| /* |
| * |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you under the Apache License, Version 2.0 (the |
| * "License"); you may not use this file except in compliance |
| * with the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, |
| * software distributed under the License is distributed on an |
| * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY |
| * KIND, either express or implied. See the License for the |
| * specific language governing permissions and limitations |
| * under the License. |
| * |
| */ |
| |
| // LZO.Net |
| // $Id: LZOCompressor.cs,v 1.1 2004/02/22 17:44:04 laptop Exp $ |
| |
| namespace Simplicit.Net.Lzo { |
| using System; |
| using System.Diagnostics; |
| using System.Runtime.InteropServices; |
| |
| /// <summary> |
| /// Wrapper class for the highly performant LZO compression library |
| /// </summary> |
| public class LZOCompressor { |
| private static TraceSwitch _traceSwitch = new TraceSwitch("Simplicit.Net.Lzo", "Switch for tracing of the LZOCompressor-Class"); |
| |
| #region Dll-Imports |
| [DllImport("lzo.dll")] |
| private static extern int __lzo_init3(); |
| [DllImport("lzo.dll")] |
| private static extern string lzo_version_string(); |
| [DllImport("lzo.dll")] |
| private static extern string lzo_version_date(); |
| [DllImport("lzo.dll")] |
| private static extern int lzo1x_1_compress( |
| byte[] src, |
| int src_len, |
| byte[] dst, |
| ref int dst_len, |
| byte[] wrkmem |
| ); |
| [DllImport("lzo.dll")] |
| private static extern int lzo1x_decompress( |
| byte[] src, |
| int src_len, |
| byte[] dst, |
| ref int dst_len, |
| byte[] wrkmem); |
| #endregion |
| |
| private byte[] _workMemory = new byte[16384L * 4]; |
| |
| static LZOCompressor() { |
| int init = __lzo_init3(); |
| if(init != 0) { |
| throw new Exception("Initialization of LZO-Compressor failed !"); |
| } |
| } |
| |
| /// <summary> |
| /// Constructor. |
| /// </summary> |
| public LZOCompressor() { |
| } |
| |
| /// <summary> |
| /// Version string of the compression library. |
| /// </summary> |
| public string Version { |
| get { |
| return lzo_version_string(); |
| } |
| } |
| |
| /// <summary> |
| /// Version date of the compression library |
| /// </summary> |
| public string VersionDate { |
| get { |
| return lzo_version_date(); |
| } |
| } |
| |
| /// <summary> |
| /// Compresses a byte array and returns the compressed data in a new |
| /// array. You need the original length of the array to decompress it. |
| /// </summary> |
| /// <param name="src">Source array for compression</param> |
| /// <returns>Byte array containing the compressed data</returns> |
| public byte[] Compress(byte[] src) { |
| if(_traceSwitch.TraceVerbose) { |
| Trace.WriteLine(String.Format("LZOCompressor: trying to compress {0}", src.Length)); |
| } |
| byte[] dst = new byte[src.Length + src.Length / 64 + 16 + 3 + 4]; |
| int outlen = 0; |
| lzo1x_1_compress(src, src.Length, dst, ref outlen, _workMemory); |
| if(_traceSwitch.TraceVerbose) { |
| Trace.WriteLine(String.Format("LZOCompressor: compressed {0} to {1} bytes", src.Length, outlen)); |
| } |
| byte[] ret = new byte[outlen + 4]; |
| Array.Copy(dst, 0, ret, 0, outlen); |
| byte[] outlenarr = BitConverter.GetBytes(src.Length); |
| Array.Copy(outlenarr, 0, ret, outlen, 4); |
| return ret; |
| } |
| |
| /// <summary> |
| /// Decompresses compressed data to its original state. |
| /// </summary> |
| /// <param name="src">Source array to be decompressed</param> |
| /// <returns>Decompressed data</returns> |
| public byte[] Decompress(byte[] src) { |
| if(_traceSwitch.TraceVerbose) { |
| Trace.WriteLine(String.Format("LZOCompressor: trying to decompress {0}", src.Length)); |
| } |
| int origlen = BitConverter.ToInt32(src, src.Length - 4); |
| byte[] dst = new byte[origlen]; |
| int outlen = origlen; |
| lzo1x_decompress(src, src.Length - 4, dst, ref outlen, _workMemory); |
| if(_traceSwitch.TraceVerbose) { |
| Trace.WriteLine(String.Format("LZOCompressor: decompressed {0} to {1} bytes", src.Length, origlen)); |
| } |
| return dst; |
| } |
| } |
| } |