lzo-2.03/src/lzo1c_cc.c

/* lzo1c_cc.c -- LZO1C 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 "config1c.h"


/***********************************************************************
// compression internal entry point.
************************************************************************/

int _lzo1c_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)
    _lzo1c_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;
    _lzo1c_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 lzo1c_stats = &lzo_statistics;


void _lzo1c_stats_init(lzo_stats_t *lzo_stats)
{
    lzo_memset(lzo_stats,0,sizeof(*lzo_stats));
}


void _lzo1c_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
*/