src/common/stringtable.c

   1 /*
   2  * Sylpheed -- a GTK+ based, lightweight, and fast e-mail client
   3  * Copyright (C) 1999-2001 Hiroyuki Yamamoto
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, write to the Free Software
  17  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  */
  19
  20 #include <glib.h>
  21 #include <string.h>
  22
  23 #include "stringtable.h"
  24 #include "utils.h"
  25
  26 /* alfons - hashed string table (I wasn't content with GStringChunk;
  27  * can't recall why :-) */
  28
  29 #if 0
  30 #define XXX_DEBUG \
  31         debug_print
  32 #else
  33 #define XXX_DEBUG \
  34         if (0) debug_print
  35 #endif
  36
  37 typedef struct StringEntry_ {
  38         gint    ref_count;
  39         gchar  *string;
  40 } StringEntry;
  41
  42 static StringEntry *string_entry_new(const gchar *str)
  43 {
  44         StringEntry *entry;
  45
  46         entry = g_new0(StringEntry, 1);
  47         entry->ref_count = 1;
  48         entry->string = g_strdup(str);
  49         return entry;
  50 }
  51
  52 static void string_entry_free(StringEntry *entry)
  53 {
  54         g_return_if_fail(entry != NULL);
  55
  56         g_free(entry->string);
  57         g_free(entry);
  58 }
  59
  60 StringTable *string_table_new(void)
  61 {
  62         StringTable *strtable;
  63
  64         strtable = g_new0(StringTable, 1);
  65         g_return_val_if_fail(strtable != NULL, NULL);
  66         strtable->hash_table = g_hash_table_new(g_str_hash, g_str_equal);
  67         g_return_val_if_fail(strtable->hash_table, NULL);
  68         return strtable;
  69 }
  70
  71 gchar *string_table_lookup_string(StringTable *table, const gchar *str)
  72 {
  73         StringEntry *entry;
  74
  75         entry = g_hash_table_lookup(table->hash_table, str);
  76
  77         if (entry) {
  78                 return entry->string;
  79         } else {
  80                 return NULL;
  81         }
  82 }
  83
  84 gchar *string_table_insert_string(StringTable *table, const gchar *str)
  85 {
  86         StringEntry *entry;
  87
  88         entry = g_hash_table_lookup(table->hash_table, str);
  89
  90         if (entry) {
  91                 entry->ref_count++;
  92                 XXX_DEBUG ("ref++ for %s (%d)\n", entry->string,
  93                            entry->ref_count);
  94         } else {
  95                 entry = string_entry_new(str);
  96                 XXX_DEBUG ("inserting %s\n", str);
  97                 /* insert entry->string instead of str, since it can be
  98                  * invalid pointer after this. */
  99                 g_hash_table_insert(table->hash_table, entry->string, entry);
 100         }
 101
 102         return entry->string;
 103 }
 104
 105 void string_table_free_string(StringTable *table, const gchar *str)
 106 {
 107         StringEntry *entry;
 108
 109         entry = g_hash_table_lookup(table->hash_table, str);
 110
 111         if (entry) {
 112                 entry->ref_count--;
 113                 if (entry->ref_count <= 0) {
 114                         XXX_DEBUG ("refcount of string %s dropped to zero\n",
 115                                    entry->string);
 116                         g_hash_table_remove(table->hash_table, str);
 117                         string_entry_free(entry);
 118                 } else {
 119                         XXX_DEBUG ("ref-- for %s (%d)\n", entry->string,
 120                                    entry->ref_count);
 121                 }
 122         }
 123 }
 124
 125 static gboolean string_table_remove_for_each_fn(gchar *key, StringEntry *entry,
 126                                                 gpointer user_data)
 127 {
 128         g_return_val_if_fail(key != NULL, TRUE);
 129         g_return_val_if_fail(entry != NULL, TRUE);
 130
 131         string_entry_free(entry);
 132
 133         return TRUE;
 134 }
 135
 136 void string_table_free(StringTable *table)
 137 {
 138         g_return_if_fail(table != NULL);
 139         g_return_if_fail(table->hash_table != NULL);
 140
 141         g_hash_table_foreach_remove(table->hash_table,
 142                                     (GHRFunc)string_table_remove_for_each_fn,
 143                                     NULL);
 144         g_hash_table_destroy(table->hash_table);
 145         g_free(table);
 146 }
 147
 148 static void string_table_stats_for_each_fn(gchar *key, StringEntry *entry,
 149                                            guint *totals)
 150 {
 151         if (entry->ref_count > 1) {
 152                 *totals += strlen(key) * (entry->ref_count - 1);
 153         }
 154 }
 155
 156 void string_table_get_stats(StringTable *table)
 157 {
 158         guint totals = 0;
 159
 160         g_hash_table_foreach(table->hash_table,
 161                              (GHFunc)string_table_stats_for_each_fn, &totals);
 162         XXX_DEBUG ("TOTAL UNSPILLED %d (%dK)\n", totals, totals / 1024);
 163 }