src/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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, 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 #define XXX_DEBUG \
  30         debug_print
  31
  32 typedef struct StringEntry_ {
  33         gint    ref_count;
  34         gchar  *string;
  35 } StringEntry;
  36
  37 static StringEntry *string_entry_new(const gchar *str)
  38 {
  39         StringEntry *entry;
  40
  41         entry = g_new0(StringEntry, 1);
  42         entry->ref_count = 1;
  43         entry->string = g_strdup(str);
  44         return entry;
  45 }
  46
  47 static void string_entry_free(StringEntry *entry)
  48 {
  49         g_return_if_fail(entry != NULL);
  50         g_return_if_fail(entry->string);
  51
  52         g_free(entry->string);
  53         g_free(entry);
  54 }
  55
  56 StringTable *string_table_new(void)
  57 {
  58         StringTable *strtable;
  59
  60         strtable = g_new0(StringTable, 1);
  61         g_return_val_if_fail(strtable != NULL, NULL);
  62         strtable->hash_table = g_hash_table_new(g_str_hash, g_str_equal);
  63         g_return_val_if_fail(strtable->hash_table, NULL);
  64         return strtable;
  65 }
  66
  67 gchar *string_table_lookup_string(StringTable *table, gchar *str)
  68 {
  69         StringEntry *entry = g_hash_table_lookup(table->hash_table,
  70                                                  (gconstpointer)str);
  71         if (!entry) {
  72                 return NULL;
  73         } else {
  74                 return entry->string;
  75         }
  76 }
  77
  78 gchar *string_table_insert_string(StringTable *table, gchar *str)
  79 {
  80         gchar *key = NULL;
  81         StringEntry *entry = NULL;
  82
  83         if (g_hash_table_lookup_extended
  84                 (table->hash_table, str, (gpointer *)&key, (gpointer *)&entry)) {
  85                 entry->ref_count++;
  86                 XXX_DEBUG ("ref++ for %s (%d)\n", entry->string, entry->ref_count);
  87         } else {
  88                 entry = string_entry_new(str);
  89                 XXX_DEBUG ("inserting %s\n", str);
  90                 /* insert entry->string instead of str, since it can be
  91                  * invalid pointer after this. */
  92                 g_hash_table_insert(table->hash_table, entry->string, entry);
  93         }
  94
  95         return entry->string;
  96 }
  97
  98 void string_table_free_string(StringTable *table, gchar *str)
  99 {
 100         StringEntry *entry;
 101
 102         entry = g_hash_table_lookup(table->hash_table, str);
 103
 104         if (entry) {
 105                 entry->ref_count--;
 106                 if (entry->ref_count <= 0) {
 107                         XXX_DEBUG ("refcount of string %s dropped to zero\n", entry->string);
 108                         g_hash_table_remove(table->hash_table, str);
 109                         g_free(entry->string);
 110                         g_free(entry);
 111                 } else {
 112                         XXX_DEBUG ("ref-- for %s (%d)\n", entry->string, entry->ref_count);
 113                 }
 114         }
 115 }
 116
 117 static gboolean string_table_remove_for_each_fn(gchar *key, StringEntry *entry,
 118                                                 gpointer user_data)
 119 {
 120         g_return_val_if_fail(key != NULL, TRUE);
 121         g_return_val_if_fail(entry != NULL, TRUE);
 122
 123         g_free(entry->string);
 124         g_free(entry);
 125
 126         return TRUE;
 127 }
 128
 129 void string_table_free(StringTable *table)
 130 {
 131         g_return_if_fail(table != NULL);
 132         g_return_if_fail(table->hash_table != NULL);
 133
 134         g_hash_table_foreach_remove(table->hash_table,
 135                                     (GHRFunc)string_table_remove_for_each_fn,
 136                                     NULL);
 137         g_hash_table_destroy(table->hash_table);
 138         g_free(table);
 139 }
 140
 141 static void string_table_stats_for_each_fn(gchar *key, StringEntry *entry,
 142                                            guint *totals)
 143 {
 144         if (entry->ref_count > 1) {
 145                 *totals += strlen(key) * (entry->ref_count - 1);
 146         }
 147 }
 148
 149 void string_table_get_stats(StringTable *table)
 150 {
 151         guint totals = 0;
 152
 153         g_hash_table_foreach(table->hash_table,
 154                              (GHFunc)string_table_stats_for_each_fn, &totals);
 155         XXX_DEBUG ("TOTAL UNSPILLED %d (%dK)\n", totals, totals / 1024);
 156 }