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comparison zlib/contrib/dotzlib/DotZLib/Deflater.cs @ 51:ae3a4bfb450b

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add some files of version 4.4.3 that have been forgotten.
author kent <kent@cr.ie.u-ryukyu.ac.jp>
date Sun, 07 Feb 2010 18:27:48 +0900
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children 04ced10e8804
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47:3bfb6c00c1e0 51:ae3a4bfb450b
1 //
2 // © Copyright Henrik Ravn 2004
3 //
4 // Use, modification and distribution are subject to the Boost Software License, Version 1.0.
5 // (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
6 //
7
8 using System;
9 using System.Diagnostics;
10 using System.Runtime.InteropServices;
11
12 namespace DotZLib
13 {
14
15 /// <summary>
16 /// Implements a data compressor, using the deflate algorithm in the ZLib dll
17 /// </summary>
18 public sealed class Deflater : CodecBase
19 {
20 #region Dll imports
21 [DllImport("ZLIB1.dll", CallingConvention=CallingConvention.Cdecl, CharSet=CharSet.Ansi)]
22 private static extern int deflateInit_(ref ZStream sz, int level, string vs, int size);
23
24 [DllImport("ZLIB1.dll", CallingConvention=CallingConvention.Cdecl)]
25 private static extern int deflate(ref ZStream sz, int flush);
26
27 [DllImport("ZLIB1.dll", CallingConvention=CallingConvention.Cdecl)]
28 private static extern int deflateReset(ref ZStream sz);
29
30 [DllImport("ZLIB1.dll", CallingConvention=CallingConvention.Cdecl)]
31 private static extern int deflateEnd(ref ZStream sz);
32 #endregion
33
34 /// <summary>
35 /// Constructs an new instance of the <c>Deflater</c>
36 /// </summary>
37 /// <param name="level">The compression level to use for this <c>Deflater</c></param>
38 public Deflater(CompressLevel level) : base()
39 {
40 int retval = deflateInit_(ref _ztream, (int)level, Info.Version, Marshal.SizeOf(_ztream));
41 if (retval != 0)
42 throw new ZLibException(retval, "Could not initialize deflater");
43
44 resetOutput();
45 }
46
47 /// <summary>
48 /// Adds more data to the codec to be processed.
49 /// </summary>
50 /// <param name="data">Byte array containing the data to be added to the codec</param>
51 /// <param name="offset">The index of the first byte to add from <c>data</c></param>
52 /// <param name="count">The number of bytes to add</param>
53 /// <remarks>Adding data may, or may not, raise the <c>DataAvailable</c> event</remarks>
54 public override void Add(byte[] data, int offset, int count)
55 {
56 if (data == null) throw new ArgumentNullException();
57 if (offset < 0 || count < 0) throw new ArgumentOutOfRangeException();
58 if ((offset+count) > data.Length) throw new ArgumentException();
59
60 int total = count;
61 int inputIndex = offset;
62 int err = 0;
63
64 while (err >= 0 && inputIndex < total)
65 {
66 copyInput(data, inputIndex, Math.Min(total - inputIndex, kBufferSize));
67 while (err >= 0 && _ztream.avail_in > 0)
68 {
69 err = deflate(ref _ztream, (int)FlushTypes.None);
70 if (err == 0)
71 while (_ztream.avail_out == 0)
72 {
73 OnDataAvailable();
74 err = deflate(ref _ztream, (int)FlushTypes.None);
75 }
76 inputIndex += (int)_ztream.total_in;
77 }
78 }
79 setChecksum( _ztream.adler );
80 }
81
82
83 /// <summary>
84 /// Finishes up any pending data that needs to be processed and handled.
85 /// </summary>
86 public override void Finish()
87 {
88 int err;
89 do
90 {
91 err = deflate(ref _ztream, (int)FlushTypes.Finish);
92 OnDataAvailable();
93 }
94 while (err == 0);
95 setChecksum( _ztream.adler );
96 deflateReset(ref _ztream);
97 resetOutput();
98 }
99
100 /// <summary>
101 /// Closes the internal zlib deflate stream
102 /// </summary>
103 protected override void CleanUp() { deflateEnd(ref _ztream); }
104
105 }
106 }