src/struniq.c

   1 /* Keeping a unique copy of strings.
   2    Copyright (C) 2002 Free Software Foundation, Inc.
   3
   4    This file is part of Bison, the GNU Compiler Compiler.
   5
   6    Bison is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 2, or (at your option)
   9    any later version.
  10
  11    Bison is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with Bison; see the file COPYING.  If not, write to
  18    the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  19    Boston, MA 02111-1307, USA.  */
  20
  21 #include "system.h"
  22 #include "quotearg.h"
  23 #include "hash.h"
  24 #include "struniq.h"
  25
  26 /*-----------------------.
  27 | A struniq hash table.  |
  28 `-----------------------*/
  29
  30 /* Initial capacity of struniq hash table.  */
  31 #define HT_INITIAL_CAPACITY 257
  32
  33 static struct hash_table *struniqs_table = NULL;
  34
  35 /*-------------------------------------.
  36 | Create the struniq for S if needed.  |
  37 `-------------------------------------*/
  38
  39 const struniq_t
  40 struniq_new (const char *s)
  41 {
  42   /* Keep the struniqs in a printable form.  */
  43   struniq_t res = hash_lookup (struniqs_table,
  44                                quotearg_style (escape_quoting_style, s));
  45
  46   if (!res)
  47     {
  48       /* First insertion in the hash. */
  49       res = xstrdup (quotearg_style (escape_quoting_style, s));
  50       hash_insert (struniqs_table, res);
  51     }
  52   return res;
  53 }
  54
  55
  56 /*--------------------.
  57 | Print the struniq.  |
  58 `--------------------*/
  59
  60 static bool
  61 struniq_print (const struniq_t s)
  62 {
  63   fprintf (stderr, "%s\n", s);
  64   return true;
  65 }
  66
  67 \f
  68 /*-----------------------.
  69 | A struniq hash table.  |
  70 `-----------------------*/
  71
  72 static bool
  73 hash_compare_struniq_t (const struniq_t m1, const struniq_t m2)
  74 {
  75   return strcmp (m1, m2) == 0;
  76 }
  77
  78 static unsigned int
  79 hash_struniq_t (const struniq_t m, unsigned int tablesize)
  80 {
  81   return hash_string (m, tablesize);
  82 }
  83
  84 /* A function to apply to each symbol. */
  85 typedef bool (*struniq_processor_t) (const struniq_t);
  86
  87 /*----------------------------.
  88 | Create the struniqs table.  |
  89 `----------------------------*/
  90
  91 void
  92 struniqs_new (void)
  93 {
  94   struniqs_table = hash_initialize (HT_INITIAL_CAPACITY,
  95                                     NULL,
  96                                     (Hash_hasher) hash_struniq_t,
  97                                     (Hash_comparator) hash_compare_struniq_t,
  98                                     (Hash_data_freer) free);
  99 }
 100
 101
 102 /*-------------------------------------.
 103 | Perform a task on all the struniqs.  |
 104 `-------------------------------------*/
 105
 106 static void
 107 struniqs_do (struniq_processor_t processor, void *processor_data)
 108 {
 109   hash_do_for_each (struniqs_table,
 110                     (Hash_processor) processor,
 111                     processor_data);
 112 }
 113
 114
 115 /*-----------------.
 116 | Print them all.  |
 117 `-----------------*/
 118
 119 void
 120 struniqs_print (void)
 121 {
 122   struniqs_do (struniq_print, NULL);
 123 }
 124
 125
 126 /*--------------------.
 127 | Free the struniqs.  |
 128 `--------------------*/
 129
 130 void
 131 struniqs_free (void)
 132 {
 133   hash_free (struniqs_table);
 134 }