Utilities/cmcompress/cmcompress.h

   1 /*
   2  * Copyright (c) 1985, 1986 The Regents of the University of California.
   3  * All rights reserved.
   4  *
   5  * This code is derived from software contributed to Berkeley by
   6  * James A. Woods, derived from original work by Spencer Thomas
   7  * and Joseph Orost.
   8  *
   9  * Redistribution and use in source and binary forms, with or without
  10  * modification, are permitted provided that the following conditions
  11  * are met:
  12  * 1. Redistributions of source code must retain the above copyright
  13  *    notice, this list of conditions and the following disclaimer.
  14  * 2. Redistributions in binary form must reproduce the above copyright
  15  *    notice, this list of conditions and the following disclaimer in the
  16  *    documentation and/or other materials provided with the distribution.
  17  * 3. All advertising materials mentioning features or use of this software
  18  *    must display the following acknowledgement:
  19  *  This product includes software developed by the University of
  20  *  California, Berkeley and its contributors.
  21  * 4. Neither the name of the University nor the names of its contributors
  22  *    may be used to endorse or promote products derived from this software
  23  *    without specific prior written permission.
  24  *
  25  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  26  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  27  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  28  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  29  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  30  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  31  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  32  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  33  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  34  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  35  * SUCH DAMAGE.
  36  */
  37
  38 #ifndef __cmcompress__h_
  39 #define __cmcompress__h_
  40
  41 #include <stdio.h>
  42
  43 #ifdef __cplusplus
  44 extern "C"
  45 {
  46 #endif
  47
  48   /*
  49    * Set USERMEM to the maximum amount of physical user memory available
  50    * in bytes.  USERMEM is used to determine the maximum BITS that can be used
  51    * for compression.
  52    *
  53    * SACREDMEM is the amount of physical memory saved for others; compress
  54    * will hog the rest.
  55    */
  56 #ifndef SACREDMEM
  57 #define SACREDMEM  0
  58 #endif
  59
  60 #ifndef USERMEM
  61 # define USERMEM   450000  /* default user memory */
  62 #endif
  63
  64 #ifdef pdp11
  65 # define BITS   12  /* max bits/code for 16-bit machine */
  66 # define NO_UCHAR  /* also if "unsigned char" functions as signed char */
  67 # undef USERMEM
  68 #endif /* pdp11 */  /* don't forget to compile with -i */
  69
  70 #ifdef USERMEM
  71 # if USERMEM >= (433484+SACREDMEM)
  72 #  define PBITS  16
  73 # else
  74 #  if USERMEM >= (229600+SACREDMEM)
  75 #   define PBITS  15
  76 #  else
  77 #   if USERMEM >= (127536+SACREDMEM)
  78 #    define PBITS  14
  79 #   else
  80 #    if USERMEM >= (73464+SACREDMEM)
  81 #     define PBITS  13
  82 #    else
  83 #     define PBITS  12
  84 #    endif
  85 #   endif
  86 #  endif
  87 # endif
  88 # undef USERMEM
  89 #endif /* USERMEM */
  90
  91 #ifdef PBITS    /* Preferred BITS for this memory size */
  92 # ifndef BITS
  93 #  define BITS PBITS
  94 # endif /* BITS */
  95 #endif /* PBITS */
  96
  97 #if BITS == 16
  98 # define HSIZE  69001    /* 95% occupancy */
  99 #endif
 100 #if BITS == 15
 101 # define HSIZE  35023    /* 94% occupancy */
 102 #endif
 103 #if BITS == 14
 104 # define HSIZE  18013    /* 91% occupancy */
 105 #endif
 106 #if BITS == 13
 107 # define HSIZE  9001    /* 91% occupancy */
 108 #endif
 109 #if BITS <= 12
 110 # define HSIZE  5003    /* 80% occupancy */
 111 #endif
 112
 113   /*
 114    * a code_int must be able to hold 2**BITS values of type int, and also -1
 115    */
 116 #if BITS > 15
 117   typedef long int  code_int;
 118 #else
 119   typedef int    code_int;
 120 #endif
 121
 122 #ifdef SIGNED_COMPARE_SLOW
 123   typedef unsigned long int count_int;
 124   typedef unsigned short int count_short;
 125 #else
 126   typedef long int    count_int;
 127 #endif
 128
 129 #ifdef NO_UCHAR
 130   typedef char  char_type;
 131 #else
 132   typedef  unsigned char  char_type;
 133 #endif /* UCHAR */
 134
 135
 136
 137   struct cmcompress_stream
 138     {
 139     int n_bits;        /* number of bits/code */
 140     int maxbits;      /* user settable max # bits/code */
 141     code_int maxcode;      /* maximum code, given n_bits */
 142     code_int maxmaxcode;  /* should NEVER generate this code */
 143
 144     count_int htab [HSIZE];
 145     unsigned short codetab [HSIZE];
 146
 147     code_int hsize;      /* for dynamic table sizing */
 148     code_int free_ent;      /* first unused entry */
 149     int nomagic;  /* Use a 3-byte magic number header, unless old file */
 150
 151     /*
 152      * block compression parameters -- after all codes are used up,
 153      * and compression rate changes, start over.
 154      */
 155     int block_compress;
 156     int clear_flg;
 157     long int ratio;
 158     count_int checkpoint;
 159
 160 #ifdef DEBUG
 161     int debug;
 162     int verbose;
 163 #endif
 164
 165     /* compress internals */
 166     int offset;
 167     long int in_count;      /* length of input */
 168     long int bytes_out;      /* length of compressed output */
 169     long int out_count;      /* # of codes output (for debugging) */
 170
 171     /* internals */
 172     code_int ent;
 173     code_int hsize_reg;
 174     int hshift;
 175
 176     long fcode;
 177     int first_pass;
 178
 179     /* For input and output */
 180     int (*input_stream)(void*);
 181     int (*output_stream)(void*, const char*,int);
 182     void* client_data;
 183     };
 184
 185   int cmcompress_compress_initialize(struct cmcompress_stream* cdata);
 186   int cmcompress_compress_start(struct cmcompress_stream* cdata);
 187   int cmcompress_compress(struct cmcompress_stream* cdata, void* buff, size_t n);
 188   int cmcompress_compress_finalize(struct cmcompress_stream* cdata);
 189
 190 #ifdef __cplusplus
 191 }
 192 #endif
 193
 194
 195 #endif /* __cmcompress__h_ */