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| 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/entry_impl.h" | |
| 26 #include "net/disk_cache/errors.h" | |
| 27 #include "net/disk_cache/experiments.h" | |
| 28 #include "net/disk_cache/file.h" | |
| 29 #include "net/disk_cache/histogram_macros.h" | |
| 30 | |
| 31 // Provide a BackendImpl object to macros from histogram_macros.h. | |
| 32 #define CACHE_UMA_BACKEND_IMPL_OBJ this | |
| 33 | |
| 34 using base::Time; | |
| 35 using base::TimeDelta; | |
| 36 using base::TimeTicks; | |
| 37 | |
| 38 namespace { | |
| 39 | |
| 40 const char* kIndexName = "index"; | |
| 41 | |
| 42 // Seems like ~240 MB correspond to less than 50k entries for 99% of the people. | |
| 43 // Note that the actual target is to keep the index table load factor under 55% | |
| 44 // for most users. | |
| 45 const int k64kEntriesStore = 240 * 1000 * 1000; | |
| 46 const int kBaseTableLen = 64 * 1024; | |
| 47 const int kDefaultCacheSize = 80 * 1024 * 1024; | |
| 48 | |
| 49 // Avoid trimming the cache for the first 5 minutes (10 timer ticks). | |
| 50 const int kTrimDelay = 10; | |
| 51 | |
| 52 int DesiredIndexTableLen(int32 storage_size) { | |
| 53 if (storage_size <= k64kEntriesStore) | |
| 54 return kBaseTableLen; | |
| 55 if (storage_size <= k64kEntriesStore * 2) | |
| 56 return kBaseTableLen * 2; | |
| 57 if (storage_size <= k64kEntriesStore * 4) | |
| 58 return kBaseTableLen * 4; | |
| 59 if (storage_size <= k64kEntriesStore * 8) | |
| 60 return kBaseTableLen * 8; | |
| 61 | |
| 62 // The biggest storage_size for int32 requires a 4 MB table. | |
| 63 return kBaseTableLen * 16; | |
| 64 } | |
| 65 | |
| 66 int MaxStorageSizeForTable(int table_len) { | |
| 67 return table_len * (k64kEntriesStore / kBaseTableLen); | |
| 68 } | |
| 69 | |
| 70 size_t GetIndexSize(int table_len) { | |
| 71 size_t table_size = sizeof(disk_cache::CacheAddr) * table_len; | |
| 72 return sizeof(disk_cache::IndexHeader) + table_size; | |
| 73 } | |
| 74 | |
| 75 // ------------------------------------------------------------------------ | |
| 76 | |
| 77 // Sets group for the current experiment. Returns false if the files should be | |
| 78 // discarded. | |
| 79 bool InitExperiment(disk_cache::IndexHeader* header, bool cache_created) { | |
| 80 if (header->experiment == disk_cache::EXPERIMENT_OLD_FILE1 || | |
| 81 header->experiment == disk_cache::EXPERIMENT_OLD_FILE2) { | |
| 82 // Discard current cache. | |
| 83 return false; | |
| 84 } | |
| 85 | |
| 86 if (base::FieldTrialList::FindFullName("SimpleCacheTrial") == | |
| 87 "ExperimentControl") { | |
| 88 if (cache_created) { | |
| 89 header->experiment = disk_cache::EXPERIMENT_SIMPLE_CONTROL; | |
| 90 return true; | |
| 91 } else if (header->experiment != disk_cache::EXPERIMENT_SIMPLE_CONTROL) { | |
| 92 return false; | |
| 93 } | |
| 94 } | |
| 95 | |
| 96 header->experiment = disk_cache::NO_EXPERIMENT; | |
| 97 return true; | |
| 98 } | |
| 99 | |
| 100 } // namespace | |
| 101 | |
| 102 // ------------------------------------------------------------------------ | |
| 103 | |
| 104 namespace disk_cache { | |
| 105 | |
| 106 BackendImpl::BackendImpl(const base::FilePath& path, | |
| 107 base::MessageLoopProxy* cache_thread, | |
| 108 net::NetLog* net_log) | |
| 109 : background_queue_(this, cache_thread), | |
| 110 path_(path), | |
| 111 block_files_(path), | |
| 112 mask_(0), | |
| 113 max_size_(0), | |
| 114 up_ticks_(0), | |
| 115 cache_type_(net::DISK_CACHE), | |
| 116 uma_report_(0), | |
| 117 user_flags_(0), | |
| 118 init_(false), | |
| 119 restarted_(false), | |
| 120 unit_test_(false), | |
| 121 read_only_(false), | |
| 122 disabled_(false), | |
| 123 new_eviction_(false), | |
| 124 first_timer_(true), | |
| 125 user_load_(false), | |
| 126 net_log_(net_log), | |
| 127 done_(true, false), | |
| 128 ptr_factory_(this) { | |
| 129 } | |
| 130 | |
| 131 int BackendImpl::SyncInit() { | |
| 132 #if defined(NET_BUILD_STRESS_CACHE) | |
| 133 // Start evictions right away. | |
| 134 up_ticks_ = kTrimDelay * 2; | |
| 135 #endif | |
| 136 DCHECK(!init_); | |
| 137 if (init_) | |
| 138 return net::ERR_FAILED; | |
| 139 | |
| 140 bool create_files = false; | |
| 141 if (!InitBackingStore(&create_files)) { | |
| 142 ReportError(ERR_STORAGE_ERROR); | |
| 143 return net::ERR_FAILED; | |
| 144 } | |
| 145 | |
| 146 num_refs_ = num_pending_io_ = max_refs_ = 0; | |
| 147 entry_count_ = byte_count_ = 0; | |
| 148 | |
| 149 if (!restarted_) { | |
| 150 buffer_bytes_ = 0; | |
| 151 trace_object_ = TraceObject::GetTraceObject(); | |
| 152 // Create a recurrent timer of 30 secs. | |
| 153 int timer_delay = unit_test_ ? 1000 : 30000; | |
| 154 timer_.reset(new base::RepeatingTimer<BackendImpl>()); | |
| 155 timer_->Start(FROM_HERE, TimeDelta::FromMilliseconds(timer_delay), this, | |
| 156 &BackendImpl::OnStatsTimer); | |
| 157 } | |
| 158 | |
| 159 init_ = true; | |
| 160 Trace("Init"); | |
| 161 | |
| 162 if (data_->header.experiment != NO_EXPERIMENT && | |
| 163 cache_type_ != net::DISK_CACHE) { | |
| 164 // No experiment for other caches. | |
| 165 return net::ERR_FAILED; | |
| 166 } | |
| 167 | |
| 168 if (!(user_flags_ & kNoRandom)) { | |
| 169 // The unit test controls directly what to test. | |
| 170 new_eviction_ = (cache_type_ == net::DISK_CACHE); | |
| 171 } | |
| 172 | |
| 173 if (!CheckIndex()) { | |
| 174 ReportError(ERR_INIT_FAILED); | |
| 175 return net::ERR_FAILED; | |
| 176 } | |
| 177 | |
| 178 if (!restarted_ && (create_files || !data_->header.num_entries)) | |
| 179 ReportError(ERR_CACHE_CREATED); | |
| 180 | |
| 181 if (!(user_flags_ & kNoRandom) && cache_type_ == net::DISK_CACHE && | |
| 182 !InitExperiment(&data_->header, create_files)) { | |
| 183 return net::ERR_FAILED; | |
| 184 } | |
| 185 | |
| 186 // We don't care if the value overflows. The only thing we care about is that | |
| 187 // the id cannot be zero, because that value is used as "not dirty". | |
| 188 // Increasing the value once per second gives us many years before we start | |
| 189 // having collisions. | |
| 190 data_->header.this_id++; | |
| 191 if (!data_->header.this_id) | |
| 192 data_->header.this_id++; | |
| 193 | |
| 194 bool previous_crash = (data_->header.crash != 0); | |
| 195 data_->header.crash = 1; | |
| 196 | |
| 197 if (!block_files_.Init(create_files)) | |
| 198 return net::ERR_FAILED; | |
| 199 | |
| 200 // We want to minimize the changes to cache for an AppCache. | |
| 201 if (cache_type() == net::APP_CACHE) { | |
| 202 DCHECK(!new_eviction_); | |
| 203 read_only_ = true; | |
| 204 } else if (cache_type() == net::SHADER_CACHE) { | |
| 205 DCHECK(!new_eviction_); | |
| 206 } | |
| 207 | |
| 208 eviction_.Init(this); | |
| 209 | |
| 210 // stats_ and rankings_ may end up calling back to us so we better be enabled. | |
| 211 disabled_ = false; | |
| 212 if (!InitStats()) | |
| 213 return net::ERR_FAILED; | |
| 214 | |
| 215 disabled_ = !rankings_.Init(this, new_eviction_); | |
| 216 | |
| 217 #if defined(STRESS_CACHE_EXTENDED_VALIDATION) | |
| 218 trace_object_->EnableTracing(false); | |
| 219 int sc = SelfCheck(); | |
| 220 if (sc < 0 && sc != ERR_NUM_ENTRIES_MISMATCH) | |
| 221 NOTREACHED(); | |
| 222 trace_object_->EnableTracing(true); | |
| 223 #endif | |
| 224 | |
| 225 if (previous_crash) { | |
| 226 ReportError(ERR_PREVIOUS_CRASH); | |
| 227 } else if (!restarted_) { | |
| 228 ReportError(ERR_NO_ERROR); | |
| 229 } | |
| 230 | |
| 231 FlushIndex(); | |
| 232 | |
| 233 return disabled_ ? net::ERR_FAILED : net::OK; | |
| 234 } | |
| 235 | |
| 236 void BackendImpl::PrepareForRestart() { | |
| 237 // Reset the mask_ if it was not given by the user. | |
| 238 if (!(user_flags_ & kMask)) | |
| 239 mask_ = 0; | |
| 240 | |
| 241 if (!(user_flags_ & kNewEviction)) | |
| 242 new_eviction_ = false; | |
| 243 | |
| 244 disabled_ = true; | |
| 245 data_->header.crash = 0; | |
| 246 index_->Flush(); | |
| 247 index_ = NULL; | |
| 248 data_ = NULL; | |
| 249 block_files_.CloseFiles(); | |
| 250 rankings_.Reset(); | |
| 251 init_ = false; | |
| 252 restarted_ = true; | |
| 253 } | |
| 254 | |
| 255 BackendImpl::~BackendImpl() { | |
| 256 if (user_flags_ & kNoRandom) { | |
| 257 // This is a unit test, so we want to be strict about not leaking entries | |
| 258 // and completing all the work. | |
| 259 background_queue_.WaitForPendingIO(); | |
| 260 } else { | |
| 261 // This is most likely not a test, so we want to do as little work as | |
| 262 // possible at this time, at the price of leaving dirty entries behind. | |
| 263 background_queue_.DropPendingIO(); | |
| 264 } | |
| 265 | |
| 266 if (background_queue_.BackgroundIsCurrentThread()) { | |
| 267 // Unit tests may use the same thread for everything. | |
| 268 CleanupCache(); | |
| 269 } else { | |
| 270 background_queue_.background_thread()->PostTask( | |
| 271 FROM_HERE, base::Bind(&FinalCleanupCallback, base::Unretained(this))); | |
| 272 // http://crbug.com/74623 | |
| 273 base::ThreadRestrictions::ScopedAllowWait allow_wait; | |
| 274 done_.Wait(); | |
| 275 } | |
| 276 } | |
| 277 | |
| 278 void BackendImpl::CleanupCache() { | |
| 279 Trace("Backend Cleanup"); | |
| 280 eviction_.Stop(); | |
| 281 timer_.reset(); | |
| 282 | |
| 283 if (init_) { | |
| 284 StoreStats(); | |
| 285 if (data_) | |
| 286 data_->header.crash = 0; | |
| 287 | |
| 288 if (user_flags_ & kNoRandom) { | |
| 289 // This is a net_unittest, verify that we are not 'leaking' entries. | |
| 290 File::WaitForPendingIO(&num_pending_io_); | |
| 291 DCHECK(!num_refs_); | |
| 292 } else { | |
| 293 File::DropPendingIO(); | |
| 294 } | |
| 295 } | |
| 296 block_files_.CloseFiles(); | |
| 297 FlushIndex(); | |
| 298 index_ = NULL; | |
| 299 ptr_factory_.InvalidateWeakPtrs(); | |
| 300 done_.Signal(); | |
| 301 } | |
| 302 | |
| 303 base::FilePath BackendImpl::GetFileName(Addr address) const { | |
| 304 if (!address.is_separate_file() || !address.is_initialized()) { | |
| 305 NOTREACHED(); | |
| 306 return base::FilePath(); | |
| 307 } | |
| 308 | |
| 309 std::string tmp = base::StringPrintf("f_%06x", address.FileNumber()); | |
| 310 return path_.AppendASCII(tmp); | |
| 311 } | |
| 312 | |
| 313 // We just created a new file so we're going to write the header and set the | |
| 314 // file length to include the hash table (zero filled). | |
| 315 bool BackendImpl::CreateBackingStore(disk_cache::File* file) { | |
| 316 AdjustMaxCacheSize(0); | |
| 317 | |
| 318 IndexHeader header; | |
| 319 header.table_len = DesiredIndexTableLen(max_size_); | |
| 320 | |
| 321 // We need file version 2.1 for the new eviction algorithm. | |
| 322 if (new_eviction_) | |
| 323 header.version = 0x20001; | |
| 324 | |
| 325 header.create_time = Time::Now().ToInternalValue(); | |
| 326 | |
| 327 if (!file->Write(&header, sizeof(header), 0)) | |
| 328 return false; | |
| 329 | |
| 330 return file->SetLength(GetIndexSize(header.table_len)); | |
| 331 } | |
| 332 | |
| 333 bool BackendImpl::InitBackingStore(bool* file_created) { | |
| 334 if (!base::CreateDirectory(path_)) | |
| 335 return false; | |
| 336 | |
| 337 base::FilePath index_name = path_.AppendASCII(kIndexName); | |
| 338 | |
| 339 int flags = base::PLATFORM_FILE_READ | | |
| 340 base::PLATFORM_FILE_WRITE | | |
| 341 base::PLATFORM_FILE_OPEN_ALWAYS | | |
| 342 base::PLATFORM_FILE_EXCLUSIVE_WRITE; | |
| 343 scoped_refptr<disk_cache::File> file(new disk_cache::File( | |
| 344 base::CreatePlatformFile(index_name, flags, file_created, NULL))); | |
| 345 | |
| 346 if (!file->IsValid()) | |
| 347 return false; | |
| 348 | |
| 349 bool ret = true; | |
| 350 if (*file_created) | |
| 351 ret = CreateBackingStore(file.get()); | |
| 352 | |
| 353 file = NULL; | |
| 354 if (!ret) | |
| 355 return false; | |
| 356 | |
| 357 index_ = new MappedFile(); | |
| 358 data_ = reinterpret_cast<Index*>(index_->Init(index_name, 0)); | |
| 359 if (!data_) { | |
| 360 LOG(ERROR) << "Unable to map Index file"; | |
| 361 return false; | |
| 362 } | |
| 363 | |
| 364 if (index_->GetLength() < sizeof(Index)) { | |
| 365 // We verify this again on CheckIndex() but it's easier to make sure now | |
| 366 // that the header is there. | |
| 367 LOG(ERROR) << "Corrupt Index file"; | |
| 368 return false; | |
| 369 } | |
| 370 | |
| 371 return true; | |
| 372 } | |
| 373 | |
| 374 void BackendImpl::ReportError(int error) { | |
| 375 STRESS_DCHECK(!error || error == ERR_PREVIOUS_CRASH || | |
| 376 error == ERR_CACHE_CREATED); | |
| 377 | |
| 378 // We transmit positive numbers, instead of direct error codes. | |
| 379 DCHECK_LE(error, 0); | |
| 380 CACHE_UMA(CACHE_ERROR, "Error", 0, error * -1); | |
| 381 } | |
| 382 | |
| 383 | |
| 384 bool BackendImpl::CheckIndex() { | |
| 385 DCHECK(data_); | |
| 386 | |
| 387 size_t current_size = index_->GetLength(); | |
| 388 if (current_size < sizeof(Index)) { | |
| 389 LOG(ERROR) << "Corrupt Index file"; | |
| 390 return false; | |
| 391 } | |
| 392 | |
| 393 if (new_eviction_) { | |
| 394 // We support versions 2.0 and 2.1, upgrading 2.0 to 2.1. | |
| 395 if (kIndexMagic != data_->header.magic || | |
| 396 kCurrentVersion >> 16 != data_->header.version >> 16) { | |
| 397 LOG(ERROR) << "Invalid file version or magic"; | |
| 398 return false; | |
| 399 } | |
| 400 if (kCurrentVersion == data_->header.version) { | |
| 401 // We need file version 2.1 for the new eviction algorithm. | |
| 402 UpgradeTo2_1(); | |
| 403 } | |
| 404 } else { | |
| 405 if (kIndexMagic != data_->header.magic || | |
| 406 kCurrentVersion != data_->header.version) { | |
| 407 LOG(ERROR) << "Invalid file version or magic"; | |
| 408 return false; | |
| 409 } | |
| 410 } | |
| 411 | |
| 412 if (!data_->header.table_len) { | |
| 413 LOG(ERROR) << "Invalid table size"; | |
| 414 return false; | |
| 415 } | |
| 416 | |
| 417 if (current_size < GetIndexSize(data_->header.table_len) || | |
| 418 data_->header.table_len & (kBaseTableLen - 1)) { | |
| 419 LOG(ERROR) << "Corrupt Index file"; | |
| 420 return false; | |
| 421 } | |
| 422 | |
| 423 AdjustMaxCacheSize(data_->header.table_len); | |
| 424 | |
| 425 #if !defined(NET_BUILD_STRESS_CACHE) | |
| 426 if (data_->header.num_bytes < 0 || | |
| 427 (max_size_ < kint32max - kDefaultCacheSize && | |
| 428 data_->header.num_bytes > max_size_ + kDefaultCacheSize)) { | |
| 429 LOG(ERROR) << "Invalid cache (current) size"; | |
| 430 return false; | |
| 431 } | |
| 432 #endif | |
| 433 | |
| 434 if (data_->header.num_entries < 0) { | |
| 435 LOG(ERROR) << "Invalid number of entries"; | |
| 436 return false; | |
| 437 } | |
| 438 | |
| 439 if (!mask_) | |
| 440 mask_ = data_->header.table_len - 1; | |
| 441 | |
| 442 // Load the table into memory with a single read. | |
| 443 scoped_ptr<char[]> buf(new char[current_size]); | |
| 444 return index_->Read(buf.get(), current_size, 0); | |
| 445 } | |
| 446 | |
| 447 bool BackendImpl::InitStats() { | |
| 448 Addr address(data_->header.stats); | |
| 449 int size = stats_.StorageSize(); | |
| 450 | |
| 451 if (!address.is_initialized()) { | |
| 452 FileType file_type = Addr::RequiredFileType(size); | |
| 453 DCHECK_NE(file_type, EXTERNAL); | |
| 454 int num_blocks = Addr::RequiredBlocks(size, file_type); | |
| 455 | |
| 456 if (!CreateBlock(file_type, num_blocks, &address)) | |
| 457 return false; | |
| 458 return stats_.Init(NULL, 0, address); | |
| 459 } | |
| 460 | |
| 461 if (!address.is_block_file()) { | |
| 462 NOTREACHED(); | |
| 463 return false; | |
| 464 } | |
| 465 | |
| 466 // Load the required data. | |
| 467 size = address.num_blocks() * address.BlockSize(); | |
| 468 MappedFile* file = File(address); | |
| 469 if (!file) | |
| 470 return false; | |
| 471 | |
| 472 scoped_ptr<char[]> data(new char[size]); | |
| 473 size_t offset = address.start_block() * address.BlockSize() + | |
| 474 kBlockHeaderSize; | |
| 475 if (!file->Read(data.get(), size, offset)) | |
| 476 return false; | |
| 477 | |
| 478 if (!stats_.Init(data.get(), size, address)) | |
| 479 return false; | |
| 480 if (cache_type_ == net::DISK_CACHE && ShouldReportAgain()) | |
| 481 stats_.InitSizeHistogram(); | |
| 482 return true; | |
| 483 } | |
| 484 | |
| 485 } // namespace disk_cache | |
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Chromium Code Reviews
Issue 121643003:
Reorganize net/disk_cache into backend specific directories. (Closed)
Base URL: svn://svn.chromium.org/chrome/trunk/src