Encoder and Decoder for ZLIB (IETF RFC1950 and RFC1951). More...

Public Member Functions
	ZlibCodec ()
	Create a ZlibCodec. More...

	ZlibCodec (CompressionMode mode)
	Create a ZlibCodec that either compresses or decompresses. More...

int	InitializeInflate ()
	Initialize the inflation state. More...

int	InitializeInflate (bool expectRfc1950Header)
	Initialize the inflation state with an explicit flag to govern the handling of RFC1950 header bytes. More...

int	InitializeInflate (int windowBits)
	Initialize the ZlibCodec for inflation, with the specified number of window bits. More...

int	InitializeInflate (int windowBits, bool expectRfc1950Header)
	Initialize the inflation state with an explicit flag to govern the handling of RFC1950 header bytes. More...

int	Inflate (int f)
	Inflate the data in the InputBuffer, placing the result in the OutputBuffer. More...

int	EndInflate ()
	Ends an inflation session. More...

int	SyncInflate ()
	I don't know what this does! More...

int	InitializeDeflate ()
	Initialize the ZlibCodec for deflation operation. More...

int	InitializeDeflate (CompressionLevel level)
	Initialize the ZlibCodec for deflation operation, using the specified CompressionLevel. More...

int	InitializeDeflate (CompressionLevel level, bool wantRfc1950Header)
	Initialize the ZlibCodec for deflation operation, using the specified CompressionLevel, and the explicit flag governing whether to emit an RFC1950 header byte pair. More...

int	InitializeDeflate (CompressionLevel level, int bits)
	Initialize the ZlibCodec for deflation operation, using the specified CompressionLevel, and the specified number of window bits. More...

int	InitializeDeflate (CompressionLevel level, int bits, bool wantRfc1950Header)
	Initialize the ZlibCodec for deflation operation, using the specified CompressionLevel, the specified number of window bits, and the explicit flag governing whether to emit an RFC1950 header byte pair. More...

int	Deflate (int flush)
	Deflate one batch of data. More...

int	EndDeflate ()
	End a deflation session. More...

int	SetDeflateParams (CompressionLevel level, CompressionStrategy strategy)
	Set the CompressionStrategy and CompressionLevel for a deflation session. More...

int	SetDictionary (byte[] dictionary)
	Set the dictionary to be used for either Inflation or Deflation. More...

Public Attributes
byte[]	InputBuffer
	The buffer from which data is taken. More...

int	NextIn
	An index into the InputBuffer array, indicating where to start reading. More...

int	AvailableBytesIn
	The number of bytes available in the InputBuffer, starting at NextIn. More...

long	TotalBytesIn
	Total number of bytes read so far, through all calls to Inflate()/Deflate(). More...

byte[]	OutputBuffer
	Buffer to store output data. More...

int	NextOut
	An index into the OutputBuffer array, indicating where to start writing. More...

int	AvailableBytesOut
	The number of bytes available in the OutputBuffer, starting at NextOut. More...

long	TotalBytesOut
	Total number of bytes written to the output so far, through all calls to Inflate()/Deflate(). More...

System.String	Message
	used for diagnostics, when something goes wrong! More...

Properties
long	Adler32 `[get]`
	The Adler32 checksum on the data transferred through the codec so far. You probably don't need to look at this. More...

Detailed Description

Encoder and Decoder for ZLIB (IETF RFC1950 and RFC1951).

This class compresses and decompresses data according to the Deflate algorithm documented in RFC1950 and RFC1951.

Constructor & Destructor Documentation

UniExtensions.Zlib.ZlibCodec.ZlibCodec ( )

inline

Create a ZlibCodec.

If you use this default constructor, you will later have to explicitly call InitializeInflate() or InitializeDeflate() before using the ZlibCodec to compress or decompress.

UniExtensions.Zlib.ZlibCodec.ZlibCodec ( CompressionMode mode )

inline

Create a ZlibCodec that either compresses or decompresses.

Parameters

mode	Indicates whether the codec should compress (deflate) or decompress (inflate).

Member Function Documentation

int UniExtensions.Zlib.ZlibCodec.Deflate ( int flush )

inline

Deflate one batch of data.

You must have set InputBuffer and OutputBuffer before calling this method.

private void DeflateBuffer(CompressionLevel level)
{
    int bufferSize = 1024;
    byte[] buffer = new byte[bufferSize];
    ZlibCodec compressor = new ZlibCodec();
    Console.WriteLine("\n============================================");
    Console.WriteLine("Size of Buffer to Deflate: {0} bytes.", UncompressedBytes.Length);
    MemoryStream ms = new MemoryStream();
    int rc = compressor.InitializeDeflate(level);
    compressor.InputBuffer = UncompressedBytes;
    compressor.NextIn = 0;
    compressor.AvailableBytesIn = UncompressedBytes.Length;
    compressor.OutputBuffer = buffer;
    // pass 1: deflate 
    do
    {
        compressor.NextOut = 0;
        compressor.AvailableBytesOut = buffer.Length;
        rc = compressor.Deflate(ZlibConstants.Z_NO_FLUSH);
        if (rc != ZlibConstants.Z_OK &amp;&amp; rc != ZlibConstants.Z_STREAM_END)
            throw new Exception("deflating: " + compressor.Message);
        ms.Write(compressor.OutputBuffer, 0, buffer.Length - compressor.AvailableBytesOut);
    }
    while (compressor.AvailableBytesIn &gt; 0 || compressor.AvailableBytesOut == 0);
    // pass 2: finish and flush
    do
    {
        compressor.NextOut = 0;
        compressor.AvailableBytesOut = buffer.Length;
        rc = compressor.Deflate(ZlibConstants.Z_FINISH);
        if (rc != ZlibConstants.Z_STREAM_END &amp;&amp; rc != ZlibConstants.Z_OK)
            throw new Exception("deflating: " + compressor.Message);
        if (buffer.Length - compressor.AvailableBytesOut &gt; 0)
            ms.Write(buffer, 0, buffer.Length - compressor.AvailableBytesOut);
    }
    while (compressor.AvailableBytesIn &gt; 0 || compressor.AvailableBytesOut == 0);
    compressor.EndDeflate();
    ms.Seek(0, SeekOrigin.Begin);
    CompressedBytes = new byte[compressor.TotalBytesOut];
    ms.Read(CompressedBytes, 0, CompressedBytes.Length);
}

Parameters

flush whether to flush all data as you deflate. Generally you will want to use Z_NO_FLUSH here, in a series of calls to Deflate(), and then call EndDeflate() to flush everything.

Returns: Z_OK if all goes well.

int UniExtensions.Zlib.ZlibCodec.EndDeflate ( )

inline

End a deflation session.

Call this after making a series of one or more calls to Deflate(). All buffers are flushed.

Returns: Z_OK if all goes well.

int UniExtensions.Zlib.ZlibCodec.EndInflate ( )

inline

Ends an inflation session.

Call this after successively calling Inflate(). This will cause all buffers to be flushed. After calling this you cannot call Inflate() without a intervening call to one of the InitializeInflate() overloads.

Returns: Z_OK if everything goes well.

int UniExtensions.Zlib.ZlibCodec.Inflate ( int f )

inline

Inflate the data in the InputBuffer, placing the result in the OutputBuffer.

You must have set InputBuffer and OutputBuffer, NextIn and NextOut, and AvailableBytesIn and AvailableBytesOut before calling this method.

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(ZlibConstants.Z_NO_FLUSH);
        if (rc != ZlibConstants.Z_OK &amp;&amp; rc != ZlibConstants.Z_STREAM_END)
            throw new Exception("inflating: " + decompressor.Message);
        ms.Write(decompressor.OutputBuffer, 0, buffer.Length - decompressor.AvailableBytesOut);
    }
    while (decompressor.AvailableBytesIn &gt; 0 || decompressor.AvailableBytesOut == 0);
    // pass 2: finish and flush
    do
    {
        decompressor.NextOut = 0;
        decompressor.AvailableBytesOut = buffer.Length;
        rc = decompressor.Inflate(ZlibConstants.Z_FINISH);
        if (rc != ZlibConstants.Z_STREAM_END &amp;&amp; rc != ZlibConstants.Z_OK)
            throw new Exception("inflating: " + decompressor.Message);
        if (buffer.Length - decompressor.AvailableBytesOut &gt; 0)
            ms.Write(buffer, 0, buffer.Length - decompressor.AvailableBytesOut);
    }
    while (decompressor.AvailableBytesIn &gt; 0 || decompressor.AvailableBytesOut == 0);
    decompressor.EndInflate();
}

Parameters

f	I think you want to set this to Z_NO_FLUSH.

Returns: Z_OK if everything goes well.

int UniExtensions.Zlib.ZlibCodec.InitializeDeflate ( )

inline

Initialize the ZlibCodec for deflation operation.

The codec will use the MAX window bits and the default level of compression.

int bufferSize = 40000;
byte[] CompressedBytes = new byte[bufferSize];
byte[] DecompressedBytes = new byte[bufferSize];
ZlibCodec compressor = new ZlibCodec();
compressor.InitializeDeflate(CompressionLevel.DEFAULT);
compressor.InputBuffer = System.Text.ASCIIEncoding.ASCII.GetBytes(TextToCompress);
compressor.NextIn = 0;
compressor.AvailableBytesIn = compressor.InputBuffer.Length;
compressor.OutputBuffer = CompressedBytes;
compressor.NextOut = 0;
compressor.AvailableBytesOut = CompressedBytes.Length;
while (compressor.TotalBytesIn != TextToCompress.Length &amp;&amp; compressor.TotalBytesOut &lt; bufferSize)
{
  compressor.Deflate(ZlibConstants.Z_NO_FLUSH);
}
while (true)
{
  int rc= compressor.Deflate(ZlibConstants.Z_FINISH);
  if (rc == ZlibConstants.Z_STREAM_END) break;
}
compressor.EndDeflate();

Returns: Z_OK if all goes well. You generally don't need to check the return code.

int UniExtensions.Zlib.ZlibCodec.InitializeDeflate ( CompressionLevel level )

inline

Initialize the ZlibCodec for deflation operation, using the specified CompressionLevel.

The codec will use the MAX window bits and the specified CompressionLevel.

Parameters

level The compression level for the codec.

Returns: Z_OK if all goes well.

int UniExtensions.Zlib.ZlibCodec.InitializeDeflate	(	CompressionLevel	level,
		bool	wantRfc1950Header
	)

inline

Initialize the ZlibCodec for deflation operation, using the specified CompressionLevel, and the explicit flag governing whether to emit an RFC1950 header byte pair.

The codec will use the MAX window bits and the specified CompressionLevel.

Parameters

level	The compression level for the codec.
wantRfc1950Header	whether to emit an initial RFC1950 byte pair in the compressed stream.

Returns: Z_OK if all goes well.

int UniExtensions.Zlib.ZlibCodec.InitializeDeflate	(	CompressionLevel	level,
		int	bits
	)

inline

Initialize the ZlibCodec for deflation operation, using the specified CompressionLevel, and the specified number of window bits.

The codec will use the specified number of window bits and the specified CompressionLevel.

Parameters

level	The compression level for the codec.
bits	the number of window bits to use. If you don't know what this means, don't use this method.

Returns: Z_OK if all goes well.

int UniExtensions.Zlib.ZlibCodec.InitializeDeflate	(	CompressionLevel	level,
		int	bits,
		bool	wantRfc1950Header
	)

inline

Initialize the ZlibCodec for deflation operation, using the specified CompressionLevel, the specified number of window bits, and the explicit flag governing whether to emit an RFC1950 header byte pair.

Parameters

level	The compression level for the codec.
wantRfc1950Header	whether to emit an initial RFC1950 byte pair in the compressed stream.
bits	the number of window bits to use. If you don't know what this means, don't use this method.

Returns: Z_OK if all goes well.

int UniExtensions.Zlib.ZlibCodec.InitializeInflate ( )

inline

Initialize the inflation state.

It is not necessary to call this before using the ZlibCodec to inflate data; It is implicitly called when you call the constructor.

Returns: Z_OK if everything goes well.

int UniExtensions.Zlib.ZlibCodec.InitializeInflate ( bool expectRfc1950Header )

inline

Initialize the inflation state with an explicit flag to govern the handling of RFC1950 header bytes.

By default, the RFC1950 header is expected. If you want to read a zlib stream you should specify true for expectRfc1950Header. If you have a deflate stream, you will want to specify false. It is only necessary to invoke this initializer explicitly if you want to specify false.

Parameters

expectRfc1950Header whether to expect an RFC1950 header byte pair when reading the stream of data to be inflated.

Returns: Z_OK if everything goes well.

int UniExtensions.Zlib.ZlibCodec.InitializeInflate ( int windowBits )

inline

Initialize the ZlibCodec for inflation, with the specified number of window bits.

Parameters

windowBits The number of window bits to use. If you need to ask what that is, then you shouldn't be calling this initializer.

Returns: Z_OK if all goes well.

int UniExtensions.Zlib.ZlibCodec.InitializeInflate	(	int	windowBits,
		bool	expectRfc1950Header
	)

inline

Initialize the inflation state with an explicit flag to govern the handling of RFC1950 header bytes.

If you want to read a zlib stream you should specify true for expectRfc1950Header. If you have a deflate stream, you will want to specify false.

Parameters

expectRfc1950Header	whether to expect an RFC1950 header byte pair when reading the stream of data to be inflated.
windowBits	The number of window bits to use. If you need to ask what that is, then you shouldn't be calling this initializer.

Returns: Z_OK if everything goes well.

int UniExtensions.Zlib.ZlibCodec.SetDeflateParams	(	CompressionLevel	level,
		CompressionStrategy	strategy
	)

inline

Set the CompressionStrategy and CompressionLevel for a deflation session.

Parameters

level	the level of compression to use.
strategy	the strategy to use for compression.

Returns: Z_OK if all goes well.

int UniExtensions.Zlib.ZlibCodec.SetDictionary ( byte[] dictionary )

inline

Set the dictionary to be used for either Inflation or Deflation.

Parameters

dictionary The dictionary bytes to use.

Returns: Z_OK if all goes well.

int UniExtensions.Zlib.ZlibCodec.SyncInflate ( )

inline

I don't know what this does!

Returns: Z_OK if everything goes well.

Member Data Documentation

int UniExtensions.Zlib.ZlibCodec.AvailableBytesIn

The number of bytes available in the InputBuffer, starting at NextIn.

Generally you should set this to InputBuffer.Length before the first Inflate() or Deflate() call. The class will update this number as calls to Inflate/Deflate are made.

int UniExtensions.Zlib.ZlibCodec.AvailableBytesOut

The number of bytes available in the OutputBuffer, starting at NextOut.

Generally you should set this to OutputBuffer.Length before the first Inflate() or Deflate() call. The class will update this number as calls to Inflate/Deflate are made.

byte [] UniExtensions.Zlib.ZlibCodec.InputBuffer

The buffer from which data is taken.

System.String UniExtensions.Zlib.ZlibCodec.Message

used for diagnostics, when something goes wrong!

int UniExtensions.Zlib.ZlibCodec.NextIn

An index into the InputBuffer array, indicating where to start reading.

int UniExtensions.Zlib.ZlibCodec.NextOut

An index into the OutputBuffer array, indicating where to start writing.

byte [] UniExtensions.Zlib.ZlibCodec.OutputBuffer

Buffer to store output data.

long UniExtensions.Zlib.ZlibCodec.TotalBytesIn

Total number of bytes read so far, through all calls to Inflate()/Deflate().

long UniExtensions.Zlib.ZlibCodec.TotalBytesOut

Total number of bytes written to the output so far, through all calls to Inflate()/Deflate().

Property Documentation

long UniExtensions.Zlib.ZlibCodec.Adler32

get

The Adler32 checksum on the data transferred through the codec so far. You probably don't need to look at this.

The documentation for this class was generated from the following file:

UniExtensions/Zlib/ZlibCodec.cs

Public Member Functions

Public Attributes

Properties

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation

Property Documentation