blob: f98e0a501ca01a9fab4a086cde2f2178a2726366 [file] [log] [blame]
/* lzo1b_cr.ch -- implementation of the LZO1B compression algorithm
This file is part of the LZO real-time data compression library.
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>
http://www.oberhumer.com/opensource/lzo/
*/
/* WARNING: this file should *not* be used by applications. It is
part of the implementation of the library and is subject
to change.
*/
/***********************************************************************
// store the current literal run
************************************************************************/
assert(ip < ip_end);
if (pd(ip,ii) > 0)
{
lzo_uint t = pd(ip,ii);
#if defined(LZO_HAVE_R1)
if (ip == r1)
{
/* Code a context sensitive R1 match. */
LZO_STATS(lzo_stats->literals += t);
LZO_STATS(lzo_stats->r1_matches++);
assert(t == 1);
/* modify marker byte */
assert((op[-2] >> M2O_BITS) == (M2_MARKER >> M2O_BITS));
op[-2] &= M2O_MASK;
assert((op[-2] >> M2O_BITS) == 0);
/* copy 1 literal */
*op++ = *ii++;
r1 = ip + (M2_MIN_LEN + 1); /* set new R1 pointer */
}
else
#endif
if (t < R0MIN)
{
/* inline the copying of a short run */
LZO_STATS(lzo_stats->literals += t);
LZO_STATS(lzo_stats->lit_runs++);
LZO_STATS(lzo_stats->lit_run[t]++);
#if defined(LZO_HAVE_M3)
if (t < LZO_SIZE(8-M3O_BITS) && op == m3)
{
/* Code a very short literal run into the low offset bits
* of the previous M3/M4 match.
*/
LZO_STATS(lzo_stats->lit_runs_after_m3_match++);
LZO_STATS(lzo_stats->lit_run_after_m3_match[t]++);
assert((m3[-2] >> M3O_BITS) == 0);
m3[-2] |= LZO_BYTE(t << M3O_BITS);
}
else
#endif
{
*op++ = LZO_BYTE(t);
}
MEMCPY_DS(op, ii, t);
#if defined(LZO_HAVE_R1)
r1 = ip + (M2_MIN_LEN + 1); /* set new R1 pointer */
#endif
}
else if (t < R0FAST)
{
/* inline the copying of a short R0 run */
LZO_STATS(lzo_stats->literals += t);
LZO_STATS(lzo_stats->r0short_runs++);
*op++ = 0; *op++ = LZO_BYTE(t - R0MIN);
MEMCPY_DS(op, ii, t);
#if defined(LZO_HAVE_R1)
r1 = ip + (M2_MIN_LEN + 1); /* set new R1 pointer */
#endif
}
else
{
op = STORE_RUN(op,ii,t);
ii = ip;
}
}
/* ii now points to the start of the current match */
assert(ii == ip);
/*
vi:ts=4:et
*/