#region Copyright notice /* C# port of the crude minilzo source version 2.06 by Frank Razenberg Beware, you should never want to see C# code like this. You were warned. I simply ran the MSVC preprocessor on the original source, changed the datatypes to their C# counterpart and fixed changed some control flow stuff to amend for the different goto semantics between C and C#. Original copyright notice is included below. */ /* minilzo.c -- mini subset of the LZO real-time data compression library This file is part of the LZO real-time data compression library. Copyright (C) 2011 Markus Franz Xaver Johannes Oberhumer Copyright (C) 2010 Markus Franz Xaver Johannes Oberhumer Copyright (C) 2009 Markus Franz Xaver Johannes Oberhumer Copyright (C) 2008 Markus Franz Xaver Johannes Oberhumer Copyright (C) 2007 Markus Franz Xaver Johannes Oberhumer Copyright (C) 2006 Markus Franz Xaver Johannes Oberhumer Copyright (C) 2005 Markus Franz Xaver Johannes Oberhumer Copyright (C) 2004 Markus Franz Xaver Johannes Oberhumer Copyright (C) 2003 Markus Franz Xaver Johannes Oberhumer Copyright (C) 2002 Markus Franz Xaver Johannes Oberhumer Copyright (C) 2001 Markus Franz Xaver Johannes Oberhumer Copyright (C) 2000 Markus Franz Xaver Johannes Oberhumer Copyright (C) 1999 Markus Franz Xaver Johannes Oberhumer Copyright (C) 1998 Markus Franz Xaver Johannes Oberhumer Copyright (C) 1997 Markus Franz Xaver Johannes Oberhumer Copyright (C) 1996 Markus Franz Xaver Johannes Oberhumer All Rights Reserved. The LZO library is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. The LZO library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with the LZO library; see the file COPYING. If not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. Markus F.X.J. Oberhumer http://www.oberhumer.com/opensource/lzo/ */ /* * NOTE: * the full LZO package can be found at * http://www.oberhumer.com/opensource/lzo/ */ #endregion using System; namespace OpenRA.Mods.Common.FileFormats { public static class LZOCompression { static unsafe int LZO1xDecompress(byte* @in, uint inLen, byte* @out, ref uint outLen, void* wrkmem) { byte* op; byte* ip; uint t; byte* mPos; byte* ipEnd = @in + inLen; outLen = 0; op = @out; ip = @in; bool gtFirstLiteralRun = false; bool gtMatchDone = false; if (*ip > 17) { t = (uint)(*ip++ - 17); if (t < 4) MatchNext(ref op, ref ip, ref t); else { do { *op++ = *ip++; } while (--t > 0); gtFirstLiteralRun = true; } } while (true) { if (gtFirstLiteralRun) { gtFirstLiteralRun = false; goto first_literal_run; } t = *ip++; if (t >= 16) goto match; if (t == 0) { while (*ip == 0) { t += 255; ip++; } t += (uint)(15 + *ip++); } *(uint*)op = *(uint*)ip; op += 4; ip += 4; if (--t > 0) { if (t >= 4) { do { *(uint*)op = *(uint*)ip; op += 4; ip += 4; t -= 4; } while (t >= 4); if (t > 0) do { *op++ = *ip++; } while (--t > 0); } else do { *op++ = *ip++; } while (--t > 0); } first_literal_run: t = *ip++; if (t >= 16) goto match; mPos = op - (1 + 0x0800); mPos -= t >> 2; mPos -= *ip++ << 2; *op++ = *mPos++; *op++ = *mPos++; *op++ = *mPos; gtMatchDone = true; match: do { if (gtMatchDone) { gtMatchDone = false; goto match_done; } if (t >= 64) { mPos = op - 1; mPos -= (t >> 2) & 7; mPos -= *ip++ << 3; t = (t >> 5) - 1; CopyMatch(ref op, ref mPos, ref t); goto match_done; } else if (t >= 32) { t &= 31; if (t == 0) { while (*ip == 0) { t += 255; ip++; } t += (uint)(31 + *ip++); } mPos = op - 1; mPos -= (*(ushort*)(void*)ip) >> 2; ip += 2; } else if (t >= 16) { mPos = op; mPos -= (t & 8) << 11; t &= 7; if (t == 0) { while (*ip == 0) { t += 255; ip++; } t += (uint)(7 + *ip++); } mPos -= (*(ushort*)ip) >> 2; ip += 2; if (mPos == op) goto eof_found; mPos -= 0x4000; } else { mPos = op - 1; mPos -= t >> 2; mPos -= *ip++ << 2; *op++ = *mPos++; *op++ = *mPos; goto match_done; } if (t >= 2 * 4 - (3 - 1) && (op - mPos) >= 4) { *(uint*)op = *(uint*)mPos; op += 4; mPos += 4; t -= 4 - (3 - 1); do { *(uint*)op = *(uint*)mPos; op += 4; mPos += 4; t -= 4; } while (t >= 4); if (t > 0) do { *op++ = *mPos++; } while (--t > 0); } else { // copy_match: *op++ = *mPos++; *op++ = *mPos++; do { *op++ = *mPos++; } while (--t > 0); } match_done: t = (uint)(ip[-2] & 3); if (t == 0) break; // match_next: *op++ = *ip++; if (t > 1) { *op++ = *ip++; if (t > 2) *op++ = *ip++; } t = *ip++; } while (true); } eof_found: outLen = (uint)(op - @out); return ip == ipEnd ? 0 : (ip < ipEnd ? (-8) : (-4)); } static unsafe void MatchNext(ref byte* op, ref byte* ip, ref uint t) { do { *op++ = *ip++; } while (--t > 0); t = *ip++; } static unsafe void CopyMatch(ref byte* op, ref byte* mPos, ref uint t) { *op++ = *mPos++; *op++ = *mPos++; do { *op++ = *mPos++; } while (--t > 0); } public static void DecodeInto(byte[] src, uint srcOffset, uint srcLength, byte[] dest, uint destOffset, ref uint destLength) { unsafe { fixed (byte* r = src, w = dest, wrkmem = new byte[IntPtr.Size * 16384]) { LZO1xDecompress(r + srcOffset, srcLength, w + destOffset, ref destLength, wrkmem); } } } } }