add cairo

1 files changed, 338 insertions, 0 deletions

diff --git a/libs/cairo-1.16.0/src/cairo-cache.c b/libs/cairo-1.16.0/src/cairo-cache.c
new file mode 100644
index 0000000..5c4e4ca
--- /dev/null
+++ b/libs/cairo-1.16.0/src/cairo-cache.c
@@ -0,0 +1,338 @@
+/* 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>
+ */
+
+#include "cairoint.h"
+#include "cairo-error-private.h"
+
+static void
+_cairo_cache_shrink_to_accommodate (cairo_cache_t *cache,
+				    unsigned long  additional);
+
+static cairo_bool_t
+_cairo_cache_entry_is_non_zero (const void *entry)
+{
+    return ((const cairo_cache_entry_t *) entry)->size;
+}
+
+
+/**
+ * _cairo_cache_init:
+ * @cache: the #cairo_cache_t to initialise
+ * @keys_equal: a function to return %TRUE if two keys are equal
+ * @entry_destroy: destroy notifier for cache entries
+ * @max_size: the maximum size for this cache
+ * Returns: the newly created #cairo_cache_t
+ *
+ * Creates a new cache using the keys_equal() function to determine
+ * the equality of entries.
+ *
+ * Data is provided to the cache in the form of user-derived version
+ * of #cairo_cache_entry_t. A cache entry must be able to hold hash
+ * code, a size, and the key/value pair being stored in the
+ * cache. Sometimes only the key will be necessary, (as in
+ * _cairo_cache_lookup()), and in these cases the value portion of the
+ * entry need not be initialized.
+ *
+ * The units for max_size can be chosen by the caller, but should be
+ * consistent with the units of the size field of cache entries. When
+ * adding an entry with _cairo_cache_insert() if the total size of
+ * entries in the cache would exceed max_size then entries will be
+ * removed at random until the new entry would fit or the cache is
+ * empty. Then the new entry is inserted.
+ *
+ * There are cases in which the automatic removal of entries is
+ * undesired. If the cache entries have reference counts, then it is a
+ * simple matter to use the reference counts to ensure that entries
+ * continue to live even after being ejected from the cache. However,
+ * in some cases the memory overhead of adding a reference count to
+ * the entry would be objectionable. In such cases, the
+ * _cairo_cache_freeze() and _cairo_cache_thaw() calls can be
+ * used to establish a window during which no automatic removal of
+ * entries will occur.
+ **/
+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)
+{
+    cache->hash_table = _cairo_hash_table_create (keys_equal);
+    if (unlikely (cache->hash_table == NULL))
+	return _cairo_error (CAIRO_STATUS_NO_MEMORY);
+
+    if (predicate == NULL)
+	predicate = _cairo_cache_entry_is_non_zero;
+    cache->predicate = predicate;
+    cache->entry_destroy = entry_destroy;
+
+    cache->max_size = max_size;
+    cache->size = 0;
+
+    cache->freeze_count = 0;
+
+    return CAIRO_STATUS_SUCCESS;
+}
+
+static void
+_cairo_cache_pluck (void *entry, void *closure)
+{
+    _cairo_cache_remove (closure, entry);
+}
+
+/**
+ * _cairo_cache_fini:
+ * @cache: a cache to destroy
+ *
+ * Immediately destroys the given cache, freeing all resources
+ * associated with it. As part of this process, the entry_destroy()
+ * function, (as passed to _cairo_cache_init()), will be called for
+ * each entry in the cache.
+ **/
+void
+_cairo_cache_fini (cairo_cache_t *cache)
+{
+    _cairo_hash_table_foreach (cache->hash_table,
+			       _cairo_cache_pluck,
+			       cache);
+    assert (cache->size == 0);
+    _cairo_hash_table_destroy (cache->hash_table);
+}
+
+/**
+ * _cairo_cache_freeze:
+ * @cache: a cache with some precious entries in it (or about to be
+ * added)
+ *
+ * Disable the automatic ejection of entries from the cache. For as
+ * long as the cache is "frozen", calls to _cairo_cache_insert() will
+ * add new entries to the cache regardless of how large the cache
+ * grows. See _cairo_cache_thaw().
+ *
+ * Note: Multiple calls to _cairo_cache_freeze() will stack, in that
+ * the cache will remain "frozen" until a corresponding number of
+ * calls are made to _cairo_cache_thaw().
+ **/
+void
+_cairo_cache_freeze (cairo_cache_t *cache)
+{
+    assert (cache->freeze_count >= 0);
+
+    cache->freeze_count++;
+}
+
+/**
+ * _cairo_cache_thaw:
+ * @cache: a cache, just after the entries in it have become less
+ * precious
+ *
+ * Cancels the effects of _cairo_cache_freeze().
+ *
+ * When a number of calls to _cairo_cache_thaw() is made corresponding
+ * to the number of calls to _cairo_cache_freeze() the cache will no
+ * longer be "frozen". If the cache had grown larger than max_size
+ * while frozen, entries will immediately be ejected (by random) from
+ * the cache until the cache is smaller than max_size. Also, the
+ * automatic ejection of entries on _cairo_cache_insert() will resume.
+ **/
+void
+_cairo_cache_thaw (cairo_cache_t *cache)
+{
+    assert (cache->freeze_count > 0);
+
+    if (--cache->freeze_count == 0)
+	_cairo_cache_shrink_to_accommodate (cache, 0);
+}
+
+/**
+ * _cairo_cache_lookup:
+ * @cache: a cache
+ * @key: the key of interest
+ * @entry_return: pointer for return value
+ *
+ * Performs a lookup in @cache looking for an entry which has a key
+ * that matches @key, (as determined by the keys_equal() function
+ * passed to _cairo_cache_init()).
+ *
+ * Return value: %TRUE if there is an entry in the cache that matches
+ * @key, (which will now be in *entry_return). %FALSE otherwise, (in
+ * which case *entry_return will be %NULL).
+ **/
+void *
+_cairo_cache_lookup (cairo_cache_t	  *cache,
+		     cairo_cache_entry_t  *key)
+{
+    return _cairo_hash_table_lookup (cache->hash_table,
+				     (cairo_hash_entry_t *) key);
+}
+
+/**
+ * _cairo_cache_remove_random:
+ * @cache: a cache
+ *
+ * Remove a random entry from the cache.
+ *
+ * Return value: %TRUE if an entry was successfully removed.
+ * %FALSE if there are no entries that can be removed.
+ **/
+static cairo_bool_t
+_cairo_cache_remove_random (cairo_cache_t *cache)
+{
+    cairo_cache_entry_t *entry;
+
+    entry = _cairo_hash_table_random_entry (cache->hash_table,
+					    cache->predicate);
+    if (unlikely (entry == NULL))
+	return FALSE;
+
+    _cairo_cache_remove (cache, entry);
+
+    return TRUE;
+}
+
+/**
+ * _cairo_cache_shrink_to_accommodate:
+ * @cache: a cache
+ * @additional: additional size requested in bytes
+ *
+ * If cache is not frozen, eject entries randomly until the size of
+ * the cache is at least @additional bytes less than
+ * cache->max_size. That is, make enough room to accommodate a new
+ * entry of size @additional.
+ **/
+static void
+_cairo_cache_shrink_to_accommodate (cairo_cache_t *cache,
+				    unsigned long  additional)
+{
+    while (cache->size + additional > cache->max_size) {
+	if (! _cairo_cache_remove_random (cache))
+	    return;
+    }
+}
+
+/**
+ * _cairo_cache_insert:
+ * @cache: a cache
+ * @entry: an entry to be inserted
+ *
+ * Insert @entry into the cache. If an entry exists in the cache with
+ * a matching key, then the old entry will be removed first, (and the
+ * entry_destroy() callback will be called on it).
+ *
+ * Return value: %CAIRO_STATUS_SUCCESS if successful or
+ * %CAIRO_STATUS_NO_MEMORY if insufficient memory is available.
+ **/
+cairo_status_t
+_cairo_cache_insert (cairo_cache_t	 *cache,
+		     cairo_cache_entry_t *entry)
+{
+    cairo_status_t status;
+
+    if (entry->size && ! cache->freeze_count)
+	_cairo_cache_shrink_to_accommodate (cache, entry->size);
+
+    status = _cairo_hash_table_insert (cache->hash_table,
+				       (cairo_hash_entry_t *) entry);
+    if (unlikely (status))
+	return status;
+
+    cache->size += entry->size;
+
+    return CAIRO_STATUS_SUCCESS;
+}
+
+/**
+ * _cairo_cache_remove:
+ * @cache: a cache
+ * @entry: an entry that exists in the cache
+ *
+ * Remove an existing entry from the cache.
+ **/
+void
+_cairo_cache_remove (cairo_cache_t	 *cache,
+		     cairo_cache_entry_t *entry)
+{
+    cache->size -= entry->size;
+
+    _cairo_hash_table_remove (cache->hash_table,
+			      (cairo_hash_entry_t *) entry);
+
+    if (cache->entry_destroy)
+	cache->entry_destroy (entry);
+}
+
+/**
+ * _cairo_cache_foreach:
+ * @cache: a cache
+ * @cache_callback: function to be called for each entry
+ * @closure: additional argument to be passed to @cache_callback
+ *
+ * Call @cache_callback for each entry in the cache, in a
+ * non-specified order.
+ **/
+void
+_cairo_cache_foreach (cairo_cache_t		      *cache,
+		      cairo_cache_callback_func_t      cache_callback,
+		      void			      *closure)
+{
+    _cairo_hash_table_foreach (cache->hash_table,
+			       cache_callback,
+			       closure);
+}
+
+unsigned long
+_cairo_hash_string (const char *c)
+{
+    /* This is the djb2 hash. */
+    unsigned long hash = _CAIRO_HASH_INIT_VALUE;
+    while (c && *c)
+	hash = ((hash << 5) + hash) + *c++;
+    return hash;
+}
+
+unsigned long
+_cairo_hash_bytes (unsigned long hash,
+		   const void *ptr,
+		   unsigned int length)
+{
+    const uint8_t *bytes = ptr;
+    /* This is the djb2 hash. */
+    while (length--)
+	hash = ((hash << 5) + hash) + *bytes++;
+    return hash;
+}