src/common/stringtable.c

   1 /*
   2  * Sylpheed -- 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 <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         cm_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         cm_return_val_if_fail(strtable != NULL, NULL);
  66         strtable->hash_table = g_hash_table_new(g_str_hash, g_str_equal);
  67         cm_return_val_if_fail(strtable->hash_table, NULL);
  68         return strtable;
  69 }
  70
  71 gchar *string_table_insert_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                 entry->ref_count++;
  79                 XXX_DEBUG ("ref++ for %s (%d)\n", entry->string,
  80                            entry->ref_count);
  81         } else {
  82                 entry = string_entry_new(str);
  83                 XXX_DEBUG ("inserting %s\n", str);
  84                 /* insert entry->string instead of str, since it can be
  85                  * invalid pointer after this. */
  86                 g_hash_table_insert(table->hash_table, entry->string, entry);
  87         }
  88
  89         return entry->string;
  90 }
  91
  92 void string_table_free_string(StringTable *table, const gchar *str)
  93 {
  94         StringEntry *entry;
  95
  96         entry = g_hash_table_lookup(table->hash_table, str);
  97
  98         if (entry) {
  99                 entry->ref_count--;
 100                 if (entry->ref_count <= 0) {
 101                         XXX_DEBUG ("refcount of string %s dropped to zero\n",
 102                                    entry->string);
 103                         g_hash_table_remove(table->hash_table, str);
 104                         string_entry_free(entry);
 105                 } else {
 106                         XXX_DEBUG ("ref-- for %s (%d)\n", entry->string,
 107                                    entry->ref_count);
 108                 }
 109         }
 110 }
 111
 112 static gboolean string_table_remove_for_each_fn(gchar *key, StringEntry *entry,
 113                                                 gpointer user_data)
 114 {
 115         cm_return_val_if_fail(key != NULL, TRUE);
 116         cm_return_val_if_fail(entry != NULL, TRUE);
 117
 118         string_entry_free(entry);
 119
 120         return TRUE;
 121 }
 122
 123 void string_table_free(StringTable *table)
 124 {
 125         cm_return_if_fail(table != NULL);
 126         cm_return_if_fail(table->hash_table != NULL);
 127
 128         g_hash_table_foreach_remove(table->hash_table,
 129                                     (GHRFunc)string_table_remove_for_each_fn,
 130                                     NULL);
 131         g_hash_table_destroy(table->hash_table);
 132         g_free(table);
 133 }
 134
 135 static void string_table_stats_for_each_fn(gchar *key, StringEntry *entry,
 136                                            guint *totals)
 137 {
 138         if (entry->ref_count > 1) {
 139                 *totals += strlen(key) * (entry->ref_count - 1);
 140         }
 141 }
 142
 143 void string_table_get_stats(StringTable *table)
 144 {
 145         guint totals = 0;
 146
 147         g_hash_table_foreach(table->hash_table,
 148                              (GHFunc)string_table_stats_for_each_fn, &totals);
 149         XXX_DEBUG ("TOTAL UNSPILLED %d (%dK)\n", totals, totals / 1024);
 150 }