release/src/router/lzo/src/lzo1c_cc.c

   1 /* lzo1c_cc.c -- LZO1C compression internal entry point
   2
   3    This file is part of the LZO real-time data compression library.
   4
   5    Copyright (C) 1996-2015 Markus Franz Xaver Johannes Oberhumer
   6    All Rights Reserved.
   7
   8    The LZO library is free software; you can redistribute it and/or
   9    modify it under the terms of the GNU General Public License as
  10    published by the Free Software Foundation; either version 2 of
  11    the License, or (at your option) any later version.
  12
  13    The LZO library is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16    GNU General Public License for more details.
  17
  18    You should have received a copy of the GNU General Public License
  19    along with the LZO library; see the file COPYING.
  20    If not, write to the Free Software Foundation, Inc.,
  21    51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  22
  23    Markus F.X.J. Oberhumer
  24    <markus@oberhumer.com>
  25    http://www.oberhumer.com/opensource/lzo/
  26  */
  27
  28
  29 #define LZO_NEED_DICT_H 1
  30 #include "config1c.h"
  31
  32
  33 /***********************************************************************
  34 // compression internal entry point.
  35 ************************************************************************/
  36
  37 LZO_LOCAL_IMPL(int)
  38 _lzo1c_do_compress ( const lzo_bytep in,  lzo_uint  in_len,
  39                            lzo_bytep out, lzo_uintp out_len,
  40                            lzo_voidp wrkmem,
  41                            lzo_compress_t func )
  42 {
  43     int r;
  44 #if defined(LZO_TEST_COMPRESS_OVERRUN)
  45     lzo_uint avail_out = *out_len;
  46 #endif
  47
  48
  49 #if (LZO_COLLECT_STATS)
  50     _lzo1c_stats_init(lzo_stats);
  51     lzo_stats->in_len = in_len;
  52 #endif
  53
  54
  55     /* don't try to compress a block that's too short */
  56     if (in_len == 0)
  57     {
  58         *out_len = 0;
  59         r = LZO_E_OK;
  60     }
  61     else if (in_len <= MIN_LOOKAHEAD + 1)
  62     {
  63 #if defined(LZO_RETURN_IF_NOT_COMPRESSIBLE)
  64         *out_len = 0;
  65         r = LZO_E_NOT_COMPRESSIBLE;
  66 #else
  67         *out_len = pd(STORE_RUN(out,in,in_len), out);
  68         r = (*out_len > in_len) ? LZO_E_OK : LZO_E_ERROR;
  69 #endif
  70     }
  71     else
  72         r = func(in,in_len,out,out_len,wrkmem);
  73
  74
  75 #if defined(LZO_EOF_CODE)
  76 #if defined(LZO_TEST_COMPRESS_OVERRUN)
  77     if (r == LZO_E_OK && avail_out - *out_len < 3)
  78         r = LZO_E_COMPRESS_OVERRUN;
  79 #endif
  80     if (r == LZO_E_OK)
  81     {
  82         lzo_bytep op = out + *out_len;
  83         op[0] = M3_MARKER | 1;
  84         op[1] = 0;
  85         op[2] = 0;
  86         *out_len += 3;
  87     }
  88 #endif
  89
  90
  91 #if (LZO_COLLECT_STATS)
  92     lzo_stats->out_len = *out_len;
  93     lzo_stats->match_bytes =
  94        1 * lzo_stats->m1_matches + 2 * lzo_stats->m2_matches +
  95        3 * lzo_stats->m3_matches + 4 * lzo_stats->m4_matches;
  96     _lzo1c_stats_calc(lzo_stats);
  97 #endif
  98
  99     return r;
 100 }
 101
 102
 103 /***********************************************************************
 104 // note: this is not thread safe, but as it is used for finetuning only
 105 //       we don't care
 106 ************************************************************************/
 107
 108 #undef lzo_stats
 109 /* lzo_stats_t is still defined */
 110
 111
 112 #if (LZO_COLLECT_STATS)
 113
 114 static lzo_stats_t lzo_statistics;
 115 lzo_stats_t * const lzo1c_stats = &lzo_statistics;
 116
 117
 118 void _lzo1c_stats_init(lzo_stats_t *lzo_stats)
 119 {
 120     lzo_memset(lzo_stats,0,sizeof(*lzo_stats));
 121 }
 122
 123
 124 void _lzo1c_stats_calc(lzo_stats_t *lzo_stats)
 125 {
 126     lzo_stats->matches =
 127        lzo_stats->m1_matches + lzo_stats->m2_matches +
 128        lzo_stats->m3_matches + lzo_stats->m4_matches;
 129
 130     lzo_stats->literal_overhead = lzo_stats->lit_runs +
 131        2 * (lzo_stats->r0short_runs + lzo_stats->r0fast_runs +
 132             lzo_stats->r0long_runs);
 133     lzo_stats->literal_bytes = lzo_stats->literals +
 134        lzo_stats->literal_overhead;
 135
 136 #if 0
 137     assert(lzo_stats->match_bytes + lzo_stats->literal_bytes ==
 138        lzo_stats->out_len);
 139 #endif
 140
 141     lzo_stats->m2_matches -= lzo_stats->r1_matches;
 142     lzo_stats->m2_match[M2_MIN_LEN] -= lzo_stats->r1_matches;
 143
 144     if (lzo_stats->literals > 0)
 145         lzo_stats->literal_overhead_percent =
 146            100.0 * lzo_stats->literal_overhead / lzo_stats->literals;
 147 }
 148
 149
 150 #endif
 151
 152
 153 /* vim:set ts=4 sw=4 et: */