1 /***************************************************************************/
5 /* The FreeType internal cache interface (body). */
7 /* Copyright 2000-2001, 2002, 2003, 2004, 2005, 2006, 2007, 2009, 2010 by */
8 /* David Turner, Robert Wilhelm, and Werner Lemberg. */
10 /* This file is part of the FreeType project, and may only be used, */
11 /* modified, and distributed under the terms of the FreeType project */
12 /* license, LICENSE.TXT. By continuing to use, modify, or distribute */
13 /* this file you indicate that you have read the license and */
14 /* understand and accept it fully. */
16 /***************************************************************************/
21 #include FT_INTERNAL_OBJECTS_H
22 #include FT_INTERNAL_DEBUG_H
28 #define FT_COMPONENT trace_cache
31 #define FTC_HASH_MAX_LOAD 2
32 #define FTC_HASH_MIN_LOAD 1
33 #define FTC_HASH_SUB_LOAD ( FTC_HASH_MAX_LOAD - FTC_HASH_MIN_LOAD )
35 /* this one _must_ be a power of 2! */
36 #define FTC_HASH_INITIAL_SIZE 8
39 /*************************************************************************/
40 /*************************************************************************/
42 /***** CACHE NODE DEFINITIONS *****/
44 /*************************************************************************/
45 /*************************************************************************/
47 /* add a new node to the head of the manager's circular MRU list */
49 ftc_node_mru_link( FTC_Node node,
52 void *nl = &manager->nodes_list;
55 FTC_MruNode_Prepend( (FTC_MruNode*)nl,
61 /* remove a node from the manager's MRU list */
63 ftc_node_mru_unlink( FTC_Node node,
66 void *nl = &manager->nodes_list;
69 FTC_MruNode_Remove( (FTC_MruNode*)nl,
77 /* move a node to the head of the manager's MRU list */
79 ftc_node_mru_up( FTC_Node node,
82 FTC_MruNode_Up( (FTC_MruNode*)&manager->nodes_list,
86 #endif /* !FTC_INLINE */
89 /* Note that this function cannot fail. If we cannot re-size the
90 * buckets array appropriately, we simply degrade the hash table's
94 ftc_cache_resize( FTC_Cache cache )
98 FTC_Node node, *pnode;
99 FT_UFast p = cache->p;
100 FT_UFast mask = cache->mask;
101 FT_UFast count = mask + p + 1; /* number of buckets */
104 /* do we need to shrink the buckets array? */
105 if ( cache->slack < 0 )
107 FTC_Node new_list = NULL;
110 /* try to expand the buckets array _before_ splitting
115 FT_Memory memory = cache->memory;
119 /* if we can't expand the array, leave immediately */
120 if ( FT_RENEW_ARRAY( cache->buckets, (mask+1)*2, (mask+1)*4 ) )
124 /* split a single bucket */
125 pnode = cache->buckets + p;
133 if ( node->hash & ( mask + 1 ) )
136 node->link = new_list;
143 cache->buckets[p + mask + 1] = new_list;
145 cache->slack += FTC_HASH_MAX_LOAD;
149 cache->mask = 2 * mask + 1;
156 /* do we need to expand the buckets array? */
157 else if ( cache->slack > (FT_Long)count * FTC_HASH_SUB_LOAD )
159 FT_UFast old_index = p + mask;
163 if ( old_index + 1 <= FTC_HASH_INITIAL_SIZE )
168 FT_Memory memory = cache->memory;
172 /* if we can't shrink the array, leave immediately */
173 if ( FT_RENEW_ARRAY( cache->buckets,
174 ( mask + 1 ) * 2, mask + 1 ) )
183 pnode = cache->buckets + p;
185 pnode = &(*pnode)->link;
187 pold = cache->buckets + old_index;
191 cache->slack -= FTC_HASH_MAX_LOAD;
194 else /* the hash table is balanced */
200 /* remove a node from its cache's hash table */
202 ftc_node_hash_unlink( FTC_Node node0,
209 idx = (FT_UInt)( node0->hash & cache->mask );
210 if ( idx < cache->p )
211 idx = (FT_UInt)( node0->hash & ( 2 * cache->mask + 1 ) );
213 pnode = cache->buckets + idx;
217 FTC_Node node = *pnode;
222 FT_TRACE0(( "ftc_node_hash_unlink: unknown node\n" ));
229 pnode = &(*pnode)->link;
232 *pnode = node0->link;
236 ftc_cache_resize( cache );
240 /* add a node to the `top' of its cache's hash table */
242 ftc_node_hash_link( FTC_Node node,
249 idx = (FT_UInt)( node->hash & cache->mask );
250 if ( idx < cache->p )
251 idx = (FT_UInt)( node->hash & (2 * cache->mask + 1 ) );
253 pnode = cache->buckets + idx;
259 ftc_cache_resize( cache );
263 /* remove a node from the cache manager */
264 #ifdef FT_CONFIG_OPTION_OLD_INTERNALS
269 ftc_node_destroy( FTC_Node node,
270 FTC_Manager manager )
275 #ifdef FT_DEBUG_ERROR
276 /* find node's cache */
277 if ( node->cache_index >= manager->num_caches )
279 FT_TRACE0(( "ftc_node_destroy: invalid node handle\n" ));
284 cache = manager->caches[node->cache_index];
286 #ifdef FT_DEBUG_ERROR
289 FT_TRACE0(( "ftc_node_destroy: invalid node handle\n" ));
294 manager->cur_weight -= cache->clazz.node_weight( node, cache );
296 /* remove node from mru list */
297 ftc_node_mru_unlink( node, manager );
299 /* remove node from cache's hash table */
300 ftc_node_hash_unlink( node, cache );
302 /* now finalize it */
303 cache->clazz.node_free( node, cache );
306 /* check, just in case of general corruption :-) */
307 if ( manager->num_nodes == 0 )
308 FT_TRACE0(( "ftc_node_destroy: invalid cache node count (%d)\n",
309 manager->num_nodes ));
314 /*************************************************************************/
315 /*************************************************************************/
317 /***** ABSTRACT CACHE CLASS *****/
319 /*************************************************************************/
320 /*************************************************************************/
323 FT_LOCAL_DEF( FT_Error )
324 FTC_Cache_Init( FTC_Cache cache )
326 return ftc_cache_init( cache );
330 FT_LOCAL_DEF( FT_Error )
331 ftc_cache_init( FTC_Cache cache )
333 FT_Memory memory = cache->memory;
338 cache->mask = FTC_HASH_INITIAL_SIZE - 1;
339 cache->slack = FTC_HASH_INITIAL_SIZE * FTC_HASH_MAX_LOAD;
341 (void)FT_NEW_ARRAY( cache->buckets, FTC_HASH_INITIAL_SIZE * 2 );
347 FTC_Cache_Clear( FTC_Cache cache )
349 if ( cache && cache->buckets )
351 FTC_Manager manager = cache->manager;
356 count = cache->p + cache->mask + 1;
358 for ( i = 0; i < count; i++ )
360 FTC_Node *pnode = cache->buckets + i, next, node = *pnode;
368 /* remove node from mru list */
369 ftc_node_mru_unlink( node, manager );
371 /* now finalize it */
372 manager->cur_weight -= cache->clazz.node_weight( node, cache );
374 cache->clazz.node_free( node, cache );
377 cache->buckets[i] = NULL;
379 ftc_cache_resize( cache );
385 ftc_cache_done( FTC_Cache cache )
389 FT_Memory memory = cache->memory;
392 FTC_Cache_Clear( cache );
394 FT_FREE( cache->buckets );
399 cache->memory = NULL;
405 FTC_Cache_Done( FTC_Cache cache )
407 ftc_cache_done( cache );
412 ftc_cache_add( FTC_Cache cache,
417 node->cache_index = (FT_UInt16) cache->index;
420 ftc_node_hash_link( node, cache );
421 ftc_node_mru_link( node, cache->manager );
424 FTC_Manager manager = cache->manager;
427 manager->cur_weight += cache->clazz.node_weight( node, cache );
429 if ( manager->cur_weight >= manager->max_weight )
432 FTC_Manager_Compress( manager );
439 FT_LOCAL_DEF( FT_Error )
440 FTC_Cache_NewNode( FTC_Cache cache,
450 * We use the FTC_CACHE_TRYLOOP macros to support out-of-memory
451 * errors (OOM) correctly, i.e., by flushing the cache progressively
452 * in order to make more room.
455 FTC_CACHE_TRYLOOP( cache )
457 error = cache->clazz.node_new( &node, query, cache );
459 FTC_CACHE_TRYLOOP_END();
465 /* don't assume that the cache has the same number of buckets, since
466 * our allocation request might have triggered global cache flushing
468 ftc_cache_add( cache, hash, node );
478 FT_LOCAL_DEF( FT_Error )
479 FTC_Cache_Lookup( FTC_Cache cache,
488 FT_Error error = FTC_Err_Ok;
490 FTC_Node_CompareFunc compare = cache->clazz.node_compare;
493 if ( cache == NULL || anode == NULL )
494 return FTC_Err_Invalid_Argument;
496 idx = hash & cache->mask;
497 if ( idx < cache->p )
498 idx = hash & ( cache->mask * 2 + 1 );
500 bucket = cache->buckets + idx;
508 if ( node->hash == hash && compare( node, query, cache ) )
514 if ( node != *bucket )
517 node->link = *bucket;
521 /* move to head of MRU list */
523 FTC_Manager manager = cache->manager;
526 if ( node != manager->nodes_list )
527 ftc_node_mru_up( node, manager );
533 return FTC_Cache_NewNode( cache, hash, query, anode );
536 #endif /* !FTC_INLINE */
540 FTC_Cache_RemoveFaceID( FTC_Cache cache,
544 FTC_Manager manager = cache->manager;
545 FTC_Node frees = NULL;
548 count = cache->p + cache->mask;
549 for ( i = 0; i < count; i++ )
551 FTC_Node* bucket = cache->buckets + i;
552 FTC_Node* pnode = bucket;
557 FTC_Node node = *pnode;
563 if ( cache->clazz.node_remove_faceid( node, face_id, cache ) )
574 /* remove all nodes in the free list */
583 manager->cur_weight -= cache->clazz.node_weight( node, cache );
584 ftc_node_mru_unlink( node, manager );
586 cache->clazz.node_free( node, cache );
591 ftc_cache_resize( cache );