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+/* 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:
+ *
+ * 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