/tags/rel-1-3-26/SWIG/Tools/WAD/Wad/string.c

  1/* ----------------------------------------------------------------------------- 
  2 * string.c
  3 *
  4 *    This file provides support for string storage in WAD.  Since strings are
  5 *    used frequently in WAD, this file implements string interning and
  6 *    some lookup functions that can be used to return a previously stored
  7 *    string rather than making a new copy.
  8 * 
  9 * Author(s) : David Beazley (beazley@cs.uchicago.edu)
 10 *
 11 * Copyright (C) 2000.  The University of Chicago. 
 12 *
 13 * This library is free software; you can redistribute it and/or
 14 * modify it under the terms of the GNU Lesser General Public
 15 * License as published by the Free Software Foundation; either
 16 * version 2.1 of the License, or (at your option) any later version.
 17 *
 18 * This library is distributed in the hope that it will be useful,
 19 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 20 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 21 * Lesser General Public License for more details.
 22 *
 23 * You should have received a copy of the GNU Lesser General Public
 24 * License along with this library; if not, write to the Free Software
 25 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 26 * 
 27 * See the file COPYING for a complete copy of the LGPL.
 28 * ----------------------------------------------------------------------------- */
 29
 30#include "wad.h"
 31
 32static char cvs[] = "$Header$";
 33
 34/* Hash table containing stab strings and such */
 35typedef struct stringtype {
 36  char             *str;
 37  struct stringtype *next;
 38} stringtype;
 39
 40#define STRING_HASH_SIZE  1013
 41
 42static stringtype *strings[STRING_HASH_SIZE];
 43static int         strings_init = 0;
 44
 45static int shash(char *name) {
 46  unsigned int h = 0;
 47  char *c;
 48  int i;
 49  c = name;
 50  for (i = 0; (i < 16) && (*c); i++, c++) {
 51    h = ((h^~i) << 6) + *c;
 52  }
 53  return h % STRING_HASH_SIZE;
 54}
 55
 56char *
 57wad_string_lookup(char *s) {
 58  int h;
 59  int i;
 60  stringtype *st;
 61
 62  if (!strings_init) {
 63    for (i = 0; i < STRING_HASH_SIZE; i++) {
 64      strings[i] = 0;
 65    }
 66    strings_init = 1;
 67  }
 68  
 69  h = shash(s);
 70  st = strings[h];
 71  while (st) {
 72    if (strcmp(st->str,s) == 0) return st->str;
 73    st = st->next;
 74  }
 75  
 76  /* Not found. Add the string to the hash table */
 77  st = (stringtype *) wad_malloc(sizeof(stringtype));
 78  st->str = wad_strdup(s);
 79  st->next = strings[h];
 80  strings[h] = st;
 81  return st->str;
 82}
 83
 84void wad_string_debug() {
 85  if (wad_debug_mode & DEBUG_STRING) {
 86    int maxdepth = 0;
 87    int total = 0;
 88    int stringlen = 0;
 89    int i;
 90
 91    for (i = 0; i < STRING_HASH_SIZE; i++) {
 92      stringtype *s;
 93      int c = 0;
 94      s = strings[i];
 95      while (s) {
 96	c++;
 97	stringlen += strlen(s->str);
 98	s = s->next;
 99      }
100      /*      wad_printf("WAD: stringhash[%d] = %d\n", i, c);*/
101      if (c > maxdepth) maxdepth = c;
102      total += c;
103    }
104    wad_printf("WAD: nstrings = %d (%d bytes)\n", total, stringlen + total*sizeof(stringtype));
105    wad_printf("WAD: maxdepth = %d\n", maxdepth);
106    }
107}
108
109/* Our own string copy */
110char *wad_strcpy(char *t, const char *s) {
111  if (s)
112    for (; *s; s++, t++) *t = *s;
113  *t = 0;
114  return t;
115}
116
117char *
118wad_strcat(char *t, const char *s) {
119  while (*t) t++;
120  return wad_strcpy(t,s);
121}
122
123int
124wad_strlen(const char *s) {
125  int count = 0;
126  while (*(s++)) count++;
127  return count;
128}
129
130
131