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      1 /*
      2  * Copyright (c) 2000-2007 Marc Alexander Lehmann <schmorp (at) schmorp.de>
      3  *
      4  * Redistribution and use in source and binary forms, with or without modifica-
      5  * tion, are permitted provided that the following conditions are met:
      6  *
      7  *   1.  Redistributions of source code must retain the above copyright notice,
      8  *       this list of conditions and the following disclaimer.
      9  *
     10  *   2.  Redistributions in binary form must reproduce the above copyright
     11  *       notice, this list of conditions and the following disclaimer in the
     12  *       documentation and/or other materials provided with the distribution.
     13  *
     14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
     15  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MER-
     16  * CHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO
     17  * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPE-
     18  * CIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
     19  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
     20  * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
     21  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTH-
     22  * ERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
     23  * OF THE POSSIBILITY OF SUCH DAMAGE.
     24  *
     25  * Alternatively, the contents of this file may be used under the terms of
     26  * the GNU General Public License ("GPL") version 2 or any later version,
     27  * in which case the provisions of the GPL are applicable instead of
     28  * the above. If you wish to allow the use of your version of this file
     29  * only under the terms of the GPL and not to allow others to use your
     30  * version of this file under the BSD license, indicate your decision
     31  * by deleting the provisions above and replace them with the notice
     32  * and other provisions required by the GPL. If you do not delete the
     33  * provisions above, a recipient may use your version of this file under
     34  * either the BSD or the GPL.
     35  */
     36 
     37 #ifndef LZFP_h
     38 #define LZFP_h
     39 
     40 #define STANDALONE 1 /* at the moment, this is ok. */
     41 
     42 #ifndef STANDALONE
     43 # include "lzf.h"
     44 #endif
     45 
     46 /*
     47  * Size of hashtable is (1 << HLOG) * sizeof (char *)
     48  * decompression is independent of the hash table size
     49  * the difference between 15 and 14 is very small
     50  * for small blocks (and 14 is usually a bit faster).
     51  * For a low-memory/faster configuration, use HLOG == 13;
     52  * For best compression, use 15 or 16 (or more, up to 22).
     53  */
     54 #ifndef HLOG
     55 # define HLOG 16
     56 #endif
     57 
     58 /*
     59  * Sacrifice very little compression quality in favour of compression speed.
     60  * This gives almost the same compression as the default code, and is
     61  * (very roughly) 15% faster. This is the preferred mode of operation.
     62  */
     63 #ifndef VERY_FAST
     64 # define VERY_FAST 1
     65 #endif
     66 
     67 /*
     68  * Sacrifice some more compression quality in favour of compression speed.
     69  * (roughly 1-2% worse compression for large blocks and
     70  * 9-10% for small, redundant, blocks and >>20% better speed in both cases)
     71  * In short: when in need for speed, enable this for binary data,
     72  * possibly disable this for text data.
     73  */
     74 #ifndef ULTRA_FAST
     75 # define ULTRA_FAST 0
     76 #endif
     77 
     78 /*
     79  * Unconditionally aligning does not cost very much, so do it if unsure
     80  */
     81 #ifndef STRICT_ALIGN
     82 # define STRICT_ALIGN !(defined(__i386) || defined (__amd64))
     83 #endif
     84 
     85 /*
     86  * You may choose to pre-set the hash table (might be faster on some
     87  * modern cpus and large (>>64k) blocks, and also makes compression
     88  * deterministic/repeatable when the configuration otherwise is the same).
     89  */
     90 #ifndef INIT_HTAB
     91 # define INIT_HTAB 0
     92 #endif
     93 
     94 /*
     95  * Avoid assigning values to errno variable? for some embedding purposes
     96  * (linux kernel for example), this is necessary. NOTE: this breaks
     97  * the documentation in lzf.h. Avoiding errno has no speed impact.
     98  */
     99 #ifndef AVOID_ERRNO
    100 # define AVOID_ERRNO 0
    101 #endif
    102 
    103 /*
    104  * Whether to pass the LZF_STATE variable as argument, or allocate it
    105  * on the stack. For small-stack environments, define this to 1.
    106  * NOTE: this breaks the prototype in lzf.h.
    107  */
    108 #ifndef LZF_STATE_ARG
    109 # define LZF_STATE_ARG 0
    110 #endif
    111 
    112 /*
    113  * Whether to add extra checks for input validity in lzf_decompress
    114  * and return EINVAL if the input stream has been corrupted. This
    115  * only shields against overflowing the input buffer and will not
    116  * detect most corrupted streams.
    117  * This check is not normally noticeable on modern hardware
    118  * (<1% slowdown), but might slow down older cpus considerably.
    119  */
    120 #ifndef CHECK_INPUT
    121 # define CHECK_INPUT 1
    122 #endif
    123 
    124 /*
    125  * Whether to store pointers or offsets inside the hash table. On
    126  * 64 bit architetcures, pointers take up twice as much space,
    127  * and might also be slower. Default is to autodetect.
    128  */
    129 /*#define LZF_USER_OFFSETS autodetect */
    130 
    131 /*****************************************************************************/
    132 /* nothing should be changed below */
    133 
    134 #ifdef __cplusplus
    135 # include <cstring>
    136 # include <climits>
    137 using namespace std;
    138 #else
    139 # include <string.h>
    140 # include <limits.h>
    141 #endif
    142 
    143 #ifndef LZF_USE_OFFSETS
    144 # if defined (WIN32)
    145 #  define LZF_USE_OFFSETS defined(_M_X64)
    146 # else
    147 #  if __cplusplus > 199711L
    148 #   include <cstdint>
    149 #  else
    150 #   include <stdint.h>
    151 #  endif
    152 #  define LZF_USE_OFFSETS (UINTPTR_MAX > 0xffffffffU)
    153 # endif
    154 #endif
    155 
    156 typedef unsigned char u8;
    157 
    158 #if LZF_USE_OFFSETS
    159 # define LZF_HSLOT_BIAS ((const u8 *)in_data)
    160   typedef unsigned int LZF_HSLOT;
    161 #else
    162 # define LZF_HSLOT_BIAS 0
    163   typedef const u8 *LZF_HSLOT;
    164 #endif
    165 
    166 typedef LZF_HSLOT LZF_STATE[1 << (HLOG)];
    167 
    168 #if !STRICT_ALIGN
    169 /* for unaligned accesses we need a 16 bit datatype. */
    170 # if USHRT_MAX == 65535
    171     typedef unsigned short u16;
    172 # elif UINT_MAX == 65535
    173     typedef unsigned int u16;
    174 # else
    175 #  undef STRICT_ALIGN
    176 #  define STRICT_ALIGN 1
    177 # endif
    178 #endif
    179 
    180 #if ULTRA_FAST
    181 # undef VERY_FAST
    182 #endif
    183 
    184 #endif
    185 
    186