/* lzo1b_cr.ch -- implementation of the LZO1B compression algorithm This file is part of the LZO real-time data compression library. Copyright (C) 1996-2014 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/ */ /* 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); /* vi:ts=4:et */