/* lzo1b_cc.c -- LZO1B compression internal entry point
This file is part of the LZO real-time data compression library.
Copyright (C) 1996-2002 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.,
59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
Markus F.X.J. Oberhumer
<markus@oberhumer.com>
*/
#define LZO_NEED_DICT_H
#include "config1b.h"
/***********************************************************************
// compression internal entry point.
************************************************************************/
int _lzo1b_do_compress ( const lzo_byte *in, lzo_uint in_len,
lzo_byte *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 = 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_byte *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)
{
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
*/