From 07162fa301835387e4da4278326ec1ff45d1dc3e Mon Sep 17 00:00:00 2001 From: Aki Date: Wed, 29 Sep 2021 21:52:57 +0200 Subject: Squashed 'zlib/' content from commit cacf7f1 git-subtree-dir: zlib git-subtree-split: cacf7f1d4e3d44d871b605da3b647f07d718623f --- contrib/dotzlib/DotZLib/Deflater.cs | 106 ++++++++++++++++++++++++++++++++++++ 1 file changed, 106 insertions(+) create mode 100644 contrib/dotzlib/DotZLib/Deflater.cs (limited to 'contrib/dotzlib/DotZLib/Deflater.cs') diff --git a/contrib/dotzlib/DotZLib/Deflater.cs b/contrib/dotzlib/DotZLib/Deflater.cs new file mode 100644 index 0000000..c247792 --- /dev/null +++ b/contrib/dotzlib/DotZLib/Deflater.cs @@ -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 +{ + + /// + /// Implements a data compressor, using the deflate algorithm in the ZLib dll + /// + 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 + + /// + /// Constructs an new instance of the Deflater + /// + /// The compression level to use for this Deflater + 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(); + } + + /// + /// Adds more data to the codec to be processed. + /// + /// Byte array containing the data to be added to the codec + /// The index of the first byte to add from data + /// The number of bytes to add + /// Adding data may, or may not, raise the DataAvailable event + 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 ); + } + + + /// + /// Finishes up any pending data that needs to be processed and handled. + /// + 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(); + } + + /// + /// Closes the internal zlib deflate stream + /// + protected override void CleanUp() { deflateEnd(ref _ztream); } + + } +} -- cgit v1.1