1 // Copyright (c) 2012 The Chromium Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 #include "net/disk_cache/blockfile/backend_impl.h" 6 7 #include "base/bind.h" 8 #include "base/bind_helpers.h" 9 #include "base/files/file.h" 10 #include "base/files/file_path.h" 11 #include "base/files/file_util.h" 12 #include "base/hash.h" 13 #include "base/message_loop/message_loop.h" 14 #include "base/metrics/field_trial.h" 15 #include "base/metrics/histogram.h" 16 #include "base/metrics/stats_counters.h" 17 #include "base/rand_util.h" 18 #include "base/single_thread_task_runner.h" 19 #include "base/strings/string_util.h" 20 #include "base/strings/stringprintf.h" 21 #include "base/sys_info.h" 22 #include "base/threading/thread_restrictions.h" 23 #include "base/time/time.h" 24 #include "base/timer/timer.h" 25 #include "net/base/net_errors.h" 26 #include "net/disk_cache/blockfile/disk_format.h" 27 #include "net/disk_cache/blockfile/entry_impl.h" 28 #include "net/disk_cache/blockfile/errors.h" 29 #include "net/disk_cache/blockfile/experiments.h" 30 #include "net/disk_cache/blockfile/file.h" 31 #include "net/disk_cache/blockfile/histogram_macros.h" 32 #include "net/disk_cache/blockfile/webfonts_histogram.h" 33 #include "net/disk_cache/cache_util.h" 34 35 // Provide a BackendImpl object to macros from histogram_macros.h. 36 #define CACHE_UMA_BACKEND_IMPL_OBJ this 37 38 using base::Time; 39 using base::TimeDelta; 40 using base::TimeTicks; 41 42 namespace { 43 44 const char* kIndexName = "index"; 45 46 // Seems like ~240 MB correspond to less than 50k entries for 99% of the people. 47 // Note that the actual target is to keep the index table load factor under 55% 48 // for most users. 49 const int k64kEntriesStore = 240 * 1000 * 1000; 50 const int kBaseTableLen = 64 * 1024; 51 52 // Avoid trimming the cache for the first 5 minutes (10 timer ticks). 53 const int kTrimDelay = 10; 54 55 int DesiredIndexTableLen(int32 storage_size) { 56 if (storage_size <= k64kEntriesStore) 57 return kBaseTableLen; 58 if (storage_size <= k64kEntriesStore * 2) 59 return kBaseTableLen * 2; 60 if (storage_size <= k64kEntriesStore * 4) 61 return kBaseTableLen * 4; 62 if (storage_size <= k64kEntriesStore * 8) 63 return kBaseTableLen * 8; 64 65 // The biggest storage_size for int32 requires a 4 MB table. 66 return kBaseTableLen * 16; 67 } 68 69 int MaxStorageSizeForTable(int table_len) { 70 return table_len * (k64kEntriesStore / kBaseTableLen); 71 } 72 73 size_t GetIndexSize(int table_len) { 74 size_t table_size = sizeof(disk_cache::CacheAddr) * table_len; 75 return sizeof(disk_cache::IndexHeader) + table_size; 76 } 77 78 // ------------------------------------------------------------------------ 79 80 // Sets group for the current experiment. Returns false if the files should be 81 // discarded. 82 bool InitExperiment(disk_cache::IndexHeader* header, bool cache_created) { 83 if (header->experiment == disk_cache::EXPERIMENT_OLD_FILE1 || 84 header->experiment == disk_cache::EXPERIMENT_OLD_FILE2) { 85 // Discard current cache. 86 return false; 87 } 88 89 if (base::FieldTrialList::FindFullName("SimpleCacheTrial") == 90 "ExperimentControl") { 91 if (cache_created) { 92 header->experiment = disk_cache::EXPERIMENT_SIMPLE_CONTROL; 93 return true; 94 } 95 return header->experiment == disk_cache::EXPERIMENT_SIMPLE_CONTROL; 96 } 97 98 header->experiment = disk_cache::NO_EXPERIMENT; 99 return true; 100 } 101 102 // A callback to perform final cleanup on the background thread. 103 void FinalCleanupCallback(disk_cache::BackendImpl* backend) { 104 backend->CleanupCache(); 105 } 106 107 } // namespace 108 109 // ------------------------------------------------------------------------ 110 111 namespace disk_cache { 112 113 BackendImpl::BackendImpl( 114 const base::FilePath& path, 115 const scoped_refptr<base::SingleThreadTaskRunner>& cache_thread, 116 net::NetLog* net_log) 117 : background_queue_(this, cache_thread), 118 path_(path), 119 block_files_(path), 120 mask_(0), 121 max_size_(0), 122 up_ticks_(0), 123 cache_type_(net::DISK_CACHE), 124 uma_report_(0), 125 user_flags_(0), 126 init_(false), 127 restarted_(false), 128 unit_test_(false), 129 read_only_(false), 130 disabled_(false), 131 new_eviction_(false), 132 first_timer_(true), 133 user_load_(false), 134 net_log_(net_log), 135 done_(true, false), 136 ptr_factory_(this) { 137 } 138 139 BackendImpl::BackendImpl( 140 const base::FilePath& path, 141 uint32 mask, 142 const scoped_refptr<base::SingleThreadTaskRunner>& cache_thread, 143 net::NetLog* net_log) 144 : background_queue_(this, cache_thread), 145 path_(path), 146 block_files_(path), 147 mask_(mask), 148 max_size_(0), 149 up_ticks_(0), 150 cache_type_(net::DISK_CACHE), 151 uma_report_(0), 152 user_flags_(kMask), 153 init_(false), 154 restarted_(false), 155 unit_test_(false), 156 read_only_(false), 157 disabled_(false), 158 new_eviction_(false), 159 first_timer_(true), 160 user_load_(false), 161 net_log_(net_log), 162 done_(true, false), 163 ptr_factory_(this) { 164 } 165 166 BackendImpl::~BackendImpl() { 167 if (user_flags_ & kNoRandom) { 168 // This is a unit test, so we want to be strict about not leaking entries 169 // and completing all the work. 170 background_queue_.WaitForPendingIO(); 171 } else { 172 // This is most likely not a test, so we want to do as little work as 173 // possible at this time, at the price of leaving dirty entries behind. 174 background_queue_.DropPendingIO(); 175 } 176 177 if (background_queue_.BackgroundIsCurrentThread()) { 178 // Unit tests may use the same thread for everything. 179 CleanupCache(); 180 } else { 181 background_queue_.background_thread()->PostTask( 182 FROM_HERE, base::Bind(&FinalCleanupCallback, base::Unretained(this))); 183 // http://crbug.com/74623 184 base::ThreadRestrictions::ScopedAllowWait allow_wait; 185 done_.Wait(); 186 } 187 } 188 189 int BackendImpl::Init(const CompletionCallback& callback) { 190 background_queue_.Init(callback); 191 return net::ERR_IO_PENDING; 192 } 193 194 int BackendImpl::SyncInit() { 195 #if defined(NET_BUILD_STRESS_CACHE) 196 // Start evictions right away. 197 up_ticks_ = kTrimDelay * 2; 198 #endif 199 DCHECK(!init_); 200 if (init_) 201 return net::ERR_FAILED; 202 203 bool create_files = false; 204 if (!InitBackingStore(&create_files)) { 205 ReportError(ERR_STORAGE_ERROR); 206 return net::ERR_FAILED; 207 } 208 209 num_refs_ = num_pending_io_ = max_refs_ = 0; 210 entry_count_ = byte_count_ = 0; 211 212 bool should_create_timer = false; 213 if (!restarted_) { 214 buffer_bytes_ = 0; 215 trace_object_ = TraceObject::GetTraceObject(); 216 should_create_timer = true; 217 } 218 219 init_ = true; 220 Trace("Init"); 221 222 if (data_->header.experiment != NO_EXPERIMENT && 223 cache_type_ != net::DISK_CACHE) { 224 // No experiment for other caches. 225 return net::ERR_FAILED; 226 } 227 228 if (!(user_flags_ & kNoRandom)) { 229 // The unit test controls directly what to test. 230 new_eviction_ = (cache_type_ == net::DISK_CACHE); 231 } 232 233 if (!CheckIndex()) { 234 ReportError(ERR_INIT_FAILED); 235 return net::ERR_FAILED; 236 } 237 238 if (!restarted_ && (create_files || !data_->header.num_entries)) 239 ReportError(ERR_CACHE_CREATED); 240 241 if (!(user_flags_ & kNoRandom) && cache_type_ == net::DISK_CACHE && 242 !InitExperiment(&data_->header, create_files)) { 243 return net::ERR_FAILED; 244 } 245 246 // We don't care if the value overflows. The only thing we care about is that 247 // the id cannot be zero, because that value is used as "not dirty". 248 // Increasing the value once per second gives us many years before we start 249 // having collisions. 250 data_->header.this_id++; 251 if (!data_->header.this_id) 252 data_->header.this_id++; 253 254 bool previous_crash = (data_->header.crash != 0); 255 data_->header.crash = 1; 256 257 if (!block_files_.Init(create_files)) 258 return net::ERR_FAILED; 259 260 // We want to minimize the changes to cache for an AppCache. 261 if (cache_type() == net::APP_CACHE) { 262 DCHECK(!new_eviction_); 263 read_only_ = true; 264 } else if (cache_type() == net::SHADER_CACHE) { 265 DCHECK(!new_eviction_); 266 } 267 268 eviction_.Init(this); 269 270 // stats_ and rankings_ may end up calling back to us so we better be enabled. 271 disabled_ = false; 272 if (!InitStats()) 273 return net::ERR_FAILED; 274 275 disabled_ = !rankings_.Init(this, new_eviction_); 276 277 #if defined(STRESS_CACHE_EXTENDED_VALIDATION) 278 trace_object_->EnableTracing(false); 279 int sc = SelfCheck(); 280 if (sc < 0 && sc != ERR_NUM_ENTRIES_MISMATCH) 281 NOTREACHED(); 282 trace_object_->EnableTracing(true); 283 #endif 284 285 if (previous_crash) { 286 ReportError(ERR_PREVIOUS_CRASH); 287 } else if (!restarted_) { 288 ReportError(ERR_NO_ERROR); 289 } 290 291 FlushIndex(); 292 293 if (!disabled_ && should_create_timer) { 294 // Create a recurrent timer of 30 secs. 295 int timer_delay = unit_test_ ? 1000 : 30000; 296 timer_.reset(new base::RepeatingTimer<BackendImpl>()); 297 timer_->Start(FROM_HERE, TimeDelta::FromMilliseconds(timer_delay), this, 298 &BackendImpl::OnStatsTimer); 299 } 300 301 return disabled_ ? net::ERR_FAILED : net::OK; 302 } 303 304 void BackendImpl::CleanupCache() { 305 Trace("Backend Cleanup"); 306 eviction_.Stop(); 307 timer_.reset(); 308 309 if (init_) { 310 StoreStats(); 311 if (data_) 312 data_->header.crash = 0; 313 314 if (user_flags_ & kNoRandom) { 315 // This is a net_unittest, verify that we are not 'leaking' entries. 316 File::WaitForPendingIO(&num_pending_io_); 317 DCHECK(!num_refs_); 318 } else { 319 File::DropPendingIO(); 320 } 321 } 322 block_files_.CloseFiles(); 323 FlushIndex(); 324 index_ = NULL; 325 ptr_factory_.InvalidateWeakPtrs(); 326 done_.Signal(); 327 } 328 329 // ------------------------------------------------------------------------ 330 331 int BackendImpl::SyncOpenEntry(const std::string& key, Entry** entry) { 332 DCHECK(entry); 333 *entry = OpenEntryImpl(key); 334 return (*entry) ? net::OK : net::ERR_FAILED; 335 } 336 337 int BackendImpl::SyncCreateEntry(const std::string& key, Entry** entry) { 338 DCHECK(entry); 339 *entry = CreateEntryImpl(key); 340 return (*entry) ? net::OK : net::ERR_FAILED; 341 } 342 343 int BackendImpl::SyncDoomEntry(const std::string& key) { 344 if (disabled_) 345 return net::ERR_FAILED; 346 347 EntryImpl* entry = OpenEntryImpl(key); 348 if (!entry) 349 return net::ERR_FAILED; 350 351 entry->DoomImpl(); 352 entry->Release(); 353 return net::OK; 354 } 355 356 int BackendImpl::SyncDoomAllEntries() { 357 // This is not really an error, but it is an interesting condition. 358 ReportError(ERR_CACHE_DOOMED); 359 stats_.OnEvent(Stats::DOOM_CACHE); 360 if (!num_refs_) { 361 RestartCache(false); 362 return disabled_ ? net::ERR_FAILED : net::OK; 363 } else { 364 if (disabled_) 365 return net::ERR_FAILED; 366 367 eviction_.TrimCache(true); 368 return net::OK; 369 } 370 } 371 372 int BackendImpl::SyncDoomEntriesBetween(const base::Time initial_time, 373 const base::Time end_time) { 374 DCHECK_NE(net::APP_CACHE, cache_type_); 375 if (end_time.is_null()) 376 return SyncDoomEntriesSince(initial_time); 377 378 DCHECK(end_time >= initial_time); 379 380 if (disabled_) 381 return net::ERR_FAILED; 382 383 EntryImpl* node; 384 scoped_ptr<Rankings::Iterator> iterator(new Rankings::Iterator()); 385 EntryImpl* next = OpenNextEntryImpl(iterator.get()); 386 if (!next) 387 return net::OK; 388 389 while (next) { 390 node = next; 391 next = OpenNextEntryImpl(iterator.get()); 392 393 if (node->GetLastUsed() >= initial_time && 394 node->GetLastUsed() < end_time) { 395 node->DoomImpl(); 396 } else if (node->GetLastUsed() < initial_time) { 397 if (next) 398 next->Release(); 399 next = NULL; 400 SyncEndEnumeration(iterator.Pass()); 401 } 402 403 node->Release(); 404 } 405 406 return net::OK; 407 } 408 409 // We use OpenNextEntryImpl to retrieve elements from the cache, until we get 410 // entries that are too old. 411 int BackendImpl::SyncDoomEntriesSince(const base::Time initial_time) { 412 DCHECK_NE(net::APP_CACHE, cache_type_); 413 if (disabled_) 414 return net::ERR_FAILED; 415 416 stats_.OnEvent(Stats::DOOM_RECENT); 417 for (;;) { 418 scoped_ptr<Rankings::Iterator> iterator(new Rankings::Iterator()); 419 EntryImpl* entry = OpenNextEntryImpl(iterator.get()); 420 if (!entry) 421 return net::OK; 422 423 if (initial_time > entry->GetLastUsed()) { 424 entry->Release(); 425 SyncEndEnumeration(iterator.Pass()); 426 return net::OK; 427 } 428 429 entry->DoomImpl(); 430 entry->Release(); 431 SyncEndEnumeration(iterator.Pass()); // The doom invalidated the iterator. 432 } 433 } 434 435 int BackendImpl::SyncOpenNextEntry(Rankings::Iterator* iterator, 436 Entry** next_entry) { 437 *next_entry = OpenNextEntryImpl(iterator); 438 return (*next_entry) ? net::OK : net::ERR_FAILED; 439 } 440 441 void BackendImpl::SyncEndEnumeration(scoped_ptr<Rankings::Iterator> iterator) { 442 iterator->Reset(); 443 } 444 445 void BackendImpl::SyncOnExternalCacheHit(const std::string& key) { 446 if (disabled_) 447 return; 448 449 uint32 hash = base::Hash(key); 450 bool error; 451 EntryImpl* cache_entry = MatchEntry(key, hash, false, Addr(), &error); 452 if (cache_entry) { 453 if (ENTRY_NORMAL == cache_entry->entry()->Data()->state) { 454 UpdateRank(cache_entry, cache_type() == net::SHADER_CACHE); 455 } 456 cache_entry->Release(); 457 } 458 } 459 460 EntryImpl* BackendImpl::OpenEntryImpl(const std::string& key) { 461 if (disabled_) 462 return NULL; 463 464 TimeTicks start = TimeTicks::Now(); 465 uint32 hash = base::Hash(key); 466 Trace("Open hash 0x%x", hash); 467 468 bool error; 469 EntryImpl* cache_entry = MatchEntry(key, hash, false, Addr(), &error); 470 if (cache_entry && ENTRY_NORMAL != cache_entry->entry()->Data()->state) { 471 // The entry was already evicted. 472 cache_entry->Release(); 473 cache_entry = NULL; 474 web_fonts_histogram::RecordEvictedEntry(key); 475 } else if (!cache_entry) { 476 web_fonts_histogram::RecordCacheMiss(key); 477 } 478 479 int current_size = data_->header.num_bytes / (1024 * 1024); 480 int64 total_hours = stats_.GetCounter(Stats::TIMER) / 120; 481 int64 no_use_hours = stats_.GetCounter(Stats::LAST_REPORT_TIMER) / 120; 482 int64 use_hours = total_hours - no_use_hours; 483 484 if (!cache_entry) { 485 CACHE_UMA(AGE_MS, "OpenTime.Miss", 0, start); 486 CACHE_UMA(COUNTS_10000, "AllOpenBySize.Miss", 0, current_size); 487 CACHE_UMA(HOURS, "AllOpenByTotalHours.Miss", 0, total_hours); 488 CACHE_UMA(HOURS, "AllOpenByUseHours.Miss", 0, use_hours); 489 stats_.OnEvent(Stats::OPEN_MISS); 490 return NULL; 491 } 492 493 eviction_.OnOpenEntry(cache_entry); 494 entry_count_++; 495 496 Trace("Open hash 0x%x end: 0x%x", hash, 497 cache_entry->entry()->address().value()); 498 CACHE_UMA(AGE_MS, "OpenTime", 0, start); 499 CACHE_UMA(COUNTS_10000, "AllOpenBySize.Hit", 0, current_size); 500 CACHE_UMA(HOURS, "AllOpenByTotalHours.Hit", 0, total_hours); 501 CACHE_UMA(HOURS, "AllOpenByUseHours.Hit", 0, use_hours); 502 stats_.OnEvent(Stats::OPEN_HIT); 503 web_fonts_histogram::RecordCacheHit(cache_entry); 504 SIMPLE_STATS_COUNTER("disk_cache.hit"); 505 return cache_entry; 506 } 507 508 EntryImpl* BackendImpl::CreateEntryImpl(const std::string& key) { 509 if (disabled_ || key.empty()) 510 return NULL; 511 512 TimeTicks start = TimeTicks::Now(); 513 uint32 hash = base::Hash(key); 514 Trace("Create hash 0x%x", hash); 515 516 scoped_refptr<EntryImpl> parent; 517 Addr entry_address(data_->table[hash & mask_]); 518 if (entry_address.is_initialized()) { 519 // We have an entry already. It could be the one we are looking for, or just 520 // a hash conflict. 521 bool error; 522 EntryImpl* old_entry = MatchEntry(key, hash, false, Addr(), &error); 523 if (old_entry) 524 return ResurrectEntry(old_entry); 525 526 EntryImpl* parent_entry = MatchEntry(key, hash, true, Addr(), &error); 527 DCHECK(!error); 528 if (parent_entry) { 529 parent.swap(&parent_entry); 530 } else if (data_->table[hash & mask_]) { 531 // We should have corrected the problem. 532 NOTREACHED(); 533 return NULL; 534 } 535 } 536 537 // The general flow is to allocate disk space and initialize the entry data, 538 // followed by saving that to disk, then linking the entry though the index 539 // and finally through the lists. If there is a crash in this process, we may 540 // end up with: 541 // a. Used, unreferenced empty blocks on disk (basically just garbage). 542 // b. Used, unreferenced but meaningful data on disk (more garbage). 543 // c. A fully formed entry, reachable only through the index. 544 // d. A fully formed entry, also reachable through the lists, but still dirty. 545 // 546 // Anything after (b) can be automatically cleaned up. We may consider saving 547 // the current operation (as we do while manipulating the lists) so that we 548 // can detect and cleanup (a) and (b). 549 550 int num_blocks = EntryImpl::NumBlocksForEntry(key.size()); 551 if (!block_files_.CreateBlock(BLOCK_256, num_blocks, &entry_address)) { 552 LOG(ERROR) << "Create entry failed " << key.c_str(); 553 stats_.OnEvent(Stats::CREATE_ERROR); 554 return NULL; 555 } 556 557 Addr node_address(0); 558 if (!block_files_.CreateBlock(RANKINGS, 1, &node_address)) { 559 block_files_.DeleteBlock(entry_address, false); 560 LOG(ERROR) << "Create entry failed " << key.c_str(); 561 stats_.OnEvent(Stats::CREATE_ERROR); 562 return NULL; 563 } 564 565 scoped_refptr<EntryImpl> cache_entry( 566 new EntryImpl(this, entry_address, false)); 567 IncreaseNumRefs(); 568 569 if (!cache_entry->CreateEntry(node_address, key, hash)) { 570 block_files_.DeleteBlock(entry_address, false); 571 block_files_.DeleteBlock(node_address, false); 572 LOG(ERROR) << "Create entry failed " << key.c_str(); 573 stats_.OnEvent(Stats::CREATE_ERROR); 574 return NULL; 575 } 576 577 cache_entry->BeginLogging(net_log_, true); 578 579 // We are not failing the operation; let's add this to the map. 580 open_entries_[entry_address.value()] = cache_entry.get(); 581 582 // Save the entry. 583 cache_entry->entry()->Store(); 584 cache_entry->rankings()->Store(); 585 IncreaseNumEntries(); 586 entry_count_++; 587 588 // Link this entry through the index. 589 if (parent.get()) { 590 parent->SetNextAddress(entry_address); 591 } else { 592 data_->table[hash & mask_] = entry_address.value(); 593 } 594 595 // Link this entry through the lists. 596 eviction_.OnCreateEntry(cache_entry.get()); 597 598 CACHE_UMA(AGE_MS, "CreateTime", 0, start); 599 stats_.OnEvent(Stats::CREATE_HIT); 600 SIMPLE_STATS_COUNTER("disk_cache.miss"); 601 Trace("create entry hit "); 602 FlushIndex(); 603 cache_entry->AddRef(); 604 return cache_entry.get(); 605 } 606 607 EntryImpl* BackendImpl::OpenNextEntryImpl(Rankings::Iterator* iterator) { 608 if (disabled_) 609 return NULL; 610 611 const int kListsToSearch = 3; 612 scoped_refptr<EntryImpl> entries[kListsToSearch]; 613 if (!iterator->my_rankings) { 614 iterator->my_rankings = &rankings_; 615 bool ret = false; 616 617 // Get an entry from each list. 618 for (int i = 0; i < kListsToSearch; i++) { 619 EntryImpl* temp = NULL; 620 ret |= OpenFollowingEntryFromList(static_cast<Rankings::List>(i), 621 &iterator->nodes[i], &temp); 622 entries[i].swap(&temp); // The entry was already addref'd. 623 } 624 if (!ret) { 625 iterator->Reset(); 626 return NULL; 627 } 628 } else { 629 // Get the next entry from the last list, and the actual entries for the 630 // elements on the other lists. 631 for (int i = 0; i < kListsToSearch; i++) { 632 EntryImpl* temp = NULL; 633 if (iterator->list == i) { 634 OpenFollowingEntryFromList( 635 iterator->list, &iterator->nodes[i], &temp); 636 } else { 637 temp = GetEnumeratedEntry(iterator->nodes[i], 638 static_cast<Rankings::List>(i)); 639 } 640 641 entries[i].swap(&temp); // The entry was already addref'd. 642 } 643 } 644 645 int newest = -1; 646 int oldest = -1; 647 Time access_times[kListsToSearch]; 648 for (int i = 0; i < kListsToSearch; i++) { 649 if (entries[i].get()) { 650 access_times[i] = entries[i]->GetLastUsed(); 651 if (newest < 0) { 652 DCHECK_LT(oldest, 0); 653 newest = oldest = i; 654 continue; 655 } 656 if (access_times[i] > access_times[newest]) 657 newest = i; 658 if (access_times[i] < access_times[oldest]) 659 oldest = i; 660 } 661 } 662 663 if (newest < 0 || oldest < 0) { 664 iterator->Reset(); 665 return NULL; 666 } 667 668 EntryImpl* next_entry; 669 next_entry = entries[newest].get(); 670 iterator->list = static_cast<Rankings::List>(newest); 671 next_entry->AddRef(); 672 return next_entry; 673 } 674 675 bool BackendImpl::SetMaxSize(int max_bytes) { 676 COMPILE_ASSERT(sizeof(max_bytes) == sizeof(max_size_), unsupported_int_model); 677 if (max_bytes < 0) 678 return false; 679 680 // Zero size means use the default. 681 if (!max_bytes) 682 return true; 683 684 // Avoid a DCHECK later on. 685 if (max_bytes >= kint32max - kint32max / 10) 686 max_bytes = kint32max - kint32max / 10 - 1; 687 688 user_flags_ |= kMaxSize; 689 max_size_ = max_bytes; 690 return true; 691 } 692 693 void BackendImpl::SetType(net::CacheType type) { 694 DCHECK_NE(net::MEMORY_CACHE, type); 695 cache_type_ = type; 696 } 697 698 base::FilePath BackendImpl::GetFileName(Addr address) const { 699 if (!address.is_separate_file() || !address.is_initialized()) { 700 NOTREACHED(); 701 return base::FilePath(); 702 } 703 704 std::string tmp = base::StringPrintf("f_%06x", address.FileNumber()); 705 return path_.AppendASCII(tmp); 706 } 707 708 MappedFile* BackendImpl::File(Addr address) { 709 if (disabled_) 710 return NULL; 711 return block_files_.GetFile(address); 712 } 713 714 base::WeakPtr<InFlightBackendIO> BackendImpl::GetBackgroundQueue() { 715 return background_queue_.GetWeakPtr(); 716 } 717 718 bool BackendImpl::CreateExternalFile(Addr* address) { 719 int file_number = data_->header.last_file + 1; 720 Addr file_address(0); 721 bool success = false; 722 for (int i = 0; i < 0x0fffffff; i++, file_number++) { 723 if (!file_address.SetFileNumber(file_number)) { 724 file_number = 1; 725 continue; 726 } 727 base::FilePath name = GetFileName(file_address); 728 int flags = base::File::FLAG_READ | base::File::FLAG_WRITE | 729 base::File::FLAG_CREATE | base::File::FLAG_EXCLUSIVE_WRITE; 730 base::File file(name, flags); 731 if (!file.IsValid()) { 732 base::File::Error error = file.error_details(); 733 if (error != base::File::FILE_ERROR_EXISTS) { 734 LOG(ERROR) << "Unable to create file: " << error; 735 return false; 736 } 737 continue; 738 } 739 740 success = true; 741 break; 742 } 743 744 DCHECK(success); 745 if (!success) 746 return false; 747 748 data_->header.last_file = file_number; 749 address->set_value(file_address.value()); 750 return true; 751 } 752 753 bool BackendImpl::CreateBlock(FileType block_type, int block_count, 754 Addr* block_address) { 755 return block_files_.CreateBlock(block_type, block_count, block_address); 756 } 757 758 void BackendImpl::DeleteBlock(Addr block_address, bool deep) { 759 block_files_.DeleteBlock(block_address, deep); 760 } 761 762 LruData* BackendImpl::GetLruData() { 763 return &data_->header.lru; 764 } 765 766 void BackendImpl::UpdateRank(EntryImpl* entry, bool modified) { 767 if (read_only_ || (!modified && cache_type() == net::SHADER_CACHE)) 768 return; 769 eviction_.UpdateRank(entry, modified); 770 } 771 772 void BackendImpl::RecoveredEntry(CacheRankingsBlock* rankings) { 773 Addr address(rankings->Data()->contents); 774 EntryImpl* cache_entry = NULL; 775 if (NewEntry(address, &cache_entry)) { 776 STRESS_NOTREACHED(); 777 return; 778 } 779 780 uint32 hash = cache_entry->GetHash(); 781 cache_entry->Release(); 782 783 // Anything on the table means that this entry is there. 784 if (data_->table[hash & mask_]) 785 return; 786 787 data_->table[hash & mask_] = address.value(); 788 FlushIndex(); 789 } 790 791 void BackendImpl::InternalDoomEntry(EntryImpl* entry) { 792 uint32 hash = entry->GetHash(); 793 std::string key = entry->GetKey(); 794 Addr entry_addr = entry->entry()->address(); 795 bool error; 796 EntryImpl* parent_entry = MatchEntry(key, hash, true, entry_addr, &error); 797 CacheAddr child(entry->GetNextAddress()); 798 799 Trace("Doom entry 0x%p", entry); 800 801 if (!entry->doomed()) { 802 // We may have doomed this entry from within MatchEntry. 803 eviction_.OnDoomEntry(entry); 804 entry->InternalDoom(); 805 if (!new_eviction_) { 806 DecreaseNumEntries(); 807 } 808 stats_.OnEvent(Stats::DOOM_ENTRY); 809 } 810 811 if (parent_entry) { 812 parent_entry->SetNextAddress(Addr(child)); 813 parent_entry->Release(); 814 } else if (!error) { 815 data_->table[hash & mask_] = child; 816 } 817 818 FlushIndex(); 819 } 820 821 #if defined(NET_BUILD_STRESS_CACHE) 822 823 CacheAddr BackendImpl::GetNextAddr(Addr address) { 824 EntriesMap::iterator it = open_entries_.find(address.value()); 825 if (it != open_entries_.end()) { 826 EntryImpl* this_entry = it->second; 827 return this_entry->GetNextAddress(); 828 } 829 DCHECK(block_files_.IsValid(address)); 830 DCHECK(!address.is_separate_file() && address.file_type() == BLOCK_256); 831 832 CacheEntryBlock entry(File(address), address); 833 CHECK(entry.Load()); 834 return entry.Data()->next; 835 } 836 837 void BackendImpl::NotLinked(EntryImpl* entry) { 838 Addr entry_addr = entry->entry()->address(); 839 uint32 i = entry->GetHash() & mask_; 840 Addr address(data_->table[i]); 841 if (!address.is_initialized()) 842 return; 843 844 for (;;) { 845 DCHECK(entry_addr.value() != address.value()); 846 address.set_value(GetNextAddr(address)); 847 if (!address.is_initialized()) 848 break; 849 } 850 } 851 #endif // NET_BUILD_STRESS_CACHE 852 853 // An entry may be linked on the DELETED list for a while after being doomed. 854 // This function is called when we want to remove it. 855 void BackendImpl::RemoveEntry(EntryImpl* entry) { 856 #if defined(NET_BUILD_STRESS_CACHE) 857 NotLinked(entry); 858 #endif 859 if (!new_eviction_) 860 return; 861 862 DCHECK_NE(ENTRY_NORMAL, entry->entry()->Data()->state); 863 864 Trace("Remove entry 0x%p", entry); 865 eviction_.OnDestroyEntry(entry); 866 DecreaseNumEntries(); 867 } 868 869 void BackendImpl::OnEntryDestroyBegin(Addr address) { 870 EntriesMap::iterator it = open_entries_.find(address.value()); 871 if (it != open_entries_.end()) 872 open_entries_.erase(it); 873 } 874 875 void BackendImpl::OnEntryDestroyEnd() { 876 DecreaseNumRefs(); 877 if (data_->header.num_bytes > max_size_ && !read_only_ && 878 (up_ticks_ > kTrimDelay || user_flags_ & kNoRandom)) 879 eviction_.TrimCache(false); 880 } 881 882 EntryImpl* BackendImpl::GetOpenEntry(CacheRankingsBlock* rankings) const { 883 DCHECK(rankings->HasData()); 884 EntriesMap::const_iterator it = 885 open_entries_.find(rankings->Data()->contents); 886 if (it != open_entries_.end()) { 887 // We have this entry in memory. 888 return it->second; 889 } 890 891 return NULL; 892 } 893 894 int32 BackendImpl::GetCurrentEntryId() const { 895 return data_->header.this_id; 896 } 897 898 int BackendImpl::MaxFileSize() const { 899 return cache_type() == net::PNACL_CACHE ? max_size_ : max_size_ / 8; 900 } 901 902 void BackendImpl::ModifyStorageSize(int32 old_size, int32 new_size) { 903 if (disabled_ || old_size == new_size) 904 return; 905 if (old_size > new_size) 906 SubstractStorageSize(old_size - new_size); 907 else 908 AddStorageSize(new_size - old_size); 909 910 FlushIndex(); 911 912 // Update the usage statistics. 913 stats_.ModifyStorageStats(old_size, new_size); 914 } 915 916 void BackendImpl::TooMuchStorageRequested(int32 size) { 917 stats_.ModifyStorageStats(0, size); 918 } 919 920 bool BackendImpl::IsAllocAllowed(int current_size, int new_size) { 921 DCHECK_GT(new_size, current_size); 922 if (user_flags_ & kNoBuffering) 923 return false; 924 925 int to_add = new_size - current_size; 926 if (buffer_bytes_ + to_add > MaxBuffersSize()) 927 return false; 928 929 buffer_bytes_ += to_add; 930 CACHE_UMA(COUNTS_50000, "BufferBytes", 0, buffer_bytes_ / 1024); 931 return true; 932 } 933 934 void BackendImpl::BufferDeleted(int size) { 935 buffer_bytes_ -= size; 936 DCHECK_GE(size, 0); 937 } 938 939 bool BackendImpl::IsLoaded() const { 940 CACHE_UMA(COUNTS, "PendingIO", 0, num_pending_io_); 941 if (user_flags_ & kNoLoadProtection) 942 return false; 943 944 return (num_pending_io_ > 5 || user_load_); 945 } 946 947 std::string BackendImpl::HistogramName(const char* name, int experiment) const { 948 if (!experiment) 949 return base::StringPrintf("DiskCache.%d.%s", cache_type_, name); 950 return base::StringPrintf("DiskCache.%d.%s_%d", cache_type_, 951 name, experiment); 952 } 953 954 base::WeakPtr<BackendImpl> BackendImpl::GetWeakPtr() { 955 return ptr_factory_.GetWeakPtr(); 956 } 957 958 // We want to remove biases from some histograms so we only send data once per 959 // week. 960 bool BackendImpl::ShouldReportAgain() { 961 if (uma_report_) 962 return uma_report_ == 2; 963 964 uma_report_++; 965 int64 last_report = stats_.GetCounter(Stats::LAST_REPORT); 966 Time last_time = Time::FromInternalValue(last_report); 967 if (!last_report || (Time::Now() - last_time).InDays() >= 7) { 968 stats_.SetCounter(Stats::LAST_REPORT, Time::Now().ToInternalValue()); 969 uma_report_++; 970 return true; 971 } 972 return false; 973 } 974 975 void BackendImpl::FirstEviction() { 976 DCHECK(data_->header.create_time); 977 if (!GetEntryCount()) 978 return; // This is just for unit tests. 979 980 Time create_time = Time::FromInternalValue(data_->header.create_time); 981 CACHE_UMA(AGE, "FillupAge", 0, create_time); 982 983 int64 use_time = stats_.GetCounter(Stats::TIMER); 984 CACHE_UMA(HOURS, "FillupTime", 0, static_cast<int>(use_time / 120)); 985 CACHE_UMA(PERCENTAGE, "FirstHitRatio", 0, stats_.GetHitRatio()); 986 987 if (!use_time) 988 use_time = 1; 989 CACHE_UMA(COUNTS_10000, "FirstEntryAccessRate", 0, 990 static_cast<int>(data_->header.num_entries / use_time)); 991 CACHE_UMA(COUNTS, "FirstByteIORate", 0, 992 static_cast<int>((data_->header.num_bytes / 1024) / use_time)); 993 994 int avg_size = data_->header.num_bytes / GetEntryCount(); 995 CACHE_UMA(COUNTS, "FirstEntrySize", 0, avg_size); 996 997 int large_entries_bytes = stats_.GetLargeEntriesSize(); 998 int large_ratio = large_entries_bytes * 100 / data_->header.num_bytes; 999 CACHE_UMA(PERCENTAGE, "FirstLargeEntriesRatio", 0, large_ratio); 1000 1001 if (new_eviction_) { 1002 CACHE_UMA(PERCENTAGE, "FirstResurrectRatio", 0, stats_.GetResurrectRatio()); 1003 CACHE_UMA(PERCENTAGE, "FirstNoUseRatio", 0, 1004 data_->header.lru.sizes[0] * 100 / data_->header.num_entries); 1005 CACHE_UMA(PERCENTAGE, "FirstLowUseRatio", 0, 1006 data_->header.lru.sizes[1] * 100 / data_->header.num_entries); 1007 CACHE_UMA(PERCENTAGE, "FirstHighUseRatio", 0, 1008 data_->header.lru.sizes[2] * 100 / data_->header.num_entries); 1009 } 1010 1011 stats_.ResetRatios(); 1012 } 1013 1014 void BackendImpl::CriticalError(int error) { 1015 STRESS_NOTREACHED(); 1016 LOG(ERROR) << "Critical error found " << error; 1017 if (disabled_) 1018 return; 1019 1020 stats_.OnEvent(Stats::FATAL_ERROR); 1021 LogStats(); 1022 ReportError(error); 1023 1024 // Setting the index table length to an invalid value will force re-creation 1025 // of the cache files. 1026 data_->header.table_len = 1; 1027 disabled_ = true; 1028 1029 if (!num_refs_) 1030 base::MessageLoop::current()->PostTask( 1031 FROM_HERE, base::Bind(&BackendImpl::RestartCache, GetWeakPtr(), true)); 1032 } 1033 1034 void BackendImpl::ReportError(int error) { 1035 STRESS_DCHECK(!error || error == ERR_PREVIOUS_CRASH || 1036 error == ERR_CACHE_CREATED); 1037 1038 // We transmit positive numbers, instead of direct error codes. 1039 DCHECK_LE(error, 0); 1040 CACHE_UMA(CACHE_ERROR, "Error", 0, error * -1); 1041 } 1042 1043 void BackendImpl::OnEvent(Stats::Counters an_event) { 1044 stats_.OnEvent(an_event); 1045 } 1046 1047 void BackendImpl::OnRead(int32 bytes) { 1048 DCHECK_GE(bytes, 0); 1049 byte_count_ += bytes; 1050 if (byte_count_ < 0) 1051 byte_count_ = kint32max; 1052 } 1053 1054 void BackendImpl::OnWrite(int32 bytes) { 1055 // We use the same implementation as OnRead... just log the number of bytes. 1056 OnRead(bytes); 1057 } 1058 1059 void BackendImpl::OnStatsTimer() { 1060 if (disabled_) 1061 return; 1062 1063 stats_.OnEvent(Stats::TIMER); 1064 int64 time = stats_.GetCounter(Stats::TIMER); 1065 int64 current = stats_.GetCounter(Stats::OPEN_ENTRIES); 1066 1067 // OPEN_ENTRIES is a sampled average of the number of open entries, avoiding 1068 // the bias towards 0. 1069 if (num_refs_ && (current != num_refs_)) { 1070 int64 diff = (num_refs_ - current) / 50; 1071 if (!diff) 1072 diff = num_refs_ > current ? 1 : -1; 1073 current = current + diff; 1074 stats_.SetCounter(Stats::OPEN_ENTRIES, current); 1075 stats_.SetCounter(Stats::MAX_ENTRIES, max_refs_); 1076 } 1077 1078 CACHE_UMA(COUNTS, "NumberOfReferences", 0, num_refs_); 1079 1080 CACHE_UMA(COUNTS_10000, "EntryAccessRate", 0, entry_count_); 1081 CACHE_UMA(COUNTS, "ByteIORate", 0, byte_count_ / 1024); 1082 1083 // These values cover about 99.5% of the population (Oct 2011). 1084 user_load_ = (entry_count_ > 300 || byte_count_ > 7 * 1024 * 1024); 1085 entry_count_ = 0; 1086 byte_count_ = 0; 1087 up_ticks_++; 1088 1089 if (!data_) 1090 first_timer_ = false; 1091 if (first_timer_) { 1092 first_timer_ = false; 1093 if (ShouldReportAgain()) 1094 ReportStats(); 1095 } 1096 1097 // Save stats to disk at 5 min intervals. 1098 if (time % 10 == 0) 1099 StoreStats(); 1100 } 1101 1102 void BackendImpl::IncrementIoCount() { 1103 num_pending_io_++; 1104 } 1105 1106 void BackendImpl::DecrementIoCount() { 1107 num_pending_io_--; 1108 } 1109 1110 void BackendImpl::SetUnitTestMode() { 1111 user_flags_ |= kUnitTestMode; 1112 unit_test_ = true; 1113 } 1114 1115 void BackendImpl::SetUpgradeMode() { 1116 user_flags_ |= kUpgradeMode; 1117 read_only_ = true; 1118 } 1119 1120 void BackendImpl::SetNewEviction() { 1121 user_flags_ |= kNewEviction; 1122 new_eviction_ = true; 1123 } 1124 1125 void BackendImpl::SetFlags(uint32 flags) { 1126 user_flags_ |= flags; 1127 } 1128 1129 void BackendImpl::ClearRefCountForTest() { 1130 num_refs_ = 0; 1131 } 1132 1133 int BackendImpl::FlushQueueForTest(const CompletionCallback& callback) { 1134 background_queue_.FlushQueue(callback); 1135 return net::ERR_IO_PENDING; 1136 } 1137 1138 int BackendImpl::RunTaskForTest(const base::Closure& task, 1139 const CompletionCallback& callback) { 1140 background_queue_.RunTask(task, callback); 1141 return net::ERR_IO_PENDING; 1142 } 1143 1144 void BackendImpl::TrimForTest(bool empty) { 1145 eviction_.SetTestMode(); 1146 eviction_.TrimCache(empty); 1147 } 1148 1149 void BackendImpl::TrimDeletedListForTest(bool empty) { 1150 eviction_.SetTestMode(); 1151 eviction_.TrimDeletedList(empty); 1152 } 1153 1154 base::RepeatingTimer<BackendImpl>* BackendImpl::GetTimerForTest() { 1155 return timer_.get(); 1156 } 1157 1158 int BackendImpl::SelfCheck() { 1159 if (!init_) { 1160 LOG(ERROR) << "Init failed"; 1161 return ERR_INIT_FAILED; 1162 } 1163 1164 int num_entries = rankings_.SelfCheck(); 1165 if (num_entries < 0) { 1166 LOG(ERROR) << "Invalid rankings list, error " << num_entries; 1167 #if !defined(NET_BUILD_STRESS_CACHE) 1168 return num_entries; 1169 #endif 1170 } 1171 1172 if (num_entries != data_->header.num_entries) { 1173 LOG(ERROR) << "Number of entries mismatch"; 1174 #if !defined(NET_BUILD_STRESS_CACHE) 1175 return ERR_NUM_ENTRIES_MISMATCH; 1176 #endif 1177 } 1178 1179 return CheckAllEntries(); 1180 } 1181 1182 void BackendImpl::FlushIndex() { 1183 if (index_.get() && !disabled_) 1184 index_->Flush(); 1185 } 1186 1187 // ------------------------------------------------------------------------ 1188 1189 net::CacheType BackendImpl::GetCacheType() const { 1190 return cache_type_; 1191 } 1192 1193 int32 BackendImpl::GetEntryCount() const { 1194 if (!index_.get() || disabled_) 1195 return 0; 1196 // num_entries includes entries already evicted. 1197 int32 not_deleted = data_->header.num_entries - 1198 data_->header.lru.sizes[Rankings::DELETED]; 1199 1200 if (not_deleted < 0) { 1201 NOTREACHED(); 1202 not_deleted = 0; 1203 } 1204 1205 return not_deleted; 1206 } 1207 1208 int BackendImpl::OpenEntry(const std::string& key, Entry** entry, 1209 const CompletionCallback& callback) { 1210 DCHECK(!callback.is_null()); 1211 background_queue_.OpenEntry(key, entry, callback); 1212 return net::ERR_IO_PENDING; 1213 } 1214 1215 int BackendImpl::CreateEntry(const std::string& key, Entry** entry, 1216 const CompletionCallback& callback) { 1217 DCHECK(!callback.is_null()); 1218 background_queue_.CreateEntry(key, entry, callback); 1219 return net::ERR_IO_PENDING; 1220 } 1221 1222 int BackendImpl::DoomEntry(const std::string& key, 1223 const CompletionCallback& callback) { 1224 DCHECK(!callback.is_null()); 1225 background_queue_.DoomEntry(key, callback); 1226 return net::ERR_IO_PENDING; 1227 } 1228 1229 int BackendImpl::DoomAllEntries(const CompletionCallback& callback) { 1230 DCHECK(!callback.is_null()); 1231 background_queue_.DoomAllEntries(callback); 1232 return net::ERR_IO_PENDING; 1233 } 1234 1235 int BackendImpl::DoomEntriesBetween(const base::Time initial_time, 1236 const base::Time end_time, 1237 const CompletionCallback& callback) { 1238 DCHECK(!callback.is_null()); 1239 background_queue_.DoomEntriesBetween(initial_time, end_time, callback); 1240 return net::ERR_IO_PENDING; 1241 } 1242 1243 int BackendImpl::DoomEntriesSince(const base::Time initial_time, 1244 const CompletionCallback& callback) { 1245 DCHECK(!callback.is_null()); 1246 background_queue_.DoomEntriesSince(initial_time, callback); 1247 return net::ERR_IO_PENDING; 1248 } 1249 1250 class BackendImpl::IteratorImpl : public Backend::Iterator { 1251 public: 1252 explicit IteratorImpl(base::WeakPtr<InFlightBackendIO> background_queue) 1253 : background_queue_(background_queue), 1254 iterator_(new Rankings::Iterator()) { 1255 } 1256 1257 virtual ~IteratorImpl() { 1258 if (background_queue_) 1259 background_queue_->EndEnumeration(iterator_.Pass()); 1260 } 1261 1262 virtual int OpenNextEntry(Entry** next_entry, 1263 const net::CompletionCallback& callback) OVERRIDE { 1264 if (!background_queue_) 1265 return net::ERR_FAILED; 1266 background_queue_->OpenNextEntry(iterator_.get(), next_entry, callback); 1267 return net::ERR_IO_PENDING; 1268 } 1269 1270 private: 1271 const base::WeakPtr<InFlightBackendIO> background_queue_; 1272 scoped_ptr<Rankings::Iterator> iterator_; 1273 }; 1274 1275 scoped_ptr<Backend::Iterator> BackendImpl::CreateIterator() { 1276 return scoped_ptr<Backend::Iterator>(new IteratorImpl(GetBackgroundQueue())); 1277 } 1278 1279 void BackendImpl::GetStats(StatsItems* stats) { 1280 if (disabled_) 1281 return; 1282 1283 std::pair<std::string, std::string> item; 1284 1285 item.first = "Entries"; 1286 item.second = base::StringPrintf("%d", data_->header.num_entries); 1287 stats->push_back(item); 1288 1289 item.first = "Pending IO"; 1290 item.second = base::StringPrintf("%d", num_pending_io_); 1291 stats->push_back(item); 1292 1293 item.first = "Max size"; 1294 item.second = base::StringPrintf("%d", max_size_); 1295 stats->push_back(item); 1296 1297 item.first = "Current size"; 1298 item.second = base::StringPrintf("%d", data_->header.num_bytes); 1299 stats->push_back(item); 1300 1301 item.first = "Cache type"; 1302 item.second = "Blockfile Cache"; 1303 stats->push_back(item); 1304 1305 stats_.GetItems(stats); 1306 } 1307 1308 void BackendImpl::OnExternalCacheHit(const std::string& key) { 1309 background_queue_.OnExternalCacheHit(key); 1310 } 1311 1312 // ------------------------------------------------------------------------ 1313 1314 // We just created a new file so we're going to write the header and set the 1315 // file length to include the hash table (zero filled). 1316 bool BackendImpl::CreateBackingStore(disk_cache::File* file) { 1317 AdjustMaxCacheSize(0); 1318 1319 IndexHeader header; 1320 header.table_len = DesiredIndexTableLen(max_size_); 1321 1322 // We need file version 2.1 for the new eviction algorithm. 1323 if (new_eviction_) 1324 header.version = 0x20001; 1325 1326 header.create_time = Time::Now().ToInternalValue(); 1327 1328 if (!file->Write(&header, sizeof(header), 0)) 1329 return false; 1330 1331 return file->SetLength(GetIndexSize(header.table_len)); 1332 } 1333 1334 bool BackendImpl::InitBackingStore(bool* file_created) { 1335 if (!base::CreateDirectory(path_)) 1336 return false; 1337 1338 base::FilePath index_name = path_.AppendASCII(kIndexName); 1339 1340 int flags = base::File::FLAG_READ | base::File::FLAG_WRITE | 1341 base::File::FLAG_OPEN_ALWAYS | base::File::FLAG_EXCLUSIVE_WRITE; 1342 base::File base_file(index_name, flags); 1343 if (!base_file.IsValid()) 1344 return false; 1345 1346 bool ret = true; 1347 *file_created = base_file.created(); 1348 1349 scoped_refptr<disk_cache::File> file(new disk_cache::File(base_file.Pass())); 1350 if (*file_created) 1351 ret = CreateBackingStore(file.get()); 1352 1353 file = NULL; 1354 if (!ret) 1355 return false; 1356 1357 index_ = new MappedFile(); 1358 data_ = static_cast<Index*>(index_->Init(index_name, 0)); 1359 if (!data_) { 1360 LOG(ERROR) << "Unable to map Index file"; 1361 return false; 1362 } 1363 1364 if (index_->GetLength() < sizeof(Index)) { 1365 // We verify this again on CheckIndex() but it's easier to make sure now 1366 // that the header is there. 1367 LOG(ERROR) << "Corrupt Index file"; 1368 return false; 1369 } 1370 1371 return true; 1372 } 1373 1374 // The maximum cache size will be either set explicitly by the caller, or 1375 // calculated by this code. 1376 void BackendImpl::AdjustMaxCacheSize(int table_len) { 1377 if (max_size_) 1378 return; 1379 1380 // If table_len is provided, the index file exists. 1381 DCHECK(!table_len || data_->header.magic); 1382 1383 // The user is not setting the size, let's figure it out. 1384 int64 available = base::SysInfo::AmountOfFreeDiskSpace(path_); 1385 if (available < 0) { 1386 max_size_ = kDefaultCacheSize; 1387 return; 1388 } 1389 1390 if (table_len) 1391 available += data_->header.num_bytes; 1392 1393 max_size_ = PreferredCacheSize(available); 1394 1395 if (!table_len) 1396 return; 1397 1398 // If we already have a table, adjust the size to it. 1399 int current_max_size = MaxStorageSizeForTable(table_len); 1400 if (max_size_ > current_max_size) 1401 max_size_= current_max_size; 1402 } 1403 1404 bool BackendImpl::InitStats() { 1405 Addr address(data_->header.stats); 1406 int size = stats_.StorageSize(); 1407 1408 if (!address.is_initialized()) { 1409 FileType file_type = Addr::RequiredFileType(size); 1410 DCHECK_NE(file_type, EXTERNAL); 1411 int num_blocks = Addr::RequiredBlocks(size, file_type); 1412 1413 if (!CreateBlock(file_type, num_blocks, &address)) 1414 return false; 1415 1416 data_->header.stats = address.value(); 1417 return stats_.Init(NULL, 0, address); 1418 } 1419 1420 if (!address.is_block_file()) { 1421 NOTREACHED(); 1422 return false; 1423 } 1424 1425 // Load the required data. 1426 size = address.num_blocks() * address.BlockSize(); 1427 MappedFile* file = File(address); 1428 if (!file) 1429 return false; 1430 1431 scoped_ptr<char[]> data(new char[size]); 1432 size_t offset = address.start_block() * address.BlockSize() + 1433 kBlockHeaderSize; 1434 if (!file->Read(data.get(), size, offset)) 1435 return false; 1436 1437 if (!stats_.Init(data.get(), size, address)) 1438 return false; 1439 if (cache_type_ == net::DISK_CACHE && ShouldReportAgain()) 1440 stats_.InitSizeHistogram(); 1441 return true; 1442 } 1443 1444 void BackendImpl::StoreStats() { 1445 int size = stats_.StorageSize(); 1446 scoped_ptr<char[]> data(new char[size]); 1447 Addr address; 1448 size = stats_.SerializeStats(data.get(), size, &address); 1449 DCHECK(size); 1450 if (!address.is_initialized()) 1451 return; 1452 1453 MappedFile* file = File(address); 1454 if (!file) 1455 return; 1456 1457 size_t offset = address.start_block() * address.BlockSize() + 1458 kBlockHeaderSize; 1459 file->Write(data.get(), size, offset); // ignore result. 1460 } 1461 1462 void BackendImpl::RestartCache(bool failure) { 1463 int64 errors = stats_.GetCounter(Stats::FATAL_ERROR); 1464 int64 full_dooms = stats_.GetCounter(Stats::DOOM_CACHE); 1465 int64 partial_dooms = stats_.GetCounter(Stats::DOOM_RECENT); 1466 int64 last_report = stats_.GetCounter(Stats::LAST_REPORT); 1467 1468 PrepareForRestart(); 1469 if (failure) { 1470 DCHECK(!num_refs_); 1471 DCHECK(!open_entries_.size()); 1472 DelayedCacheCleanup(path_); 1473 } else { 1474 DeleteCache(path_, false); 1475 } 1476 1477 // Don't call Init() if directed by the unit test: we are simulating a failure 1478 // trying to re-enable the cache. 1479 if (unit_test_) 1480 init_ = true; // Let the destructor do proper cleanup. 1481 else if (SyncInit() == net::OK) { 1482 stats_.SetCounter(Stats::FATAL_ERROR, errors); 1483 stats_.SetCounter(Stats::DOOM_CACHE, full_dooms); 1484 stats_.SetCounter(Stats::DOOM_RECENT, partial_dooms); 1485 stats_.SetCounter(Stats::LAST_REPORT, last_report); 1486 } 1487 } 1488 1489 void BackendImpl::PrepareForRestart() { 1490 // Reset the mask_ if it was not given by the user. 1491 if (!(user_flags_ & kMask)) 1492 mask_ = 0; 1493 1494 if (!(user_flags_ & kNewEviction)) 1495 new_eviction_ = false; 1496 1497 disabled_ = true; 1498 data_->header.crash = 0; 1499 index_->Flush(); 1500 index_ = NULL; 1501 data_ = NULL; 1502 block_files_.CloseFiles(); 1503 rankings_.Reset(); 1504 init_ = false; 1505 restarted_ = true; 1506 } 1507 1508 int BackendImpl::NewEntry(Addr address, EntryImpl** entry) { 1509 EntriesMap::iterator it = open_entries_.find(address.value()); 1510 if (it != open_entries_.end()) { 1511 // Easy job. This entry is already in memory. 1512 EntryImpl* this_entry = it->second; 1513 this_entry->AddRef(); 1514 *entry = this_entry; 1515 return 0; 1516 } 1517 1518 STRESS_DCHECK(block_files_.IsValid(address)); 1519 1520 if (!address.SanityCheckForEntryV2()) { 1521 LOG(WARNING) << "Wrong entry address."; 1522 STRESS_NOTREACHED(); 1523 return ERR_INVALID_ADDRESS; 1524 } 1525 1526 scoped_refptr<EntryImpl> cache_entry( 1527 new EntryImpl(this, address, read_only_)); 1528 IncreaseNumRefs(); 1529 *entry = NULL; 1530 1531 TimeTicks start = TimeTicks::Now(); 1532 if (!cache_entry->entry()->Load()) 1533 return ERR_READ_FAILURE; 1534 1535 if (IsLoaded()) { 1536 CACHE_UMA(AGE_MS, "LoadTime", 0, start); 1537 } 1538 1539 if (!cache_entry->SanityCheck()) { 1540 LOG(WARNING) << "Messed up entry found."; 1541 STRESS_NOTREACHED(); 1542 return ERR_INVALID_ENTRY; 1543 } 1544 1545 STRESS_DCHECK(block_files_.IsValid( 1546 Addr(cache_entry->entry()->Data()->rankings_node))); 1547 1548 if (!cache_entry->LoadNodeAddress()) 1549 return ERR_READ_FAILURE; 1550 1551 if (!rankings_.SanityCheck(cache_entry->rankings(), false)) { 1552 STRESS_NOTREACHED(); 1553 cache_entry->SetDirtyFlag(0); 1554 // Don't remove this from the list (it is not linked properly). Instead, 1555 // break the link back to the entry because it is going away, and leave the 1556 // rankings node to be deleted if we find it through a list. 1557 rankings_.SetContents(cache_entry->rankings(), 0); 1558 } else if (!rankings_.DataSanityCheck(cache_entry->rankings(), false)) { 1559 STRESS_NOTREACHED(); 1560 cache_entry->SetDirtyFlag(0); 1561 rankings_.SetContents(cache_entry->rankings(), address.value()); 1562 } 1563 1564 if (!cache_entry->DataSanityCheck()) { 1565 LOG(WARNING) << "Messed up entry found."; 1566 cache_entry->SetDirtyFlag(0); 1567 cache_entry->FixForDelete(); 1568 } 1569 1570 // Prevent overwriting the dirty flag on the destructor. 1571 cache_entry->SetDirtyFlag(GetCurrentEntryId()); 1572 1573 if (cache_entry->dirty()) { 1574 Trace("Dirty entry 0x%p 0x%x", reinterpret_cast<void*>(cache_entry.get()), 1575 address.value()); 1576 } 1577 1578 open_entries_[address.value()] = cache_entry.get(); 1579 1580 cache_entry->BeginLogging(net_log_, false); 1581 cache_entry.swap(entry); 1582 return 0; 1583 } 1584 1585 EntryImpl* BackendImpl::MatchEntry(const std::string& key, uint32 hash, 1586 bool find_parent, Addr entry_addr, 1587 bool* match_error) { 1588 Addr address(data_->table[hash & mask_]); 1589 scoped_refptr<EntryImpl> cache_entry, parent_entry; 1590 EntryImpl* tmp = NULL; 1591 bool found = false; 1592 std::set<CacheAddr> visited; 1593 *match_error = false; 1594 1595 for (;;) { 1596 if (disabled_) 1597 break; 1598 1599 if (visited.find(address.value()) != visited.end()) { 1600 // It's possible for a buggy version of the code to write a loop. Just 1601 // break it. 1602 Trace("Hash collision loop 0x%x", address.value()); 1603 address.set_value(0); 1604 parent_entry->SetNextAddress(address); 1605 } 1606 visited.insert(address.value()); 1607 1608 if (!address.is_initialized()) { 1609 if (find_parent) 1610 found = true; 1611 break; 1612 } 1613 1614 int error = NewEntry(address, &tmp); 1615 cache_entry.swap(&tmp); 1616 1617 if (error || cache_entry->dirty()) { 1618 // This entry is dirty on disk (it was not properly closed): we cannot 1619 // trust it. 1620 Addr child(0); 1621 if (!error) 1622 child.set_value(cache_entry->GetNextAddress()); 1623 1624 if (parent_entry.get()) { 1625 parent_entry->SetNextAddress(child); 1626 parent_entry = NULL; 1627 } else { 1628 data_->table[hash & mask_] = child.value(); 1629 } 1630 1631 Trace("MatchEntry dirty %d 0x%x 0x%x", find_parent, entry_addr.value(), 1632 address.value()); 1633 1634 if (!error) { 1635 // It is important to call DestroyInvalidEntry after removing this 1636 // entry from the table. 1637 DestroyInvalidEntry(cache_entry.get()); 1638 cache_entry = NULL; 1639 } else { 1640 Trace("NewEntry failed on MatchEntry 0x%x", address.value()); 1641 } 1642 1643 // Restart the search. 1644 address.set_value(data_->table[hash & mask_]); 1645 visited.clear(); 1646 continue; 1647 } 1648 1649 DCHECK_EQ(hash & mask_, cache_entry->entry()->Data()->hash & mask_); 1650 if (cache_entry->IsSameEntry(key, hash)) { 1651 if (!cache_entry->Update()) 1652 cache_entry = NULL; 1653 found = true; 1654 if (find_parent && entry_addr.value() != address.value()) { 1655 Trace("Entry not on the index 0x%x", address.value()); 1656 *match_error = true; 1657 parent_entry = NULL; 1658 } 1659 break; 1660 } 1661 if (!cache_entry->Update()) 1662 cache_entry = NULL; 1663 parent_entry = cache_entry; 1664 cache_entry = NULL; 1665 if (!parent_entry.get()) 1666 break; 1667 1668 address.set_value(parent_entry->GetNextAddress()); 1669 } 1670 1671 if (parent_entry.get() && (!find_parent || !found)) 1672 parent_entry = NULL; 1673 1674 if (find_parent && entry_addr.is_initialized() && !cache_entry.get()) { 1675 *match_error = true; 1676 parent_entry = NULL; 1677 } 1678 1679 if (cache_entry.get() && (find_parent || !found)) 1680 cache_entry = NULL; 1681 1682 find_parent ? parent_entry.swap(&tmp) : cache_entry.swap(&tmp); 1683 FlushIndex(); 1684 return tmp; 1685 } 1686 1687 bool BackendImpl::OpenFollowingEntryFromList(Rankings::List list, 1688 CacheRankingsBlock** from_entry, 1689 EntryImpl** next_entry) { 1690 if (disabled_) 1691 return false; 1692 1693 if (!new_eviction_ && Rankings::NO_USE != list) 1694 return false; 1695 1696 Rankings::ScopedRankingsBlock rankings(&rankings_, *from_entry); 1697 CacheRankingsBlock* next_block = rankings_.GetNext(rankings.get(), list); 1698 Rankings::ScopedRankingsBlock next(&rankings_, next_block); 1699 *from_entry = NULL; 1700 1701 *next_entry = GetEnumeratedEntry(next.get(), list); 1702 if (!*next_entry) 1703 return false; 1704 1705 *from_entry = next.release(); 1706 return true; 1707 } 1708 1709 EntryImpl* BackendImpl::GetEnumeratedEntry(CacheRankingsBlock* next, 1710 Rankings::List list) { 1711 if (!next || disabled_) 1712 return NULL; 1713 1714 EntryImpl* entry; 1715 int rv = NewEntry(Addr(next->Data()->contents), &entry); 1716 if (rv) { 1717 STRESS_NOTREACHED(); 1718 rankings_.Remove(next, list, false); 1719 if (rv == ERR_INVALID_ADDRESS) { 1720 // There is nothing linked from the index. Delete the rankings node. 1721 DeleteBlock(next->address(), true); 1722 } 1723 return NULL; 1724 } 1725 1726 if (entry->dirty()) { 1727 // We cannot trust this entry. 1728 InternalDoomEntry(entry); 1729 entry->Release(); 1730 return NULL; 1731 } 1732 1733 if (!entry->Update()) { 1734 STRESS_NOTREACHED(); 1735 entry->Release(); 1736 return NULL; 1737 } 1738 1739 // Note that it is unfortunate (but possible) for this entry to be clean, but 1740 // not actually the real entry. In other words, we could have lost this entry 1741 // from the index, and it could have been replaced with a newer one. It's not 1742 // worth checking that this entry is "the real one", so we just return it and 1743 // let the enumeration continue; this entry will be evicted at some point, and 1744 // the regular path will work with the real entry. With time, this problem 1745 // will disasappear because this scenario is just a bug. 1746 1747 // Make sure that we save the key for later. 1748 entry->GetKey(); 1749 1750 return entry; 1751 } 1752 1753 EntryImpl* BackendImpl::ResurrectEntry(EntryImpl* deleted_entry) { 1754 if (ENTRY_NORMAL == deleted_entry->entry()->Data()->state) { 1755 deleted_entry->Release(); 1756 stats_.OnEvent(Stats::CREATE_MISS); 1757 Trace("create entry miss "); 1758 return NULL; 1759 } 1760 1761 // We are attempting to create an entry and found out that the entry was 1762 // previously deleted. 1763 1764 eviction_.OnCreateEntry(deleted_entry); 1765 entry_count_++; 1766 1767 stats_.OnEvent(Stats::RESURRECT_HIT); 1768 Trace("Resurrect entry hit "); 1769 return deleted_entry; 1770 } 1771 1772 void BackendImpl::DestroyInvalidEntry(EntryImpl* entry) { 1773 LOG(WARNING) << "Destroying invalid entry."; 1774 Trace("Destroying invalid entry 0x%p", entry); 1775 1776 entry->SetPointerForInvalidEntry(GetCurrentEntryId()); 1777 1778 eviction_.OnDoomEntry(entry); 1779 entry->InternalDoom(); 1780 1781 if (!new_eviction_) 1782 DecreaseNumEntries(); 1783 stats_.OnEvent(Stats::INVALID_ENTRY); 1784 } 1785 1786 void BackendImpl::AddStorageSize(int32 bytes) { 1787 data_->header.num_bytes += bytes; 1788 DCHECK_GE(data_->header.num_bytes, 0); 1789 } 1790 1791 void BackendImpl::SubstractStorageSize(int32 bytes) { 1792 data_->header.num_bytes -= bytes; 1793 DCHECK_GE(data_->header.num_bytes, 0); 1794 } 1795 1796 void BackendImpl::IncreaseNumRefs() { 1797 num_refs_++; 1798 if (max_refs_ < num_refs_) 1799 max_refs_ = num_refs_; 1800 } 1801 1802 void BackendImpl::DecreaseNumRefs() { 1803 DCHECK(num_refs_); 1804 num_refs_--; 1805 1806 if (!num_refs_ && disabled_) 1807 base::MessageLoop::current()->PostTask( 1808 FROM_HERE, base::Bind(&BackendImpl::RestartCache, GetWeakPtr(), true)); 1809 } 1810 1811 void BackendImpl::IncreaseNumEntries() { 1812 data_->header.num_entries++; 1813 DCHECK_GT(data_->header.num_entries, 0); 1814 } 1815 1816 void BackendImpl::DecreaseNumEntries() { 1817 data_->header.num_entries--; 1818 if (data_->header.num_entries < 0) { 1819 NOTREACHED(); 1820 data_->header.num_entries = 0; 1821 } 1822 } 1823 1824 void BackendImpl::LogStats() { 1825 StatsItems stats; 1826 GetStats(&stats); 1827 1828 for (size_t index = 0; index < stats.size(); index++) 1829 VLOG(1) << stats[index].first << ": " << stats[index].second; 1830 } 1831 1832 void BackendImpl::ReportStats() { 1833 CACHE_UMA(COUNTS, "Entries", 0, data_->header.num_entries); 1834 1835 int current_size = data_->header.num_bytes / (1024 * 1024); 1836 int max_size = max_size_ / (1024 * 1024); 1837 int hit_ratio_as_percentage = stats_.GetHitRatio(); 1838 1839 CACHE_UMA(COUNTS_10000, "Size2", 0, current_size); 1840 // For any bin in HitRatioBySize2, the hit ratio of caches of that size is the 1841 // ratio of that bin's total count to the count in the same bin in the Size2 1842 // histogram. 1843 if (base::RandInt(0, 99) < hit_ratio_as_percentage) 1844 CACHE_UMA(COUNTS_10000, "HitRatioBySize2", 0, current_size); 1845 CACHE_UMA(COUNTS_10000, "MaxSize2", 0, max_size); 1846 if (!max_size) 1847 max_size++; 1848 CACHE_UMA(PERCENTAGE, "UsedSpace", 0, current_size * 100 / max_size); 1849 1850 CACHE_UMA(COUNTS_10000, "AverageOpenEntries2", 0, 1851 static_cast<int>(stats_.GetCounter(Stats::OPEN_ENTRIES))); 1852 CACHE_UMA(COUNTS_10000, "MaxOpenEntries2", 0, 1853 static_cast<int>(stats_.GetCounter(Stats::MAX_ENTRIES))); 1854 stats_.SetCounter(Stats::MAX_ENTRIES, 0); 1855 1856 CACHE_UMA(COUNTS_10000, "TotalFatalErrors", 0, 1857 static_cast<int>(stats_.GetCounter(Stats::FATAL_ERROR))); 1858 CACHE_UMA(COUNTS_10000, "TotalDoomCache", 0, 1859 static_cast<int>(stats_.GetCounter(Stats::DOOM_CACHE))); 1860 CACHE_UMA(COUNTS_10000, "TotalDoomRecentEntries", 0, 1861 static_cast<int>(stats_.GetCounter(Stats::DOOM_RECENT))); 1862 stats_.SetCounter(Stats::FATAL_ERROR, 0); 1863 stats_.SetCounter(Stats::DOOM_CACHE, 0); 1864 stats_.SetCounter(Stats::DOOM_RECENT, 0); 1865 1866 int age = (Time::Now() - 1867 Time::FromInternalValue(data_->header.create_time)).InHours(); 1868 if (age) 1869 CACHE_UMA(HOURS, "FilesAge", 0, age); 1870 1871 int64 total_hours = stats_.GetCounter(Stats::TIMER) / 120; 1872 if (!data_->header.create_time || !data_->header.lru.filled) { 1873 int cause = data_->header.create_time ? 0 : 1; 1874 if (!data_->header.lru.filled) 1875 cause |= 2; 1876 CACHE_UMA(CACHE_ERROR, "ShortReport", 0, cause); 1877 CACHE_UMA(HOURS, "TotalTimeNotFull", 0, static_cast<int>(total_hours)); 1878 return; 1879 } 1880 1881 // This is an up to date client that will report FirstEviction() data. After 1882 // that event, start reporting this: 1883 1884 CACHE_UMA(HOURS, "TotalTime", 0, static_cast<int>(total_hours)); 1885 // For any bin in HitRatioByTotalTime, the hit ratio of caches of that total 1886 // time is the ratio of that bin's total count to the count in the same bin in 1887 // the TotalTime histogram. 1888 if (base::RandInt(0, 99) < hit_ratio_as_percentage) 1889 CACHE_UMA(HOURS, "HitRatioByTotalTime", 0, implicit_cast<int>(total_hours)); 1890 1891 int64 use_hours = stats_.GetCounter(Stats::LAST_REPORT_TIMER) / 120; 1892 stats_.SetCounter(Stats::LAST_REPORT_TIMER, stats_.GetCounter(Stats::TIMER)); 1893 1894 // We may see users with no use_hours at this point if this is the first time 1895 // we are running this code. 1896 if (use_hours) 1897 use_hours = total_hours - use_hours; 1898 1899 if (!use_hours || !GetEntryCount() || !data_->header.num_bytes) 1900 return; 1901 1902 CACHE_UMA(HOURS, "UseTime", 0, static_cast<int>(use_hours)); 1903 // For any bin in HitRatioByUseTime, the hit ratio of caches of that use time 1904 // is the ratio of that bin's total count to the count in the same bin in the 1905 // UseTime histogram. 1906 if (base::RandInt(0, 99) < hit_ratio_as_percentage) 1907 CACHE_UMA(HOURS, "HitRatioByUseTime", 0, implicit_cast<int>(use_hours)); 1908 CACHE_UMA(PERCENTAGE, "HitRatio", 0, hit_ratio_as_percentage); 1909 1910 int64 trim_rate = stats_.GetCounter(Stats::TRIM_ENTRY) / use_hours; 1911 CACHE_UMA(COUNTS, "TrimRate", 0, static_cast<int>(trim_rate)); 1912 1913 int avg_size = data_->header.num_bytes / GetEntryCount(); 1914 CACHE_UMA(COUNTS, "EntrySize", 0, avg_size); 1915 CACHE_UMA(COUNTS, "EntriesFull", 0, data_->header.num_entries); 1916 1917 CACHE_UMA(PERCENTAGE, "IndexLoad", 0, 1918 data_->header.num_entries * 100 / (mask_ + 1)); 1919 1920 int large_entries_bytes = stats_.GetLargeEntriesSize(); 1921 int large_ratio = large_entries_bytes * 100 / data_->header.num_bytes; 1922 CACHE_UMA(PERCENTAGE, "LargeEntriesRatio", 0, large_ratio); 1923 1924 if (new_eviction_) { 1925 CACHE_UMA(PERCENTAGE, "ResurrectRatio", 0, stats_.GetResurrectRatio()); 1926 CACHE_UMA(PERCENTAGE, "NoUseRatio", 0, 1927 data_->header.lru.sizes[0] * 100 / data_->header.num_entries); 1928 CACHE_UMA(PERCENTAGE, "LowUseRatio", 0, 1929 data_->header.lru.sizes[1] * 100 / data_->header.num_entries); 1930 CACHE_UMA(PERCENTAGE, "HighUseRatio", 0, 1931 data_->header.lru.sizes[2] * 100 / data_->header.num_entries); 1932 CACHE_UMA(PERCENTAGE, "DeletedRatio", 0, 1933 data_->header.lru.sizes[4] * 100 / data_->header.num_entries); 1934 } 1935 1936 stats_.ResetRatios(); 1937 stats_.SetCounter(Stats::TRIM_ENTRY, 0); 1938 1939 if (cache_type_ == net::DISK_CACHE) 1940 block_files_.ReportStats(); 1941 } 1942 1943 void BackendImpl::UpgradeTo2_1() { 1944 // 2.1 is basically the same as 2.0, except that new fields are actually 1945 // updated by the new eviction algorithm. 1946 DCHECK(0x20000 == data_->header.version); 1947 data_->header.version = 0x20001; 1948 data_->header.lru.sizes[Rankings::NO_USE] = data_->header.num_entries; 1949 } 1950 1951 bool BackendImpl::CheckIndex() { 1952 DCHECK(data_); 1953 1954 size_t current_size = index_->GetLength(); 1955 if (current_size < sizeof(Index)) { 1956 LOG(ERROR) << "Corrupt Index file"; 1957 return false; 1958 } 1959 1960 if (new_eviction_) { 1961 // We support versions 2.0 and 2.1, upgrading 2.0 to 2.1. 1962 if (kIndexMagic != data_->header.magic || 1963 kCurrentVersion >> 16 != data_->header.version >> 16) { 1964 LOG(ERROR) << "Invalid file version or magic"; 1965 return false; 1966 } 1967 if (kCurrentVersion == data_->header.version) { 1968 // We need file version 2.1 for the new eviction algorithm. 1969 UpgradeTo2_1(); 1970 } 1971 } else { 1972 if (kIndexMagic != data_->header.magic || 1973 kCurrentVersion != data_->header.version) { 1974 LOG(ERROR) << "Invalid file version or magic"; 1975 return false; 1976 } 1977 } 1978 1979 if (!data_->header.table_len) { 1980 LOG(ERROR) << "Invalid table size"; 1981 return false; 1982 } 1983 1984 if (current_size < GetIndexSize(data_->header.table_len) || 1985 data_->header.table_len & (kBaseTableLen - 1)) { 1986 LOG(ERROR) << "Corrupt Index file"; 1987 return false; 1988 } 1989 1990 AdjustMaxCacheSize(data_->header.table_len); 1991 1992 #if !defined(NET_BUILD_STRESS_CACHE) 1993 if (data_->header.num_bytes < 0 || 1994 (max_size_ < kint32max - kDefaultCacheSize && 1995 data_->header.num_bytes > max_size_ + kDefaultCacheSize)) { 1996 LOG(ERROR) << "Invalid cache (current) size"; 1997 return false; 1998 } 1999 #endif 2000 2001 if (data_->header.num_entries < 0) { 2002 LOG(ERROR) << "Invalid number of entries"; 2003 return false; 2004 } 2005 2006 if (!mask_) 2007 mask_ = data_->header.table_len - 1; 2008 2009 // Load the table into memory. 2010 return index_->Preload(); 2011 } 2012 2013 int BackendImpl::CheckAllEntries() { 2014 int num_dirty = 0; 2015 int num_entries = 0; 2016 DCHECK(mask_ < kuint32max); 2017 for (unsigned int i = 0; i <= mask_; i++) { 2018 Addr address(data_->table[i]); 2019 if (!address.is_initialized()) 2020 continue; 2021 for (;;) { 2022 EntryImpl* tmp; 2023 int ret = NewEntry(address, &tmp); 2024 if (ret) { 2025 STRESS_NOTREACHED(); 2026 return ret; 2027 } 2028 scoped_refptr<EntryImpl> cache_entry; 2029 cache_entry.swap(&tmp); 2030 2031 if (cache_entry->dirty()) 2032 num_dirty++; 2033 else if (CheckEntry(cache_entry.get())) 2034 num_entries++; 2035 else 2036 return ERR_INVALID_ENTRY; 2037 2038 DCHECK_EQ(i, cache_entry->entry()->Data()->hash & mask_); 2039 address.set_value(cache_entry->GetNextAddress()); 2040 if (!address.is_initialized()) 2041 break; 2042 } 2043 } 2044 2045 Trace("CheckAllEntries End"); 2046 if (num_entries + num_dirty != data_->header.num_entries) { 2047 LOG(ERROR) << "Number of entries " << num_entries << " " << num_dirty << 2048 " " << data_->header.num_entries; 2049 DCHECK_LT(num_entries, data_->header.num_entries); 2050 return ERR_NUM_ENTRIES_MISMATCH; 2051 } 2052 2053 return num_dirty; 2054 } 2055 2056 bool BackendImpl::CheckEntry(EntryImpl* cache_entry) { 2057 bool ok = block_files_.IsValid(cache_entry->entry()->address()); 2058 ok = ok && block_files_.IsValid(cache_entry->rankings()->address()); 2059 EntryStore* data = cache_entry->entry()->Data(); 2060 for (size_t i = 0; i < arraysize(data->data_addr); i++) { 2061 if (data->data_addr[i]) { 2062 Addr address(data->data_addr[i]); 2063 if (address.is_block_file()) 2064 ok = ok && block_files_.IsValid(address); 2065 } 2066 } 2067 2068 return ok && cache_entry->rankings()->VerifyHash(); 2069 } 2070 2071 int BackendImpl::MaxBuffersSize() { 2072 static int64 total_memory = base::SysInfo::AmountOfPhysicalMemory(); 2073 static bool done = false; 2074 2075 if (!done) { 2076 const int kMaxBuffersSize = 30 * 1024 * 1024; 2077 2078 // We want to use up to 2% of the computer's memory. 2079 total_memory = total_memory * 2 / 100; 2080 if (total_memory > kMaxBuffersSize || total_memory <= 0) 2081 total_memory = kMaxBuffersSize; 2082 2083 done = true; 2084 } 2085 2086 return static_cast<int>(total_memory); 2087 } 2088 2089 } // namespace disk_cache 2090
