1 /***************************************************************************/
5 /* The FreeType internal cache interface (body). */
7 /* Copyright 2000-2001, 2002, 2003, 2004, 2005, 2006, 2007, 2009, 2010, */
9 /* David Turner, Robert Wilhelm, and Werner Lemberg. */
11 /* This file is part of the FreeType project, and may only be used, */
12 /* modified, and distributed under the terms of the FreeType project */
13 /* license, LICENSE.TXT. By continuing to use, modify, or distribute */
14 /* this file you indicate that you have read the license and */
15 /* understand and accept it fully. */
17 /***************************************************************************/
22 #include FT_INTERNAL_OBJECTS_H
23 #include FT_INTERNAL_DEBUG_H
29 #define FT_COMPONENT trace_cache
32 #define FTC_HASH_MAX_LOAD 2
33 #define FTC_HASH_MIN_LOAD 1
34 #define FTC_HASH_SUB_LOAD ( FTC_HASH_MAX_LOAD - FTC_HASH_MIN_LOAD )
36 /* this one _must_ be a power of 2! */
37 #define FTC_HASH_INITIAL_SIZE 8
40 /*************************************************************************/
41 /*************************************************************************/
43 /***** CACHE NODE DEFINITIONS *****/
45 /*************************************************************************/
46 /*************************************************************************/
48 /* add a new node to the head of the manager's circular MRU list */
50 ftc_node_mru_link( FTC_Node node,
53 void *nl = &manager->nodes_list;
56 FTC_MruNode_Prepend( (FTC_MruNode*)nl,
62 /* remove a node from the manager's MRU list */
64 ftc_node_mru_unlink( FTC_Node node,
67 void *nl = &manager->nodes_list;
70 FTC_MruNode_Remove( (FTC_MruNode*)nl,
78 /* move a node to the head of the manager's MRU list */
80 ftc_node_mru_up( FTC_Node node,
83 FTC_MruNode_Up( (FTC_MruNode*)&manager->nodes_list,
88 /* get a top bucket for specified hash from cache,
89 * body for FTC_NODE__TOP_FOR_HASH( cache, hash )
91 FT_LOCAL_DEF( FTC_Node* )
92 ftc_get_top_node_for_hash( FTC_Cache cache,
99 idx = (FT_UInt)( hash & cache->mask );
100 if ( idx < cache->p )
101 idx = (FT_UInt)( hash & ( 2 * cache->mask + 1 ) );
102 pnode = cache->buckets + idx;
106 #endif /* !FTC_INLINE */
109 /* Note that this function cannot fail. If we cannot re-size the
110 * buckets array appropriately, we simply degrade the hash table's
114 ftc_cache_resize( FTC_Cache cache )
118 FTC_Node node, *pnode;
119 FT_UFast p = cache->p;
120 FT_UFast mask = cache->mask;
121 FT_UFast count = mask + p + 1; /* number of buckets */
124 /* do we need to shrink the buckets array? */
125 if ( cache->slack < 0 )
127 FTC_Node new_list = NULL;
130 /* try to expand the buckets array _before_ splitting
135 FT_Memory memory = cache->memory;
139 /* if we can't expand the array, leave immediately */
140 if ( FT_RENEW_ARRAY( cache->buckets,
141 ( mask + 1 ) * 2, ( mask + 1 ) * 4 ) )
145 /* split a single bucket */
146 pnode = cache->buckets + p;
154 if ( node->hash & ( mask + 1 ) )
157 node->link = new_list;
164 cache->buckets[p + mask + 1] = new_list;
166 cache->slack += FTC_HASH_MAX_LOAD;
170 cache->mask = 2 * mask + 1;
177 /* do we need to expand the buckets array? */
178 else if ( cache->slack > (FT_Long)count * FTC_HASH_SUB_LOAD )
180 FT_UFast old_index = p + mask;
184 if ( old_index + 1 <= FTC_HASH_INITIAL_SIZE )
189 FT_Memory memory = cache->memory;
193 /* if we can't shrink the array, leave immediately */
194 if ( FT_RENEW_ARRAY( cache->buckets,
195 ( mask + 1 ) * 2, mask + 1 ) )
204 pnode = cache->buckets + p;
206 pnode = &(*pnode)->link;
208 pold = cache->buckets + old_index;
212 cache->slack -= FTC_HASH_MAX_LOAD;
216 /* otherwise, the hash table is balanced */
223 /* remove a node from its cache's hash table */
225 ftc_node_hash_unlink( FTC_Node node0,
228 FTC_Node *pnode = FTC_NODE__TOP_FOR_HASH( cache, node0->hash );
233 FTC_Node node = *pnode;
238 FT_TRACE0(( "ftc_node_hash_unlink: unknown node\n" ));
245 pnode = &(*pnode)->link;
248 *pnode = node0->link;
252 ftc_cache_resize( cache );
256 /* add a node to the `top' of its cache's hash table */
258 ftc_node_hash_link( FTC_Node node,
261 FTC_Node *pnode = FTC_NODE__TOP_FOR_HASH( cache, node->hash );
268 ftc_cache_resize( cache );
272 /* remove a node from the cache manager */
273 #ifdef FT_CONFIG_OPTION_OLD_INTERNALS
278 ftc_node_destroy( FTC_Node node,
279 FTC_Manager manager )
284 #ifdef FT_DEBUG_ERROR
285 /* find node's cache */
286 if ( node->cache_index >= manager->num_caches )
288 FT_TRACE0(( "ftc_node_destroy: invalid node handle\n" ));
293 cache = manager->caches[node->cache_index];
295 #ifdef FT_DEBUG_ERROR
298 FT_TRACE0(( "ftc_node_destroy: invalid node handle\n" ));
303 manager->cur_weight -= cache->clazz.node_weight( node, cache );
305 /* remove node from mru list */
306 ftc_node_mru_unlink( node, manager );
308 /* remove node from cache's hash table */
309 ftc_node_hash_unlink( node, cache );
311 /* now finalize it */
312 cache->clazz.node_free( node, cache );
315 /* check, just in case of general corruption :-) */
316 if ( manager->num_nodes == 0 )
317 FT_TRACE0(( "ftc_node_destroy: invalid cache node count (%d)\n",
318 manager->num_nodes ));
323 /*************************************************************************/
324 /*************************************************************************/
326 /***** ABSTRACT CACHE CLASS *****/
328 /*************************************************************************/
329 /*************************************************************************/
332 FT_LOCAL_DEF( FT_Error )
333 FTC_Cache_Init( FTC_Cache cache )
335 return ftc_cache_init( cache );
339 FT_LOCAL_DEF( FT_Error )
340 ftc_cache_init( FTC_Cache cache )
342 FT_Memory memory = cache->memory;
347 cache->mask = FTC_HASH_INITIAL_SIZE - 1;
348 cache->slack = FTC_HASH_INITIAL_SIZE * FTC_HASH_MAX_LOAD;
350 (void)FT_NEW_ARRAY( cache->buckets, FTC_HASH_INITIAL_SIZE * 2 );
356 FTC_Cache_Clear( FTC_Cache cache )
358 if ( cache && cache->buckets )
360 FTC_Manager manager = cache->manager;
365 count = cache->p + cache->mask + 1;
367 for ( i = 0; i < count; i++ )
369 FTC_Node *pnode = cache->buckets + i, next, node = *pnode;
377 /* remove node from mru list */
378 ftc_node_mru_unlink( node, manager );
380 /* now finalize it */
381 manager->cur_weight -= cache->clazz.node_weight( node, cache );
383 cache->clazz.node_free( node, cache );
386 cache->buckets[i] = NULL;
388 ftc_cache_resize( cache );
394 ftc_cache_done( FTC_Cache cache )
398 FT_Memory memory = cache->memory;
401 FTC_Cache_Clear( cache );
403 FT_FREE( cache->buckets );
408 cache->memory = NULL;
414 FTC_Cache_Done( FTC_Cache cache )
416 ftc_cache_done( cache );
421 ftc_cache_add( FTC_Cache cache,
426 node->cache_index = (FT_UInt16)cache->index;
429 ftc_node_hash_link( node, cache );
430 ftc_node_mru_link( node, cache->manager );
433 FTC_Manager manager = cache->manager;
436 manager->cur_weight += cache->clazz.node_weight( node, cache );
438 if ( manager->cur_weight >= manager->max_weight )
441 FTC_Manager_Compress( manager );
448 FT_LOCAL_DEF( FT_Error )
449 FTC_Cache_NewNode( FTC_Cache cache,
459 * We use the FTC_CACHE_TRYLOOP macros to support out-of-memory
460 * errors (OOM) correctly, i.e., by flushing the cache progressively
461 * in order to make more room.
464 FTC_CACHE_TRYLOOP( cache )
466 error = cache->clazz.node_new( &node, query, cache );
468 FTC_CACHE_TRYLOOP_END( NULL );
474 /* don't assume that the cache has the same number of buckets, since
475 * our allocation request might have triggered global cache flushing
477 ftc_cache_add( cache, hash, node );
487 FT_LOCAL_DEF( FT_Error )
488 FTC_Cache_Lookup( FTC_Cache cache,
496 FT_Error error = FTC_Err_Ok;
497 FT_Bool list_changed = FALSE;
499 FTC_Node_CompareFunc compare = cache->clazz.node_compare;
502 if ( cache == NULL || anode == NULL )
503 return FTC_Err_Invalid_Argument;
505 /* Go to the `top' node of the list sharing same masked hash */
506 bucket = pnode = FTC_NODE__TOP_FOR_HASH( cache, hash );
508 /* Lookup a node with exactly same hash and queried properties. */
509 /* NOTE: _nodcomp() may change the linked list to reduce memory. */
516 if ( node->hash == hash &&
517 compare( node, query, cache, &list_changed ) )
525 /* Update bucket by modified linked list */
526 bucket = pnode = FTC_NODE__TOP_FOR_HASH( cache, hash );
528 /* Update pnode by modified linked list */
529 while ( *pnode != node )
531 if ( *pnode == NULL )
533 FT_ERROR(( "FTC_Cache_Lookup: oops!!! node missing\n" ));
537 pnode = &((*pnode)->link);
541 /* Reorder the list to move the found node to the `top' */
542 if ( node != *bucket )
545 node->link = *bucket;
549 /* move to head of MRU list */
551 FTC_Manager manager = cache->manager;
554 if ( node != manager->nodes_list )
555 ftc_node_mru_up( node, manager );
562 return FTC_Cache_NewNode( cache, hash, query, anode );
565 #endif /* !FTC_INLINE */
569 FTC_Cache_RemoveFaceID( FTC_Cache cache,
573 FTC_Manager manager = cache->manager;
574 FTC_Node frees = NULL;
577 count = cache->p + cache->mask + 1;
578 for ( i = 0; i < count; i++ )
580 FTC_Node* bucket = cache->buckets + i;
581 FTC_Node* pnode = bucket;
586 FTC_Node node = *pnode;
587 FT_Bool list_changed = FALSE;
593 if ( cache->clazz.node_remove_faceid( node, face_id,
594 cache, &list_changed ) )
605 /* remove all nodes in the free list */
614 manager->cur_weight -= cache->clazz.node_weight( node, cache );
615 ftc_node_mru_unlink( node, manager );
617 cache->clazz.node_free( node, cache );
622 ftc_cache_resize( cache );