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657 lines
26 KiB
C#
657 lines
26 KiB
C#
namespace Wabbajack.Common
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{
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using ICSharpCode.SharpZipLib.BZip2;
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using System;
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using System.IO;
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/*
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The original bsdiff.c source code (http://www.daemonology.net/bsdiff/) is
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distributed under the following license:
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Copyright 2003-2005 Colin Percival
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All rights reserved
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Redistribution and use in source and binary forms, with or without
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modification, are permitted providing that the following conditions
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are met:
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1. Redistributions of source code must retain the above copyright
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notice, this list of conditions and the following disclaimer.
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2. Redistributions in binary form must reproduce the above copyright
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notice, this list of conditions and the following disclaimer in the
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documentation and/or other materials provided with the distribution.
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THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
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WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
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DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
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STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
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IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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POSSIBILITY OF SUCH DAMAGE.
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*/
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public class BSDiff
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{
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/// <summary>
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/// Creates a binary patch (in <a href="http://www.daemonology.net/bsdiff/">bsdiff</a> format) that can be used
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/// (by <see cref="Apply"/>) to transform <paramref name="oldData"/> into <paramref name="newData"/>.
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/// </summary>
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/// <param name="oldData">The original binary data.</param>
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/// <param name="newData">The new binary data.</param>
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/// <param name="output">A <see cref="Stream"/> to which the patch will be written.</param>
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public static void Create(byte[] oldData, byte[] newData, Stream output)
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{
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// check arguments
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if (oldData == null)
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throw new ArgumentNullException("oldData");
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if (newData == null)
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throw new ArgumentNullException("newData");
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if (output == null)
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throw new ArgumentNullException("output");
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if (!output.CanSeek)
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throw new ArgumentException("Output stream must be seekable.", "output");
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if (!output.CanWrite)
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throw new ArgumentException("Output stream must be writable.", "output");
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/* Header is
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0 8 "BSDIFF40"
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8 8 length of bzip2ed ctrl block
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16 8 length of bzip2ed diff block
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24 8 length of new file */
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/* File is
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0 32 Header
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32 ?? Bzip2ed ctrl block
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?? ?? Bzip2ed diff block
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?? ?? Bzip2ed extra block */
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byte[] header = new byte[c_headerSize];
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WriteInt64(c_fileSignature, header, 0); // "BSDIFF40"
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WriteInt64(0, header, 8);
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WriteInt64(0, header, 16);
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WriteInt64(newData.Length, header, 24);
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long startPosition = output.Position;
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output.Write(header, 0, header.Length);
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int[] I = SuffixSort(oldData);
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byte[] db = new byte[newData.Length];
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byte[] eb = new byte[newData.Length];
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int dblen = 0;
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int eblen = 0;
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using (BZip2OutputStream bz2Stream = new BZip2OutputStream(output) { IsStreamOwner = false })
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{
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// compute the differences, writing ctrl as we go
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int scan = 0;
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int pos = 0;
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int len = 0;
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int lastscan = 0;
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int lastpos = 0;
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int lastoffset = 0;
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while (scan < newData.Length)
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{
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int oldscore = 0;
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for (int scsc = scan += len; scan < newData.Length; scan++)
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{
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len = Search(I, oldData, newData, scan, 0, oldData.Length, out pos);
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for (; scsc < scan + len; scsc++)
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{
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if ((scsc + lastoffset < oldData.Length) && (oldData[scsc + lastoffset] == newData[scsc]))
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oldscore++;
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}
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if ((len == oldscore && len != 0) || (len > oldscore + 8))
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break;
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if ((scan + lastoffset < oldData.Length) && (oldData[scan + lastoffset] == newData[scan]))
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oldscore--;
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}
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if (len != oldscore || scan == newData.Length)
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{
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int s = 0;
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int sf = 0;
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int lenf = 0;
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for (int i = 0; (lastscan + i < scan) && (lastpos + i < oldData.Length);)
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{
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if (oldData[lastpos + i] == newData[lastscan + i])
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s++;
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i++;
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if (s * 2 - i > sf * 2 - lenf)
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{
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sf = s;
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lenf = i;
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}
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}
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int lenb = 0;
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if (scan < newData.Length)
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{
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s = 0;
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int sb = 0;
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for (int i = 1; (scan >= lastscan + i) && (pos >= i); i++)
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{
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if (oldData[pos - i] == newData[scan - i])
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s++;
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if (s * 2 - i > sb * 2 - lenb)
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{
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sb = s;
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lenb = i;
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}
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}
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}
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if (lastscan + lenf > scan - lenb)
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{
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int overlap = (lastscan + lenf) - (scan - lenb);
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s = 0;
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int ss = 0;
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int lens = 0;
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for (int i = 0; i < overlap; i++)
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{
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if (newData[lastscan + lenf - overlap + i] == oldData[lastpos + lenf - overlap + i])
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s++;
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if (newData[scan - lenb + i] == oldData[pos - lenb + i])
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s--;
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if (s > ss)
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{
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ss = s;
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lens = i + 1;
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}
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}
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lenf += lens - overlap;
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lenb -= lens;
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}
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for (int i = 0; i < lenf; i++)
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db[dblen + i] = (byte)(newData[lastscan + i] - oldData[lastpos + i]);
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for (int i = 0; i < (scan - lenb) - (lastscan + lenf); i++)
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eb[eblen + i] = newData[lastscan + lenf + i];
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dblen += lenf;
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eblen += (scan - lenb) - (lastscan + lenf);
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byte[] buf = new byte[8];
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WriteInt64(lenf, buf, 0);
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bz2Stream.Write(buf, 0, 8);
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WriteInt64((scan - lenb) - (lastscan + lenf), buf, 0);
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bz2Stream.Write(buf, 0, 8);
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WriteInt64((pos - lenb) - (lastpos + lenf), buf, 0);
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bz2Stream.Write(buf, 0, 8);
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lastscan = scan - lenb;
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lastpos = pos - lenb;
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lastoffset = pos - scan;
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}
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}
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}
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// compute size of compressed ctrl data
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long controlEndPosition = output.Position;
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WriteInt64(controlEndPosition - startPosition - c_headerSize, header, 8);
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// write compressed diff data
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using (BZip2OutputStream bz2Stream = new BZip2OutputStream(output) { IsStreamOwner = false })
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{
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bz2Stream.Write(db, 0, dblen);
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}
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// compute size of compressed diff data
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long diffEndPosition = output.Position;
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WriteInt64(diffEndPosition - controlEndPosition, header, 16);
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// write compressed extra data
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using (BZip2OutputStream bz2Stream = new BZip2OutputStream(output) { IsStreamOwner = false })
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{
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bz2Stream.Write(eb, 0, eblen);
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}
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// seek to the beginning, write the header, then seek back to end
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long endPosition = output.Position;
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output.Position = startPosition;
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output.Write(header, 0, header.Length);
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output.Position = endPosition;
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}
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/// <summary>
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/// Applies a binary patch (in <a href="http://www.daemonology.net/bsdiff/">bsdiff</a> format) to the data in
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/// <paramref name="input"/> and writes the results of patching to <paramref name="output"/>.
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/// </summary>
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/// <param name="input">A <see cref="Stream"/> containing the input data.</param>
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/// <param name="openPatchStream">A func that can open a <see cref="Stream"/> positioned at the start of the patch data.
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/// This stream must support reading and seeking, and <paramref name="openPatchStream"/> must allow multiple streams on
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/// the patch to be opened concurrently.</param>
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/// <param name="output">A <see cref="Stream"/> to which the patched data is written.</param>
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public static void Apply(Stream input, Func<Stream> openPatchStream, Stream output)
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{
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// check arguments
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if (input == null)
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throw new ArgumentNullException("input");
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if (openPatchStream == null)
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throw new ArgumentNullException("openPatchStream");
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if (output == null)
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throw new ArgumentNullException("output");
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/*
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File format:
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0 8 "BSDIFF40"
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8 8 X
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16 8 Y
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24 8 sizeof(newfile)
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32 X bzip2(control block)
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32+X Y bzip2(diff block)
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32+X+Y ??? bzip2(extra block)
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with control block a set of triples (x,y,z) meaning "add x bytes
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from oldfile to x bytes from the diff block; copy y bytes from the
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extra block; seek forwards in oldfile by z bytes".
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*/
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// read header
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long controlLength, diffLength, newSize;
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using (Stream patchStream = openPatchStream())
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{
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// check patch stream capabilities
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if (!patchStream.CanRead)
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throw new ArgumentException("Patch stream must be readable.", "openPatchStream");
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if (!patchStream.CanSeek)
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throw new ArgumentException("Patch stream must be seekable.", "openPatchStream");
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byte[] header = ReadExactly(patchStream, c_headerSize);
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// check for appropriate magic
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long signature = ReadInt64(header, 0);
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if (signature != c_fileSignature)
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throw new InvalidOperationException("Corrupt patch.");
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// read lengths from header
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controlLength = ReadInt64(header, 8);
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diffLength = ReadInt64(header, 16);
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newSize = ReadInt64(header, 24);
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if (controlLength < 0 || diffLength < 0 || newSize < 0)
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throw new InvalidOperationException("Corrupt patch.");
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}
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// preallocate buffers for reading and writing
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const int c_bufferSize = 1048576;
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byte[] newData = new byte[c_bufferSize];
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byte[] oldData = new byte[c_bufferSize];
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// prepare to read three parts of the patch in parallel
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using (Stream compressedControlStream = openPatchStream())
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using (Stream compressedDiffStream = openPatchStream())
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using (Stream compressedExtraStream = openPatchStream())
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{
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// seek to the start of each part
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compressedControlStream.Seek(c_headerSize, SeekOrigin.Current);
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compressedDiffStream.Seek(c_headerSize + controlLength, SeekOrigin.Current);
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compressedExtraStream.Seek(c_headerSize + controlLength + diffLength, SeekOrigin.Current);
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// decompress each part (to read it)
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using (BZip2InputStream controlStream = new BZip2InputStream(compressedControlStream))
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using (BZip2InputStream diffStream = new BZip2InputStream(compressedDiffStream))
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using (BZip2InputStream extraStream = new BZip2InputStream(compressedExtraStream))
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{
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long[] control = new long[3];
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byte[] buffer = new byte[8];
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int oldPosition = 0;
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int newPosition = 0;
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while (newPosition < newSize)
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{
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// read control data
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for (int i = 0; i < 3; i++)
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{
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ReadExactly(controlStream, buffer, 0, 8);
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control[i] = ReadInt64(buffer, 0);
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}
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// sanity-check
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if (newPosition + control[0] > newSize)
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throw new InvalidOperationException("Corrupt patch.");
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// seek old file to the position that the new data is diffed against
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input.Position = oldPosition;
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int bytesToCopy = (int)control[0];
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while (bytesToCopy > 0)
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{
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int actualBytesToCopy = Math.Min(bytesToCopy, c_bufferSize);
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// read diff string
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ReadExactly(diffStream, newData, 0, actualBytesToCopy);
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// add old data to diff string
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int availableInputBytes = Math.Min(actualBytesToCopy, (int)(input.Length - input.Position));
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ReadExactly(input, oldData, 0, availableInputBytes);
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for (int index = 0; index < availableInputBytes; index++)
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newData[index] += oldData[index];
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output.Write(newData, 0, actualBytesToCopy);
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// adjust counters
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newPosition += actualBytesToCopy;
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oldPosition += actualBytesToCopy;
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bytesToCopy -= actualBytesToCopy;
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}
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// sanity-check
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if (newPosition + control[1] > newSize)
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throw new InvalidOperationException("Corrupt patch.");
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// read extra string
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bytesToCopy = (int)control[1];
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while (bytesToCopy > 0)
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{
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int actualBytesToCopy = Math.Min(bytesToCopy, c_bufferSize);
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ReadExactly(extraStream, newData, 0, actualBytesToCopy);
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output.Write(newData, 0, actualBytesToCopy);
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newPosition += actualBytesToCopy;
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bytesToCopy -= actualBytesToCopy;
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}
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// adjust position
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oldPosition = (int)(oldPosition + control[2]);
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}
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}
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}
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}
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private static int CompareBytes(byte[] left, int leftOffset, byte[] right, int rightOffset)
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{
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for (int index = 0; index < left.Length - leftOffset && index < right.Length - rightOffset; index++)
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{
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int diff = left[index + leftOffset] - right[index + rightOffset];
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if (diff != 0)
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return diff;
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}
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return 0;
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}
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private static int MatchLength(byte[] oldData, int oldOffset, byte[] newData, int newOffset)
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{
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int i;
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for (i = 0; i < oldData.Length - oldOffset && i < newData.Length - newOffset; i++)
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{
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if (oldData[i + oldOffset] != newData[i + newOffset])
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break;
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}
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return i;
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}
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private static int Search(int[] I, byte[] oldData, byte[] newData, int newOffset, int start, int end, out int pos)
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{
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if (end - start < 2)
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{
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int startLength = MatchLength(oldData, I[start], newData, newOffset);
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int endLength = MatchLength(oldData, I[end], newData, newOffset);
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if (startLength > endLength)
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{
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pos = I[start];
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return startLength;
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}
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else
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{
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pos = I[end];
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return endLength;
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}
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}
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else
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{
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int midPoint = start + (end - start) / 2;
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return CompareBytes(oldData, I[midPoint], newData, newOffset) < 0 ?
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Search(I, oldData, newData, newOffset, midPoint, end, out pos) :
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Search(I, oldData, newData, newOffset, start, midPoint, out pos);
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}
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}
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private static void Split(int[] I, int[] v, int start, int len, int h)
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{
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if (len < 16)
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{
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int j;
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for (int k = start; k < start + len; k += j)
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{
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j = 1;
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int x = v[I[k] + h];
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for (int i = 1; k + i < start + len; i++)
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{
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if (v[I[k + i] + h] < x)
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{
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x = v[I[k + i] + h];
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j = 0;
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}
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if (v[I[k + i] + h] == x)
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{
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Swap(ref I[k + j], ref I[k + i]);
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j++;
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}
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}
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for (int i = 0; i < j; i++)
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v[I[k + i]] = k + j - 1;
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if (j == 1)
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I[k] = -1;
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}
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}
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else
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{
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int x = v[I[start + len / 2] + h];
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int jj = 0;
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int kk = 0;
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for (int i2 = start; i2 < start + len; i2++)
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{
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if (v[I[i2] + h] < x)
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jj++;
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if (v[I[i2] + h] == x)
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kk++;
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}
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jj += start;
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kk += jj;
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int i = start;
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int j = 0;
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int k = 0;
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while (i < jj)
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{
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if (v[I[i] + h] < x)
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{
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i++;
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}
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else if (v[I[i] + h] == x)
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{
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Swap(ref I[i], ref I[jj + j]);
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j++;
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}
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else
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{
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Swap(ref I[i], ref I[kk + k]);
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k++;
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}
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}
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while (jj + j < kk)
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{
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if (v[I[jj + j] + h] == x)
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{
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j++;
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}
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else
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{
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Swap(ref I[jj + j], ref I[kk + k]);
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k++;
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}
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}
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if (jj > start)
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Split(I, v, start, jj - start, h);
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for (i = 0; i < kk - jj; i++)
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v[I[jj + i]] = kk - 1;
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if (jj == kk - 1)
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I[jj] = -1;
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if (start + len > kk)
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Split(I, v, kk, start + len - kk, h);
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}
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}
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private static int[] SuffixSort(byte[] oldData)
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{
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int[] buckets = new int[256];
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foreach (byte oldByte in oldData)
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buckets[oldByte]++;
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for (int i = 1; i < 256; i++)
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buckets[i] += buckets[i - 1];
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for (int i = 255; i > 0; i--)
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buckets[i] = buckets[i - 1];
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buckets[0] = 0;
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int[] I = new int[oldData.Length + 1];
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for (int i = 0; i < oldData.Length; i++)
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I[++buckets[oldData[i]]] = i;
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|
int[] v = new int[oldData.Length + 1];
|
|
for (int i = 0; i < oldData.Length; i++)
|
|
v[i] = buckets[oldData[i]];
|
|
|
|
for (int i = 1; i < 256; i++)
|
|
{
|
|
if (buckets[i] == buckets[i - 1] + 1)
|
|
I[buckets[i]] = -1;
|
|
}
|
|
I[0] = -1;
|
|
|
|
for (int h = 1; I[0] != -(oldData.Length + 1); h += h)
|
|
{
|
|
int len = 0;
|
|
int i = 0;
|
|
while (i < oldData.Length + 1)
|
|
{
|
|
if (I[i] < 0)
|
|
{
|
|
len -= I[i];
|
|
i -= I[i];
|
|
}
|
|
else
|
|
{
|
|
if (len != 0)
|
|
I[i - len] = -len;
|
|
len = v[I[i]] + 1 - i;
|
|
Split(I, v, i, len, h);
|
|
i += len;
|
|
len = 0;
|
|
}
|
|
}
|
|
|
|
if (len != 0)
|
|
I[i - len] = -len;
|
|
}
|
|
|
|
for (int i = 0; i < oldData.Length + 1; i++)
|
|
I[v[i]] = i;
|
|
|
|
return I;
|
|
}
|
|
|
|
private static void Swap(ref int first, ref int second)
|
|
{
|
|
int temp = first;
|
|
first = second;
|
|
second = temp;
|
|
}
|
|
|
|
private static long ReadInt64(byte[] buf, int offset)
|
|
{
|
|
long value = buf[offset + 7] & 0x7F;
|
|
|
|
for (int index = 6; index >= 0; index--)
|
|
{
|
|
value *= 256;
|
|
value += buf[offset + index];
|
|
}
|
|
|
|
if ((buf[offset + 7] & 0x80) != 0)
|
|
value = -value;
|
|
|
|
return value;
|
|
}
|
|
|
|
private static void WriteInt64(long value, byte[] buf, int offset)
|
|
{
|
|
long valueToWrite = value < 0 ? -value : value;
|
|
|
|
for (int byteIndex = 0; byteIndex < 8; byteIndex++)
|
|
{
|
|
buf[offset + byteIndex] = unchecked((byte)valueToWrite);
|
|
valueToWrite >>= 8;
|
|
}
|
|
|
|
if (value < 0)
|
|
buf[offset + 7] |= 0x80;
|
|
}
|
|
|
|
/// <summary>
|
|
/// Reads exactly <paramref name="count"/> bytes from <paramref name="stream"/>.
|
|
/// </summary>
|
|
/// <param name="stream">The stream to read from.</param>
|
|
/// <param name="count">The count of bytes to read.</param>
|
|
/// <returns>A new byte array containing the data read from the stream.</returns>
|
|
private static byte[] ReadExactly(Stream stream, int count)
|
|
{
|
|
if (count < 0)
|
|
throw new ArgumentOutOfRangeException("count");
|
|
byte[] buffer = new byte[count];
|
|
ReadExactly(stream, buffer, 0, count);
|
|
return buffer;
|
|
}
|
|
|
|
/// <summary>
|
|
/// Reads exactly <paramref name="count"/> bytes from <paramref name="stream"/> into
|
|
/// <paramref name="buffer"/>, starting at the byte given by <paramref name="offset"/>.
|
|
/// </summary>
|
|
/// <param name="stream">The stream to read from.</param>
|
|
/// <param name="buffer">The buffer to read data into.</param>
|
|
/// <param name="offset">The offset within the buffer at which data is first written.</param>
|
|
/// <param name="count">The count of bytes to read.</param>
|
|
private static void ReadExactly(Stream stream, byte[] buffer, int offset, int count)
|
|
{
|
|
// check arguments
|
|
if (stream == null)
|
|
throw new ArgumentNullException("stream");
|
|
if (buffer == null)
|
|
throw new ArgumentNullException("buffer");
|
|
if (offset < 0 || offset > buffer.Length)
|
|
throw new ArgumentOutOfRangeException("offset");
|
|
if (count < 0 || buffer.Length - offset < count)
|
|
throw new ArgumentOutOfRangeException("count");
|
|
|
|
while (count > 0)
|
|
{
|
|
// read data
|
|
int bytesRead = stream.Read(buffer, offset, count);
|
|
|
|
// check for failure to read
|
|
if (bytesRead == 0)
|
|
throw new EndOfStreamException();
|
|
|
|
// move to next block
|
|
offset += bytesRead;
|
|
count -= bytesRead;
|
|
}
|
|
}
|
|
|
|
const long c_fileSignature = 0x3034464649445342L;
|
|
const int c_headerSize = 32;
|
|
}
|
|
}
|