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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 | |
| 30 // Define BLOCKFILE_BACKEND_IMPL_OBJ to be a disk_cache::BackendImpl* in order | |
| 31 // to use the CACHE_UMA histogram macro. | |
| 32 #define BLOCKFILE_BACKEND_IMPL_OBJ this | |
| 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 } else if (header->experiment != disk_cache::EXPERIMENT_SIMPLE_CONTROL) { | |
| 93 return false; | |
| 94 } | |
| 95 } | |
| 96 | |
| 97 header->experiment = disk_cache::NO_EXPERIMENT; | |
| 98 return true; | |
| 99 } | |
| 100 | |
| 101 } // namespace | |
| 102 | |
| 103 // ------------------------------------------------------------------------ | |
| 104 | |
| 105 namespace disk_cache { | |
| 106 | |
| 107 BackendImpl::BackendImpl(const base::FilePath& path, | |
| 108 base::MessageLoopProxy* cache_thread, | |
| 109 net::NetLog* net_log) | |
| 110 : background_queue_(this, cache_thread), | |
| 111 path_(path), | |
| 112 block_files_(path), | |
| 113 mask_(0), | |
| 114 max_size_(0), | |
| 115 up_ticks_(0), | |
| 116 cache_type_(net::DISK_CACHE), | |
| 117 uma_report_(0), | |
| 118 user_flags_(0), | |
| 119 init_(false), | |
| 120 restarted_(false), | |
| 121 unit_test_(false), | |
| 122 read_only_(false), | |
| 123 disabled_(false), | |
| 124 new_eviction_(false), | |
| 125 first_timer_(true), | |
| 126 user_load_(false), | |
| 127 net_log_(net_log), | |
| 128 done_(true, false), | |
| 129 ptr_factory_(this) { | |
| 130 } | |
| 131 | |
| 132 int BackendImpl::SyncInit() { | |
| 133 #if defined(NET_BUILD_STRESS_CACHE) | |
| 134 // Start evictions right away. | |
| 135 up_ticks_ = kTrimDelay * 2; | |
| 136 #endif | |
| 137 DCHECK(!init_); | |
| 138 if (init_) | |
| 139 return net::ERR_FAILED; | |
| 140 | |
| 141 bool create_files = false; | |
| 142 if (!InitBackingStore(&create_files)) { | |
| 143 ReportError(ERR_STORAGE_ERROR); | |
| 144 return net::ERR_FAILED; | |
| 145 } | |
| 146 | |
| 147 num_refs_ = num_pending_io_ = max_refs_ = 0; | |
| 148 entry_count_ = byte_count_ = 0; | |
| 149 | |
| 150 if (!restarted_) { | |
| 151 buffer_bytes_ = 0; | |
| 152 trace_object_ = TraceObject::GetTraceObject(); | |
| 153 // Create a recurrent timer of 30 secs. | |
| 154 int timer_delay = unit_test_ ? 1000 : 30000; | |
| 155 timer_.reset(new base::RepeatingTimer<BackendImpl>()); | |
| 156 timer_->Start(FROM_HERE, TimeDelta::FromMilliseconds(timer_delay), this, | |
| 157 &BackendImpl::OnStatsTimer); | |
| 158 } | |
| 159 | |
| 160 init_ = true; | |
| 161 Trace("Init"); | |
| 162 | |
| 163 if (data_->header.experiment != NO_EXPERIMENT && | |
| 164 cache_type_ != net::DISK_CACHE) { | |
| 165 // No experiment for other caches. | |
| 166 return net::ERR_FAILED; | |
| 167 } | |
| 168 | |
| 169 if (!(user_flags_ & kNoRandom)) { | |
| 170 // The unit test controls directly what to test. | |
| 171 new_eviction_ = (cache_type_ == net::DISK_CACHE); | |
| 172 } | |
| 173 | |
| 174 if (!CheckIndex()) { | |
| 175 ReportError(ERR_INIT_FAILED); | |
| 176 return net::ERR_FAILED; | |
| 177 } | |
| 178 | |
| 179 if (!restarted_ && (create_files || !data_->header.num_entries)) | |
| 180 ReportError(ERR_CACHE_CREATED); | |
| 181 | |
| 182 if (!(user_flags_ & kNoRandom) && cache_type_ == net::DISK_CACHE && | |
| 183 !InitExperiment(&data_->header, create_files)) { | |
| 184 return net::ERR_FAILED; | |
| 185 } | |
| 186 | |
| 187 // We don't care if the value overflows. The only thing we care about is that | |
| 188 // the id cannot be zero, because that value is used as "not dirty". | |
| 189 // Increasing the value once per second gives us many years before we start | |
| 190 // having collisions. | |
| 191 data_->header.this_id++; | |
| 192 if (!data_->header.this_id) | |
| 193 data_->header.this_id++; | |
| 194 | |
| 195 bool previous_crash = (data_->header.crash != 0); | |
| 196 data_->header.crash = 1; | |
| 197 | |
| 198 if (!block_files_.Init(create_files)) | |
| 199 return net::ERR_FAILED; | |
| 200 | |
| 201 // We want to minimize the changes to cache for an AppCache. | |
| 202 if (cache_type() == net::APP_CACHE) { | |
| 203 DCHECK(!new_eviction_); | |
| 204 read_only_ = true; | |
| 205 } else if (cache_type() == net::SHADER_CACHE) { | |
| 206 DCHECK(!new_eviction_); | |
| 207 } | |
| 208 | |
| 209 eviction_.Init(this); | |
| 210 | |
| 211 // stats_ and rankings_ may end up calling back to us so we better be enabled. | |
| 212 disabled_ = false; | |
| 213 if (!InitStats()) | |
| 214 return net::ERR_FAILED; | |
| 215 | |
| 216 disabled_ = !rankings_.Init(this, new_eviction_); | |
| 217 | |
| 218 #if defined(STRESS_CACHE_EXTENDED_VALIDATION) | |
| 219 trace_object_->EnableTracing(false); | |
| 220 int sc = SelfCheck(); | |
| 221 if (sc < 0 && sc != ERR_NUM_ENTRIES_MISMATCH) | |
| 222 NOTREACHED(); | |
| 223 trace_object_->EnableTracing(true); | |
| 224 #endif | |
| 225 | |
| 226 if (previous_crash) { | |
| 227 ReportError(ERR_PREVIOUS_CRASH); | |
| 228 } else if (!restarted_) { | |
| 229 ReportError(ERR_NO_ERROR); | |
| 230 } | |
| 231 | |
| 232 FlushIndex(); | |
| 233 | |
| 234 return disabled_ ? net::ERR_FAILED : net::OK; | |
| 235 } | |
| 236 | |
| 237 void BackendImpl::PrepareForRestart() { | |
| 238 // Reset the mask_ if it was not given by the user. | |
| 239 if (!(user_flags_ & kMask)) | |
| 240 mask_ = 0; | |
| 241 | |
| 242 if (!(user_flags_ & kNewEviction)) | |
| 243 new_eviction_ = false; | |
| 244 | |
| 245 disabled_ = true; | |
| 246 data_->header.crash = 0; | |
| 247 index_->Flush(); | |
| 248 index_ = NULL; | |
| 249 data_ = NULL; | |
| 250 block_files_.CloseFiles(); | |
| 251 rankings_.Reset(); | |
| 252 init_ = false; | |
| 253 restarted_ = true; | |
| 254 } | |
| 255 | |
| 256 BackendImpl::~BackendImpl() { | |
| 257 if (user_flags_ & kNoRandom) { | |
| 258 // This is a unit test, so we want to be strict about not leaking entries | |
| 259 // and completing all the work. | |
| 260 background_queue_.WaitForPendingIO(); | |
| 261 } else { | |
| 262 // This is most likely not a test, so we want to do as little work as | |
| 263 // possible at this time, at the price of leaving dirty entries behind. | |
| 264 background_queue_.DropPendingIO(); | |
| 265 } | |
| 266 | |
| 267 if (background_queue_.BackgroundIsCurrentThread()) { | |
| 268 // Unit tests may use the same thread for everything. | |
| 269 CleanupCache(); | |
| 270 } else { | |
| 271 background_queue_.background_thread()->PostTask( | |
| 272 FROM_HERE, base::Bind(&FinalCleanupCallback, base::Unretained(this))); | |
| 273 // http://crbug.com/74623 | |
| 274 base::ThreadRestrictions::ScopedAllowWait allow_wait; | |
| 275 done_.Wait(); | |
| 276 } | |
| 277 } | |
| 278 | |
| 279 void BackendImpl::CleanupCache() { | |
| 280 Trace("Backend Cleanup"); | |
| 281 eviction_.Stop(); | |
| 282 timer_.reset(); | |
| 283 | |
| 284 if (init_) { | |
| 285 StoreStats(); | |
| 286 if (data_) | |
| 287 data_->header.crash = 0; | |
| 288 | |
| 289 if (user_flags_ & kNoRandom) { | |
| 290 // This is a net_unittest, verify that we are not 'leaking' entries. | |
| 291 File::WaitForPendingIO(&num_pending_io_); | |
| 292 DCHECK(!num_refs_); | |
| 293 } else { | |
| 294 File::DropPendingIO(); | |
| 295 } | |
| 296 } | |
| 297 block_files_.CloseFiles(); | |
| 298 FlushIndex(); | |
| 299 index_ = NULL; | |
| 300 ptr_factory_.InvalidateWeakPtrs(); | |
| 301 done_.Signal(); | |
| 302 } | |
| 303 | |
| 304 base::FilePath BackendImpl::GetFileName(Addr address) const { | |
| 305 if (!address.is_separate_file() || !address.is_initialized()) { | |
| 306 NOTREACHED(); | |
| 307 return base::FilePath(); | |
| 308 } | |
| 309 | |
| 310 std::string tmp = base::StringPrintf("f_%06x", address.FileNumber()); | |
| 311 return path_.AppendASCII(tmp); | |
| 312 } | |
| 313 | |
| 314 // We just created a new file so we're going to write the header and set the | |
| 315 // file length to include the hash table (zero filled). | |
| 316 bool BackendImpl::CreateBackingStore(disk_cache::File* file) { | |
| 317 AdjustMaxCacheSize(0); | |
| 318 | |
| 319 IndexHeader header; | |
| 320 header.table_len = DesiredIndexTableLen(max_size_); | |
| 321 | |
| 322 // We need file version 2.1 for the new eviction algorithm. | |
| 323 if (new_eviction_) | |
| 324 header.version = 0x20001; | |
| 325 | |
| 326 header.create_time = Time::Now().ToInternalValue(); | |
| 327 | |
| 328 if (!file->Write(&header, sizeof(header), 0)) | |
| 329 return false; | |
| 330 | |
| 331 return file->SetLength(GetIndexSize(header.table_len)); | |
| 332 } | |
| 333 | |
| 334 bool BackendImpl::InitBackingStore(bool* file_created) { | |
| 335 if (!base::CreateDirectory(path_)) | |
| 336 return false; | |
| 337 | |
| 338 base::FilePath index_name = path_.AppendASCII(kIndexName); | |
| 339 | |
| 340 int flags = base::PLATFORM_FILE_READ | | |
| 341 base::PLATFORM_FILE_WRITE | | |
| 342 base::PLATFORM_FILE_OPEN_ALWAYS | | |
| 343 base::PLATFORM_FILE_EXCLUSIVE_WRITE; | |
| 344 scoped_refptr<disk_cache::File> file(new disk_cache::File( | |
| 345 base::CreatePlatformFile(index_name, flags, file_created, NULL))); | |
| 346 | |
| 347 if (!file->IsValid()) | |
| 348 return false; | |
| 349 | |
| 350 bool ret = true; | |
| 351 if (*file_created) | |
| 352 ret = CreateBackingStore(file.get()); | |
| 353 | |
| 354 file = NULL; | |
| 355 if (!ret) | |
| 356 return false; | |
| 357 | |
| 358 index_ = new MappedFile(); | |
| 359 data_ = reinterpret_cast<Index*>(index_->Init(index_name, 0)); | |
| 360 if (!data_) { | |
| 361 LOG(ERROR) << "Unable to map Index file"; | |
| 362 return false; | |
| 363 } | |
| 364 | |
| 365 if (index_->GetLength() < sizeof(Index)) { | |
| 366 // We verify this again on CheckIndex() but it's easier to make sure now | |
| 367 // that the header is there. | |
| 368 LOG(ERROR) << "Corrupt Index file"; | |
| 369 return false; | |
| 370 } | |
| 371 | |
| 372 return true; | |
| 373 } | |
| 374 | |
| 375 void BackendImpl::ReportError(int error) { | |
| 376 STRESS_DCHECK(!error || error == ERR_PREVIOUS_CRASH || | |
| 377 error == ERR_CACHE_CREATED); | |
| 378 | |
| 379 // We transmit positive numbers, instead of direct error codes. | |
| 380 DCHECK_LE(error, 0); | |
| 381 CACHE_UMA(CACHE_ERROR, "Error", 0, error * -1); | |
| 382 } | |
| 383 | |
| 384 | |
| 385 bool BackendImpl::CheckIndex() { | |
| 386 DCHECK(data_); | |
| 387 | |
| 388 size_t current_size = index_->GetLength(); | |
| 389 if (current_size < sizeof(Index)) { | |
| 390 LOG(ERROR) << "Corrupt Index file"; | |
| 391 return false; | |
| 392 } | |
| 393 | |
| 394 if (new_eviction_) { | |
| 395 // We support versions 2.0 and 2.1, upgrading 2.0 to 2.1. | |
| 396 if (kIndexMagic != data_->header.magic || | |
| 397 kCurrentVersion >> 16 != data_->header.version >> 16) { | |
| 398 LOG(ERROR) << "Invalid file version or magic"; | |
| 399 return false; | |
| 400 } | |
| 401 if (kCurrentVersion == data_->header.version) { | |
| 402 // We need file version 2.1 for the new eviction algorithm. | |
| 403 UpgradeTo2_1(); | |
| 404 } | |
| 405 } else { | |
| 406 if (kIndexMagic != data_->header.magic || | |
| 407 kCurrentVersion != data_->header.version) { | |
| 408 LOG(ERROR) << "Invalid file version or magic"; | |
| 409 return false; | |
| 410 } | |
| 411 } | |
| 412 | |
| 413 if (!data_->header.table_len) { | |
| 414 LOG(ERROR) << "Invalid table size"; | |
| 415 return false; | |
| 416 } | |
| 417 | |
| 418 if (current_size < GetIndexSize(data_->header.table_len) || | |
| 419 data_->header.table_len & (kBaseTableLen - 1)) { | |
| 420 LOG(ERROR) << "Corrupt Index file"; | |
| 421 return false; | |
| 422 } | |
| 423 | |
| 424 AdjustMaxCacheSize(data_->header.table_len); | |
| 425 | |
| 426 #if !defined(NET_BUILD_STRESS_CACHE) | |
| 427 if (data_->header.num_bytes < 0 || | |
| 428 (max_size_ < kint32max - kDefaultCacheSize && | |
| 429 data_->header.num_bytes > max_size_ + kDefaultCacheSize)) { | |
| 430 LOG(ERROR) << "Invalid cache (current) size"; | |
| 431 return false; | |
| 432 } | |
| 433 #endif | |
| 434 | |
| 435 if (data_->header.num_entries < 0) { | |
| 436 LOG(ERROR) << "Invalid number of entries"; | |
| 437 return false; | |
| 438 } | |
| 439 | |
| 440 if (!mask_) | |
| 441 mask_ = data_->header.table_len - 1; | |
| 442 | |
| 443 // Load the table into memory with a single read. | |
| 444 scoped_ptr<char[]> buf(new char[current_size]); | |
| 445 return index_->Read(buf.get(), current_size, 0); | |
| 446 } | |
| 447 | |
| 448 bool BackendImpl::InitStats() { | |
| 449 Addr address(data_->header.stats); | |
| 450 int size = stats_.StorageSize(); | |
| 451 | |
| 452 if (!address.is_initialized()) { | |
| 453 FileType file_type = Addr::RequiredFileType(size); | |
| 454 DCHECK_NE(file_type, EXTERNAL); | |
| 455 int num_blocks = Addr::RequiredBlocks(size, file_type); | |
| 456 | |
| 457 if (!CreateBlock(file_type, num_blocks, &address)) | |
| 458 return false; | |
| 459 return stats_.Init(NULL, 0, address); | |
| 460 } | |
| 461 | |
| 462 if (!address.is_block_file()) { | |
| 463 NOTREACHED(); | |
| 464 return false; | |
| 465 } | |
| 466 | |
| 467 // Load the required data. | |
| 468 size = address.num_blocks() * address.BlockSize(); | |
| 469 MappedFile* file = File(address); | |
| 470 if (!file) | |
| 471 return false; | |
| 472 | |
| 473 scoped_ptr<char[]> data(new char[size]); | |
| 474 size_t offset = address.start_block() * address.BlockSize() + | |
| 475 kBlockHeaderSize; | |
| 476 if (!file->Read(data.get(), size, offset)) | |
| 477 return false; | |
| 478 | |
| 479 if (!stats_.Init(data.get(), size, address)) | |
| 480 return false; | |
| 481 if (cache_type_ == net::DISK_CACHE && ShouldReportAgain()) | |
| 482 stats_.InitSizeHistogram(); | |
| 483 return true; | |
| 484 } | |
| 485 | |
| 486 } // namespace disk_cache | |
| OLD | NEW |
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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