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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/blockfile/backend_worker_v3.h" | |
6 | |
7 #include "base/bind.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" | |
20 | |
21 using base::Time; | |
22 using base::TimeDelta; | |
23 using base::TimeTicks; | |
24 | |
25 namespace { | |
26 | |
27 #if defined(V3_NOT_JUST_YET_READY) | |
28 | |
29 const char kIndexName[] = "index"; | |
30 | |
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% | |
33 // for most users. | |
34 const int k64kEntriesStore = 240 * 1000 * 1000; | |
35 const int kBaseTableLen = 64 * 1024; | |
36 const int kDefaultCacheSize = 80 * 1024 * 1024; | |
37 | |
38 // Avoid trimming the cache for the first 5 minutes (10 timer ticks). | |
39 const int kTrimDelay = 10; | |
40 | |
41 int DesiredIndexTableLen(int32 storage_size) { | |
42 if (storage_size <= k64kEntriesStore) | |
43 return kBaseTableLen; | |
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; | |
50 | |
51 // The biggest storage_size for int32 requires a 4 MB table. | |
52 return kBaseTableLen * 16; | |
53 } | |
54 | |
55 int MaxStorageSizeForTable(int table_len) { | |
56 return table_len * (k64kEntriesStore / kBaseTableLen); | |
57 } | |
58 | |
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; | |
62 } | |
63 | |
64 // ------------------------------------------------------------------------ | |
65 | |
66 // Sets group for the current experiment. Returns false if the files should be | |
67 // discarded. | |
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. | |
72 return false; | |
73 } | |
74 | |
75 if (base::FieldTrialList::FindFullName("SimpleCacheTrial") == | |
76 "ExperimentControl") { | |
77 if (cache_created) { | |
78 header->experiment = disk_cache::EXPERIMENT_SIMPLE_CONTROL; | |
79 return true; | |
80 } else if (header->experiment != disk_cache::EXPERIMENT_SIMPLE_CONTROL) { | |
81 return false; | |
82 } | |
83 } | |
84 | |
85 header->experiment = disk_cache::NO_EXPERIMENT; | |
86 return true; | |
87 } | |
88 #endif // defined(V3_NOT_JUST_YET_READY). | |
89 | |
90 } // namespace | |
91 | |
92 // ------------------------------------------------------------------------ | |
93 | |
94 namespace disk_cache { | |
95 | |
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) { | |
100 } | |
101 | |
102 #if defined(V3_NOT_JUST_YET_READY) | |
103 | |
104 int BackendImpl::SyncInit() { | |
105 #if defined(NET_BUILD_STRESS_CACHE) | |
106 // Start evictions right away. | |
107 up_ticks_ = kTrimDelay * 2; | |
108 #endif | |
109 DCHECK(!init_); | |
110 if (init_) | |
111 return net::ERR_FAILED; | |
112 | |
113 bool create_files = false; | |
114 if (!InitBackingStore(&create_files)) { | |
115 ReportError(ERR_STORAGE_ERROR); | |
116 return net::ERR_FAILED; | |
117 } | |
118 | |
119 num_refs_ = num_pending_io_ = max_refs_ = 0; | |
120 entry_count_ = byte_count_ = 0; | |
121 | |
122 if (!restarted_) { | |
123 buffer_bytes_ = 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); | |
130 } | |
131 | |
132 init_ = true; | |
133 Trace("Init"); | |
134 | |
135 if (data_->header.experiment != NO_EXPERIMENT && | |
136 cache_type_ != net::DISK_CACHE) { | |
137 // No experiment for other caches. | |
138 return net::ERR_FAILED; | |
139 } | |
140 | |
141 if (!(user_flags_ & kNoRandom)) { | |
142 // The unit test controls directly what to test. | |
143 new_eviction_ = (cache_type_ == net::DISK_CACHE); | |
144 } | |
145 | |
146 if (!CheckIndex()) { | |
147 ReportError(ERR_INIT_FAILED); | |
148 return net::ERR_FAILED; | |
149 } | |
150 | |
151 if (!restarted_ && (create_files || !data_->header.num_entries)) | |
152 ReportError(ERR_CACHE_CREATED); | |
153 | |
154 if (!(user_flags_ & kNoRandom) && cache_type_ == net::DISK_CACHE && | |
155 !InitExperiment(&data_->header, create_files)) { | |
156 return net::ERR_FAILED; | |
157 } | |
158 | |
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++; | |
166 | |
167 bool previous_crash = (data_->header.crash != 0); | |
168 data_->header.crash = 1; | |
169 | |
170 if (!block_files_.Init(create_files)) | |
171 return net::ERR_FAILED; | |
172 | |
173 // We want to minimize the changes to cache for an AppCache. | |
174 if (cache_type() == net::APP_CACHE) { | |
175 DCHECK(!new_eviction_); | |
176 read_only_ = true; | |
177 } else if (cache_type() == net::SHADER_CACHE) { | |
178 DCHECK(!new_eviction_); | |
179 } | |
180 | |
181 eviction_.Init(this); | |
182 | |
183 // stats_ and rankings_ may end up calling back to us so we better be enabled. | |
184 disabled_ = false; | |
185 if (!InitStats()) | |
186 return net::ERR_FAILED; | |
187 | |
188 disabled_ = !rankings_.Init(this, new_eviction_); | |
189 | |
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) | |
194 NOTREACHED(); | |
195 trace_object_->EnableTracing(true); | |
196 #endif | |
197 | |
198 if (previous_crash) { | |
199 ReportError(ERR_PREVIOUS_CRASH); | |
200 } else if (!restarted_) { | |
201 ReportError(ERR_NO_ERROR); | |
202 } | |
203 | |
204 FlushIndex(); | |
205 | |
206 return disabled_ ? net::ERR_FAILED : net::OK; | |
207 } | |
208 | |
209 void BackendImpl::PrepareForRestart() { | |
210 // Reset the mask_ if it was not given by the user. | |
211 if (!(user_flags_ & kMask)) | |
212 mask_ = 0; | |
213 | |
214 if (!(user_flags_ & kNewEviction)) | |
215 new_eviction_ = false; | |
216 | |
217 disabled_ = true; | |
218 data_->header.crash = 0; | |
219 index_->Flush(); | |
220 index_ = NULL; | |
221 data_ = NULL; | |
222 block_files_.CloseFiles(); | |
223 rankings_.Reset(); | |
224 init_ = false; | |
225 restarted_ = true; | |
226 } | |
227 | |
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(); | |
233 } else { | |
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(); | |
237 } | |
238 | |
239 if (background_queue_.BackgroundIsCurrentThread()) { | |
240 // Unit tests may use the same thread for everything. | |
241 CleanupCache(); | |
242 } else { | |
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; | |
247 done_.Wait(); | |
248 } | |
249 } | |
250 | |
251 void BackendImpl::CleanupCache() { | |
252 Trace("Backend Cleanup"); | |
253 eviction_.Stop(); | |
254 timer_.reset(); | |
255 | |
256 if (init_) { | |
257 StoreStats(); | |
258 if (data_) | |
259 data_->header.crash = 0; | |
260 | |
261 if (user_flags_ & kNoRandom) { | |
262 // This is a net_unittest, verify that we are not 'leaking' entries. | |
263 File::WaitForPendingIO(&num_pending_io_); | |
264 DCHECK(!num_refs_); | |
265 } else { | |
266 File::DropPendingIO(); | |
267 } | |
268 } | |
269 block_files_.CloseFiles(); | |
270 FlushIndex(); | |
271 index_ = NULL; | |
272 ptr_factory_.InvalidateWeakPtrs(); | |
273 done_.Signal(); | |
274 } | |
275 | |
276 base::FilePath BackendImpl::GetFileName(Addr address) const { | |
277 if (!address.is_separate_file() || !address.is_initialized()) { | |
278 NOTREACHED(); | |
279 return base::FilePath(); | |
280 } | |
281 | |
282 std::string tmp = base::StringPrintf("f_%06x", address.FileNumber()); | |
283 return path_.AppendASCII(tmp); | |
284 } | |
285 | |
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); | |
290 | |
291 IndexHeader header; | |
292 header.table_len = DesiredIndexTableLen(max_size_); | |
293 | |
294 // We need file version 2.1 for the new eviction algorithm. | |
295 if (new_eviction_) | |
296 header.version = 0x20001; | |
297 | |
298 header.create_time = Time::Now().ToInternalValue(); | |
299 | |
300 if (!file->Write(&header, sizeof(header), 0)) | |
301 return false; | |
302 | |
303 return file->SetLength(GetIndexSize(header.table_len)); | |
304 } | |
305 | |
306 bool BackendImpl::InitBackingStore(bool* file_created) { | |
307 if (!base::CreateDirectory(path_)) | |
308 return false; | |
309 | |
310 base::FilePath index_name = path_.AppendASCII(kIndexName); | |
311 | |
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))); | |
318 | |
319 if (!file->IsValid()) | |
320 return false; | |
321 | |
322 bool ret = true; | |
323 if (*file_created) | |
324 ret = CreateBackingStore(file.get()); | |
325 | |
326 file = NULL; | |
327 if (!ret) | |
328 return false; | |
329 | |
330 index_ = new MappedFile(); | |
331 data_ = reinterpret_cast<Index*>(index_->Init(index_name, 0)); | |
332 if (!data_) { | |
333 LOG(ERROR) << "Unable to map Index file"; | |
334 return false; | |
335 } | |
336 | |
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"; | |
341 return false; | |
342 } | |
343 | |
344 return true; | |
345 } | |
346 | |
347 void BackendImpl::ReportError(int error) { | |
348 STRESS_DCHECK(!error || error == ERR_PREVIOUS_CRASH || | |
349 error == ERR_CACHE_CREATED); | |
350 | |
351 // We transmit positive numbers, instead of direct error codes. | |
352 DCHECK_LE(error, 0); | |
353 CACHE_UMA(CACHE_ERROR, "Error", 0, error * -1); | |
354 } | |
355 | |
356 | |
357 bool BackendImpl::CheckIndex() { | |
358 DCHECK(data_); | |
359 | |
360 size_t current_size = index_->GetLength(); | |
361 if (current_size < sizeof(Index)) { | |
362 LOG(ERROR) << "Corrupt Index file"; | |
363 return false; | |
364 } | |
365 | |
366 if (new_eviction_) { | |
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"; | |
371 return false; | |
372 } | |
373 if (kCurrentVersion == data_->header.version) { | |
374 // We need file version 2.1 for the new eviction algorithm. | |
375 UpgradeTo2_1(); | |
376 } | |
377 } else { | |
378 if (kIndexMagic != data_->header.magic || | |
379 kCurrentVersion != data_->header.version) { | |
380 LOG(ERROR) << "Invalid file version or magic"; | |
381 return false; | |
382 } | |
383 } | |
384 | |
385 if (!data_->header.table_len) { | |
386 LOG(ERROR) << "Invalid table size"; | |
387 return false; | |
388 } | |
389 | |
390 if (current_size < GetIndexSize(data_->header.table_len) || | |
391 data_->header.table_len & (kBaseTableLen - 1)) { | |
392 LOG(ERROR) << "Corrupt Index file"; | |
393 return false; | |
394 } | |
395 | |
396 AdjustMaxCacheSize(data_->header.table_len); | |
397 | |
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"; | |
403 return false; | |
404 } | |
405 #endif | |
406 | |
407 if (data_->header.num_entries < 0) { | |
408 LOG(ERROR) << "Invalid number of entries"; | |
409 return false; | |
410 } | |
411 | |
412 if (!mask_) | |
413 mask_ = data_->header.table_len - 1; | |
414 | |
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); | |
418 } | |
419 | |
420 bool BackendImpl::InitStats() { | |
421 Addr address(data_->header.stats); | |
422 int size = stats_.StorageSize(); | |
423 | |
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); | |
428 | |
429 if (!CreateBlock(file_type, num_blocks, &address)) | |
430 return false; | |
431 return stats_.Init(NULL, 0, address); | |
432 } | |
433 | |
434 if (!address.is_block_file()) { | |
435 NOTREACHED(); | |
436 return false; | |
437 } | |
438 | |
439 // Load the required data. | |
440 size = address.num_blocks() * address.BlockSize(); | |
441 MappedFile* file = File(address); | |
442 if (!file) | |
443 return false; | |
444 | |
445 scoped_ptr<char[]> data(new char[size]); | |
446 size_t offset = address.start_block() * address.BlockSize() + | |
447 kBlockHeaderSize; | |
448 if (!file->Read(data.get(), size, offset)) | |
449 return false; | |
450 | |
451 if (!stats_.Init(data.get(), size, address)) | |
452 return false; | |
453 if (cache_type_ == net::DISK_CACHE && ShouldReportAgain()) | |
454 stats_.InitSizeHistogram(); | |
455 return true; | |
456 } | |
457 | |
458 #endif // defined(V3_NOT_JUST_YET_READY). | |
459 | |
460 int BackendImplV3::Worker::Init(const CompletionCallback& callback) { | |
461 return net::ERR_FAILED; | |
462 } | |
463 | |
464 BackendImplV3::Worker::~Worker() { | |
465 } | |
466 | |
467 } // namespace disk_cache | |
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