/modules/freetype2/src/cache/ftccache.c
C | 595 lines | 379 code | 149 blank | 67 comment | 57 complexity | a30b4d69a8f767bac4851789e85ddc1e MD5 | raw file
1/***************************************************************************/ 2/* */ 3/* ftccache.c */ 4/* */ 5/* The FreeType internal cache interface (body). */ 6/* */ 7/* Copyright 2000-2001, 2002, 2003, 2004, 2005, 2006, 2007, 2009, 2010 by */ 8/* David Turner, Robert Wilhelm, and Werner Lemberg. */ 9/* */ 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. */ 15/* */ 16/***************************************************************************/ 17 18 19#include <ft2build.h> 20#include "ftcmanag.h" 21#include FT_INTERNAL_OBJECTS_H 22#include FT_INTERNAL_DEBUG_H 23 24#include "ftccback.h" 25#include "ftcerror.h" 26 27#undef FT_COMPONENT 28#define FT_COMPONENT trace_cache 29 30 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 ) 34 35/* this one _must_ be a power of 2! */ 36#define FTC_HASH_INITIAL_SIZE 8 37 38 39 /*************************************************************************/ 40 /*************************************************************************/ 41 /***** *****/ 42 /***** CACHE NODE DEFINITIONS *****/ 43 /***** *****/ 44 /*************************************************************************/ 45 /*************************************************************************/ 46 47 /* add a new node to the head of the manager's circular MRU list */ 48 static void 49 ftc_node_mru_link( FTC_Node node, 50 FTC_Manager manager ) 51 { 52 void *nl = &manager->nodes_list; 53 54 55 FTC_MruNode_Prepend( (FTC_MruNode*)nl, 56 (FTC_MruNode)node ); 57 manager->num_nodes++; 58 } 59 60 61 /* remove a node from the manager's MRU list */ 62 static void 63 ftc_node_mru_unlink( FTC_Node node, 64 FTC_Manager manager ) 65 { 66 void *nl = &manager->nodes_list; 67 68 69 FTC_MruNode_Remove( (FTC_MruNode*)nl, 70 (FTC_MruNode)node ); 71 manager->num_nodes--; 72 } 73 74 75#ifndef FTC_INLINE 76 77 /* move a node to the head of the manager's MRU list */ 78 static void 79 ftc_node_mru_up( FTC_Node node, 80 FTC_Manager manager ) 81 { 82 FTC_MruNode_Up( (FTC_MruNode*)&manager->nodes_list, 83 (FTC_MruNode)node ); 84 } 85 86#endif /* !FTC_INLINE */ 87 88 89 /* Note that this function cannot fail. If we cannot re-size the 90 * buckets array appropriately, we simply degrade the hash table's 91 * performance! 92 */ 93 static void 94 ftc_cache_resize( FTC_Cache cache ) 95 { 96 for (;;) 97 { 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 */ 102 103 104 /* do we need to shrink the buckets array? */ 105 if ( cache->slack < 0 ) 106 { 107 FTC_Node new_list = NULL; 108 109 110 /* try to expand the buckets array _before_ splitting 111 * the bucket lists 112 */ 113 if ( p >= mask ) 114 { 115 FT_Memory memory = cache->memory; 116 FT_Error error; 117 118 119 /* if we can't expand the array, leave immediately */ 120 if ( FT_RENEW_ARRAY( cache->buckets, (mask+1)*2, (mask+1)*4 ) ) 121 break; 122 } 123 124 /* split a single bucket */ 125 pnode = cache->buckets + p; 126 127 for (;;) 128 { 129 node = *pnode; 130 if ( node == NULL ) 131 break; 132 133 if ( node->hash & ( mask + 1 ) ) 134 { 135 *pnode = node->link; 136 node->link = new_list; 137 new_list = node; 138 } 139 else 140 pnode = &node->link; 141 } 142 143 cache->buckets[p + mask + 1] = new_list; 144 145 cache->slack += FTC_HASH_MAX_LOAD; 146 147 if ( p >= mask ) 148 { 149 cache->mask = 2 * mask + 1; 150 cache->p = 0; 151 } 152 else 153 cache->p = p + 1; 154 } 155 156 /* do we need to expand the buckets array? */ 157 else if ( cache->slack > (FT_Long)count * FTC_HASH_SUB_LOAD ) 158 { 159 FT_UFast old_index = p + mask; 160 FTC_Node* pold; 161 162 163 if ( old_index + 1 <= FTC_HASH_INITIAL_SIZE ) 164 break; 165 166 if ( p == 0 ) 167 { 168 FT_Memory memory = cache->memory; 169 FT_Error error; 170 171 172 /* if we can't shrink the array, leave immediately */ 173 if ( FT_RENEW_ARRAY( cache->buckets, 174 ( mask + 1 ) * 2, mask + 1 ) ) 175 break; 176 177 cache->mask >>= 1; 178 p = cache->mask; 179 } 180 else 181 p--; 182 183 pnode = cache->buckets + p; 184 while ( *pnode ) 185 pnode = &(*pnode)->link; 186 187 pold = cache->buckets + old_index; 188 *pnode = *pold; 189 *pold = NULL; 190 191 cache->slack -= FTC_HASH_MAX_LOAD; 192 cache->p = p; 193 } 194 else /* the hash table is balanced */ 195 break; 196 } 197 } 198 199 200 /* remove a node from its cache's hash table */ 201 static void 202 ftc_node_hash_unlink( FTC_Node node0, 203 FTC_Cache cache ) 204 { 205 FTC_Node *pnode; 206 FT_UInt idx; 207 208 209 idx = (FT_UInt)( node0->hash & cache->mask ); 210 if ( idx < cache->p ) 211 idx = (FT_UInt)( node0->hash & ( 2 * cache->mask + 1 ) ); 212 213 pnode = cache->buckets + idx; 214 215 for (;;) 216 { 217 FTC_Node node = *pnode; 218 219 220 if ( node == NULL ) 221 { 222 FT_TRACE0(( "ftc_node_hash_unlink: unknown node\n" )); 223 return; 224 } 225 226 if ( node == node0 ) 227 break; 228 229 pnode = &(*pnode)->link; 230 } 231 232 *pnode = node0->link; 233 node0->link = NULL; 234 235 cache->slack++; 236 ftc_cache_resize( cache ); 237 } 238 239 240 /* add a node to the `top' of its cache's hash table */ 241 static void 242 ftc_node_hash_link( FTC_Node node, 243 FTC_Cache cache ) 244 { 245 FTC_Node *pnode; 246 FT_UInt idx; 247 248 249 idx = (FT_UInt)( node->hash & cache->mask ); 250 if ( idx < cache->p ) 251 idx = (FT_UInt)( node->hash & (2 * cache->mask + 1 ) ); 252 253 pnode = cache->buckets + idx; 254 255 node->link = *pnode; 256 *pnode = node; 257 258 cache->slack--; 259 ftc_cache_resize( cache ); 260 } 261 262 263 /* remove a node from the cache manager */ 264#ifdef FT_CONFIG_OPTION_OLD_INTERNALS 265 FT_BASE_DEF( void ) 266#else 267 FT_LOCAL_DEF( void ) 268#endif 269 ftc_node_destroy( FTC_Node node, 270 FTC_Manager manager ) 271 { 272 FTC_Cache cache; 273 274 275#ifdef FT_DEBUG_ERROR 276 /* find node's cache */ 277 if ( node->cache_index >= manager->num_caches ) 278 { 279 FT_TRACE0(( "ftc_node_destroy: invalid node handle\n" )); 280 return; 281 } 282#endif 283 284 cache = manager->caches[node->cache_index]; 285 286#ifdef FT_DEBUG_ERROR 287 if ( cache == NULL ) 288 { 289 FT_TRACE0(( "ftc_node_destroy: invalid node handle\n" )); 290 return; 291 } 292#endif 293 294 manager->cur_weight -= cache->clazz.node_weight( node, cache ); 295 296 /* remove node from mru list */ 297 ftc_node_mru_unlink( node, manager ); 298 299 /* remove node from cache's hash table */ 300 ftc_node_hash_unlink( node, cache ); 301 302 /* now finalize it */ 303 cache->clazz.node_free( node, cache ); 304 305#if 0 306 /* 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 )); 310#endif 311 } 312 313 314 /*************************************************************************/ 315 /*************************************************************************/ 316 /***** *****/ 317 /***** ABSTRACT CACHE CLASS *****/ 318 /***** *****/ 319 /*************************************************************************/ 320 /*************************************************************************/ 321 322 323 FT_LOCAL_DEF( FT_Error ) 324 FTC_Cache_Init( FTC_Cache cache ) 325 { 326 return ftc_cache_init( cache ); 327 } 328 329 330 FT_LOCAL_DEF( FT_Error ) 331 ftc_cache_init( FTC_Cache cache ) 332 { 333 FT_Memory memory = cache->memory; 334 FT_Error error; 335 336 337 cache->p = 0; 338 cache->mask = FTC_HASH_INITIAL_SIZE - 1; 339 cache->slack = FTC_HASH_INITIAL_SIZE * FTC_HASH_MAX_LOAD; 340 341 (void)FT_NEW_ARRAY( cache->buckets, FTC_HASH_INITIAL_SIZE * 2 ); 342 return error; 343 } 344 345 346 static void 347 FTC_Cache_Clear( FTC_Cache cache ) 348 { 349 if ( cache && cache->buckets ) 350 { 351 FTC_Manager manager = cache->manager; 352 FT_UFast i; 353 FT_UFast count; 354 355 356 count = cache->p + cache->mask + 1; 357 358 for ( i = 0; i < count; i++ ) 359 { 360 FTC_Node *pnode = cache->buckets + i, next, node = *pnode; 361 362 363 while ( node ) 364 { 365 next = node->link; 366 node->link = NULL; 367 368 /* remove node from mru list */ 369 ftc_node_mru_unlink( node, manager ); 370 371 /* now finalize it */ 372 manager->cur_weight -= cache->clazz.node_weight( node, cache ); 373 374 cache->clazz.node_free( node, cache ); 375 node = next; 376 } 377 cache->buckets[i] = NULL; 378 } 379 ftc_cache_resize( cache ); 380 } 381 } 382 383 384 FT_LOCAL_DEF( void ) 385 ftc_cache_done( FTC_Cache cache ) 386 { 387 if ( cache->memory ) 388 { 389 FT_Memory memory = cache->memory; 390 391 392 FTC_Cache_Clear( cache ); 393 394 FT_FREE( cache->buckets ); 395 cache->mask = 0; 396 cache->p = 0; 397 cache->slack = 0; 398 399 cache->memory = NULL; 400 } 401 } 402 403 404 FT_LOCAL_DEF( void ) 405 FTC_Cache_Done( FTC_Cache cache ) 406 { 407 ftc_cache_done( cache ); 408 } 409 410 411 static void 412 ftc_cache_add( FTC_Cache cache, 413 FT_UInt32 hash, 414 FTC_Node node ) 415 { 416 node->hash = hash; 417 node->cache_index = (FT_UInt16) cache->index; 418 node->ref_count = 0; 419 420 ftc_node_hash_link( node, cache ); 421 ftc_node_mru_link( node, cache->manager ); 422 423 { 424 FTC_Manager manager = cache->manager; 425 426 427 manager->cur_weight += cache->clazz.node_weight( node, cache ); 428 429 if ( manager->cur_weight >= manager->max_weight ) 430 { 431 node->ref_count++; 432 FTC_Manager_Compress( manager ); 433 node->ref_count--; 434 } 435 } 436 } 437 438 439 FT_LOCAL_DEF( FT_Error ) 440 FTC_Cache_NewNode( FTC_Cache cache, 441 FT_UInt32 hash, 442 FT_Pointer query, 443 FTC_Node *anode ) 444 { 445 FT_Error error; 446 FTC_Node node; 447 448 449 /* 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. 453 */ 454 455 FTC_CACHE_TRYLOOP( cache ) 456 { 457 error = cache->clazz.node_new( &node, query, cache ); 458 } 459 FTC_CACHE_TRYLOOP_END(); 460 461 if ( error ) 462 node = NULL; 463 else 464 { 465 /* don't assume that the cache has the same number of buckets, since 466 * our allocation request might have triggered global cache flushing 467 */ 468 ftc_cache_add( cache, hash, node ); 469 } 470 471 *anode = node; 472 return error; 473 } 474 475 476#ifndef FTC_INLINE 477 478 FT_LOCAL_DEF( FT_Error ) 479 FTC_Cache_Lookup( FTC_Cache cache, 480 FT_UInt32 hash, 481 FT_Pointer query, 482 FTC_Node *anode ) 483 { 484 FT_UFast idx; 485 FTC_Node* bucket; 486 FTC_Node* pnode; 487 FTC_Node node; 488 FT_Error error = FTC_Err_Ok; 489 490 FTC_Node_CompareFunc compare = cache->clazz.node_compare; 491 492 493 if ( cache == NULL || anode == NULL ) 494 return FTC_Err_Invalid_Argument; 495 496 idx = hash & cache->mask; 497 if ( idx < cache->p ) 498 idx = hash & ( cache->mask * 2 + 1 ); 499 500 bucket = cache->buckets + idx; 501 pnode = bucket; 502 for (;;) 503 { 504 node = *pnode; 505 if ( node == NULL ) 506 goto NewNode; 507 508 if ( node->hash == hash && compare( node, query, cache ) ) 509 break; 510 511 pnode = &node->link; 512 } 513 514 if ( node != *bucket ) 515 { 516 *pnode = node->link; 517 node->link = *bucket; 518 *bucket = node; 519 } 520 521 /* move to head of MRU list */ 522 { 523 FTC_Manager manager = cache->manager; 524 525 526 if ( node != manager->nodes_list ) 527 ftc_node_mru_up( node, manager ); 528 } 529 *anode = node; 530 return error; 531 532 NewNode: 533 return FTC_Cache_NewNode( cache, hash, query, anode ); 534 } 535 536#endif /* !FTC_INLINE */ 537 538 539 FT_LOCAL_DEF( void ) 540 FTC_Cache_RemoveFaceID( FTC_Cache cache, 541 FTC_FaceID face_id ) 542 { 543 FT_UFast i, count; 544 FTC_Manager manager = cache->manager; 545 FTC_Node frees = NULL; 546 547 548 count = cache->p + cache->mask; 549 for ( i = 0; i < count; i++ ) 550 { 551 FTC_Node* bucket = cache->buckets + i; 552 FTC_Node* pnode = bucket; 553 554 555 for ( ;; ) 556 { 557 FTC_Node node = *pnode; 558 559 560 if ( node == NULL ) 561 break; 562 563 if ( cache->clazz.node_remove_faceid( node, face_id, cache ) ) 564 { 565 *pnode = node->link; 566 node->link = frees; 567 frees = node; 568 } 569 else 570 pnode = &node->link; 571 } 572 } 573 574 /* remove all nodes in the free list */ 575 while ( frees ) 576 { 577 FTC_Node node; 578 579 580 node = frees; 581 frees = node->link; 582 583 manager->cur_weight -= cache->clazz.node_weight( node, cache ); 584 ftc_node_mru_unlink( node, manager ); 585 586 cache->clazz.node_free( node, cache ); 587 588 cache->slack++; 589 } 590 591 ftc_cache_resize( cache ); 592 } 593 594 595/* END */