Files
OpenRA/OpenRA.Mods.Cnc/FileFormats/LZOCompression.cs
2024-06-03 10:25:06 +02:00

292 lines
6.8 KiB
C#

#region Copyright & License Information
/*
* Copyright (c) The OpenRA Developers and Contributors
* This file is part of OpenRA, which is free software. It is made
* available to you under the terms of the GNU General Public License
* as published by the Free Software Foundation, either version 3 of
* the License, or (at your option) any later version. For more
* information, see COPYING.
*/
#endregion
#region Additional Copyright & License Information
/*
* C# port of the crude minilzo source version 2.06 by Frank Razenberg
* The full LZO package can be found at https://www.oberhumer.com/opensource/lzo/
*
* 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
* <markus@oberhumer.com>
* https://www.oberhumer.com/opensource/lzo/
*/
#endregion
using System;
namespace OpenRA.Mods.Cnc.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;
var ipEnd = @in + inLen;
outLen = 0;
op = @out;
ip = @in;
var gtFirstLiteralRun = false;
var 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*)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);
}
}
}
}
}