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, */ 8/* 2011 by */ 9/* David Turner, Robert Wilhelm, and Werner Lemberg. */ 10/* */ 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. */ 16/* */ 17/***************************************************************************/ 18 19 20#include <ft2build.h> 21#include "ftcmanag.h" 22#include FT_INTERNAL_OBJECTS_H 23#include FT_INTERNAL_DEBUG_H 24 25#include "ftccback.h" 26#include "ftcerror.h" 27 28#undef FT_COMPONENT 29#define FT_COMPONENT trace_cache 30 31 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 ) 35 36 /* this one _must_ be a power of 2! */ 37#define FTC_HASH_INITIAL_SIZE 8 38 39 40 /*************************************************************************/ 41 /*************************************************************************/ 42 /***** *****/ 43 /***** CACHE NODE DEFINITIONS *****/ 44 /***** *****/ 45 /*************************************************************************/ 46 /*************************************************************************/ 47 48 /* add a new node to the head of the manager's circular MRU list */ 49 static void 50 ftc_node_mru_link( FTC_Node node, 51 FTC_Manager manager ) 52 { 53 void *nl = &manager->nodes_list; 54 55 56 FTC_MruNode_Prepend( (FTC_MruNode*)nl, 57 (FTC_MruNode)node ); 58 manager->num_nodes++; 59 } 60 61 62 /* remove a node from the manager's MRU list */ 63 static void 64 ftc_node_mru_unlink( FTC_Node node, 65 FTC_Manager manager ) 66 { 67 void *nl = &manager->nodes_list; 68 69 70 FTC_MruNode_Remove( (FTC_MruNode*)nl, 71 (FTC_MruNode)node ); 72 manager->num_nodes--; 73 } 74 75 76#ifndef FTC_INLINE 77 78 /* move a node to the head of the manager's MRU list */ 79 static void 80 ftc_node_mru_up( FTC_Node node, 81 FTC_Manager manager ) 82 { 83 FTC_MruNode_Up( (FTC_MruNode*)&manager->nodes_list, 84 (FTC_MruNode)node ); 85 } 86 87 88 /* get a top bucket for specified hash from cache, 89 * body for FTC_NODE__TOP_FOR_HASH( cache, hash ) 90 */ 91 FT_LOCAL_DEF( FTC_Node* ) 92 ftc_get_top_node_for_hash( FTC_Cache cache, 93 FT_PtrDist hash ) 94 { 95 FTC_Node* pnode; 96 FT_UInt idx; 97 98 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; 103 return pnode; 104 } 105 106#endif /* !FTC_INLINE */ 107 108 109 /* Note that this function cannot fail. If we cannot re-size the 110 * buckets array appropriately, we simply degrade the hash table's 111 * performance! 112 */ 113 static void 114 ftc_cache_resize( FTC_Cache cache ) 115 { 116 for (;;) 117 { 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 */ 122 123 124 /* do we need to shrink the buckets array? */ 125 if ( cache->slack < 0 ) 126 { 127 FTC_Node new_list = NULL; 128 129 130 /* try to expand the buckets array _before_ splitting 131 * the bucket lists 132 */ 133 if ( p >= mask ) 134 { 135 FT_Memory memory = cache->memory; 136 FT_Error error; 137 138 139 /* if we can't expand the array, leave immediately */ 140 if ( FT_RENEW_ARRAY( cache->buckets, 141 ( mask + 1 ) * 2, ( mask + 1 ) * 4 ) ) 142 break; 143 } 144 145 /* split a single bucket */ 146 pnode = cache->buckets + p; 147 148 for (;;) 149 { 150 node = *pnode; 151 if ( node == NULL ) 152 break; 153 154 if ( node->hash & ( mask + 1 ) ) 155 { 156 *pnode = node->link; 157 node->link = new_list; 158 new_list = node; 159 } 160 else 161 pnode = &node->link; 162 } 163 164 cache->buckets[p + mask + 1] = new_list; 165 166 cache->slack += FTC_HASH_MAX_LOAD; 167 168 if ( p >= mask ) 169 { 170 cache->mask = 2 * mask + 1; 171 cache->p = 0; 172 } 173 else 174 cache->p = p + 1; 175 } 176 177 /* do we need to expand the buckets array? */ 178 else if ( cache->slack > (FT_Long)count * FTC_HASH_SUB_LOAD ) 179 { 180 FT_UFast old_index = p + mask; 181 FTC_Node* pold; 182 183 184 if ( old_index + 1 <= FTC_HASH_INITIAL_SIZE ) 185 break; 186 187 if ( p == 0 ) 188 { 189 FT_Memory memory = cache->memory; 190 FT_Error error; 191 192 193 /* if we can't shrink the array, leave immediately */ 194 if ( FT_RENEW_ARRAY( cache->buckets, 195 ( mask + 1 ) * 2, mask + 1 ) ) 196 break; 197 198 cache->mask >>= 1; 199 p = cache->mask; 200 } 201 else 202 p--; 203 204 pnode = cache->buckets + p; 205 while ( *pnode ) 206 pnode = &(*pnode)->link; 207 208 pold = cache->buckets + old_index; 209 *pnode = *pold; 210 *pold = NULL; 211 212 cache->slack -= FTC_HASH_MAX_LOAD; 213 cache->p = p; 214 } 215 216 /* otherwise, the hash table is balanced */ 217 else 218 break; 219 } 220 } 221 222 223 /* remove a node from its cache's hash table */ 224 static void 225 ftc_node_hash_unlink( FTC_Node node0, 226 FTC_Cache cache ) 227 { 228 FTC_Node *pnode = FTC_NODE__TOP_FOR_HASH( cache, node0->hash ); 229 230 231 for (;;) 232 { 233 FTC_Node node = *pnode; 234 235 236 if ( node == NULL ) 237 { 238 FT_TRACE0(( "ftc_node_hash_unlink: unknown node\n" )); 239 return; 240 } 241 242 if ( node == node0 ) 243 break; 244 245 pnode = &(*pnode)->link; 246 } 247 248 *pnode = node0->link; 249 node0->link = NULL; 250 251 cache->slack++; 252 ftc_cache_resize( cache ); 253 } 254 255 256 /* add a node to the `top' of its cache's hash table */ 257 static void 258 ftc_node_hash_link( FTC_Node node, 259 FTC_Cache cache ) 260 { 261 FTC_Node *pnode = FTC_NODE__TOP_FOR_HASH( cache, node->hash ); 262 263 264 node->link = *pnode; 265 *pnode = node; 266 267 cache->slack--; 268 ftc_cache_resize( cache ); 269 } 270 271 272 /* remove a node from the cache manager */ 273#ifdef FT_CONFIG_OPTION_OLD_INTERNALS 274 FT_BASE_DEF( void ) 275#else 276 FT_LOCAL_DEF( void ) 277#endif 278 ftc_node_destroy( FTC_Node node, 279 FTC_Manager manager ) 280 { 281 FTC_Cache cache; 282 283 284#ifdef FT_DEBUG_ERROR 285 /* find node's cache */ 286 if ( node->cache_index >= manager->num_caches ) 287 { 288 FT_TRACE0(( "ftc_node_destroy: invalid node handle\n" )); 289 return; 290 } 291#endif 292 293 cache = manager->caches[node->cache_index]; 294 295#ifdef FT_DEBUG_ERROR 296 if ( cache == NULL ) 297 { 298 FT_TRACE0(( "ftc_node_destroy: invalid node handle\n" )); 299 return; 300 } 301#endif 302 303 manager->cur_weight -= cache->clazz.node_weight( node, cache ); 304 305 /* remove node from mru list */ 306 ftc_node_mru_unlink( node, manager ); 307 308 /* remove node from cache's hash table */ 309 ftc_node_hash_unlink( node, cache ); 310 311 /* now finalize it */ 312 cache->clazz.node_free( node, cache ); 313 314#if 0 315 /* 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 )); 319#endif 320 } 321 322 323 /*************************************************************************/ 324 /*************************************************************************/ 325 /***** *****/ 326 /***** ABSTRACT CACHE CLASS *****/ 327 /***** *****/ 328 /*************************************************************************/ 329 /*************************************************************************/ 330 331 332 FT_LOCAL_DEF( FT_Error ) 333 FTC_Cache_Init( FTC_Cache cache ) 334 { 335 return ftc_cache_init( cache ); 336 } 337 338 339 FT_LOCAL_DEF( FT_Error ) 340 ftc_cache_init( FTC_Cache cache ) 341 { 342 FT_Memory memory = cache->memory; 343 FT_Error error; 344 345 346 cache->p = 0; 347 cache->mask = FTC_HASH_INITIAL_SIZE - 1; 348 cache->slack = FTC_HASH_INITIAL_SIZE * FTC_HASH_MAX_LOAD; 349 350 (void)FT_NEW_ARRAY( cache->buckets, FTC_HASH_INITIAL_SIZE * 2 ); 351 return error; 352 } 353 354 355 static void 356 FTC_Cache_Clear( FTC_Cache cache ) 357 { 358 if ( cache && cache->buckets ) 359 { 360 FTC_Manager manager = cache->manager; 361 FT_UFast i; 362 FT_UFast count; 363 364 365 count = cache->p + cache->mask + 1; 366 367 for ( i = 0; i < count; i++ ) 368 { 369 FTC_Node *pnode = cache->buckets + i, next, node = *pnode; 370 371 372 while ( node ) 373 { 374 next = node->link; 375 node->link = NULL; 376 377 /* remove node from mru list */ 378 ftc_node_mru_unlink( node, manager ); 379 380 /* now finalize it */ 381 manager->cur_weight -= cache->clazz.node_weight( node, cache ); 382 383 cache->clazz.node_free( node, cache ); 384 node = next; 385 } 386 cache->buckets[i] = NULL; 387 } 388 ftc_cache_resize( cache ); 389 } 390 } 391 392 393 FT_LOCAL_DEF( void ) 394 ftc_cache_done( FTC_Cache cache ) 395 { 396 if ( cache->memory ) 397 { 398 FT_Memory memory = cache->memory; 399 400 401 FTC_Cache_Clear( cache ); 402 403 FT_FREE( cache->buckets ); 404 cache->mask = 0; 405 cache->p = 0; 406 cache->slack = 0; 407 408 cache->memory = NULL; 409 } 410 } 411 412 413 FT_LOCAL_DEF( void ) 414 FTC_Cache_Done( FTC_Cache cache ) 415 { 416 ftc_cache_done( cache ); 417 } 418 419 420 static void 421 ftc_cache_add( FTC_Cache cache, 422 FT_PtrDist hash, 423 FTC_Node node ) 424 { 425 node->hash = hash; 426 node->cache_index = (FT_UInt16)cache->index; 427 node->ref_count = 0; 428 429 ftc_node_hash_link( node, cache ); 430 ftc_node_mru_link( node, cache->manager ); 431 432 { 433 FTC_Manager manager = cache->manager; 434 435 436 manager->cur_weight += cache->clazz.node_weight( node, cache ); 437 438 if ( manager->cur_weight >= manager->max_weight ) 439 { 440 node->ref_count++; 441 FTC_Manager_Compress( manager ); 442 node->ref_count--; 443 } 444 } 445 } 446 447 448 FT_LOCAL_DEF( FT_Error ) 449 FTC_Cache_NewNode( FTC_Cache cache, 450 FT_PtrDist hash, 451 FT_Pointer query, 452 FTC_Node *anode ) 453 { 454 FT_Error error; 455 FTC_Node node; 456 457 458 /* 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. 462 */ 463 464 FTC_CACHE_TRYLOOP( cache ) 465 { 466 error = cache->clazz.node_new( &node, query, cache ); 467 } 468 FTC_CACHE_TRYLOOP_END( NULL ); 469 470 if ( error ) 471 node = NULL; 472 else 473 { 474 /* don't assume that the cache has the same number of buckets, since 475 * our allocation request might have triggered global cache flushing 476 */ 477 ftc_cache_add( cache, hash, node ); 478 } 479 480 *anode = node; 481 return error; 482 } 483 484 485#ifndef FTC_INLINE 486 487 FT_LOCAL_DEF( FT_Error ) 488 FTC_Cache_Lookup( FTC_Cache cache, 489 FT_PtrDist hash, 490 FT_Pointer query, 491 FTC_Node *anode ) 492 { 493 FTC_Node* bucket; 494 FTC_Node* pnode; 495 FTC_Node node; 496 FT_Error error = FTC_Err_Ok; 497 FT_Bool list_changed = FALSE; 498 499 FTC_Node_CompareFunc compare = cache->clazz.node_compare; 500 501 502 if ( cache == NULL || anode == NULL ) 503 return FTC_Err_Invalid_Argument; 504 505 /* Go to the `top' node of the list sharing same masked hash */ 506 bucket = pnode = FTC_NODE__TOP_FOR_HASH( cache, hash ); 507 508 /* Lookup a node with exactly same hash and queried properties. */ 509 /* NOTE: _nodcomp() may change the linked list to reduce memory. */ 510 for (;;) 511 { 512 node = *pnode; 513 if ( node == NULL ) 514 goto NewNode; 515 516 if ( node->hash == hash && 517 compare( node, query, cache, &list_changed ) ) 518 break; 519 520 pnode = &node->link; 521 } 522 523 if ( list_changed ) 524 { 525 /* Update bucket by modified linked list */ 526 bucket = pnode = FTC_NODE__TOP_FOR_HASH( cache, hash ); 527 528 /* Update pnode by modified linked list */ 529 while ( *pnode != node ) 530 { 531 if ( *pnode == NULL ) 532 { 533 FT_ERROR(( "FTC_Cache_Lookup: oops!!! node missing\n" )); 534 goto NewNode; 535 } 536 else 537 pnode = &((*pnode)->link); 538 } 539 } 540 541 /* Reorder the list to move the found node to the `top' */ 542 if ( node != *bucket ) 543 { 544 *pnode = node->link; 545 node->link = *bucket; 546 *bucket = node; 547 } 548 549 /* move to head of MRU list */ 550 { 551 FTC_Manager manager = cache->manager; 552 553 554 if ( node != manager->nodes_list ) 555 ftc_node_mru_up( node, manager ); 556 } 557 *anode = node; 558 559 return error; 560 561 NewNode: 562 return FTC_Cache_NewNode( cache, hash, query, anode ); 563 } 564 565#endif /* !FTC_INLINE */ 566 567 568 FT_LOCAL_DEF( void ) 569 FTC_Cache_RemoveFaceID( FTC_Cache cache, 570 FTC_FaceID face_id ) 571 { 572 FT_UFast i, count; 573 FTC_Manager manager = cache->manager; 574 FTC_Node frees = NULL; 575 576 577 count = cache->p + cache->mask + 1; 578 for ( i = 0; i < count; i++ ) 579 { 580 FTC_Node* bucket = cache->buckets + i; 581 FTC_Node* pnode = bucket; 582 583 584 for ( ;; ) 585 { 586 FTC_Node node = *pnode; 587 FT_Bool list_changed = FALSE; 588 589 590 if ( node == NULL ) 591 break; 592 593 if ( cache->clazz.node_remove_faceid( node, face_id, 594 cache, &list_changed ) ) 595 { 596 *pnode = node->link; 597 node->link = frees; 598 frees = node; 599 } 600 else 601 pnode = &node->link; 602 } 603 } 604 605 /* remove all nodes in the free list */ 606 while ( frees ) 607 { 608 FTC_Node node; 609 610 611 node = frees; 612 frees = node->link; 613 614 manager->cur_weight -= cache->clazz.node_weight( node, cache ); 615 ftc_node_mru_unlink( node, manager ); 616 617 cache->clazz.node_free( node, cache ); 618 619 cache->slack++; 620 } 621 622 ftc_cache_resize( cache ); 623 } 624 625 626/* END */ 627