diff options
Diffstat (limited to 'src/lzo1b_cr.ch')
| -rw-r--r-- | src/lzo1b_cr.ch | 126 |
1 files changed, 126 insertions, 0 deletions
diff --git a/src/lzo1b_cr.ch b/src/lzo1b_cr.ch new file mode 100644 index 0000000..f98e0a5 --- /dev/null +++ b/src/lzo1b_cr.ch @@ -0,0 +1,126 @@ +/* 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 +*/ |