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.
5 #include "net/disk_cache/blockfile/backend_worker_v3.h"
8 #include "base/bind_helpers.h"
9 #include "base/files/file_path.h"
10 #include "base/files/file_util.h"
11 #include "base/message_loop/message_loop.h"
12 #include "base/strings/string_util.h"
13 #include "base/strings/stringprintf.h"
14 #include "base/time/time.h"
15 #include "base/timer/timer.h"
16 #include "net/base/net_errors.h"
17 #include "net/disk_cache/blockfile/errors.h"
18 #include "net/disk_cache/blockfile/experiments.h"
19 #include "net/disk_cache/blockfile/file.h"
22 using base::TimeDelta;
23 using base::TimeTicks;
27 #if defined(V3_NOT_JUST_YET_READY)
29 const char* kIndexName = "index";
31 // Seems like ~240 MB correspond to less than 50k entries for 99% of the people.
32 // Note that the actual target is to keep the index table load factor under 55%
34 const int k64kEntriesStore = 240 * 1000 * 1000;
35 const int kBaseTableLen = 64 * 1024;
36 const int kDefaultCacheSize = 80 * 1024 * 1024;
38 // Avoid trimming the cache for the first 5 minutes (10 timer ticks).
39 const int kTrimDelay = 10;
41 int DesiredIndexTableLen(int32 storage_size) {
42 if (storage_size <= k64kEntriesStore)
44 if (storage_size <= k64kEntriesStore * 2)
45 return kBaseTableLen * 2;
46 if (storage_size <= k64kEntriesStore * 4)
47 return kBaseTableLen * 4;
48 if (storage_size <= k64kEntriesStore * 8)
49 return kBaseTableLen * 8;
51 // The biggest storage_size for int32 requires a 4 MB table.
52 return kBaseTableLen * 16;
55 int MaxStorageSizeForTable(int table_len) {
56 return table_len * (k64kEntriesStore / kBaseTableLen);
59 size_t GetIndexSize(int table_len) {
60 size_t table_size = sizeof(disk_cache::CacheAddr) * table_len;
61 return sizeof(disk_cache::IndexHeader) + table_size;
64 // ------------------------------------------------------------------------
66 // Sets group for the current experiment. Returns false if the files should be
68 bool InitExperiment(disk_cache::IndexHeader* header, bool cache_created) {
69 if (header->experiment == disk_cache::EXPERIMENT_OLD_FILE1 ||
70 header->experiment == disk_cache::EXPERIMENT_OLD_FILE2) {
71 // Discard current cache.
75 if (base::FieldTrialList::FindFullName("SimpleCacheTrial") ==
76 "ExperimentControl") {
78 header->experiment = disk_cache::EXPERIMENT_SIMPLE_CONTROL;
80 } else if (header->experiment != disk_cache::EXPERIMENT_SIMPLE_CONTROL) {
85 header->experiment = disk_cache::NO_EXPERIMENT;
88 #endif // defined(V3_NOT_JUST_YET_READY).
92 // ------------------------------------------------------------------------
94 namespace disk_cache {
96 BackendImplV3::Worker::Worker(
97 const base::FilePath& path,
98 const scoped_refptr<base::SingleThreadTaskRunner>& main_thread)
99 : path_(path), block_files_(path), init_(false) {
102 #if defined(V3_NOT_JUST_YET_READY)
104 int BackendImpl::SyncInit() {
105 #if defined(NET_BUILD_STRESS_CACHE)
106 // Start evictions right away.
107 up_ticks_ = kTrimDelay * 2;
111 return net::ERR_FAILED;
113 bool create_files = false;
114 if (!InitBackingStore(&create_files)) {
115 ReportError(ERR_STORAGE_ERROR);
116 return net::ERR_FAILED;
119 num_refs_ = num_pending_io_ = max_refs_ = 0;
120 entry_count_ = byte_count_ = 0;
124 trace_object_ = TraceObject::GetTraceObject();
125 // Create a recurrent timer of 30 secs.
126 int timer_delay = unit_test_ ? 1000 : 30000;
127 timer_.reset(new base::RepeatingTimer<BackendImpl>());
128 timer_->Start(FROM_HERE, TimeDelta::FromMilliseconds(timer_delay), this,
129 &BackendImpl::OnStatsTimer);
135 if (data_->header.experiment != NO_EXPERIMENT &&
136 cache_type_ != net::DISK_CACHE) {
137 // No experiment for other caches.
138 return net::ERR_FAILED;
141 if (!(user_flags_ & kNoRandom)) {
142 // The unit test controls directly what to test.
143 new_eviction_ = (cache_type_ == net::DISK_CACHE);
147 ReportError(ERR_INIT_FAILED);
148 return net::ERR_FAILED;
151 if (!restarted_ && (create_files || !data_->header.num_entries))
152 ReportError(ERR_CACHE_CREATED);
154 if (!(user_flags_ & kNoRandom) && cache_type_ == net::DISK_CACHE &&
155 !InitExperiment(&data_->header, create_files)) {
156 return net::ERR_FAILED;
159 // We don't care if the value overflows. The only thing we care about is that
160 // the id cannot be zero, because that value is used as "not dirty".
161 // Increasing the value once per second gives us many years before we start
162 // having collisions.
163 data_->header.this_id++;
164 if (!data_->header.this_id)
165 data_->header.this_id++;
167 bool previous_crash = (data_->header.crash != 0);
168 data_->header.crash = 1;
170 if (!block_files_.Init(create_files))
171 return net::ERR_FAILED;
173 // We want to minimize the changes to cache for an AppCache.
174 if (cache_type() == net::APP_CACHE) {
175 DCHECK(!new_eviction_);
177 } else if (cache_type() == net::SHADER_CACHE) {
178 DCHECK(!new_eviction_);
181 eviction_.Init(this);
183 // stats_ and rankings_ may end up calling back to us so we better be enabled.
186 return net::ERR_FAILED;
188 disabled_ = !rankings_.Init(this, new_eviction_);
190 #if defined(STRESS_CACHE_EXTENDED_VALIDATION)
191 trace_object_->EnableTracing(false);
192 int sc = SelfCheck();
193 if (sc < 0 && sc != ERR_NUM_ENTRIES_MISMATCH)
195 trace_object_->EnableTracing(true);
198 if (previous_crash) {
199 ReportError(ERR_PREVIOUS_CRASH);
200 } else if (!restarted_) {
201 ReportError(ERR_NO_ERROR);
206 return disabled_ ? net::ERR_FAILED : net::OK;
209 void BackendImpl::PrepareForRestart() {
210 // Reset the mask_ if it was not given by the user.
211 if (!(user_flags_ & kMask))
214 if (!(user_flags_ & kNewEviction))
215 new_eviction_ = false;
218 data_->header.crash = 0;
222 block_files_.CloseFiles();
228 BackendImpl::~BackendImpl() {
229 if (user_flags_ & kNoRandom) {
230 // This is a unit test, so we want to be strict about not leaking entries
231 // and completing all the work.
232 background_queue_.WaitForPendingIO();
234 // This is most likely not a test, so we want to do as little work as
235 // possible at this time, at the price of leaving dirty entries behind.
236 background_queue_.DropPendingIO();
239 if (background_queue_.BackgroundIsCurrentThread()) {
240 // Unit tests may use the same thread for everything.
243 background_queue_.background_thread()->PostTask(
244 FROM_HERE, base::Bind(&FinalCleanupCallback, base::Unretained(this)));
245 // http://crbug.com/74623
246 base::ThreadRestrictions::ScopedAllowWait allow_wait;
251 void BackendImpl::CleanupCache() {
252 Trace("Backend Cleanup");
259 data_->header.crash = 0;
261 if (user_flags_ & kNoRandom) {
262 // This is a net_unittest, verify that we are not 'leaking' entries.
263 File::WaitForPendingIO(&num_pending_io_);
266 File::DropPendingIO();
269 block_files_.CloseFiles();
272 ptr_factory_.InvalidateWeakPtrs();
276 base::FilePath BackendImpl::GetFileName(Addr address) const {
277 if (!address.is_separate_file() || !address.is_initialized()) {
279 return base::FilePath();
282 std::string tmp = base::StringPrintf("f_%06x", address.FileNumber());
283 return path_.AppendASCII(tmp);
286 // We just created a new file so we're going to write the header and set the
287 // file length to include the hash table (zero filled).
288 bool BackendImpl::CreateBackingStore(disk_cache::File* file) {
289 AdjustMaxCacheSize(0);
292 header.table_len = DesiredIndexTableLen(max_size_);
294 // We need file version 2.1 for the new eviction algorithm.
296 header.version = 0x20001;
298 header.create_time = Time::Now().ToInternalValue();
300 if (!file->Write(&header, sizeof(header), 0))
303 return file->SetLength(GetIndexSize(header.table_len));
306 bool BackendImpl::InitBackingStore(bool* file_created) {
307 if (!base::CreateDirectory(path_))
310 base::FilePath index_name = path_.AppendASCII(kIndexName);
312 int flags = base::PLATFORM_FILE_READ |
313 base::PLATFORM_FILE_WRITE |
314 base::PLATFORM_FILE_OPEN_ALWAYS |
315 base::PLATFORM_FILE_EXCLUSIVE_WRITE;
316 scoped_refptr<disk_cache::File> file(new disk_cache::File(
317 base::CreatePlatformFile(index_name, flags, file_created, NULL)));
319 if (!file->IsValid())
324 ret = CreateBackingStore(file.get());
330 index_ = new MappedFile();
331 data_ = reinterpret_cast<Index*>(index_->Init(index_name, 0));
333 LOG(ERROR) << "Unable to map Index file";
337 if (index_->GetLength() < sizeof(Index)) {
338 // We verify this again on CheckIndex() but it's easier to make sure now
339 // that the header is there.
340 LOG(ERROR) << "Corrupt Index file";
347 void BackendImpl::ReportError(int error) {
348 STRESS_DCHECK(!error || error == ERR_PREVIOUS_CRASH ||
349 error == ERR_CACHE_CREATED);
351 // We transmit positive numbers, instead of direct error codes.
353 CACHE_UMA(CACHE_ERROR, "Error", 0, error * -1);
357 bool BackendImpl::CheckIndex() {
360 size_t current_size = index_->GetLength();
361 if (current_size < sizeof(Index)) {
362 LOG(ERROR) << "Corrupt Index file";
367 // We support versions 2.0 and 2.1, upgrading 2.0 to 2.1.
368 if (kIndexMagic != data_->header.magic ||
369 kCurrentVersion >> 16 != data_->header.version >> 16) {
370 LOG(ERROR) << "Invalid file version or magic";
373 if (kCurrentVersion == data_->header.version) {
374 // We need file version 2.1 for the new eviction algorithm.
378 if (kIndexMagic != data_->header.magic ||
379 kCurrentVersion != data_->header.version) {
380 LOG(ERROR) << "Invalid file version or magic";
385 if (!data_->header.table_len) {
386 LOG(ERROR) << "Invalid table size";
390 if (current_size < GetIndexSize(data_->header.table_len) ||
391 data_->header.table_len & (kBaseTableLen - 1)) {
392 LOG(ERROR) << "Corrupt Index file";
396 AdjustMaxCacheSize(data_->header.table_len);
398 #if !defined(NET_BUILD_STRESS_CACHE)
399 if (data_->header.num_bytes < 0 ||
400 (max_size_ < kint32max - kDefaultCacheSize &&
401 data_->header.num_bytes > max_size_ + kDefaultCacheSize)) {
402 LOG(ERROR) << "Invalid cache (current) size";
407 if (data_->header.num_entries < 0) {
408 LOG(ERROR) << "Invalid number of entries";
413 mask_ = data_->header.table_len - 1;
415 // Load the table into memory with a single read.
416 scoped_ptr<char[]> buf(new char[current_size]);
417 return index_->Read(buf.get(), current_size, 0);
420 bool BackendImpl::InitStats() {
421 Addr address(data_->header.stats);
422 int size = stats_.StorageSize();
424 if (!address.is_initialized()) {
425 FileType file_type = Addr::RequiredFileType(size);
426 DCHECK_NE(file_type, EXTERNAL);
427 int num_blocks = Addr::RequiredBlocks(size, file_type);
429 if (!CreateBlock(file_type, num_blocks, &address))
431 return stats_.Init(NULL, 0, address);
434 if (!address.is_block_file()) {
439 // Load the required data.
440 size = address.num_blocks() * address.BlockSize();
441 MappedFile* file = File(address);
445 scoped_ptr<char[]> data(new char[size]);
446 size_t offset = address.start_block() * address.BlockSize() +
448 if (!file->Read(data.get(), size, offset))
451 if (!stats_.Init(data.get(), size, address))
453 if (cache_type_ == net::DISK_CACHE && ShouldReportAgain())
454 stats_.InitSizeHistogram();
458 #endif // defined(V3_NOT_JUST_YET_READY).
460 int BackendImplV3::Worker::Init(const CompletionCallback& callback) {
461 return net::ERR_FAILED;
464 BackendImplV3::Worker::~Worker() {
467 } // namespace disk_cache