Mercurial > hg > sv-dependency-builds
diff src/zlib-1.2.7/contrib/dotzlib/DotZLib/Deflater.cs @ 4:e13257ea84a4
Add bzip2, zlib, liblo, portaudio sources
author | Chris Cannam |
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date | Wed, 20 Mar 2013 13:59:52 +0000 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/src/zlib-1.2.7/contrib/dotzlib/DotZLib/Deflater.cs Wed Mar 20 13:59:52 2013 +0000 @@ -0,0 +1,106 @@ +// +// © Copyright Henrik Ravn 2004 +// +// Use, modification and distribution are subject to the Boost Software License, Version 1.0. +// (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) +// + +using System; +using System.Diagnostics; +using System.Runtime.InteropServices; + +namespace DotZLib +{ + + /// <summary> + /// Implements a data compressor, using the deflate algorithm in the ZLib dll + /// </summary> + public sealed class Deflater : CodecBase + { + #region Dll imports + [DllImport("ZLIB1.dll", CallingConvention=CallingConvention.Cdecl, CharSet=CharSet.Ansi)] + private static extern int deflateInit_(ref ZStream sz, int level, string vs, int size); + + [DllImport("ZLIB1.dll", CallingConvention=CallingConvention.Cdecl)] + private static extern int deflate(ref ZStream sz, int flush); + + [DllImport("ZLIB1.dll", CallingConvention=CallingConvention.Cdecl)] + private static extern int deflateReset(ref ZStream sz); + + [DllImport("ZLIB1.dll", CallingConvention=CallingConvention.Cdecl)] + private static extern int deflateEnd(ref ZStream sz); + #endregion + + /// <summary> + /// Constructs an new instance of the <c>Deflater</c> + /// </summary> + /// <param name="level">The compression level to use for this <c>Deflater</c></param> + public Deflater(CompressLevel level) : base() + { + int retval = deflateInit_(ref _ztream, (int)level, Info.Version, Marshal.SizeOf(_ztream)); + if (retval != 0) + throw new ZLibException(retval, "Could not initialize deflater"); + + resetOutput(); + } + + /// <summary> + /// Adds more data to the codec to be processed. + /// </summary> + /// <param name="data">Byte array containing the data to be added to the codec</param> + /// <param name="offset">The index of the first byte to add from <c>data</c></param> + /// <param name="count">The number of bytes to add</param> + /// <remarks>Adding data may, or may not, raise the <c>DataAvailable</c> event</remarks> + public override void Add(byte[] data, int offset, int count) + { + if (data == null) throw new ArgumentNullException(); + if (offset < 0 || count < 0) throw new ArgumentOutOfRangeException(); + if ((offset+count) > data.Length) throw new ArgumentException(); + + int total = count; + int inputIndex = offset; + int err = 0; + + while (err >= 0 && inputIndex < total) + { + copyInput(data, inputIndex, Math.Min(total - inputIndex, kBufferSize)); + while (err >= 0 && _ztream.avail_in > 0) + { + err = deflate(ref _ztream, (int)FlushTypes.None); + if (err == 0) + while (_ztream.avail_out == 0) + { + OnDataAvailable(); + err = deflate(ref _ztream, (int)FlushTypes.None); + } + inputIndex += (int)_ztream.total_in; + } + } + setChecksum( _ztream.adler ); + } + + + /// <summary> + /// Finishes up any pending data that needs to be processed and handled. + /// </summary> + public override void Finish() + { + int err; + do + { + err = deflate(ref _ztream, (int)FlushTypes.Finish); + OnDataAvailable(); + } + while (err == 0); + setChecksum( _ztream.adler ); + deflateReset(ref _ztream); + resetOutput(); + } + + /// <summary> + /// Closes the internal zlib deflate stream + /// </summary> + protected override void CleanUp() { deflateEnd(ref _ztream); } + + } +}