/* cairo - a vector graphics library with display and print output * * Copyright © 2004 Red Hat, Inc. * Copyright © 2005 Red Hat, Inc. * * This library is free software; you can redistribute it and/or * modify it either under the terms of the GNU Lesser General Public * License version 2.1 as published by the Free Software Foundation * (the "LGPL") or, at your option, under the terms of the Mozilla * Public License Version 1.1 (the "MPL"). If you do not alter this * notice, a recipient may use your version of this file under either * the MPL or the LGPL. * * You should have received a copy of the LGPL along with this library * in the file COPYING-LGPL-2.1; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Suite 500, Boston, MA 02110-1335, USA * You should have received a copy of the MPL along with this library * in the file COPYING-MPL-1.1 * * The contents of this file are subject to the Mozilla Public License * Version 1.1 (the "License"); you may not use this file except in * compliance with the License. You may obtain a copy of the License at * http://www.mozilla.org/MPL/ * * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY * OF ANY KIND, either express or implied. See the LGPL or the MPL for * the specific language governing rights and limitations. * * The Original Code is the cairo graphics library. * * The Initial Developer of the Original Code is Red Hat, Inc. * * Contributor(s): * Keith Packard <keithp@keithp.com> * Graydon Hoare <graydon@redhat.com> * Carl Worth <cworth@cworth.org> */ #ifndef CAIRO_CACHE_PRIVATE_H #define CAIRO_CACHE_PRIVATE_H #include "cairo-compiler-private.h" #include "cairo-types-private.h" /** * cairo_cache_entry_t: * * A #cairo_cache_entry_t contains both a key and a value for * #cairo_cache_t. User-derived types for #cairo_cache_entry_t must * have a #cairo_cache_entry_t as their first field. For example: * * typedef _my_entry { * cairo_cache_entry_t base; * ... Remainder of key and value fields here .. * } my_entry_t; * * which then allows a pointer to my_entry_t to be passed to any of * the #cairo_cache_t functions as follows without requiring a cast: * * _cairo_cache_insert (cache, &my_entry->base, size); * * IMPORTANT: The caller is responsible for initializing * my_entry->base.hash with a hash code derived from the key. The * essential property of the hash code is that keys_equal must never * return %TRUE for two keys that have different hashes. The best hash * code will reduce the frequency of two keys with the same code for * which keys_equal returns %FALSE. * * The user must also initialize my_entry->base.size to indicate * the size of the current entry. What units to use for size is * entirely up to the caller, (though the same units must be used for * the max_size parameter passed to _cairo_cache_create()). If all * entries are close to the same size, the simplest thing to do is to * just use units of "entries", (eg. set size==1 in all entries and * set max_size to the number of entries which you want to be saved * in the cache). * * Which parts of the entry make up the "key" and which part make up * the value are entirely up to the caller, (as determined by the * computation going into base.hash as well as the keys_equal * function). A few of the #cairo_cache_t functions accept an entry which * will be used exclusively as a "key", (indicated by a parameter name * of key). In these cases, the value-related fields of the entry need * not be initialized if so desired. **/ typedef struct _cairo_cache_entry { unsigned long hash; unsigned long size; } cairo_cache_entry_t; typedef cairo_bool_t (*cairo_cache_predicate_func_t) (const void *entry); struct _cairo_cache { cairo_hash_table_t *hash_table; cairo_cache_predicate_func_t predicate; cairo_destroy_func_t entry_destroy; unsigned long max_size; unsigned long size; int freeze_count; }; typedef cairo_bool_t (*cairo_cache_keys_equal_func_t) (const void *key_a, const void *key_b); typedef void (*cairo_cache_callback_func_t) (void *entry, void *closure); cairo_private cairo_status_t _cairo_cache_init (cairo_cache_t *cache, cairo_cache_keys_equal_func_t keys_equal, cairo_cache_predicate_func_t predicate, cairo_destroy_func_t entry_destroy, unsigned long max_size); cairo_private void _cairo_cache_fini (cairo_cache_t *cache); cairo_private void _cairo_cache_freeze (cairo_cache_t *cache); cairo_private void _cairo_cache_thaw (cairo_cache_t *cache); cairo_private void * _cairo_cache_lookup (cairo_cache_t *cache, cairo_cache_entry_t *key); cairo_private cairo_status_t _cairo_cache_insert (cairo_cache_t *cache, cairo_cache_entry_t *entry); cairo_private void _cairo_cache_remove (cairo_cache_t *cache, cairo_cache_entry_t *entry); cairo_private void _cairo_cache_foreach (cairo_cache_t *cache, cairo_cache_callback_func_t cache_callback, void *closure); #endif