beagled/Lucene.Net/SharpZipLibAdapter.cs

   1 /*
   2  * Copyright 2004 The Apache Software Foundation
   3  *
   4  * Licensed under the Apache License, Version 2.0 (the "License");
   5  * you may not use this file except in compliance with the License.
   6  * You may obtain a copy of the License at
   7  *
   8  * http://www.apache.org/licenses/LICENSE-2.0
   9  *
  10  * Unless required by applicable law or agreed to in writing, software
  11  * distributed under the License is distributed on an "AS IS" BASIS,
  12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13  * See the License for the specific language governing permissions and
  14  * limitations under the License.
  15  */
  16
  17 /// To enable compression support in Lucene.Net 1.9 using .NET 1.1. Framework,
  18 /// you will need to define 'SHARP_ZIP_LIB' and referance the SharpLibZip
  19 /// library.  The SharpLibZip library can be downloaded from:
  20 /// http://www.icsharpcode.net/OpenSource/SharpZipLib/
  21 ///
  22 /// You can use any other cmpression library you have by plugging it into this
  23 /// code or by providing your own adapter as in this one.
  24
  25
  26 #if SHARP_ZIP_LIB
  27
  28 using System;
  29
  30 using ICSharpCode.SharpZipLib;
  31 using ICSharpCode.SharpZipLib.Zip.Compression;
  32 using System.IO;
  33
  34 namespace Lucene.Net.Index.Compression
  35 {
  36     public class SharpZipLibAdapter : SupportClass.CompressionSupport.ICompressionAdapter
  37     {
  38         public byte[] Compress(byte[] input)
  39         {
  40             // Create the compressor with highest level of compression
  41             Deflater compressor = new Deflater();
  42             compressor.SetLevel(Deflater.BEST_COMPRESSION);
  43
  44             // Give the compressor the data to compress
  45             compressor.SetInput(input);
  46             compressor.Finish();
  47
  48             /*
  49              * Create an expandable byte array to hold the compressed data.
  50              * You cannot use an array that's the same size as the orginal because
  51              * there is no guarantee that the compressed data will be smaller than
  52              * the uncompressed data.
  53              */
  54             MemoryStream bos = new MemoryStream(input.Length);
  55
  56             // Compress the data
  57             byte[] buf = new byte[1024];
  58             while (!compressor.IsFinished)
  59             {
  60                 int count = compressor.Deflate(buf);
  61                 bos.Write(buf, 0, count);
  62             }
  63
  64             // Get the compressed data
  65             return bos.ToArray();
  66         }
  67
  68         public byte[] Uncompress(byte[] input)
  69         {
  70             Inflater decompressor = new Inflater();
  71             decompressor.SetInput(input);
  72
  73             // Create an expandable byte array to hold the decompressed data
  74             MemoryStream bos = new MemoryStream(input.Length);
  75
  76             // Decompress the data
  77             byte[] buf = new byte[1024];
  78             while (!decompressor.IsFinished)
  79             {
  80                 int count = decompressor.Inflate(buf);
  81                 bos.Write(buf, 0, count);
  82             }
  83
  84             // Get the decompressed data
  85             return bos.ToArray();
  86         }
  87     }
  88 }
  89
  90 #endif