src/common/stringtable.c

   1 /*
   2  * Claws Mail -- a GTK based, lightweight, and fast e-mail client
   3  * Copyright (C) 1999-2012 Hiroyuki Yamamoto and the Claws Mail team
   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 3 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, see <http://www.gnu.org/licenses/>.
  17  *
  18  */
  19
  20 #include "config.h"
  21
  22 #include <glib.h>
  23 #include <string.h>
  24
  25 #include "stringtable.h"
  26 #include "utils.h"
  27
  28 /* alfons - hashed string table (I wasn't content with GStringChunk;
  29  * can't recall why :-) */
  30
  31 #if 0
  32 #define XXX_DEBUG \
  33         debug_print
  34 #else
  35 #define XXX_DEBUG \
  36         if (0) debug_print
  37 #endif
  38
  39 typedef struct StringEntry_ {
  40         gint    ref_count;
  41         gchar  *string;
  42 } StringEntry;
  43
  44 static StringEntry *string_entry_new(const gchar *str)
  45 {
  46         StringEntry *entry;
  47
  48         entry = g_new0(StringEntry, 1);
  49         entry->ref_count = 1;
  50         entry->string = g_strdup(str);
  51         return entry;
  52 }
  53
  54 static void string_entry_free(StringEntry *entry)
  55 {
  56         cm_return_if_fail(entry != NULL);
  57
  58         g_free(entry->string);
  59         g_free(entry);
  60 }
  61
  62 StringTable *string_table_new(void)
  63 {
  64         StringTable *strtable;
  65
  66         strtable = g_new0(StringTable, 1);
  67         cm_return_val_if_fail(strtable != NULL, NULL);
  68         strtable->hash_table = g_hash_table_new(g_str_hash, g_str_equal);
  69         if (strtable->hash_table == NULL) {
  70                 g_free(strtable);
  71                 return NULL;
  72         }
  73         return strtable;
  74 }
  75
  76 gchar *string_table_insert_string(StringTable *table, const gchar *str)
  77 {
  78         StringEntry *entry;
  79
  80         entry = g_hash_table_lookup(table->hash_table, str);
  81
  82         if (entry) {
  83                 entry->ref_count++;
  84                 XXX_DEBUG ("ref++ for %s (%d)\n", entry->string,
  85                            entry->ref_count);
  86         } else {
  87                 entry = string_entry_new(str);
  88                 XXX_DEBUG ("inserting %s\n", str);
  89                 /* insert entry->string instead of str, since it can be
  90                  * invalid pointer after this. */
  91                 g_hash_table_insert(table->hash_table, entry->string, entry);
  92         }
  93
  94         return entry->string;
  95 }
  96
  97 void string_table_free_string(StringTable *table, const gchar *str)
  98 {
  99         StringEntry *entry;
 100
 101         entry = g_hash_table_lookup(table->hash_table, str);
 102
 103         if (entry) {
 104                 entry->ref_count--;
 105                 if (entry->ref_count <= 0) {
 106                         XXX_DEBUG ("refcount of string %s dropped to zero\n",
 107                                    entry->string);
 108                         g_hash_table_remove(table->hash_table, str);
 109                         string_entry_free(entry);
 110                 } else {
 111                         XXX_DEBUG ("ref-- for %s (%d)\n", entry->string,
 112                                    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         cm_return_val_if_fail(key != NULL, TRUE);
 121         cm_return_val_if_fail(entry != NULL, TRUE);
 122
 123         string_entry_free(entry);
 124
 125         return TRUE;
 126 }
 127
 128 void string_table_free(StringTable *table)
 129 {
 130         cm_return_if_fail(table != NULL);
 131         cm_return_if_fail(table->hash_table != NULL);
 132
 133         g_hash_table_foreach_remove(table->hash_table,
 134                                     (GHRFunc)string_table_remove_for_each_fn,
 135                                     NULL);
 136         g_hash_table_destroy(table->hash_table);
 137         g_free(table);
 138 }
 139
 140 static void string_table_stats_for_each_fn(gchar *key, StringEntry *entry,
 141                                            guint *totals)
 142 {
 143         if (entry->ref_count > 1) {
 144                 *totals += strlen(key) * (entry->ref_count - 1);
 145         }
 146 }
 147
 148 void string_table_get_stats(StringTable *table)
 149 {
 150         guint totals = 0;
 151
 152         g_hash_table_foreach(table->hash_table,
 153                              (GHFunc)string_table_stats_for_each_fn, &totals);
 154         XXX_DEBUG ("TOTAL UNSPILLED %d (%dK)\n", totals, totals / 1024);
 155 }