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/backend_impl.h" 6 7 #include "base/bind.h" 8 #include "base/bind_helpers.h" 9 #include "base/file_util.h" 10 #include "base/files/file_path.h" 11 #include "base/hash.h" 12 #include "base/message_loop/message_loop.h" 13 #include "base/metrics/field_trial.h" 14 #include "base/metrics/histogram.h" 15 #include "base/metrics/stats_counters.h" 16 #include "base/rand_util.h" 17 #include "base/strings/string_util.h" 18 #include "base/strings/stringprintf.h" 19 #include "base/sys_info.h" 20 #include "base/threading/thread_restrictions.h" 21 #include "base/time/time.h" 22 #include "base/timer/timer.h" 23 #include "net/base/net_errors.h" 24 #include "net/disk_cache/cache_util.h" 25 #include "net/disk_cache/disk_format.h" 26 #include "net/disk_cache/entry_impl.h" 27 #include "net/disk_cache/errors.h" 28 #include "net/disk_cache/experiments.h" 29 #include "net/disk_cache/file.h" 30 31 // This has to be defined before including histogram_macros.h from this file. 32 #define NET_DISK_CACHE_BACKEND_IMPL_CC_ 33 #include "net/disk_cache/histogram_macros.h" 34 35 using base::Time; 36 using base::TimeDelta; 37 using base::TimeTicks; 38 39 namespace { 40 41 const char* kIndexName = "index"; 42 43 // Seems like ~240 MB correspond to less than 50k entries for 99% of the people. 44 // Note that the actual target is to keep the index table load factor under 55% 45 // for most users. 46 const int k64kEntriesStore = 240 * 1000 * 1000; 47 const int kBaseTableLen = 64 * 1024; 48 const int kDefaultCacheSize = 80 * 1024 * 1024; 49 50 // Avoid trimming the cache for the first 5 minutes (10 timer ticks). 51 const int kTrimDelay = 10; 52 53 int DesiredIndexTableLen(int32 storage_size) { 54 if (storage_size <= k64kEntriesStore) 55 return kBaseTableLen; 56 if (storage_size <= k64kEntriesStore * 2) 57 return kBaseTableLen * 2; 58 if (storage_size <= k64kEntriesStore * 4) 59 return kBaseTableLen * 4; 60 if (storage_size <= k64kEntriesStore * 8) 61 return kBaseTableLen * 8; 62 63 // The biggest storage_size for int32 requires a 4 MB table. 64 return kBaseTableLen * 16; 65 } 66 67 int MaxStorageSizeForTable(int table_len) { 68 return table_len * (k64kEntriesStore / kBaseTableLen); 69 } 70 71 size_t GetIndexSize(int table_len) { 72 size_t table_size = sizeof(disk_cache::CacheAddr) * table_len; 73 return sizeof(disk_cache::IndexHeader) + table_size; 74 } 75 76 // ------------------------------------------------------------------------ 77 78 // Sets group for the current experiment. Returns false if the files should be 79 // discarded. 80 bool InitExperiment(disk_cache::IndexHeader* header, bool cache_created) { 81 if (header->experiment == disk_cache::EXPERIMENT_OLD_FILE1 || 82 header->experiment == disk_cache::EXPERIMENT_OLD_FILE2) { 83 // Discard current cache. 84 return false; 85 } 86 87 if (base::FieldTrialList::FindFullName("SimpleCacheTrial") == 88 "ExperimentControl") { 89 if (cache_created) { 90 header->experiment = disk_cache::EXPERIMENT_SIMPLE_CONTROL; 91 return true; 92 } 93 return header->experiment == disk_cache::EXPERIMENT_SIMPLE_CONTROL; 94 } 95 96 header->experiment = disk_cache::NO_EXPERIMENT; 97 return true; 98 } 99 100 // A callback to perform final cleanup on the background thread. 101 void FinalCleanupCallback(disk_cache::BackendImpl* backend) { 102 backend->CleanupCache(); 103 } 104 105 } // namespace 106 107 // ------------------------------------------------------------------------ 108 109 namespace disk_cache { 110 111 // Returns the preferred maximum number of bytes for the cache given the 112 // number of available bytes. 113 int PreferedCacheSize(int64 available) { 114 // Return 80% of the available space if there is not enough space to use 115 // kDefaultCacheSize. 116 if (available < kDefaultCacheSize * 10 / 8) 117 return static_cast<int32>(available * 8 / 10); 118 119 // Return kDefaultCacheSize if it uses 80% to 10% of the available space. 120 if (available < kDefaultCacheSize * 10) 121 return kDefaultCacheSize; 122 123 // Return 10% of the available space if the target size 124 // (2.5 * kDefaultCacheSize) is more than 10%. 125 if (available < static_cast<int64>(kDefaultCacheSize) * 25) 126 return static_cast<int32>(available / 10); 127 128 // Return the target size (2.5 * kDefaultCacheSize) if it uses 10% to 1% 129 // of the available space. 130 if (available < static_cast<int64>(kDefaultCacheSize) * 250) 131 return kDefaultCacheSize * 5 / 2; 132 133 // Return 1% of the available space if it does not exceed kint32max. 134 if (available < static_cast<int64>(kint32max) * 100) 135 return static_cast<int32>(available / 100); 136 137 return kint32max; 138 } 139 140 // ------------------------------------------------------------------------ 141 142 BackendImpl::BackendImpl(const base::FilePath& path, 143 base::MessageLoopProxy* cache_thread, 144 net::NetLog* net_log) 145 : background_queue_(this, cache_thread), 146 path_(path), 147 block_files_(path), 148 mask_(0), 149 max_size_(0), 150 up_ticks_(0), 151 cache_type_(net::DISK_CACHE), 152 uma_report_(0), 153 user_flags_(0), 154 init_(false), 155 restarted_(false), 156 unit_test_(false), 157 read_only_(false), 158 disabled_(false), 159 new_eviction_(false), 160 first_timer_(true), 161 user_load_(false), 162 net_log_(net_log), 163 done_(true, false), 164 ptr_factory_(this) { 165 } 166 167 BackendImpl::BackendImpl(const base::FilePath& path, 168 uint32 mask, 169 base::MessageLoopProxy* cache_thread, 170 net::NetLog* net_log) 171 : background_queue_(this, cache_thread), 172 path_(path), 173 block_files_(path), 174 mask_(mask), 175 max_size_(0), 176 up_ticks_(0), 177 cache_type_(net::DISK_CACHE), 178 uma_report_(0), 179 user_flags_(kMask), 180 init_(false), 181 restarted_(false), 182 unit_test_(false), 183 read_only_(false), 184 disabled_(false), 185 new_eviction_(false), 186 first_timer_(true), 187 user_load_(false), 188 net_log_(net_log), 189 done_(true, false), 190 ptr_factory_(this) { 191 } 192 193 BackendImpl::~BackendImpl() { 194 if (user_flags_ & kNoRandom) { 195 // This is a unit test, so we want to be strict about not leaking entries 196 // and completing all the work. 197 background_queue_.WaitForPendingIO(); 198 } else { 199 // This is most likely not a test, so we want to do as little work as 200 // possible at this time, at the price of leaving dirty entries behind. 201 background_queue_.DropPendingIO(); 202 } 203 204 if (background_queue_.BackgroundIsCurrentThread()) { 205 // Unit tests may use the same thread for everything. 206 CleanupCache(); 207 } else { 208 background_queue_.background_thread()->PostTask( 209 FROM_HERE, base::Bind(&FinalCleanupCallback, base::Unretained(this))); 210 // http://crbug.com/74623 211 base::ThreadRestrictions::ScopedAllowWait allow_wait; 212 done_.Wait(); 213 } 214 } 215 216 int BackendImpl::Init(const CompletionCallback& callback) { 217 background_queue_.Init(callback); 218 return net::ERR_IO_PENDING; 219 } 220 221 int BackendImpl::SyncInit() { 222 #if defined(NET_BUILD_STRESS_CACHE) 223 // Start evictions right away. 224 up_ticks_ = kTrimDelay * 2; 225 #endif 226 DCHECK(!init_); 227 if (init_) 228 return net::ERR_FAILED; 229 230 bool create_files = false; 231 if (!InitBackingStore(&create_files)) { 232 ReportError(ERR_STORAGE_ERROR); 233 return net::ERR_FAILED; 234 } 235 236 num_refs_ = num_pending_io_ = max_refs_ = 0; 237 entry_count_ = byte_count_ = 0; 238 239 if (!restarted_) { 240 buffer_bytes_ = 0; 241 trace_object_ = TraceObject::GetTraceObject(); 242 // Create a recurrent timer of 30 secs. 243 int timer_delay = unit_test_ ? 1000 : 30000; 244 timer_.reset(new base::RepeatingTimer<BackendImpl>()); 245 timer_->Start(FROM_HERE, TimeDelta::FromMilliseconds(timer_delay), this, 246 &BackendImpl::OnStatsTimer); 247 } 248 249 init_ = true; 250 Trace("Init"); 251 252 if (data_->header.experiment != NO_EXPERIMENT && 253 cache_type_ != net::DISK_CACHE) { 254 // No experiment for other caches. 255 return net::ERR_FAILED; 256 } 257 258 if (!(user_flags_ & kNoRandom)) { 259 // The unit test controls directly what to test. 260 new_eviction_ = (cache_type_ == net::DISK_CACHE); 261 } 262 263 if (!CheckIndex()) { 264 ReportError(ERR_INIT_FAILED); 265 return net::ERR_FAILED; 266 } 267 268 if (!restarted_ && (create_files || !data_->header.num_entries)) 269 ReportError(ERR_CACHE_CREATED); 270 271 if (!(user_flags_ & kNoRandom) && cache_type_ == net::DISK_CACHE && 272 !InitExperiment(&data_->header, create_files)) { 273 return net::ERR_FAILED; 274 } 275 276 // We don't care if the value overflows. The only thing we care about is that 277 // the id cannot be zero, because that value is used as "not dirty". 278 // Increasing the value once per second gives us many years before we start 279 // having collisions. 280 data_->header.this_id++; 281 if (!data_->header.this_id) 282 data_->header.this_id++; 283 284 bool previous_crash = (data_->header.crash != 0); 285 data_->header.crash = 1; 286 287 if (!block_files_.Init(create_files)) 288 return net::ERR_FAILED; 289 290 // We want to minimize the changes to cache for an AppCache. 291 if (cache_type() == net::APP_CACHE) { 292 DCHECK(!new_eviction_); 293 read_only_ = true; 294 } else if (cache_type() == net::SHADER_CACHE) { 295 DCHECK(!new_eviction_); 296 } 297 298 eviction_.Init(this); 299 300 // stats_ and rankings_ may end up calling back to us so we better be enabled. 301 disabled_ = false; 302 if (!InitStats()) 303 return net::ERR_FAILED; 304 305 disabled_ = !rankings_.Init(this, new_eviction_); 306 307 #if defined(STRESS_CACHE_EXTENDED_VALIDATION) 308 trace_object_->EnableTracing(false); 309 int sc = SelfCheck(); 310 if (sc < 0 && sc != ERR_NUM_ENTRIES_MISMATCH) 311 NOTREACHED(); 312 trace_object_->EnableTracing(true); 313 #endif 314 315 if (previous_crash) { 316 ReportError(ERR_PREVIOUS_CRASH); 317 } else if (!restarted_) { 318 ReportError(ERR_NO_ERROR); 319 } 320 321 FlushIndex(); 322 323 return disabled_ ? net::ERR_FAILED : net::OK; 324 } 325 326 void BackendImpl::CleanupCache() { 327 Trace("Backend Cleanup"); 328 eviction_.Stop(); 329 timer_.reset(); 330 331 if (init_) { 332 StoreStats(); 333 if (data_) 334 data_->header.crash = 0; 335 336 if (user_flags_ & kNoRandom) { 337 // This is a net_unittest, verify that we are not 'leaking' entries. 338 File::WaitForPendingIO(&num_pending_io_); 339 DCHECK(!num_refs_); 340 } else { 341 File::DropPendingIO(); 342 } 343 } 344 block_files_.CloseFiles(); 345 FlushIndex(); 346 index_ = NULL; 347 ptr_factory_.InvalidateWeakPtrs(); 348 done_.Signal(); 349 } 350 351 // ------------------------------------------------------------------------ 352 353 int BackendImpl::OpenPrevEntry(void** iter, Entry** prev_entry, 354 const CompletionCallback& callback) { 355 DCHECK(!callback.is_null()); 356 background_queue_.OpenPrevEntry(iter, prev_entry, callback); 357 return net::ERR_IO_PENDING; 358 } 359 360 int BackendImpl::SyncOpenEntry(const std::string& key, Entry** entry) { 361 DCHECK(entry); 362 *entry = OpenEntryImpl(key); 363 return (*entry) ? net::OK : net::ERR_FAILED; 364 } 365 366 int BackendImpl::SyncCreateEntry(const std::string& key, Entry** entry) { 367 DCHECK(entry); 368 *entry = CreateEntryImpl(key); 369 return (*entry) ? net::OK : net::ERR_FAILED; 370 } 371 372 int BackendImpl::SyncDoomEntry(const std::string& key) { 373 if (disabled_) 374 return net::ERR_FAILED; 375 376 EntryImpl* entry = OpenEntryImpl(key); 377 if (!entry) 378 return net::ERR_FAILED; 379 380 entry->DoomImpl(); 381 entry->Release(); 382 return net::OK; 383 } 384 385 int BackendImpl::SyncDoomAllEntries() { 386 // This is not really an error, but it is an interesting condition. 387 ReportError(ERR_CACHE_DOOMED); 388 stats_.OnEvent(Stats::DOOM_CACHE); 389 if (!num_refs_) { 390 RestartCache(false); 391 return disabled_ ? net::ERR_FAILED : net::OK; 392 } else { 393 if (disabled_) 394 return net::ERR_FAILED; 395 396 eviction_.TrimCache(true); 397 return net::OK; 398 } 399 } 400 401 int BackendImpl::SyncDoomEntriesBetween(const base::Time initial_time, 402 const base::Time end_time) { 403 DCHECK_NE(net::APP_CACHE, cache_type_); 404 if (end_time.is_null()) 405 return SyncDoomEntriesSince(initial_time); 406 407 DCHECK(end_time >= initial_time); 408 409 if (disabled_) 410 return net::ERR_FAILED; 411 412 EntryImpl* node; 413 void* iter = NULL; 414 EntryImpl* next = OpenNextEntryImpl(&iter); 415 if (!next) 416 return net::OK; 417 418 while (next) { 419 node = next; 420 next = OpenNextEntryImpl(&iter); 421 422 if (node->GetLastUsed() >= initial_time && 423 node->GetLastUsed() < end_time) { 424 node->DoomImpl(); 425 } else if (node->GetLastUsed() < initial_time) { 426 if (next) 427 next->Release(); 428 next = NULL; 429 SyncEndEnumeration(iter); 430 } 431 432 node->Release(); 433 } 434 435 return net::OK; 436 } 437 438 // We use OpenNextEntryImpl to retrieve elements from the cache, until we get 439 // entries that are too old. 440 int BackendImpl::SyncDoomEntriesSince(const base::Time initial_time) { 441 DCHECK_NE(net::APP_CACHE, cache_type_); 442 if (disabled_) 443 return net::ERR_FAILED; 444 445 stats_.OnEvent(Stats::DOOM_RECENT); 446 for (;;) { 447 void* iter = NULL; 448 EntryImpl* entry = OpenNextEntryImpl(&iter); 449 if (!entry) 450 return net::OK; 451 452 if (initial_time > entry->GetLastUsed()) { 453 entry->Release(); 454 SyncEndEnumeration(iter); 455 return net::OK; 456 } 457 458 entry->DoomImpl(); 459 entry->Release(); 460 SyncEndEnumeration(iter); // Dooming the entry invalidates the iterator. 461 } 462 } 463 464 int BackendImpl::SyncOpenNextEntry(void** iter, Entry** next_entry) { 465 *next_entry = OpenNextEntryImpl(iter); 466 return (*next_entry) ? net::OK : net::ERR_FAILED; 467 } 468 469 int BackendImpl::SyncOpenPrevEntry(void** iter, Entry** prev_entry) { 470 *prev_entry = OpenPrevEntryImpl(iter); 471 return (*prev_entry) ? net::OK : net::ERR_FAILED; 472 } 473 474 void BackendImpl::SyncEndEnumeration(void* iter) { 475 scoped_ptr<Rankings::Iterator> iterator( 476 reinterpret_cast<Rankings::Iterator*>(iter)); 477 } 478 479 void BackendImpl::SyncOnExternalCacheHit(const std::string& key) { 480 if (disabled_) 481 return; 482 483 uint32 hash = base::Hash(key); 484 bool error; 485 EntryImpl* cache_entry = MatchEntry(key, hash, false, Addr(), &error); 486 if (cache_entry) { 487 if (ENTRY_NORMAL == cache_entry->entry()->Data()->state) { 488 UpdateRank(cache_entry, cache_type() == net::SHADER_CACHE); 489 } 490 cache_entry->Release(); 491 } 492 } 493 494 EntryImpl* BackendImpl::OpenEntryImpl(const std::string& key) { 495 if (disabled_) 496 return NULL; 497 498 TimeTicks start = TimeTicks::Now(); 499 uint32 hash = base::Hash(key); 500 Trace("Open hash 0x%x", hash); 501 502 bool error; 503 EntryImpl* cache_entry = MatchEntry(key, hash, false, Addr(), &error); 504 if (cache_entry && ENTRY_NORMAL != cache_entry->entry()->Data()->state) { 505 // The entry was already evicted. 506 cache_entry->Release(); 507 cache_entry = NULL; 508 } 509 510 int current_size = data_->header.num_bytes / (1024 * 1024); 511 int64 total_hours = stats_.GetCounter(Stats::TIMER) / 120; 512 int64 no_use_hours = stats_.GetCounter(Stats::LAST_REPORT_TIMER) / 120; 513 int64 use_hours = total_hours - no_use_hours; 514 515 if (!cache_entry) { 516 CACHE_UMA(AGE_MS, "OpenTime.Miss", 0, start); 517 CACHE_UMA(COUNTS_10000, "AllOpenBySize.Miss", 0, current_size); 518 CACHE_UMA(HOURS, "AllOpenByTotalHours.Miss", 0, total_hours); 519 CACHE_UMA(HOURS, "AllOpenByUseHours.Miss", 0, use_hours); 520 stats_.OnEvent(Stats::OPEN_MISS); 521 return NULL; 522 } 523 524 eviction_.OnOpenEntry(cache_entry); 525 entry_count_++; 526 527 Trace("Open hash 0x%x end: 0x%x", hash, 528 cache_entry->entry()->address().value()); 529 CACHE_UMA(AGE_MS, "OpenTime", 0, start); 530 CACHE_UMA(COUNTS_10000, "AllOpenBySize.Hit", 0, current_size); 531 CACHE_UMA(HOURS, "AllOpenByTotalHours.Hit", 0, total_hours); 532 CACHE_UMA(HOURS, "AllOpenByUseHours.Hit", 0, use_hours); 533 stats_.OnEvent(Stats::OPEN_HIT); 534 SIMPLE_STATS_COUNTER("disk_cache.hit"); 535 return cache_entry; 536 } 537 538 EntryImpl* BackendImpl::CreateEntryImpl(const std::string& key) { 539 if (disabled_ || key.empty()) 540 return NULL; 541 542 TimeTicks start = TimeTicks::Now(); 543 uint32 hash = base::Hash(key); 544 Trace("Create hash 0x%x", hash); 545 546 scoped_refptr<EntryImpl> parent; 547 Addr entry_address(data_->table[hash & mask_]); 548 if (entry_address.is_initialized()) { 549 // We have an entry already. It could be the one we are looking for, or just 550 // a hash conflict. 551 bool error; 552 EntryImpl* old_entry = MatchEntry(key, hash, false, Addr(), &error); 553 if (old_entry) 554 return ResurrectEntry(old_entry); 555 556 EntryImpl* parent_entry = MatchEntry(key, hash, true, Addr(), &error); 557 DCHECK(!error); 558 if (parent_entry) { 559 parent.swap(&parent_entry); 560 } else if (data_->table[hash & mask_]) { 561 // We should have corrected the problem. 562 NOTREACHED(); 563 return NULL; 564 } 565 } 566 567 // The general flow is to allocate disk space and initialize the entry data, 568 // followed by saving that to disk, then linking the entry though the index 569 // and finally through the lists. If there is a crash in this process, we may 570 // end up with: 571 // a. Used, unreferenced empty blocks on disk (basically just garbage). 572 // b. Used, unreferenced but meaningful data on disk (more garbage). 573 // c. A fully formed entry, reachable only through the index. 574 // d. A fully formed entry, also reachable through the lists, but still dirty. 575 // 576 // Anything after (b) can be automatically cleaned up. We may consider saving 577 // the current operation (as we do while manipulating the lists) so that we 578 // can detect and cleanup (a) and (b). 579 580 int num_blocks = EntryImpl::NumBlocksForEntry(key.size()); 581 if (!block_files_.CreateBlock(BLOCK_256, num_blocks, &entry_address)) { 582 LOG(ERROR) << "Create entry failed " << key.c_str(); 583 stats_.OnEvent(Stats::CREATE_ERROR); 584 return NULL; 585 } 586 587 Addr node_address(0); 588 if (!block_files_.CreateBlock(RANKINGS, 1, &node_address)) { 589 block_files_.DeleteBlock(entry_address, false); 590 LOG(ERROR) << "Create entry failed " << key.c_str(); 591 stats_.OnEvent(Stats::CREATE_ERROR); 592 return NULL; 593 } 594 595 scoped_refptr<EntryImpl> cache_entry( 596 new EntryImpl(this, entry_address, false)); 597 IncreaseNumRefs(); 598 599 if (!cache_entry->CreateEntry(node_address, key, hash)) { 600 block_files_.DeleteBlock(entry_address, false); 601 block_files_.DeleteBlock(node_address, false); 602 LOG(ERROR) << "Create entry failed " << key.c_str(); 603 stats_.OnEvent(Stats::CREATE_ERROR); 604 return NULL; 605 } 606 607 cache_entry->BeginLogging(net_log_, true); 608 609 // We are not failing the operation; let's add this to the map. 610 open_entries_[entry_address.value()] = cache_entry.get(); 611 612 // Save the entry. 613 cache_entry->entry()->Store(); 614 cache_entry->rankings()->Store(); 615 IncreaseNumEntries(); 616 entry_count_++; 617 618 // Link this entry through the index. 619 if (parent.get()) { 620 parent->SetNextAddress(entry_address); 621 } else { 622 data_->table[hash & mask_] = entry_address.value(); 623 } 624 625 // Link this entry through the lists. 626 eviction_.OnCreateEntry(cache_entry.get()); 627 628 CACHE_UMA(AGE_MS, "CreateTime", 0, start); 629 stats_.OnEvent(Stats::CREATE_HIT); 630 SIMPLE_STATS_COUNTER("disk_cache.miss"); 631 Trace("create entry hit "); 632 FlushIndex(); 633 cache_entry->AddRef(); 634 return cache_entry.get(); 635 } 636 637 EntryImpl* BackendImpl::OpenNextEntryImpl(void** iter) { 638 return OpenFollowingEntry(true, iter); 639 } 640 641 EntryImpl* BackendImpl::OpenPrevEntryImpl(void** iter) { 642 return OpenFollowingEntry(false, iter); 643 } 644 645 bool BackendImpl::SetMaxSize(int max_bytes) { 646 COMPILE_ASSERT(sizeof(max_bytes) == sizeof(max_size_), unsupported_int_model); 647 if (max_bytes < 0) 648 return false; 649 650 // Zero size means use the default. 651 if (!max_bytes) 652 return true; 653 654 // Avoid a DCHECK later on. 655 if (max_bytes >= kint32max - kint32max / 10) 656 max_bytes = kint32max - kint32max / 10 - 1; 657 658 user_flags_ |= kMaxSize; 659 max_size_ = max_bytes; 660 return true; 661 } 662 663 void BackendImpl::SetType(net::CacheType type) { 664 DCHECK_NE(net::MEMORY_CACHE, type); 665 cache_type_ = type; 666 } 667 668 base::FilePath BackendImpl::GetFileName(Addr address) const { 669 if (!address.is_separate_file() || !address.is_initialized()) { 670 NOTREACHED(); 671 return base::FilePath(); 672 } 673 674 std::string tmp = base::StringPrintf("f_%06x", address.FileNumber()); 675 return path_.AppendASCII(tmp); 676 } 677 678 MappedFile* BackendImpl::File(Addr address) { 679 if (disabled_) 680 return NULL; 681 return block_files_.GetFile(address); 682 } 683 684 base::WeakPtr<InFlightBackendIO> BackendImpl::GetBackgroundQueue() { 685 return background_queue_.GetWeakPtr(); 686 } 687 688 bool BackendImpl::CreateExternalFile(Addr* address) { 689 int file_number = data_->header.last_file + 1; 690 Addr file_address(0); 691 bool success = false; 692 for (int i = 0; i < 0x0fffffff; i++, file_number++) { 693 if (!file_address.SetFileNumber(file_number)) { 694 file_number = 1; 695 continue; 696 } 697 base::FilePath name = GetFileName(file_address); 698 int flags = base::PLATFORM_FILE_READ | 699 base::PLATFORM_FILE_WRITE | 700 base::PLATFORM_FILE_CREATE | 701 base::PLATFORM_FILE_EXCLUSIVE_WRITE; 702 base::PlatformFileError error; 703 scoped_refptr<disk_cache::File> file(new disk_cache::File( 704 base::CreatePlatformFile(name, flags, NULL, &error))); 705 if (!file->IsValid()) { 706 if (error != base::PLATFORM_FILE_ERROR_EXISTS) { 707 LOG(ERROR) << "Unable to create file: " << error; 708 return false; 709 } 710 continue; 711 } 712 713 success = true; 714 break; 715 } 716 717 DCHECK(success); 718 if (!success) 719 return false; 720 721 data_->header.last_file = file_number; 722 address->set_value(file_address.value()); 723 return true; 724 } 725 726 bool BackendImpl::CreateBlock(FileType block_type, int block_count, 727 Addr* block_address) { 728 return block_files_.CreateBlock(block_type, block_count, block_address); 729 } 730 731 void BackendImpl::DeleteBlock(Addr block_address, bool deep) { 732 block_files_.DeleteBlock(block_address, deep); 733 } 734 735 LruData* BackendImpl::GetLruData() { 736 return &data_->header.lru; 737 } 738 739 void BackendImpl::UpdateRank(EntryImpl* entry, bool modified) { 740 if (read_only_ || (!modified && cache_type() == net::SHADER_CACHE)) 741 return; 742 eviction_.UpdateRank(entry, modified); 743 } 744 745 void BackendImpl::RecoveredEntry(CacheRankingsBlock* rankings) { 746 Addr address(rankings->Data()->contents); 747 EntryImpl* cache_entry = NULL; 748 if (NewEntry(address, &cache_entry)) { 749 STRESS_NOTREACHED(); 750 return; 751 } 752 753 uint32 hash = cache_entry->GetHash(); 754 cache_entry->Release(); 755 756 // Anything on the table means that this entry is there. 757 if (data_->table[hash & mask_]) 758 return; 759 760 data_->table[hash & mask_] = address.value(); 761 FlushIndex(); 762 } 763 764 void BackendImpl::InternalDoomEntry(EntryImpl* entry) { 765 uint32 hash = entry->GetHash(); 766 std::string key = entry->GetKey(); 767 Addr entry_addr = entry->entry()->address(); 768 bool error; 769 EntryImpl* parent_entry = MatchEntry(key, hash, true, entry_addr, &error); 770 CacheAddr child(entry->GetNextAddress()); 771 772 Trace("Doom entry 0x%p", entry); 773 774 if (!entry->doomed()) { 775 // We may have doomed this entry from within MatchEntry. 776 eviction_.OnDoomEntry(entry); 777 entry->InternalDoom(); 778 if (!new_eviction_) { 779 DecreaseNumEntries(); 780 } 781 stats_.OnEvent(Stats::DOOM_ENTRY); 782 } 783 784 if (parent_entry) { 785 parent_entry->SetNextAddress(Addr(child)); 786 parent_entry->Release(); 787 } else if (!error) { 788 data_->table[hash & mask_] = child; 789 } 790 791 FlushIndex(); 792 } 793 794 #if defined(NET_BUILD_STRESS_CACHE) 795 796 CacheAddr BackendImpl::GetNextAddr(Addr address) { 797 EntriesMap::iterator it = open_entries_.find(address.value()); 798 if (it != open_entries_.end()) { 799 EntryImpl* this_entry = it->second; 800 return this_entry->GetNextAddress(); 801 } 802 DCHECK(block_files_.IsValid(address)); 803 DCHECK(!address.is_separate_file() && address.file_type() == BLOCK_256); 804 805 CacheEntryBlock entry(File(address), address); 806 CHECK(entry.Load()); 807 return entry.Data()->next; 808 } 809 810 void BackendImpl::NotLinked(EntryImpl* entry) { 811 Addr entry_addr = entry->entry()->address(); 812 uint32 i = entry->GetHash() & mask_; 813 Addr address(data_->table[i]); 814 if (!address.is_initialized()) 815 return; 816 817 for (;;) { 818 DCHECK(entry_addr.value() != address.value()); 819 address.set_value(GetNextAddr(address)); 820 if (!address.is_initialized()) 821 break; 822 } 823 } 824 #endif // NET_BUILD_STRESS_CACHE 825 826 // An entry may be linked on the DELETED list for a while after being doomed. 827 // This function is called when we want to remove it. 828 void BackendImpl::RemoveEntry(EntryImpl* entry) { 829 #if defined(NET_BUILD_STRESS_CACHE) 830 NotLinked(entry); 831 #endif 832 if (!new_eviction_) 833 return; 834 835 DCHECK_NE(ENTRY_NORMAL, entry->entry()->Data()->state); 836 837 Trace("Remove entry 0x%p", entry); 838 eviction_.OnDestroyEntry(entry); 839 DecreaseNumEntries(); 840 } 841 842 void BackendImpl::OnEntryDestroyBegin(Addr address) { 843 EntriesMap::iterator it = open_entries_.find(address.value()); 844 if (it != open_entries_.end()) 845 open_entries_.erase(it); 846 } 847 848 void BackendImpl::OnEntryDestroyEnd() { 849 DecreaseNumRefs(); 850 if (data_->header.num_bytes > max_size_ && !read_only_ && 851 (up_ticks_ > kTrimDelay || user_flags_ & kNoRandom)) 852 eviction_.TrimCache(false); 853 } 854 855 EntryImpl* BackendImpl::GetOpenEntry(CacheRankingsBlock* rankings) const { 856 DCHECK(rankings->HasData()); 857 EntriesMap::const_iterator it = 858 open_entries_.find(rankings->Data()->contents); 859 if (it != open_entries_.end()) { 860 // We have this entry in memory. 861 return it->second; 862 } 863 864 return NULL; 865 } 866 867 int32 BackendImpl::GetCurrentEntryId() const { 868 return data_->header.this_id; 869 } 870 871 int BackendImpl::MaxFileSize() const { 872 return max_size_ / 8; 873 } 874 875 void BackendImpl::ModifyStorageSize(int32 old_size, int32 new_size) { 876 if (disabled_ || old_size == new_size) 877 return; 878 if (old_size > new_size) 879 SubstractStorageSize(old_size - new_size); 880 else 881 AddStorageSize(new_size - old_size); 882 883 FlushIndex(); 884 885 // Update the usage statistics. 886 stats_.ModifyStorageStats(old_size, new_size); 887 } 888 889 void BackendImpl::TooMuchStorageRequested(int32 size) { 890 stats_.ModifyStorageStats(0, size); 891 } 892 893 bool BackendImpl::IsAllocAllowed(int current_size, int new_size) { 894 DCHECK_GT(new_size, current_size); 895 if (user_flags_ & kNoBuffering) 896 return false; 897 898 int to_add = new_size - current_size; 899 if (buffer_bytes_ + to_add > MaxBuffersSize()) 900 return false; 901 902 buffer_bytes_ += to_add; 903 CACHE_UMA(COUNTS_50000, "BufferBytes", 0, buffer_bytes_ / 1024); 904 return true; 905 } 906 907 void BackendImpl::BufferDeleted(int size) { 908 buffer_bytes_ -= size; 909 DCHECK_GE(size, 0); 910 } 911 912 bool BackendImpl::IsLoaded() const { 913 CACHE_UMA(COUNTS, "PendingIO", 0, num_pending_io_); 914 if (user_flags_ & kNoLoadProtection) 915 return false; 916 917 return (num_pending_io_ > 5 || user_load_); 918 } 919 920 std::string BackendImpl::HistogramName(const char* name, int experiment) const { 921 if (!experiment) 922 return base::StringPrintf("DiskCache.%d.%s", cache_type_, name); 923 return base::StringPrintf("DiskCache.%d.%s_%d", cache_type_, 924 name, experiment); 925 } 926 927 base::WeakPtr<BackendImpl> BackendImpl::GetWeakPtr() { 928 return ptr_factory_.GetWeakPtr(); 929 } 930 931 // We want to remove biases from some histograms so we only send data once per 932 // week. 933 bool BackendImpl::ShouldReportAgain() { 934 if (uma_report_) 935 return uma_report_ == 2; 936 937 uma_report_++; 938 int64 last_report = stats_.GetCounter(Stats::LAST_REPORT); 939 Time last_time = Time::FromInternalValue(last_report); 940 if (!last_report || (Time::Now() - last_time).InDays() >= 7) { 941 stats_.SetCounter(Stats::LAST_REPORT, Time::Now().ToInternalValue()); 942 uma_report_++; 943 return true; 944 } 945 return false; 946 } 947 948 void BackendImpl::FirstEviction() { 949 DCHECK(data_->header.create_time); 950 if (!GetEntryCount()) 951 return; // This is just for unit tests. 952 953 Time create_time = Time::FromInternalValue(data_->header.create_time); 954 CACHE_UMA(AGE, "FillupAge", 0, create_time); 955 956 int64 use_time = stats_.GetCounter(Stats::TIMER); 957 CACHE_UMA(HOURS, "FillupTime", 0, static_cast<int>(use_time / 120)); 958 CACHE_UMA(PERCENTAGE, "FirstHitRatio", 0, stats_.GetHitRatio()); 959 960 if (!use_time) 961 use_time = 1; 962 CACHE_UMA(COUNTS_10000, "FirstEntryAccessRate", 0, 963 static_cast<int>(data_->header.num_entries / use_time)); 964 CACHE_UMA(COUNTS, "FirstByteIORate", 0, 965 static_cast<int>((data_->header.num_bytes / 1024) / use_time)); 966 967 int avg_size = data_->header.num_bytes / GetEntryCount(); 968 CACHE_UMA(COUNTS, "FirstEntrySize", 0, avg_size); 969 970 int large_entries_bytes = stats_.GetLargeEntriesSize(); 971 int large_ratio = large_entries_bytes * 100 / data_->header.num_bytes; 972 CACHE_UMA(PERCENTAGE, "FirstLargeEntriesRatio", 0, large_ratio); 973 974 if (new_eviction_) { 975 CACHE_UMA(PERCENTAGE, "FirstResurrectRatio", 0, stats_.GetResurrectRatio()); 976 CACHE_UMA(PERCENTAGE, "FirstNoUseRatio", 0, 977 data_->header.lru.sizes[0] * 100 / data_->header.num_entries); 978 CACHE_UMA(PERCENTAGE, "FirstLowUseRatio", 0, 979 data_->header.lru.sizes[1] * 100 / data_->header.num_entries); 980 CACHE_UMA(PERCENTAGE, "FirstHighUseRatio", 0, 981 data_->header.lru.sizes[2] * 100 / data_->header.num_entries); 982 } 983 984 stats_.ResetRatios(); 985 } 986 987 void BackendImpl::CriticalError(int error) { 988 STRESS_NOTREACHED(); 989 LOG(ERROR) << "Critical error found " << error; 990 if (disabled_) 991 return; 992 993 stats_.OnEvent(Stats::FATAL_ERROR); 994 LogStats(); 995 ReportError(error); 996 997 // Setting the index table length to an invalid value will force re-creation 998 // of the cache files. 999 data_->header.table_len = 1; 1000 disabled_ = true; 1001 1002 if (!num_refs_) 1003 base::MessageLoop::current()->PostTask( 1004 FROM_HERE, base::Bind(&BackendImpl::RestartCache, GetWeakPtr(), true)); 1005 } 1006 1007 void BackendImpl::ReportError(int error) { 1008 STRESS_DCHECK(!error || error == ERR_PREVIOUS_CRASH || 1009 error == ERR_CACHE_CREATED); 1010 1011 // We transmit positive numbers, instead of direct error codes. 1012 DCHECK_LE(error, 0); 1013 CACHE_UMA(CACHE_ERROR, "Error", 0, error * -1); 1014 } 1015 1016 void BackendImpl::OnEvent(Stats::Counters an_event) { 1017 stats_.OnEvent(an_event); 1018 } 1019 1020 void BackendImpl::OnRead(int32 bytes) { 1021 DCHECK_GE(bytes, 0); 1022 byte_count_ += bytes; 1023 if (byte_count_ < 0) 1024 byte_count_ = kint32max; 1025 } 1026 1027 void BackendImpl::OnWrite(int32 bytes) { 1028 // We use the same implementation as OnRead... just log the number of bytes. 1029 OnRead(bytes); 1030 } 1031 1032 void BackendImpl::OnStatsTimer() { 1033 stats_.OnEvent(Stats::TIMER); 1034 int64 time = stats_.GetCounter(Stats::TIMER); 1035 int64 current = stats_.GetCounter(Stats::OPEN_ENTRIES); 1036 1037 // OPEN_ENTRIES is a sampled average of the number of open entries, avoiding 1038 // the bias towards 0. 1039 if (num_refs_ && (current != num_refs_)) { 1040 int64 diff = (num_refs_ - current) / 50; 1041 if (!diff) 1042 diff = num_refs_ > current ? 1 : -1; 1043 current = current + diff; 1044 stats_.SetCounter(Stats::OPEN_ENTRIES, current); 1045 stats_.SetCounter(Stats::MAX_ENTRIES, max_refs_); 1046 } 1047 1048 CACHE_UMA(COUNTS, "NumberOfReferences", 0, num_refs_); 1049 1050 CACHE_UMA(COUNTS_10000, "EntryAccessRate", 0, entry_count_); 1051 CACHE_UMA(COUNTS, "ByteIORate", 0, byte_count_ / 1024); 1052 1053 // These values cover about 99.5% of the population (Oct 2011). 1054 user_load_ = (entry_count_ > 300 || byte_count_ > 7 * 1024 * 1024); 1055 entry_count_ = 0; 1056 byte_count_ = 0; 1057 up_ticks_++; 1058 1059 if (!data_) 1060 first_timer_ = false; 1061 if (first_timer_) { 1062 first_timer_ = false; 1063 if (ShouldReportAgain()) 1064 ReportStats(); 1065 } 1066 1067 // Save stats to disk at 5 min intervals. 1068 if (time % 10 == 0) 1069 StoreStats(); 1070 } 1071 1072 void BackendImpl::IncrementIoCount() { 1073 num_pending_io_++; 1074 } 1075 1076 void BackendImpl::DecrementIoCount() { 1077 num_pending_io_--; 1078 } 1079 1080 void BackendImpl::SetUnitTestMode() { 1081 user_flags_ |= kUnitTestMode; 1082 unit_test_ = true; 1083 } 1084 1085 void BackendImpl::SetUpgradeMode() { 1086 user_flags_ |= kUpgradeMode; 1087 read_only_ = true; 1088 } 1089 1090 void BackendImpl::SetNewEviction() { 1091 user_flags_ |= kNewEviction; 1092 new_eviction_ = true; 1093 } 1094 1095 void BackendImpl::SetFlags(uint32 flags) { 1096 user_flags_ |= flags; 1097 } 1098 1099 void BackendImpl::ClearRefCountForTest() { 1100 num_refs_ = 0; 1101 } 1102 1103 int BackendImpl::FlushQueueForTest(const CompletionCallback& callback) { 1104 background_queue_.FlushQueue(callback); 1105 return net::ERR_IO_PENDING; 1106 } 1107 1108 int BackendImpl::RunTaskForTest(const base::Closure& task, 1109 const CompletionCallback& callback) { 1110 background_queue_.RunTask(task, callback); 1111 return net::ERR_IO_PENDING; 1112 } 1113 1114 void BackendImpl::TrimForTest(bool empty) { 1115 eviction_.SetTestMode(); 1116 eviction_.TrimCache(empty); 1117 } 1118 1119 void BackendImpl::TrimDeletedListForTest(bool empty) { 1120 eviction_.SetTestMode(); 1121 eviction_.TrimDeletedList(empty); 1122 } 1123 1124 int BackendImpl::SelfCheck() { 1125 if (!init_) { 1126 LOG(ERROR) << "Init failed"; 1127 return ERR_INIT_FAILED; 1128 } 1129 1130 int num_entries = rankings_.SelfCheck(); 1131 if (num_entries < 0) { 1132 LOG(ERROR) << "Invalid rankings list, error " << num_entries; 1133 #if !defined(NET_BUILD_STRESS_CACHE) 1134 return num_entries; 1135 #endif 1136 } 1137 1138 if (num_entries != data_->header.num_entries) { 1139 LOG(ERROR) << "Number of entries mismatch"; 1140 #if !defined(NET_BUILD_STRESS_CACHE) 1141 return ERR_NUM_ENTRIES_MISMATCH; 1142 #endif 1143 } 1144 1145 return CheckAllEntries(); 1146 } 1147 1148 void BackendImpl::FlushIndex() { 1149 if (index_.get() && !disabled_) 1150 index_->Flush(); 1151 } 1152 1153 // ------------------------------------------------------------------------ 1154 1155 net::CacheType BackendImpl::GetCacheType() const { 1156 return cache_type_; 1157 } 1158 1159 int32 BackendImpl::GetEntryCount() const { 1160 if (!index_.get() || disabled_) 1161 return 0; 1162 // num_entries includes entries already evicted. 1163 int32 not_deleted = data_->header.num_entries - 1164 data_->header.lru.sizes[Rankings::DELETED]; 1165 1166 if (not_deleted < 0) { 1167 NOTREACHED(); 1168 not_deleted = 0; 1169 } 1170 1171 return not_deleted; 1172 } 1173 1174 int BackendImpl::OpenEntry(const std::string& key, Entry** entry, 1175 const CompletionCallback& callback) { 1176 DCHECK(!callback.is_null()); 1177 background_queue_.OpenEntry(key, entry, callback); 1178 return net::ERR_IO_PENDING; 1179 } 1180 1181 int BackendImpl::CreateEntry(const std::string& key, Entry** entry, 1182 const CompletionCallback& callback) { 1183 DCHECK(!callback.is_null()); 1184 background_queue_.CreateEntry(key, entry, callback); 1185 return net::ERR_IO_PENDING; 1186 } 1187 1188 int BackendImpl::DoomEntry(const std::string& key, 1189 const CompletionCallback& callback) { 1190 DCHECK(!callback.is_null()); 1191 background_queue_.DoomEntry(key, callback); 1192 return net::ERR_IO_PENDING; 1193 } 1194 1195 int BackendImpl::DoomAllEntries(const CompletionCallback& callback) { 1196 DCHECK(!callback.is_null()); 1197 background_queue_.DoomAllEntries(callback); 1198 return net::ERR_IO_PENDING; 1199 } 1200 1201 int BackendImpl::DoomEntriesBetween(const base::Time initial_time, 1202 const base::Time end_time, 1203 const CompletionCallback& callback) { 1204 DCHECK(!callback.is_null()); 1205 background_queue_.DoomEntriesBetween(initial_time, end_time, callback); 1206 return net::ERR_IO_PENDING; 1207 } 1208 1209 int BackendImpl::DoomEntriesSince(const base::Time initial_time, 1210 const CompletionCallback& callback) { 1211 DCHECK(!callback.is_null()); 1212 background_queue_.DoomEntriesSince(initial_time, callback); 1213 return net::ERR_IO_PENDING; 1214 } 1215 1216 int BackendImpl::OpenNextEntry(void** iter, Entry** next_entry, 1217 const CompletionCallback& callback) { 1218 DCHECK(!callback.is_null()); 1219 background_queue_.OpenNextEntry(iter, next_entry, callback); 1220 return net::ERR_IO_PENDING; 1221 } 1222 1223 void BackendImpl::EndEnumeration(void** iter) { 1224 background_queue_.EndEnumeration(*iter); 1225 *iter = NULL; 1226 } 1227 1228 void BackendImpl::GetStats(StatsItems* stats) { 1229 if (disabled_) 1230 return; 1231 1232 std::pair<std::string, std::string> item; 1233 1234 item.first = "Entries"; 1235 item.second = base::StringPrintf("%d", data_->header.num_entries); 1236 stats->push_back(item); 1237 1238 item.first = "Pending IO"; 1239 item.second = base::StringPrintf("%d", num_pending_io_); 1240 stats->push_back(item); 1241 1242 item.first = "Max size"; 1243 item.second = base::StringPrintf("%d", max_size_); 1244 stats->push_back(item); 1245 1246 item.first = "Current size"; 1247 item.second = base::StringPrintf("%d", data_->header.num_bytes); 1248 stats->push_back(item); 1249 1250 item.first = "Cache type"; 1251 item.second = "Blockfile Cache"; 1252 stats->push_back(item); 1253 1254 stats_.GetItems(stats); 1255 } 1256 1257 void BackendImpl::OnExternalCacheHit(const std::string& key) { 1258 background_queue_.OnExternalCacheHit(key); 1259 } 1260 1261 // ------------------------------------------------------------------------ 1262 1263 // We just created a new file so we're going to write the header and set the 1264 // file length to include the hash table (zero filled). 1265 bool BackendImpl::CreateBackingStore(disk_cache::File* file) { 1266 AdjustMaxCacheSize(0); 1267 1268 IndexHeader header; 1269 header.table_len = DesiredIndexTableLen(max_size_); 1270 1271 // We need file version 2.1 for the new eviction algorithm. 1272 if (new_eviction_) 1273 header.version = 0x20001; 1274 1275 header.create_time = Time::Now().ToInternalValue(); 1276 1277 if (!file->Write(&header, sizeof(header), 0)) 1278 return false; 1279 1280 return file->SetLength(GetIndexSize(header.table_len)); 1281 } 1282 1283 bool BackendImpl::InitBackingStore(bool* file_created) { 1284 if (!file_util::CreateDirectory(path_)) 1285 return false; 1286 1287 base::FilePath index_name = path_.AppendASCII(kIndexName); 1288 1289 int flags = base::PLATFORM_FILE_READ | 1290 base::PLATFORM_FILE_WRITE | 1291 base::PLATFORM_FILE_OPEN_ALWAYS | 1292 base::PLATFORM_FILE_EXCLUSIVE_WRITE; 1293 scoped_refptr<disk_cache::File> file(new disk_cache::File( 1294 base::CreatePlatformFile(index_name, flags, file_created, NULL))); 1295 1296 if (!file->IsValid()) 1297 return false; 1298 1299 bool ret = true; 1300 if (*file_created) 1301 ret = CreateBackingStore(file.get()); 1302 1303 file = NULL; 1304 if (!ret) 1305 return false; 1306 1307 index_ = new MappedFile(); 1308 data_ = reinterpret_cast<Index*>(index_->Init(index_name, 0)); 1309 if (!data_) { 1310 LOG(ERROR) << "Unable to map Index file"; 1311 return false; 1312 } 1313 1314 if (index_->GetLength() < sizeof(Index)) { 1315 // We verify this again on CheckIndex() but it's easier to make sure now 1316 // that the header is there. 1317 LOG(ERROR) << "Corrupt Index file"; 1318 return false; 1319 } 1320 1321 return true; 1322 } 1323 1324 // The maximum cache size will be either set explicitly by the caller, or 1325 // calculated by this code. 1326 void BackendImpl::AdjustMaxCacheSize(int table_len) { 1327 if (max_size_) 1328 return; 1329 1330 // If table_len is provided, the index file exists. 1331 DCHECK(!table_len || data_->header.magic); 1332 1333 // The user is not setting the size, let's figure it out. 1334 int64 available = base::SysInfo::AmountOfFreeDiskSpace(path_); 1335 if (available < 0) { 1336 max_size_ = kDefaultCacheSize; 1337 return; 1338 } 1339 1340 if (table_len) 1341 available += data_->header.num_bytes; 1342 1343 max_size_ = PreferedCacheSize(available); 1344 1345 // Let's not use more than the default size while we tune-up the performance 1346 // of bigger caches. TODO(rvargas): remove this limit. 1347 if (max_size_ > kDefaultCacheSize * 4) 1348 max_size_ = kDefaultCacheSize * 4; 1349 1350 if (!table_len) 1351 return; 1352 1353 // If we already have a table, adjust the size to it. 1354 int current_max_size = MaxStorageSizeForTable(table_len); 1355 if (max_size_ > current_max_size) 1356 max_size_= current_max_size; 1357 } 1358 1359 bool BackendImpl::InitStats() { 1360 Addr address(data_->header.stats); 1361 int size = stats_.StorageSize(); 1362 1363 if (!address.is_initialized()) { 1364 FileType file_type = Addr::RequiredFileType(size); 1365 DCHECK_NE(file_type, EXTERNAL); 1366 int num_blocks = Addr::RequiredBlocks(size, file_type); 1367 1368 if (!CreateBlock(file_type, num_blocks, &address)) 1369 return false; 1370 1371 data_->header.stats = address.value(); 1372 return stats_.Init(NULL, 0, address); 1373 } 1374 1375 if (!address.is_block_file()) { 1376 NOTREACHED(); 1377 return false; 1378 } 1379 1380 // Load the required data. 1381 size = address.num_blocks() * address.BlockSize(); 1382 MappedFile* file = File(address); 1383 if (!file) 1384 return false; 1385 1386 scoped_ptr<char[]> data(new char[size]); 1387 size_t offset = address.start_block() * address.BlockSize() + 1388 kBlockHeaderSize; 1389 if (!file->Read(data.get(), size, offset)) 1390 return false; 1391 1392 if (!stats_.Init(data.get(), size, address)) 1393 return false; 1394 if (cache_type_ == net::DISK_CACHE && ShouldReportAgain()) 1395 stats_.InitSizeHistogram(); 1396 return true; 1397 } 1398 1399 void BackendImpl::StoreStats() { 1400 int size = stats_.StorageSize(); 1401 scoped_ptr<char[]> data(new char[size]); 1402 Addr address; 1403 size = stats_.SerializeStats(data.get(), size, &address); 1404 DCHECK(size); 1405 if (!address.is_initialized()) 1406 return; 1407 1408 MappedFile* file = File(address); 1409 if (!file) 1410 return; 1411 1412 size_t offset = address.start_block() * address.BlockSize() + 1413 kBlockHeaderSize; 1414 file->Write(data.get(), size, offset); // ignore result. 1415 } 1416 1417 void BackendImpl::RestartCache(bool failure) { 1418 int64 errors = stats_.GetCounter(Stats::FATAL_ERROR); 1419 int64 full_dooms = stats_.GetCounter(Stats::DOOM_CACHE); 1420 int64 partial_dooms = stats_.GetCounter(Stats::DOOM_RECENT); 1421 int64 last_report = stats_.GetCounter(Stats::LAST_REPORT); 1422 1423 PrepareForRestart(); 1424 if (failure) { 1425 DCHECK(!num_refs_); 1426 DCHECK(!open_entries_.size()); 1427 DelayedCacheCleanup(path_); 1428 } else { 1429 DeleteCache(path_, false); 1430 } 1431 1432 // Don't call Init() if directed by the unit test: we are simulating a failure 1433 // trying to re-enable the cache. 1434 if (unit_test_) 1435 init_ = true; // Let the destructor do proper cleanup. 1436 else if (SyncInit() == net::OK) { 1437 stats_.SetCounter(Stats::FATAL_ERROR, errors); 1438 stats_.SetCounter(Stats::DOOM_CACHE, full_dooms); 1439 stats_.SetCounter(Stats::DOOM_RECENT, partial_dooms); 1440 stats_.SetCounter(Stats::LAST_REPORT, last_report); 1441 } 1442 } 1443 1444 void BackendImpl::PrepareForRestart() { 1445 // Reset the mask_ if it was not given by the user. 1446 if (!(user_flags_ & kMask)) 1447 mask_ = 0; 1448 1449 if (!(user_flags_ & kNewEviction)) 1450 new_eviction_ = false; 1451 1452 disabled_ = true; 1453 data_->header.crash = 0; 1454 index_->Flush(); 1455 index_ = NULL; 1456 data_ = NULL; 1457 block_files_.CloseFiles(); 1458 rankings_.Reset(); 1459 init_ = false; 1460 restarted_ = true; 1461 } 1462 1463 int BackendImpl::NewEntry(Addr address, EntryImpl** entry) { 1464 EntriesMap::iterator it = open_entries_.find(address.value()); 1465 if (it != open_entries_.end()) { 1466 // Easy job. This entry is already in memory. 1467 EntryImpl* this_entry = it->second; 1468 this_entry->AddRef(); 1469 *entry = this_entry; 1470 return 0; 1471 } 1472 1473 STRESS_DCHECK(block_files_.IsValid(address)); 1474 1475 if (!address.SanityCheckForEntryV2()) { 1476 LOG(WARNING) << "Wrong entry address."; 1477 STRESS_NOTREACHED(); 1478 return ERR_INVALID_ADDRESS; 1479 } 1480 1481 scoped_refptr<EntryImpl> cache_entry( 1482 new EntryImpl(this, address, read_only_)); 1483 IncreaseNumRefs(); 1484 *entry = NULL; 1485 1486 TimeTicks start = TimeTicks::Now(); 1487 if (!cache_entry->entry()->Load()) 1488 return ERR_READ_FAILURE; 1489 1490 if (IsLoaded()) { 1491 CACHE_UMA(AGE_MS, "LoadTime", 0, start); 1492 } 1493 1494 if (!cache_entry->SanityCheck()) { 1495 LOG(WARNING) << "Messed up entry found."; 1496 STRESS_NOTREACHED(); 1497 return ERR_INVALID_ENTRY; 1498 } 1499 1500 STRESS_DCHECK(block_files_.IsValid( 1501 Addr(cache_entry->entry()->Data()->rankings_node))); 1502 1503 if (!cache_entry->LoadNodeAddress()) 1504 return ERR_READ_FAILURE; 1505 1506 if (!rankings_.SanityCheck(cache_entry->rankings(), false)) { 1507 STRESS_NOTREACHED(); 1508 cache_entry->SetDirtyFlag(0); 1509 // Don't remove this from the list (it is not linked properly). Instead, 1510 // break the link back to the entry because it is going away, and leave the 1511 // rankings node to be deleted if we find it through a list. 1512 rankings_.SetContents(cache_entry->rankings(), 0); 1513 } else if (!rankings_.DataSanityCheck(cache_entry->rankings(), false)) { 1514 STRESS_NOTREACHED(); 1515 cache_entry->SetDirtyFlag(0); 1516 rankings_.SetContents(cache_entry->rankings(), address.value()); 1517 } 1518 1519 if (!cache_entry->DataSanityCheck()) { 1520 LOG(WARNING) << "Messed up entry found."; 1521 cache_entry->SetDirtyFlag(0); 1522 cache_entry->FixForDelete(); 1523 } 1524 1525 // Prevent overwriting the dirty flag on the destructor. 1526 cache_entry->SetDirtyFlag(GetCurrentEntryId()); 1527 1528 if (cache_entry->dirty()) { 1529 Trace("Dirty entry 0x%p 0x%x", reinterpret_cast<void*>(cache_entry.get()), 1530 address.value()); 1531 } 1532 1533 open_entries_[address.value()] = cache_entry.get(); 1534 1535 cache_entry->BeginLogging(net_log_, false); 1536 cache_entry.swap(entry); 1537 return 0; 1538 } 1539 1540 EntryImpl* BackendImpl::MatchEntry(const std::string& key, uint32 hash, 1541 bool find_parent, Addr entry_addr, 1542 bool* match_error) { 1543 Addr address(data_->table[hash & mask_]); 1544 scoped_refptr<EntryImpl> cache_entry, parent_entry; 1545 EntryImpl* tmp = NULL; 1546 bool found = false; 1547 std::set<CacheAddr> visited; 1548 *match_error = false; 1549 1550 for (;;) { 1551 if (disabled_) 1552 break; 1553 1554 if (visited.find(address.value()) != visited.end()) { 1555 // It's possible for a buggy version of the code to write a loop. Just 1556 // break it. 1557 Trace("Hash collision loop 0x%x", address.value()); 1558 address.set_value(0); 1559 parent_entry->SetNextAddress(address); 1560 } 1561 visited.insert(address.value()); 1562 1563 if (!address.is_initialized()) { 1564 if (find_parent) 1565 found = true; 1566 break; 1567 } 1568 1569 int error = NewEntry(address, &tmp); 1570 cache_entry.swap(&tmp); 1571 1572 if (error || cache_entry->dirty()) { 1573 // This entry is dirty on disk (it was not properly closed): we cannot 1574 // trust it. 1575 Addr child(0); 1576 if (!error) 1577 child.set_value(cache_entry->GetNextAddress()); 1578 1579 if (parent_entry.get()) { 1580 parent_entry->SetNextAddress(child); 1581 parent_entry = NULL; 1582 } else { 1583 data_->table[hash & mask_] = child.value(); 1584 } 1585 1586 Trace("MatchEntry dirty %d 0x%x 0x%x", find_parent, entry_addr.value(), 1587 address.value()); 1588 1589 if (!error) { 1590 // It is important to call DestroyInvalidEntry after removing this 1591 // entry from the table. 1592 DestroyInvalidEntry(cache_entry.get()); 1593 cache_entry = NULL; 1594 } else { 1595 Trace("NewEntry failed on MatchEntry 0x%x", address.value()); 1596 } 1597 1598 // Restart the search. 1599 address.set_value(data_->table[hash & mask_]); 1600 visited.clear(); 1601 continue; 1602 } 1603 1604 DCHECK_EQ(hash & mask_, cache_entry->entry()->Data()->hash & mask_); 1605 if (cache_entry->IsSameEntry(key, hash)) { 1606 if (!cache_entry->Update()) 1607 cache_entry = NULL; 1608 found = true; 1609 if (find_parent && entry_addr.value() != address.value()) { 1610 Trace("Entry not on the index 0x%x", address.value()); 1611 *match_error = true; 1612 parent_entry = NULL; 1613 } 1614 break; 1615 } 1616 if (!cache_entry->Update()) 1617 cache_entry = NULL; 1618 parent_entry = cache_entry; 1619 cache_entry = NULL; 1620 if (!parent_entry.get()) 1621 break; 1622 1623 address.set_value(parent_entry->GetNextAddress()); 1624 } 1625 1626 if (parent_entry.get() && (!find_parent || !found)) 1627 parent_entry = NULL; 1628 1629 if (find_parent && entry_addr.is_initialized() && !cache_entry.get()) { 1630 *match_error = true; 1631 parent_entry = NULL; 1632 } 1633 1634 if (cache_entry.get() && (find_parent || !found)) 1635 cache_entry = NULL; 1636 1637 find_parent ? parent_entry.swap(&tmp) : cache_entry.swap(&tmp); 1638 FlushIndex(); 1639 return tmp; 1640 } 1641 1642 // This is the actual implementation for OpenNextEntry and OpenPrevEntry. 1643 EntryImpl* BackendImpl::OpenFollowingEntry(bool forward, void** iter) { 1644 if (disabled_) 1645 return NULL; 1646 1647 DCHECK(iter); 1648 1649 const int kListsToSearch = 3; 1650 scoped_refptr<EntryImpl> entries[kListsToSearch]; 1651 scoped_ptr<Rankings::Iterator> iterator( 1652 reinterpret_cast<Rankings::Iterator*>(*iter)); 1653 *iter = NULL; 1654 1655 if (!iterator.get()) { 1656 iterator.reset(new Rankings::Iterator(&rankings_)); 1657 bool ret = false; 1658 1659 // Get an entry from each list. 1660 for (int i = 0; i < kListsToSearch; i++) { 1661 EntryImpl* temp = NULL; 1662 ret |= OpenFollowingEntryFromList(forward, static_cast<Rankings::List>(i), 1663 &iterator->nodes[i], &temp); 1664 entries[i].swap(&temp); // The entry was already addref'd. 1665 } 1666 if (!ret) 1667 return NULL; 1668 } else { 1669 // Get the next entry from the last list, and the actual entries for the 1670 // elements on the other lists. 1671 for (int i = 0; i < kListsToSearch; i++) { 1672 EntryImpl* temp = NULL; 1673 if (iterator->list == i) { 1674 OpenFollowingEntryFromList(forward, iterator->list, 1675 &iterator->nodes[i], &temp); 1676 } else { 1677 temp = GetEnumeratedEntry(iterator->nodes[i], 1678 static_cast<Rankings::List>(i)); 1679 } 1680 1681 entries[i].swap(&temp); // The entry was already addref'd. 1682 } 1683 } 1684 1685 int newest = -1; 1686 int oldest = -1; 1687 Time access_times[kListsToSearch]; 1688 for (int i = 0; i < kListsToSearch; i++) { 1689 if (entries[i].get()) { 1690 access_times[i] = entries[i]->GetLastUsed(); 1691 if (newest < 0) { 1692 DCHECK_LT(oldest, 0); 1693 newest = oldest = i; 1694 continue; 1695 } 1696 if (access_times[i] > access_times[newest]) 1697 newest = i; 1698 if (access_times[i] < access_times[oldest]) 1699 oldest = i; 1700 } 1701 } 1702 1703 if (newest < 0 || oldest < 0) 1704 return NULL; 1705 1706 EntryImpl* next_entry; 1707 if (forward) { 1708 next_entry = entries[newest].get(); 1709 iterator->list = static_cast<Rankings::List>(newest); 1710 } else { 1711 next_entry = entries[oldest].get(); 1712 iterator->list = static_cast<Rankings::List>(oldest); 1713 } 1714 1715 *iter = iterator.release(); 1716 next_entry->AddRef(); 1717 return next_entry; 1718 } 1719 1720 bool BackendImpl::OpenFollowingEntryFromList(bool forward, Rankings::List list, 1721 CacheRankingsBlock** from_entry, 1722 EntryImpl** next_entry) { 1723 if (disabled_) 1724 return false; 1725 1726 if (!new_eviction_ && Rankings::NO_USE != list) 1727 return false; 1728 1729 Rankings::ScopedRankingsBlock rankings(&rankings_, *from_entry); 1730 CacheRankingsBlock* next_block = forward ? 1731 rankings_.GetNext(rankings.get(), list) : 1732 rankings_.GetPrev(rankings.get(), list); 1733 Rankings::ScopedRankingsBlock next(&rankings_, next_block); 1734 *from_entry = NULL; 1735 1736 *next_entry = GetEnumeratedEntry(next.get(), list); 1737 if (!*next_entry) 1738 return false; 1739 1740 *from_entry = next.release(); 1741 return true; 1742 } 1743 1744 EntryImpl* BackendImpl::GetEnumeratedEntry(CacheRankingsBlock* next, 1745 Rankings::List list) { 1746 if (!next || disabled_) 1747 return NULL; 1748 1749 EntryImpl* entry; 1750 int rv = NewEntry(Addr(next->Data()->contents), &entry); 1751 if (rv) { 1752 STRESS_NOTREACHED(); 1753 rankings_.Remove(next, list, false); 1754 if (rv == ERR_INVALID_ADDRESS) { 1755 // There is nothing linked from the index. Delete the rankings node. 1756 DeleteBlock(next->address(), true); 1757 } 1758 return NULL; 1759 } 1760 1761 if (entry->dirty()) { 1762 // We cannot trust this entry. 1763 InternalDoomEntry(entry); 1764 entry->Release(); 1765 return NULL; 1766 } 1767 1768 if (!entry->Update()) { 1769 STRESS_NOTREACHED(); 1770 entry->Release(); 1771 return NULL; 1772 } 1773 1774 // Note that it is unfortunate (but possible) for this entry to be clean, but 1775 // not actually the real entry. In other words, we could have lost this entry 1776 // from the index, and it could have been replaced with a newer one. It's not 1777 // worth checking that this entry is "the real one", so we just return it and 1778 // let the enumeration continue; this entry will be evicted at some point, and 1779 // the regular path will work with the real entry. With time, this problem 1780 // will disasappear because this scenario is just a bug. 1781 1782 // Make sure that we save the key for later. 1783 entry->GetKey(); 1784 1785 return entry; 1786 } 1787 1788 EntryImpl* BackendImpl::ResurrectEntry(EntryImpl* deleted_entry) { 1789 if (ENTRY_NORMAL == deleted_entry->entry()->Data()->state) { 1790 deleted_entry->Release(); 1791 stats_.OnEvent(Stats::CREATE_MISS); 1792 Trace("create entry miss "); 1793 return NULL; 1794 } 1795 1796 // We are attempting to create an entry and found out that the entry was 1797 // previously deleted. 1798 1799 eviction_.OnCreateEntry(deleted_entry); 1800 entry_count_++; 1801 1802 stats_.OnEvent(Stats::RESURRECT_HIT); 1803 Trace("Resurrect entry hit "); 1804 return deleted_entry; 1805 } 1806 1807 void BackendImpl::DestroyInvalidEntry(EntryImpl* entry) { 1808 LOG(WARNING) << "Destroying invalid entry."; 1809 Trace("Destroying invalid entry 0x%p", entry); 1810 1811 entry->SetPointerForInvalidEntry(GetCurrentEntryId()); 1812 1813 eviction_.OnDoomEntry(entry); 1814 entry->InternalDoom(); 1815 1816 if (!new_eviction_) 1817 DecreaseNumEntries(); 1818 stats_.OnEvent(Stats::INVALID_ENTRY); 1819 } 1820 1821 void BackendImpl::AddStorageSize(int32 bytes) { 1822 data_->header.num_bytes += bytes; 1823 DCHECK_GE(data_->header.num_bytes, 0); 1824 } 1825 1826 void BackendImpl::SubstractStorageSize(int32 bytes) { 1827 data_->header.num_bytes -= bytes; 1828 DCHECK_GE(data_->header.num_bytes, 0); 1829 } 1830 1831 void BackendImpl::IncreaseNumRefs() { 1832 num_refs_++; 1833 if (max_refs_ < num_refs_) 1834 max_refs_ = num_refs_; 1835 } 1836 1837 void BackendImpl::DecreaseNumRefs() { 1838 DCHECK(num_refs_); 1839 num_refs_--; 1840 1841 if (!num_refs_ && disabled_) 1842 base::MessageLoop::current()->PostTask( 1843 FROM_HERE, base::Bind(&BackendImpl::RestartCache, GetWeakPtr(), true)); 1844 } 1845 1846 void BackendImpl::IncreaseNumEntries() { 1847 data_->header.num_entries++; 1848 DCHECK_GT(data_->header.num_entries, 0); 1849 } 1850 1851 void BackendImpl::DecreaseNumEntries() { 1852 data_->header.num_entries--; 1853 if (data_->header.num_entries < 0) { 1854 NOTREACHED(); 1855 data_->header.num_entries = 0; 1856 } 1857 } 1858 1859 void BackendImpl::LogStats() { 1860 StatsItems stats; 1861 GetStats(&stats); 1862 1863 for (size_t index = 0; index < stats.size(); index++) 1864 VLOG(1) << stats[index].first << ": " << stats[index].second; 1865 } 1866 1867 void BackendImpl::ReportStats() { 1868 CACHE_UMA(COUNTS, "Entries", 0, data_->header.num_entries); 1869 1870 int current_size = data_->header.num_bytes / (1024 * 1024); 1871 int max_size = max_size_ / (1024 * 1024); 1872 int hit_ratio_as_percentage = stats_.GetHitRatio(); 1873 1874 CACHE_UMA(COUNTS_10000, "Size2", 0, current_size); 1875 // For any bin in HitRatioBySize2, the hit ratio of caches of that size is the 1876 // ratio of that bin's total count to the count in the same bin in the Size2 1877 // histogram. 1878 if (base::RandInt(0, 99) < hit_ratio_as_percentage) 1879 CACHE_UMA(COUNTS_10000, "HitRatioBySize2", 0, current_size); 1880 CACHE_UMA(COUNTS_10000, "MaxSize2", 0, max_size); 1881 if (!max_size) 1882 max_size++; 1883 CACHE_UMA(PERCENTAGE, "UsedSpace", 0, current_size * 100 / max_size); 1884 1885 CACHE_UMA(COUNTS_10000, "AverageOpenEntries2", 0, 1886 static_cast<int>(stats_.GetCounter(Stats::OPEN_ENTRIES))); 1887 CACHE_UMA(COUNTS_10000, "MaxOpenEntries2", 0, 1888 static_cast<int>(stats_.GetCounter(Stats::MAX_ENTRIES))); 1889 stats_.SetCounter(Stats::MAX_ENTRIES, 0); 1890 1891 CACHE_UMA(COUNTS_10000, "TotalFatalErrors", 0, 1892 static_cast<int>(stats_.GetCounter(Stats::FATAL_ERROR))); 1893 CACHE_UMA(COUNTS_10000, "TotalDoomCache", 0, 1894 static_cast<int>(stats_.GetCounter(Stats::DOOM_CACHE))); 1895 CACHE_UMA(COUNTS_10000, "TotalDoomRecentEntries", 0, 1896 static_cast<int>(stats_.GetCounter(Stats::DOOM_RECENT))); 1897 stats_.SetCounter(Stats::FATAL_ERROR, 0); 1898 stats_.SetCounter(Stats::DOOM_CACHE, 0); 1899 stats_.SetCounter(Stats::DOOM_RECENT, 0); 1900 1901 int64 total_hours = stats_.GetCounter(Stats::TIMER) / 120; 1902 if (!data_->header.create_time || !data_->header.lru.filled) { 1903 int cause = data_->header.create_time ? 0 : 1; 1904 if (!data_->header.lru.filled) 1905 cause |= 2; 1906 CACHE_UMA(CACHE_ERROR, "ShortReport", 0, cause); 1907 CACHE_UMA(HOURS, "TotalTimeNotFull", 0, static_cast<int>(total_hours)); 1908 return; 1909 } 1910 1911 // This is an up to date client that will report FirstEviction() data. After 1912 // that event, start reporting this: 1913 1914 CACHE_UMA(HOURS, "TotalTime", 0, static_cast<int>(total_hours)); 1915 // For any bin in HitRatioByTotalTime, the hit ratio of caches of that total 1916 // time is the ratio of that bin's total count to the count in the same bin in 1917 // the TotalTime histogram. 1918 if (base::RandInt(0, 99) < hit_ratio_as_percentage) 1919 CACHE_UMA(HOURS, "HitRatioByTotalTime", 0, implicit_cast<int>(total_hours)); 1920 1921 int64 use_hours = stats_.GetCounter(Stats::LAST_REPORT_TIMER) / 120; 1922 stats_.SetCounter(Stats::LAST_REPORT_TIMER, stats_.GetCounter(Stats::TIMER)); 1923 1924 // We may see users with no use_hours at this point if this is the first time 1925 // we are running this code. 1926 if (use_hours) 1927 use_hours = total_hours - use_hours; 1928 1929 if (!use_hours || !GetEntryCount() || !data_->header.num_bytes) 1930 return; 1931 1932 CACHE_UMA(HOURS, "UseTime", 0, static_cast<int>(use_hours)); 1933 // For any bin in HitRatioByUseTime, the hit ratio of caches of that use time 1934 // is the ratio of that bin's total count to the count in the same bin in the 1935 // UseTime histogram. 1936 if (base::RandInt(0, 99) < hit_ratio_as_percentage) 1937 CACHE_UMA(HOURS, "HitRatioByUseTime", 0, implicit_cast<int>(use_hours)); 1938 CACHE_UMA(PERCENTAGE, "HitRatio", 0, hit_ratio_as_percentage); 1939 1940 int64 trim_rate = stats_.GetCounter(Stats::TRIM_ENTRY) / use_hours; 1941 CACHE_UMA(COUNTS, "TrimRate", 0, static_cast<int>(trim_rate)); 1942 1943 int avg_size = data_->header.num_bytes / GetEntryCount(); 1944 CACHE_UMA(COUNTS, "EntrySize", 0, avg_size); 1945 CACHE_UMA(COUNTS, "EntriesFull", 0, data_->header.num_entries); 1946 1947 CACHE_UMA(PERCENTAGE, "IndexLoad", 0, 1948 data_->header.num_entries * 100 / (mask_ + 1)); 1949 1950 int large_entries_bytes = stats_.GetLargeEntriesSize(); 1951 int large_ratio = large_entries_bytes * 100 / data_->header.num_bytes; 1952 CACHE_UMA(PERCENTAGE, "LargeEntriesRatio", 0, large_ratio); 1953 1954 if (new_eviction_) { 1955 CACHE_UMA(PERCENTAGE, "ResurrectRatio", 0, stats_.GetResurrectRatio()); 1956 CACHE_UMA(PERCENTAGE, "NoUseRatio", 0, 1957 data_->header.lru.sizes[0] * 100 / data_->header.num_entries); 1958 CACHE_UMA(PERCENTAGE, "LowUseRatio", 0, 1959 data_->header.lru.sizes[1] * 100 / data_->header.num_entries); 1960 CACHE_UMA(PERCENTAGE, "HighUseRatio", 0, 1961 data_->header.lru.sizes[2] * 100 / data_->header.num_entries); 1962 CACHE_UMA(PERCENTAGE, "DeletedRatio", 0, 1963 data_->header.lru.sizes[4] * 100 / data_->header.num_entries); 1964 } 1965 1966 stats_.ResetRatios(); 1967 stats_.SetCounter(Stats::TRIM_ENTRY, 0); 1968 1969 if (cache_type_ == net::DISK_CACHE) 1970 block_files_.ReportStats(); 1971 } 1972 1973 void BackendImpl::UpgradeTo2_1() { 1974 // 2.1 is basically the same as 2.0, except that new fields are actually 1975 // updated by the new eviction algorithm. 1976 DCHECK(0x20000 == data_->header.version); 1977 data_->header.version = 0x20001; 1978 data_->header.lru.sizes[Rankings::NO_USE] = data_->header.num_entries; 1979 } 1980 1981 bool BackendImpl::CheckIndex() { 1982 DCHECK(data_); 1983 1984 size_t current_size = index_->GetLength(); 1985 if (current_size < sizeof(Index)) { 1986 LOG(ERROR) << "Corrupt Index file"; 1987 return false; 1988 } 1989 1990 if (new_eviction_) { 1991 // We support versions 2.0 and 2.1, upgrading 2.0 to 2.1. 1992 if (kIndexMagic != data_->header.magic || 1993 kCurrentVersion >> 16 != data_->header.version >> 16) { 1994 LOG(ERROR) << "Invalid file version or magic"; 1995 return false; 1996 } 1997 if (kCurrentVersion == data_->header.version) { 1998 // We need file version 2.1 for the new eviction algorithm. 1999 UpgradeTo2_1(); 2000 } 2001 } else { 2002 if (kIndexMagic != data_->header.magic || 2003 kCurrentVersion != data_->header.version) { 2004 LOG(ERROR) << "Invalid file version or magic"; 2005 return false; 2006 } 2007 } 2008 2009 if (!data_->header.table_len) { 2010 LOG(ERROR) << "Invalid table size"; 2011 return false; 2012 } 2013 2014 if (current_size < GetIndexSize(data_->header.table_len) || 2015 data_->header.table_len & (kBaseTableLen - 1)) { 2016 LOG(ERROR) << "Corrupt Index file"; 2017 return false; 2018 } 2019 2020 AdjustMaxCacheSize(data_->header.table_len); 2021 2022 #if !defined(NET_BUILD_STRESS_CACHE) 2023 if (data_->header.num_bytes < 0 || 2024 (max_size_ < kint32max - kDefaultCacheSize && 2025 data_->header.num_bytes > max_size_ + kDefaultCacheSize)) { 2026 LOG(ERROR) << "Invalid cache (current) size"; 2027 return false; 2028 } 2029 #endif 2030 2031 if (data_->header.num_entries < 0) { 2032 LOG(ERROR) << "Invalid number of entries"; 2033 return false; 2034 } 2035 2036 if (!mask_) 2037 mask_ = data_->header.table_len - 1; 2038 2039 // Load the table into memory with a single read. 2040 scoped_ptr<char[]> buf(new char[current_size]); 2041 return index_->Read(buf.get(), current_size, 0); 2042 } 2043 2044 int BackendImpl::CheckAllEntries() { 2045 int num_dirty = 0; 2046 int num_entries = 0; 2047 DCHECK(mask_ < kuint32max); 2048 for (unsigned int i = 0; i <= mask_; i++) { 2049 Addr address(data_->table[i]); 2050 if (!address.is_initialized()) 2051 continue; 2052 for (;;) { 2053 EntryImpl* tmp; 2054 int ret = NewEntry(address, &tmp); 2055 if (ret) { 2056 STRESS_NOTREACHED(); 2057 return ret; 2058 } 2059 scoped_refptr<EntryImpl> cache_entry; 2060 cache_entry.swap(&tmp); 2061 2062 if (cache_entry->dirty()) 2063 num_dirty++; 2064 else if (CheckEntry(cache_entry.get())) 2065 num_entries++; 2066 else 2067 return ERR_INVALID_ENTRY; 2068 2069 DCHECK_EQ(i, cache_entry->entry()->Data()->hash & mask_); 2070 address.set_value(cache_entry->GetNextAddress()); 2071 if (!address.is_initialized()) 2072 break; 2073 } 2074 } 2075 2076 Trace("CheckAllEntries End"); 2077 if (num_entries + num_dirty != data_->header.num_entries) { 2078 LOG(ERROR) << "Number of entries " << num_entries << " " << num_dirty << 2079 " " << data_->header.num_entries; 2080 DCHECK_LT(num_entries, data_->header.num_entries); 2081 return ERR_NUM_ENTRIES_MISMATCH; 2082 } 2083 2084 return num_dirty; 2085 } 2086 2087 bool BackendImpl::CheckEntry(EntryImpl* cache_entry) { 2088 bool ok = block_files_.IsValid(cache_entry->entry()->address()); 2089 ok = ok && block_files_.IsValid(cache_entry->rankings()->address()); 2090 EntryStore* data = cache_entry->entry()->Data(); 2091 for (size_t i = 0; i < arraysize(data->data_addr); i++) { 2092 if (data->data_addr[i]) { 2093 Addr address(data->data_addr[i]); 2094 if (address.is_block_file()) 2095 ok = ok && block_files_.IsValid(address); 2096 } 2097 } 2098 2099 return ok && cache_entry->rankings()->VerifyHash(); 2100 } 2101 2102 int BackendImpl::MaxBuffersSize() { 2103 static int64 total_memory = base::SysInfo::AmountOfPhysicalMemory(); 2104 static bool done = false; 2105 2106 if (!done) { 2107 const int kMaxBuffersSize = 30 * 1024 * 1024; 2108 2109 // We want to use up to 2% of the computer's memory. 2110 total_memory = total_memory * 2 / 100; 2111 if (total_memory > kMaxBuffersSize || total_memory <= 0) 2112 total_memory = kMaxBuffersSize; 2113 2114 done = true; 2115 } 2116 2117 return static_cast<int>(total_memory); 2118 } 2119 2120 } // namespace disk_cache 2121