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Diffstat (limited to 'src/lzo1b_cc.c')
| -rw-r--r-- | src/lzo1b_cc.c | 167 |
1 files changed, 167 insertions, 0 deletions
diff --git a/src/lzo1b_cc.c b/src/lzo1b_cc.c new file mode 100644 index 0000000..45b0f85 --- /dev/null +++ b/src/lzo1b_cc.c @@ -0,0 +1,167 @@ +/* lzo1b_cc.c -- LZO1B compression internal entry point + + 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/ + */ + + +#define LZO_NEED_DICT_H +#include "config1b.h" + + +/*********************************************************************** +// compression internal entry point. +************************************************************************/ + +int _lzo1b_do_compress ( const lzo_bytep in, lzo_uint in_len, + lzo_bytep out, lzo_uintp out_len, + lzo_voidp wrkmem, + lzo_compress_t func ) +{ + int r; +#if defined(LZO_TEST_COMPRESS_OVERRUN) + lzo_uint avail_out = *out_len; +#endif + + +#if defined(LZO_COLLECT_STATS) + _lzo1b_stats_init(lzo_stats); + lzo_stats->in_len = in_len; +#endif + + + /* don't try to compress a block that's too short */ + if (in_len <= 0) + { + *out_len = 0; + r = LZO_E_OK; + } + else if (in_len <= MIN_LOOKAHEAD + 1) + { +#if defined(LZO_RETURN_IF_NOT_COMPRESSIBLE) + *out_len = 0; + r = LZO_E_NOT_COMPRESSIBLE; +#else + *out_len = pd(STORE_RUN(out,in,in_len), out); + r = (*out_len > in_len) ? LZO_E_OK : LZO_E_ERROR; +#endif + } + else + r = func(in,in_len,out,out_len,wrkmem); + + +#if defined(LZO_EOF_CODE) +#if defined(LZO_TEST_COMPRESS_OVERRUN) + if (r == LZO_E_OK && avail_out - *out_len < 3) + r = LZO_E_COMPRESS_OVERRUN; +#endif + if (r == LZO_E_OK) + { + lzo_bytep op = out + *out_len; + *op++ = M3_MARKER | 1; + *op++ = 0; + *op++ = 0; + *out_len += 3; + } +#endif + + +#if defined(LZO_COLLECT_STATS) + lzo_stats->out_len = *out_len; + lzo_stats->match_bytes = + 1 * lzo_stats->m1_matches + 2 * lzo_stats->m2_matches + + 3 * lzo_stats->m3_matches + 4 * lzo_stats->m4_matches; + _lzo1b_stats_calc(lzo_stats); +#endif + + return r; +} + + +/*********************************************************************** +// note: this is not thread safe, but as it is used for finetuning only +// we don't care +************************************************************************/ + +#undef lzo_stats +/* lzo_stats_t is still defined */ + + +#if defined(LZO_COLLECT_STATS) + +static lzo_stats_t lzo_statistics; +lzo_stats_t * const lzo1b_stats = &lzo_statistics; + + +void _lzo1b_stats_init(lzo_stats_t *lzo_stats) +{ + lzo_memset(lzo_stats,0,sizeof(*lzo_stats)); +} + + +void _lzo1b_stats_calc(lzo_stats_t *lzo_stats) +{ + lzo_stats->matches = + lzo_stats->m1_matches + lzo_stats->m2_matches + + lzo_stats->m3_matches + lzo_stats->m4_matches; + + lzo_stats->literal_overhead = lzo_stats->lit_runs + + 2 * (lzo_stats->r0short_runs + lzo_stats->r0fast_runs + + lzo_stats->r0long_runs); + lzo_stats->literal_bytes = lzo_stats->literals + + lzo_stats->literal_overhead; + +#if 0 + assert(lzo_stats->match_bytes + lzo_stats->literal_bytes == + lzo_stats->out_len); +#endif + + lzo_stats->m2_matches -= lzo_stats->r1_matches; + lzo_stats->m2_match[M2_MIN_LEN] -= lzo_stats->r1_matches; + + if (lzo_stats->literals > 0) + lzo_stats->literal_overhead_percent = + 100.0 * lzo_stats->literal_overhead / lzo_stats->literals; +} + + +#endif + + +/* +vi:ts=4:et +*/ + |