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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 <stdint.h> | |
8 | |
9 #include <limits> | |
10 | |
11 #include "base/bind.h" | |
12 #include "base/bind_helpers.h" | |
13 #include "base/files/file_path.h" | |
14 #include "base/files/file_util.h" | |
15 #include "base/message_loop/message_loop.h" | |
16 #include "base/strings/string_util.h" | |
17 #include "base/strings/stringprintf.h" | |
18 #include "base/time/time.h" | |
19 #include "base/timer/timer.h" | |
20 #include "net/base/net_errors.h" | |
21 #include "net/disk_cache/blockfile/errors.h" | |
22 #include "net/disk_cache/blockfile/experiments.h" | |
23 #include "net/disk_cache/blockfile/file.h" | |
24 | |
25 using base::Time; | |
26 using base::TimeDelta; | |
27 using base::TimeTicks; | |
28 | |
29 namespace { | |
30 | |
31 #if defined(V3_NOT_JUST_YET_READY) | |
32 | |
33 const char kIndexName[] = "index"; | |
34 | |
35 // Seems like ~240 MB correspond to less than 50k entries for 99% of the people. | |
36 // Note that the actual target is to keep the index table load factor under 55% | |
37 // for most users. | |
38 const int k64kEntriesStore = 240 * 1000 * 1000; | |
39 const int kBaseTableLen = 64 * 1024; | |
40 const int kDefaultCacheSize = 80 * 1024 * 1024; | |
41 | |
42 // Avoid trimming the cache for the first 5 minutes (10 timer ticks). | |
43 const int kTrimDelay = 10; | |
44 | |
45 int DesiredIndexTableLen(int32_t storage_size) { | |
46 if (storage_size <= k64kEntriesStore) | |
47 return kBaseTableLen; | |
48 if (storage_size <= k64kEntriesStore * 2) | |
49 return kBaseTableLen * 2; | |
50 if (storage_size <= k64kEntriesStore * 4) | |
51 return kBaseTableLen * 4; | |
52 if (storage_size <= k64kEntriesStore * 8) | |
53 return kBaseTableLen * 8; | |
54 | |
55 // The biggest storage_size for int32_t requires a 4 MB table. | |
56 return kBaseTableLen * 16; | |
57 } | |
58 | |
59 int MaxStorageSizeForTable(int table_len) { | |
60 return table_len * (k64kEntriesStore / kBaseTableLen); | |
61 } | |
62 | |
63 size_t GetIndexSize(int table_len) { | |
64 size_t table_size = sizeof(disk_cache::CacheAddr) * table_len; | |
65 return sizeof(disk_cache::IndexHeader) + table_size; | |
66 } | |
67 | |
68 // ------------------------------------------------------------------------ | |
69 | |
70 // Sets group for the current experiment. Returns false if the files should be | |
71 // discarded. | |
72 bool InitExperiment(disk_cache::IndexHeader* header, bool cache_created) { | |
73 if (header->experiment == disk_cache::EXPERIMENT_OLD_FILE1 || | |
74 header->experiment == disk_cache::EXPERIMENT_OLD_FILE2) { | |
75 // Discard current cache. | |
76 return false; | |
77 } | |
78 | |
79 if (base::FieldTrialList::FindFullName("SimpleCacheTrial") == | |
80 "ExperimentControl") { | |
81 if (cache_created) { | |
82 header->experiment = disk_cache::EXPERIMENT_SIMPLE_CONTROL; | |
83 return true; | |
84 } else if (header->experiment != disk_cache::EXPERIMENT_SIMPLE_CONTROL) { | |
85 return false; | |
86 } | |
87 } | |
88 | |
89 header->experiment = disk_cache::NO_EXPERIMENT; | |
90 return true; | |
91 } | |
92 #endif // defined(V3_NOT_JUST_YET_READY). | |
93 | |
94 } // namespace | |
95 | |
96 // ------------------------------------------------------------------------ | |
97 | |
98 namespace disk_cache { | |
99 | |
100 BackendImplV3::Worker::Worker( | |
101 const base::FilePath& path, | |
102 const scoped_refptr<base::SingleThreadTaskRunner>& main_thread) | |
103 : path_(path), block_files_(path), init_(false) { | |
104 } | |
105 | |
106 #if defined(V3_NOT_JUST_YET_READY) | |
107 | |
108 int BackendImpl::SyncInit() { | |
109 #if defined(NET_BUILD_STRESS_CACHE) | |
110 // Start evictions right away. | |
111 up_ticks_ = kTrimDelay * 2; | |
112 #endif | |
113 DCHECK(!init_); | |
114 if (init_) | |
115 return net::ERR_FAILED; | |
116 | |
117 bool create_files = false; | |
118 if (!InitBackingStore(&create_files)) { | |
119 ReportError(ERR_STORAGE_ERROR); | |
120 return net::ERR_FAILED; | |
121 } | |
122 | |
123 num_refs_ = num_pending_io_ = max_refs_ = 0; | |
124 entry_count_ = byte_count_ = 0; | |
125 | |
126 if (!restarted_) { | |
127 buffer_bytes_ = 0; | |
128 trace_object_ = TraceObject::GetTraceObject(); | |
129 // Create a recurrent timer of 30 secs. | |
130 int timer_delay = unit_test_ ? 1000 : 30000; | |
131 timer_.reset(new base::RepeatingTimer()); | |
132 timer_->Start(FROM_HERE, TimeDelta::FromMilliseconds(timer_delay), this, | |
133 &BackendImpl::OnStatsTimer); | |
134 } | |
135 | |
136 init_ = true; | |
137 Trace("Init"); | |
138 | |
139 if (data_->header.experiment != NO_EXPERIMENT && | |
140 cache_type_ != net::DISK_CACHE) { | |
141 // No experiment for other caches. | |
142 return net::ERR_FAILED; | |
143 } | |
144 | |
145 if (!(user_flags_ & kNoRandom)) { | |
146 // The unit test controls directly what to test. | |
147 new_eviction_ = (cache_type_ == net::DISK_CACHE); | |
148 } | |
149 | |
150 if (!CheckIndex()) { | |
151 ReportError(ERR_INIT_FAILED); | |
152 return net::ERR_FAILED; | |
153 } | |
154 | |
155 if (!restarted_ && (create_files || !data_->header.num_entries)) | |
156 ReportError(ERR_CACHE_CREATED); | |
157 | |
158 if (!(user_flags_ & kNoRandom) && cache_type_ == net::DISK_CACHE && | |
159 !InitExperiment(&data_->header, create_files)) { | |
160 return net::ERR_FAILED; | |
161 } | |
162 | |
163 // We don't care if the value overflows. The only thing we care about is that | |
164 // the id cannot be zero, because that value is used as "not dirty". | |
165 // Increasing the value once per second gives us many years before we start | |
166 // having collisions. | |
167 data_->header.this_id++; | |
168 if (!data_->header.this_id) | |
169 data_->header.this_id++; | |
170 | |
171 bool previous_crash = (data_->header.crash != 0); | |
172 data_->header.crash = 1; | |
173 | |
174 if (!block_files_.Init(create_files)) | |
175 return net::ERR_FAILED; | |
176 | |
177 // We want to minimize the changes to cache for an AppCache. | |
178 if (cache_type() == net::APP_CACHE) { | |
179 DCHECK(!new_eviction_); | |
180 read_only_ = true; | |
181 } else if (cache_type() == net::SHADER_CACHE) { | |
182 DCHECK(!new_eviction_); | |
183 } | |
184 | |
185 eviction_.Init(this); | |
186 | |
187 // stats_ and rankings_ may end up calling back to us so we better be enabled. | |
188 disabled_ = false; | |
189 if (!InitStats()) | |
190 return net::ERR_FAILED; | |
191 | |
192 disabled_ = !rankings_.Init(this, new_eviction_); | |
193 | |
194 #if defined(STRESS_CACHE_EXTENDED_VALIDATION) | |
195 trace_object_->EnableTracing(false); | |
196 int sc = SelfCheck(); | |
197 if (sc < 0 && sc != ERR_NUM_ENTRIES_MISMATCH) | |
198 NOTREACHED(); | |
199 trace_object_->EnableTracing(true); | |
200 #endif | |
201 | |
202 if (previous_crash) { | |
203 ReportError(ERR_PREVIOUS_CRASH); | |
204 } else if (!restarted_) { | |
205 ReportError(ERR_NO_ERROR); | |
206 } | |
207 | |
208 FlushIndex(); | |
209 | |
210 return disabled_ ? net::ERR_FAILED : net::OK; | |
211 } | |
212 | |
213 void BackendImpl::PrepareForRestart() { | |
214 // Reset the mask_ if it was not given by the user. | |
215 if (!(user_flags_ & kMask)) | |
216 mask_ = 0; | |
217 | |
218 if (!(user_flags_ & kNewEviction)) | |
219 new_eviction_ = false; | |
220 | |
221 disabled_ = true; | |
222 data_->header.crash = 0; | |
223 index_->Flush(); | |
224 index_ = NULL; | |
225 data_ = NULL; | |
226 block_files_.CloseFiles(); | |
227 rankings_.Reset(); | |
228 init_ = false; | |
229 restarted_ = true; | |
230 } | |
231 | |
232 BackendImpl::~BackendImpl() { | |
233 if (user_flags_ & kNoRandom) { | |
234 // This is a unit test, so we want to be strict about not leaking entries | |
235 // and completing all the work. | |
236 background_queue_.WaitForPendingIO(); | |
237 } else { | |
238 // This is most likely not a test, so we want to do as little work as | |
239 // possible at this time, at the price of leaving dirty entries behind. | |
240 background_queue_.DropPendingIO(); | |
241 } | |
242 | |
243 if (background_queue_.BackgroundIsCurrentThread()) { | |
244 // Unit tests may use the same thread for everything. | |
245 CleanupCache(); | |
246 } else { | |
247 background_queue_.background_thread()->PostTask( | |
248 FROM_HERE, base::Bind(&FinalCleanupCallback, base::Unretained(this))); | |
249 // http://crbug.com/74623 | |
250 base::ThreadRestrictions::ScopedAllowWait allow_wait; | |
251 done_.Wait(); | |
252 } | |
253 } | |
254 | |
255 void BackendImpl::CleanupCache() { | |
256 Trace("Backend Cleanup"); | |
257 eviction_.Stop(); | |
258 timer_.reset(); | |
259 | |
260 if (init_) { | |
261 StoreStats(); | |
262 if (data_) | |
263 data_->header.crash = 0; | |
264 | |
265 if (user_flags_ & kNoRandom) { | |
266 // This is a net_unittest, verify that we are not 'leaking' entries. | |
267 File::WaitForPendingIO(&num_pending_io_); | |
268 DCHECK(!num_refs_); | |
269 } else { | |
270 File::DropPendingIO(); | |
271 } | |
272 } | |
273 block_files_.CloseFiles(); | |
274 FlushIndex(); | |
275 index_ = NULL; | |
276 ptr_factory_.InvalidateWeakPtrs(); | |
277 done_.Signal(); | |
278 } | |
279 | |
280 base::FilePath BackendImpl::GetFileName(Addr address) const { | |
281 if (!address.is_separate_file() || !address.is_initialized()) { | |
282 NOTREACHED(); | |
283 return base::FilePath(); | |
284 } | |
285 | |
286 std::string tmp = base::StringPrintf("f_%06x", address.FileNumber()); | |
287 return path_.AppendASCII(tmp); | |
288 } | |
289 | |
290 // We just created a new file so we're going to write the header and set the | |
291 // file length to include the hash table (zero filled). | |
292 bool BackendImpl::CreateBackingStore(disk_cache::File* file) { | |
293 AdjustMaxCacheSize(0); | |
294 | |
295 IndexHeader header; | |
296 header.table_len = DesiredIndexTableLen(max_size_); | |
297 | |
298 // We need file version 2.1 for the new eviction algorithm. | |
299 if (new_eviction_) | |
300 header.version = 0x20001; | |
301 | |
302 header.create_time = Time::Now().ToInternalValue(); | |
303 | |
304 if (!file->Write(&header, sizeof(header), 0)) | |
305 return false; | |
306 | |
307 return file->SetLength(GetIndexSize(header.table_len)); | |
308 } | |
309 | |
310 bool BackendImpl::InitBackingStore(bool* file_created) { | |
311 if (!base::CreateDirectory(path_)) | |
312 return false; | |
313 | |
314 base::FilePath index_name = path_.AppendASCII(kIndexName); | |
315 | |
316 int flags = base::PLATFORM_FILE_READ | | |
317 base::PLATFORM_FILE_WRITE | | |
318 base::PLATFORM_FILE_OPEN_ALWAYS | | |
319 base::PLATFORM_FILE_EXCLUSIVE_WRITE; | |
320 scoped_refptr<disk_cache::File> file(new disk_cache::File( | |
321 base::CreatePlatformFile(index_name, flags, file_created, NULL))); | |
322 | |
323 if (!file->IsValid()) | |
324 return false; | |
325 | |
326 bool ret = true; | |
327 if (*file_created) | |
328 ret = CreateBackingStore(file.get()); | |
329 | |
330 file = NULL; | |
331 if (!ret) | |
332 return false; | |
333 | |
334 index_ = new MappedFile(); | |
335 data_ = reinterpret_cast<Index*>(index_->Init(index_name, 0)); | |
336 if (!data_) { | |
337 LOG(ERROR) << "Unable to map Index file"; | |
338 return false; | |
339 } | |
340 | |
341 if (index_->GetLength() < sizeof(Index)) { | |
342 // We verify this again on CheckIndex() but it's easier to make sure now | |
343 // that the header is there. | |
344 LOG(ERROR) << "Corrupt Index file"; | |
345 return false; | |
346 } | |
347 | |
348 return true; | |
349 } | |
350 | |
351 void BackendImpl::ReportError(int error) { | |
352 STRESS_DCHECK(!error || error == ERR_PREVIOUS_CRASH || | |
353 error == ERR_CACHE_CREATED); | |
354 | |
355 // We transmit positive numbers, instead of direct error codes. | |
356 DCHECK_LE(error, 0); | |
357 CACHE_UMA(CACHE_ERROR, "Error", 0, error * -1); | |
358 } | |
359 | |
360 | |
361 bool BackendImpl::CheckIndex() { | |
362 DCHECK(data_); | |
363 | |
364 size_t current_size = index_->GetLength(); | |
365 if (current_size < sizeof(Index)) { | |
366 LOG(ERROR) << "Corrupt Index file"; | |
367 return false; | |
368 } | |
369 | |
370 if (new_eviction_) { | |
371 // We support versions 2.0 and 2.1, upgrading 2.0 to 2.1. | |
372 if (kIndexMagic != data_->header.magic || | |
373 kCurrentVersion >> 16 != data_->header.version >> 16) { | |
374 LOG(ERROR) << "Invalid file version or magic"; | |
375 return false; | |
376 } | |
377 if (kCurrentVersion == data_->header.version) { | |
378 // We need file version 2.1 for the new eviction algorithm. | |
379 UpgradeTo2_1(); | |
380 } | |
381 } else { | |
382 if (kIndexMagic != data_->header.magic || | |
383 kCurrentVersion != data_->header.version) { | |
384 LOG(ERROR) << "Invalid file version or magic"; | |
385 return false; | |
386 } | |
387 } | |
388 | |
389 if (!data_->header.table_len) { | |
390 LOG(ERROR) << "Invalid table size"; | |
391 return false; | |
392 } | |
393 | |
394 if (current_size < GetIndexSize(data_->header.table_len) || | |
395 data_->header.table_len & (kBaseTableLen - 1)) { | |
396 LOG(ERROR) << "Corrupt Index file"; | |
397 return false; | |
398 } | |
399 | |
400 AdjustMaxCacheSize(data_->header.table_len); | |
401 | |
402 #if !defined(NET_BUILD_STRESS_CACHE) | |
403 if (data_->header.num_bytes < 0 || | |
404 (max_size_ < std::numeric_limits<int32_t>::max() - kDefaultCacheSize && | |
405 data_->header.num_bytes > max_size_ + kDefaultCacheSize)) { | |
406 LOG(ERROR) << "Invalid cache (current) size"; | |
407 return false; | |
408 } | |
409 #endif | |
410 | |
411 if (data_->header.num_entries < 0) { | |
412 LOG(ERROR) << "Invalid number of entries"; | |
413 return false; | |
414 } | |
415 | |
416 if (!mask_) | |
417 mask_ = data_->header.table_len - 1; | |
418 | |
419 // Load the table into memory with a single read. | |
420 std::unique_ptr<char[]> buf(new char[current_size]); | |
421 return index_->Read(buf.get(), current_size, 0); | |
422 } | |
423 | |
424 bool BackendImpl::InitStats() { | |
425 Addr address(data_->header.stats); | |
426 int size = stats_.StorageSize(); | |
427 | |
428 if (!address.is_initialized()) { | |
429 FileType file_type = Addr::RequiredFileType(size); | |
430 DCHECK_NE(file_type, EXTERNAL); | |
431 int num_blocks = Addr::RequiredBlocks(size, file_type); | |
432 | |
433 if (!CreateBlock(file_type, num_blocks, &address)) | |
434 return false; | |
435 return stats_.Init(NULL, 0, address); | |
436 } | |
437 | |
438 if (!address.is_block_file()) { | |
439 NOTREACHED(); | |
440 return false; | |
441 } | |
442 | |
443 // Load the required data. | |
444 size = address.num_blocks() * address.BlockSize(); | |
445 MappedFile* file = File(address); | |
446 if (!file) | |
447 return false; | |
448 | |
449 std::unique_ptr<char[]> data(new char[size]); | |
450 size_t offset = address.start_block() * address.BlockSize() + | |
451 kBlockHeaderSize; | |
452 if (!file->Read(data.get(), size, offset)) | |
453 return false; | |
454 | |
455 if (!stats_.Init(data.get(), size, address)) | |
456 return false; | |
457 if (cache_type_ == net::DISK_CACHE && ShouldReportAgain()) | |
458 stats_.InitSizeHistogram(); | |
459 return true; | |
460 } | |
461 | |
462 #endif // defined(V3_NOT_JUST_YET_READY). | |
463 | |
464 int BackendImplV3::Worker::Init(const CompletionCallback& callback) { | |
465 return net::ERR_FAILED; | |
466 } | |
467 | |
468 BackendImplV3::Worker::~Worker() { | |
469 } | |
470 | |
471 } // namespace disk_cache | |
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