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/* lzo1b_cr.ch -- implementation of the LZO1B compression algorithm
This file is part of the LZO real-time data compression library.
Copyright (C) 1996-2017 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(m3[-2] | (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);
/* vim:set ts=4 sw=4 et: */
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