while (decompressor.AvailableBytesIn > 0 || decompressor.AvailableBytesOut == 0);
///
/// decompressor.EndInflate();
/// }
///
/// </code>
/// </example>
/// <param name="flush">The flush to use when inflating.</param>
/// <returns>Z_OK if everything goes well.</returns>
internal int Inflate(FlushType flush)
{
if (istate == null)
{
throw new ZlibException("No Inflate State!");
}
return(istate.Inflate(flush));
}
