src/zlib/maketree.c

   1 /* maketree.c -- make inffixed.h table for decoding fixed codes
   2  * Copyright (C) 1998 Mark Adler
   3  * For conditions of distribution and use, see copyright notice in zlib.h
   4  */
   5
   6 /* WARNING: this file should *not* be used by applications. It is
   7    part of the implementation of the compression library and is
   8    subject to change. Applications should only use zlib.h.
   9  */
  10
  11 /* This program is included in the distribution for completeness.
  12    You do not need to compile or run this program since inffixed.h
  13    is already included in the distribution.  To use this program
  14    you need to compile zlib with BUILDFIXED defined and then compile
  15    and link this program with the zlib library.  Then the output of
  16    this program can be piped to inffixed.h. */
  17
  18 #include <stdio.h>
  19 #include <stdlib.h>
  20 #include "zutil.h"
  21 #include "inftrees.h"
  22
  23 /* simplify the use of the inflate_huft type with some defines */
  24 #define exop word.what.Exop
  25 #define bits word.what.Bits
  26
  27 /* showtree is only used for debugging purposes */
  28 void showtree(uInt b, inflate_huft *t, int d)
  29 {
  30   int i, e;
  31   char p[2*d+1];
  32
  33   for (i = 0; i < 2*d; i++)
  34     p[i] = ' ';
  35   p[i] = 0;
  36   printf("%s[%d]\n", p, 1<<b);
  37   for (i = 0; i < (1<<b); i++)
  38   {
  39     e = t[i].exop;
  40     if (e == 0)                 /* simple code */
  41       printf("%s%d(%d): literal=%d\n", p, i, t[i].bits, t[i].base);
  42     else if (e & 16)            /* length */
  43       printf("%s%d(%d): length/distance=%d+(%d)\n",
  44                 p, i, t[i].bits, t[i].base, e & 15);
  45     else if ((e & 64) == 0)     /* next table */
  46     {
  47       printf("%s%d(%d): *sub table*\n", p, i, t[i].bits);
  48       showtree(e, t + t[i].base, d + 1);
  49     }
  50     else if (e & 32)            /* end of block */
  51       printf("%s%d(%d): end of block\n", p, i, t[i].bits);
  52     else                        /* bad code */
  53       printf("%s%d: bad code\n", p, i);
  54   }
  55 }
  56
  57 /* generate initialization table for an inflate_huft structure array */
  58 void maketree(uInt b, inflate_huft *t)
  59 {
  60   int i, e;
  61
  62   i = 0;
  63   while (1)
  64   {
  65     e = t[i].exop;
  66     if (e && (e & (16+64)) == 0)        /* table pointer */
  67     {
  68       fprintf(stderr, "maketree: cannot initialize sub-tables!\n");
  69       exit(1);
  70     }
  71     if (i % 5 == 0)
  72       printf("\n   ");
  73     printf(" {{%u,%u},%u}", t[i].exop, t[i].bits, t[i].base);
  74     if (++i == (1<<b))
  75       break;
  76     putchar(',');
  77   }
  78   puts("");
  79 }
  80
  81 /* create the fixed tables in C initialization syntax */
  82 void main(void)
  83 {
  84   int r;
  85   uInt bl, bd;
  86   inflate_huft *tl, *td;
  87   z_stream z;
  88
  89   z.zalloc = zcalloc;
  90   z.opaque = (voidpf)0;
  91   z.zfree = zcfree;
  92   r = inflate_trees_fixed(&bl, &bd, &tl, &td, &z);
  93   if (r)
  94   {
  95     fprintf(stderr, "inflate_trees_fixed error %d\n", r);
  96     return;
  97   }
  98   /* puts("Literal/Length Tree:");
  99      showtree(bl, tl, 1);
 100      puts("Distance Tree:");
 101      showtree(bd, td, 1); */
 102   puts("/* inffixed.h -- table for decoding fixed codes");
 103   puts(" * Generated automatically by the maketree.c program");
 104   puts(" */");
 105   puts("");
 106   puts("/* WARNING: this file should *not* be used by applications. It is");
 107   puts("   part of the implementation of the compression library and is");
 108   puts("   subject to change. Applications should only use zlib.h.");
 109   puts(" */");
 110   puts("");
 111   printf("local uInt fixed_bl = %d;\n", bl);
 112   printf("local uInt fixed_bd = %d;\n", bd);
 113   printf("local inflate_huft fixed_tl[] = {");
 114   maketree(bl, tl);
 115   puts("  };");
 116   printf("local inflate_huft fixed_td[] = {");
 117   maketree(bd, td);
 118   puts("  };");
 119 }