add cairo

1 files changed, 578 insertions, 0 deletions

diff --git a/libs/cairo-1.16.0/src/cairo-hash.c b/libs/cairo-1.16.0/src/cairo-hash.c
new file mode 100644
index 0000000..5a78990
--- /dev/null
+++ b/libs/cairo-1.16.0/src/cairo-hash.c
@@ -0,0 +1,578 @@
+/* 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"
+
+/*
+ * An entry can be in one of three states:
+ *
+ * FREE: Entry has never been used, terminates all searches.
+ *       Appears in the table as a %NULL pointer.
+ *
+ * DEAD: Entry had been live in the past. A dead entry can be reused
+ *       but does not terminate a search for an exact entry.
+ *       Appears in the table as a pointer to DEAD_ENTRY.
+ *
+ * LIVE: Entry is currently being used.
+ *       Appears in the table as any non-%NULL, non-DEAD_ENTRY pointer.
+ */
+
+#define DEAD_ENTRY ((cairo_hash_entry_t *) 0x1)
+
+#define ENTRY_IS_FREE(entry) ((entry) == NULL)
+#define ENTRY_IS_DEAD(entry) ((entry) == DEAD_ENTRY)
+#define ENTRY_IS_LIVE(entry) ((entry) >  DEAD_ENTRY)
+
+/*
+ * This table is open-addressed with double hashing. Each table size
+ * is a prime and it makes for the "first" hash modulus; a second
+ * prime (2 less than the first prime) serves as the "second" hash
+ * modulus, which is smaller and thus guarantees a complete
+ * permutation of table indices.
+ *
+ * Hash tables are rehashed in order to keep between 12.5% and 50%
+ * entries in the hash table alive and at least 25% free. When table
+ * size is changed, the new table has about 25% live elements.
+ *
+ * The free entries guarantee an expected constant-time lookup.
+ * Doubling/halving the table in the described fashion guarantees
+ * amortized O(1) insertion/removal.
+ *
+ * This structure, and accompanying table, is borrowed/modified from the
+ * file xserver/render/glyph.c in the freedesktop.org x server, with
+ * permission (and suggested modification of doubling sizes) by Keith
+ * Packard.
+ */
+
+static const unsigned long hash_table_sizes[] = {
+    43,
+    73,
+    151,
+    283,
+    571,
+    1153,
+    2269,
+    4519,
+    9013,
+    18043,
+    36109,
+    72091,
+    144409,
+    288361,
+    576883,
+    1153459,
+    2307163,
+    4613893,
+    9227641,
+    18455029,
+    36911011,
+    73819861,
+    147639589,
+    295279081,
+    590559793
+};
+
+struct _cairo_hash_table {
+    cairo_hash_keys_equal_func_t keys_equal;
+
+    cairo_hash_entry_t *cache[32];
+
+    const unsigned long *table_size;
+    cairo_hash_entry_t **entries;
+
+    unsigned long live_entries;
+    unsigned long free_entries;
+    unsigned long iterating;   /* Iterating, no insert, no resize */
+};
+
+/**
+ * _cairo_hash_table_uid_keys_equal:
+ * @key_a: the first key to be compared
+ * @key_b: the second key to be compared
+ *
+ * Provides a #cairo_hash_keys_equal_func_t which always returns
+ * %TRUE. This is useful to create hash tables using keys whose hash
+ * completely describes the key, because in this special case
+ * comparing the hashes is sufficient to guarantee that the keys are
+ * equal.
+ *
+ * Return value: %TRUE.
+ **/
+static cairo_bool_t
+_cairo_hash_table_uid_keys_equal (const void *key_a, const void *key_b)
+{
+    return TRUE;
+}
+
+/**
+ * _cairo_hash_table_create:
+ * @keys_equal: a function to return %TRUE if two keys are equal
+ *
+ * Creates a new hash table which will use the keys_equal() function
+ * to compare hash keys. Data is provided to the hash table in the
+ * form of user-derived versions of #cairo_hash_entry_t. A hash entry
+ * must be able to hold both a key (including a hash code) and a
+ * value. Sometimes only the key will be necessary, (as in
+ * _cairo_hash_table_remove), and other times both a key and a value
+ * will be necessary, (as in _cairo_hash_table_insert).
+ *
+ * If @keys_equal is %NULL, two keys will be considered equal if and
+ * only if their hashes are equal.
+ *
+ * See #cairo_hash_entry_t for more details.
+ *
+ * Return value: the new hash table or %NULL if out of memory.
+ **/
+cairo_hash_table_t *
+_cairo_hash_table_create (cairo_hash_keys_equal_func_t keys_equal)
+{
+    cairo_hash_table_t *hash_table;
+
+    hash_table = _cairo_malloc (sizeof (cairo_hash_table_t));
+    if (unlikely (hash_table == NULL)) {
+	_cairo_error_throw (CAIRO_STATUS_NO_MEMORY);
+	return NULL;
+    }
+
+    if (keys_equal == NULL)
+	hash_table->keys_equal = _cairo_hash_table_uid_keys_equal;
+    else
+	hash_table->keys_equal = keys_equal;
+
+    memset (&hash_table->cache, 0, sizeof (hash_table->cache));
+    hash_table->table_size = &hash_table_sizes[0];
+
+    hash_table->entries = calloc (*hash_table->table_size,
+				  sizeof (cairo_hash_entry_t *));
+    if (unlikely (hash_table->entries == NULL)) {
+	_cairo_error_throw (CAIRO_STATUS_NO_MEMORY);
+	free (hash_table);
+	return NULL;
+    }
+
+    hash_table->live_entries = 0;
+    hash_table->free_entries = *hash_table->table_size;
+    hash_table->iterating = 0;
+
+    return hash_table;
+}
+
+/**
+ * _cairo_hash_table_destroy:
+ * @hash_table: an empty hash table to destroy
+ *
+ * Immediately destroys the given hash table, freeing all resources
+ * associated with it.
+ *
+ * WARNING: The hash_table must have no live entries in it before
+ * _cairo_hash_table_destroy is called. It is a fatal error otherwise,
+ * and this function will halt. The rationale for this behavior is to
+ * avoid memory leaks and to avoid needless complication of the API
+ * with destroy notifiy callbacks.
+ *
+ * WARNING: The hash_table must have no running iterators in it when
+ * _cairo_hash_table_destroy is called. It is a fatal error otherwise,
+ * and this function will halt.
+ **/
+void
+_cairo_hash_table_destroy (cairo_hash_table_t *hash_table)
+{
+    /* The hash table must be empty. Otherwise, halt. */
+    assert (hash_table->live_entries == 0);
+    /* No iterators can be running. Otherwise, halt. */
+    assert (hash_table->iterating == 0);
+
+    free (hash_table->entries);
+    free (hash_table);
+}
+
+static cairo_hash_entry_t **
+_cairo_hash_table_lookup_unique_key (cairo_hash_table_t *hash_table,
+				     cairo_hash_entry_t *key)
+{
+    unsigned long table_size, i, idx, step;
+    cairo_hash_entry_t **entry;
+
+    table_size = *hash_table->table_size;
+    idx = key->hash % table_size;
+
+    entry = &hash_table->entries[idx];
+    if (! ENTRY_IS_LIVE (*entry))
+	return entry;
+
+    i = 1;
+    step = 1 + key->hash % (table_size - 2);
+    do {
+	idx += step;
+	if (idx >= table_size)
+	    idx -= table_size;
+
+	entry = &hash_table->entries[idx];
+	if (! ENTRY_IS_LIVE (*entry))
+	    return entry;
+    } while (++i < table_size);
+
+    ASSERT_NOT_REACHED;
+    return NULL;
+}
+
+/**
+ * _cairo_hash_table_manage:
+ * @hash_table: a hash table
+ *
+ * Resize the hash table if the number of entries has gotten much
+ * bigger or smaller than the ideal number of entries for the current
+ * size and guarantee some free entries to be used as lookup
+ * termination points.
+ *
+ * Return value: %CAIRO_STATUS_SUCCESS if successful or
+ * %CAIRO_STATUS_NO_MEMORY if out of memory.
+ **/
+static cairo_status_t
+_cairo_hash_table_manage (cairo_hash_table_t *hash_table)
+{
+    cairo_hash_table_t tmp;
+    unsigned long new_size, i;
+
+    /* Keep between 12.5% and 50% entries in the hash table alive and
+     * at least 25% free. */
+    unsigned long live_high = *hash_table->table_size >> 1;
+    unsigned long live_low = live_high >> 2;
+    unsigned long free_low = live_high >> 1;
+
+    tmp = *hash_table;
+
+    if (hash_table->live_entries > live_high)
+    {
+	tmp.table_size = hash_table->table_size + 1;
+	/* This code is being abused if we can't make a table big enough. */
+	assert (tmp.table_size - hash_table_sizes <
+		ARRAY_LENGTH (hash_table_sizes));
+    }
+    else if (hash_table->live_entries < live_low)
+    {
+	/* Can't shrink if we're at the smallest size */
+	if (hash_table->table_size == &hash_table_sizes[0])
+	    tmp.table_size = hash_table->table_size;
+	else
+	    tmp.table_size = hash_table->table_size - 1;
+    }
+
+    if (tmp.table_size == hash_table->table_size &&
+	hash_table->free_entries > free_low)
+    {
+	/* The number of live entries is within the desired bounds
+	 * (we're not going to resize the table) and we have enough
+	 * free entries. Do nothing. */
+	return CAIRO_STATUS_SUCCESS;
+    }
+
+    new_size = *tmp.table_size;
+    tmp.entries = calloc (new_size, sizeof (cairo_hash_entry_t*));
+    if (unlikely (tmp.entries == NULL))
+	return _cairo_error (CAIRO_STATUS_NO_MEMORY);
+
+    for (i = 0; i < *hash_table->table_size; ++i) {
+	if (ENTRY_IS_LIVE (hash_table->entries[i])) {
+	    *_cairo_hash_table_lookup_unique_key (&tmp, hash_table->entries[i])
+		= hash_table->entries[i];
+	}
+    }
+
+    free (hash_table->entries);
+    hash_table->entries = tmp.entries;
+    hash_table->table_size = tmp.table_size;
+    hash_table->free_entries = new_size - hash_table->live_entries;
+
+    return CAIRO_STATUS_SUCCESS;
+}
+
+/**
+ * _cairo_hash_table_lookup:
+ * @hash_table: a hash table
+ * @key: the key of interest
+ *
+ * Performs a lookup in @hash_table looking for an entry which has a
+ * key that matches @key, (as determined by the keys_equal() function
+ * passed to _cairo_hash_table_create).
+ *
+ * Return value: the matching entry, of %NULL if no match was found.
+ **/
+void *
+_cairo_hash_table_lookup (cairo_hash_table_t *hash_table,
+			  cairo_hash_entry_t *key)
+{
+    cairo_hash_entry_t *entry;
+    unsigned long table_size, i, idx, step;
+    unsigned long hash = key->hash;
+
+    entry = hash_table->cache[hash & 31];
+    if (entry && entry->hash == hash && hash_table->keys_equal (key, entry))
+	return entry;
+
+    table_size = *hash_table->table_size;
+    idx = hash % table_size;
+
+    entry = hash_table->entries[idx];
+    if (ENTRY_IS_LIVE (entry)) {
+	if (entry->hash == hash && hash_table->keys_equal (key, entry))
+		goto insert_cache;
+    } else if (ENTRY_IS_FREE (entry))
+	return NULL;
+
+    i = 1;
+    step = 1 + hash % (table_size - 2);
+    do {
+	idx += step;
+	if (idx >= table_size)
+	    idx -= table_size;
+
+	entry = hash_table->entries[idx];
+	if (ENTRY_IS_LIVE (entry)) {
+	    if (entry->hash == hash && hash_table->keys_equal (key, entry))
+		    goto insert_cache;
+	} else if (ENTRY_IS_FREE (entry))
+	    return NULL;
+    } while (++i < table_size);
+
+    ASSERT_NOT_REACHED;
+    return NULL;
+
+insert_cache:
+    hash_table->cache[hash & 31] = entry;
+    return entry;
+}
+
+/**
+ * _cairo_hash_table_random_entry:
+ * @hash_table: a hash table
+ * @predicate: a predicate function.
+ *
+ * Find a random entry in the hash table satisfying the given
+ * @predicate.
+ *
+ * We use the same algorithm as the lookup algorithm to walk over the
+ * entries in the hash table in a pseudo-random order. Walking
+ * linearly would favor entries following gaps in the hash table. We
+ * could also call rand() repeatedly, which works well for almost-full
+ * tables, but degrades when the table is almost empty, or predicate
+ * returns %TRUE for most entries.
+ *
+ * Return value: a random live entry or %NULL if there are no entries
+ * that match the given predicate. In particular, if predicate is
+ * %NULL, a %NULL return value indicates that the table is empty.
+ **/
+void *
+_cairo_hash_table_random_entry (cairo_hash_table_t	   *hash_table,
+				cairo_hash_predicate_func_t predicate)
+{
+    cairo_hash_entry_t *entry;
+    unsigned long hash;
+    unsigned long table_size, i, idx, step;
+
+    assert (predicate != NULL);
+
+    table_size = *hash_table->table_size;
+    hash = rand ();
+    idx = hash % table_size;
+
+    entry = hash_table->entries[idx];
+    if (ENTRY_IS_LIVE (entry) && predicate (entry))
+	return entry;
+
+    i = 1;
+    step = 1 + hash % (table_size - 2);
+    do {
+	idx += step;
+	if (idx >= table_size)
+	    idx -= table_size;
+
+	entry = hash_table->entries[idx];
+	if (ENTRY_IS_LIVE (entry) && predicate (entry))
+	    return entry;
+    } while (++i < table_size);
+
+    return NULL;
+}
+
+/**
+ * _cairo_hash_table_insert:
+ * @hash_table: a hash table
+ * @key_and_value: an entry to be inserted
+ *
+ * Insert the entry #key_and_value into the hash table.
+ *
+ * WARNING: There must not be an existing entry in the hash table
+ * with a matching key.
+ *
+ * WARNING: It is a fatal error to insert an element while
+ * an iterator is running
+ *
+ * Instead of using insert to replace an entry, consider just editing
+ * the entry obtained with _cairo_hash_table_lookup. Or if absolutely
+ * necessary, use _cairo_hash_table_remove first.
+ *
+ * Return value: %CAIRO_STATUS_SUCCESS if successful or
+ * %CAIRO_STATUS_NO_MEMORY if insufficient memory is available.
+ **/
+cairo_status_t
+_cairo_hash_table_insert (cairo_hash_table_t *hash_table,
+			  cairo_hash_entry_t *key_and_value)
+{
+    cairo_hash_entry_t **entry;
+    cairo_status_t status;
+
+    /* Insert is illegal while an iterator is running. */
+    assert (hash_table->iterating == 0);
+
+    status = _cairo_hash_table_manage (hash_table);
+    if (unlikely (status))
+	return status;
+
+    entry = _cairo_hash_table_lookup_unique_key (hash_table, key_and_value);
+
+    if (ENTRY_IS_FREE (*entry))
+	hash_table->free_entries--;
+
+    *entry = key_and_value;
+    hash_table->cache[key_and_value->hash & 31] = key_and_value;
+    hash_table->live_entries++;
+
+    return CAIRO_STATUS_SUCCESS;
+}
+
+static cairo_hash_entry_t **
+_cairo_hash_table_lookup_exact_key (cairo_hash_table_t *hash_table,
+				    cairo_hash_entry_t *key)
+{
+    unsigned long table_size, i, idx, step;
+    cairo_hash_entry_t **entry;
+
+    table_size = *hash_table->table_size;
+    idx = key->hash % table_size;
+
+    entry = &hash_table->entries[idx];
+    if (*entry == key)
+	return entry;
+
+    i = 1;
+    step = 1 + key->hash % (table_size - 2);
+    do {
+	idx += step;
+	if (idx >= table_size)
+	    idx -= table_size;
+
+	entry = &hash_table->entries[idx];
+	if (*entry == key)
+	    return entry;
+    } while (++i < table_size);
+
+    ASSERT_NOT_REACHED;
+    return NULL;
+}
+/**
+ * _cairo_hash_table_remove:
+ * @hash_table: a hash table
+ * @key: key of entry to be removed
+ *
+ * Remove an entry from the hash table which points to @key.
+ *
+ * Return value: %CAIRO_STATUS_SUCCESS if successful or
+ * %CAIRO_STATUS_NO_MEMORY if out of memory.
+ **/
+void
+_cairo_hash_table_remove (cairo_hash_table_t *hash_table,
+			  cairo_hash_entry_t *key)
+{
+    *_cairo_hash_table_lookup_exact_key (hash_table, key) = DEAD_ENTRY;
+    hash_table->live_entries--;
+    hash_table->cache[key->hash & 31] = NULL;
+
+    /* Check for table resize. Don't do this when iterating as this will
+     * reorder elements of the table and cause the iteration to potentially
+     * skip some elements. */
+    if (hash_table->iterating == 0) {
+	/* This call _can_ fail, but only in failing to allocate new
+	 * memory to shrink the hash table. It does leave the table in a
+	 * consistent state, and we've already succeeded in removing the
+	 * entry, so we don't examine the failure status of this call. */
+	_cairo_hash_table_manage (hash_table);
+    }
+}
+
+/**
+ * _cairo_hash_table_foreach:
+ * @hash_table: a hash table
+ * @hash_callback: function to be called for each live entry
+ * @closure: additional argument to be passed to @hash_callback
+ *
+ * Call @hash_callback for each live entry in the hash table, in a
+ * non-specified order.
+ *
+ * Entries in @hash_table may be removed by code executed from @hash_callback.
+ *
+ * Entries may not be inserted to @hash_table, nor may @hash_table
+ * be destroyed by code executed from @hash_callback. The relevant
+ * functions will halt in these cases.
+ **/
+void
+_cairo_hash_table_foreach (cairo_hash_table_t	      *hash_table,
+			   cairo_hash_callback_func_t  hash_callback,
+			   void			      *closure)
+{
+    unsigned long i;
+    cairo_hash_entry_t *entry;
+
+    /* Mark the table for iteration */
+    ++hash_table->iterating;
+    for (i = 0; i < *hash_table->table_size; i++) {
+	entry = hash_table->entries[i];
+	if (ENTRY_IS_LIVE(entry))
+	    hash_callback (entry, closure);
+    }
+    /* If some elements were deleted during the iteration,
+     * the table may need resizing. Just do this every time
+     * as the check is inexpensive.
+     */
+    if (--hash_table->iterating == 0) {
+	/* Should we fail to shrink the hash table, it is left unaltered,
+	 * and we don't need to propagate the error status. */
+	_cairo_hash_table_manage (hash_table);
+    }
+}