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Issue 992733002: Remove //net (except for Android test stuff) and sdch (Closed) Base URL: git@github.com:domokit/mojo.git@master
Patch Set: Created 5 years, 9 months ago
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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_impl.h"
6
7 #include "base/bind.h"
8 #include "base/bind_helpers.h"
9 #include "base/files/file.h"
10 #include "base/files/file_path.h"
11 #include "base/files/file_util.h"
12 #include "base/hash.h"
13 #include "base/message_loop/message_loop.h"
14 #include "base/metrics/field_trial.h"
15 #include "base/metrics/histogram.h"
16 #include "base/rand_util.h"
17 #include "base/single_thread_task_runner.h"
18 #include "base/strings/string_util.h"
19 #include "base/strings/stringprintf.h"
20 #include "base/sys_info.h"
21 #include "base/threading/thread_restrictions.h"
22 #include "base/time/time.h"
23 #include "base/timer/timer.h"
24 #include "net/base/net_errors.h"
25 #include "net/disk_cache/blockfile/disk_format.h"
26 #include "net/disk_cache/blockfile/entry_impl.h"
27 #include "net/disk_cache/blockfile/errors.h"
28 #include "net/disk_cache/blockfile/experiments.h"
29 #include "net/disk_cache/blockfile/file.h"
30 #include "net/disk_cache/blockfile/histogram_macros.h"
31 #include "net/disk_cache/blockfile/webfonts_histogram.h"
32 #include "net/disk_cache/cache_util.h"
33
34 // Provide a BackendImpl object to macros from histogram_macros.h.
35 #define CACHE_UMA_BACKEND_IMPL_OBJ this
36
37 using base::Time;
38 using base::TimeDelta;
39 using base::TimeTicks;
40
41 namespace {
42
43 const char kIndexName[] = "index";
44
45 // Seems like ~240 MB correspond to less than 50k entries for 99% of the people.
46 // Note that the actual target is to keep the index table load factor under 55%
47 // for most users.
48 const int k64kEntriesStore = 240 * 1000 * 1000;
49 const int kBaseTableLen = 64 * 1024;
50
51 // Avoid trimming the cache for the first 5 minutes (10 timer ticks).
52 const int kTrimDelay = 10;
53
54 int DesiredIndexTableLen(int32 storage_size) {
55 if (storage_size <= k64kEntriesStore)
56 return kBaseTableLen;
57 if (storage_size <= k64kEntriesStore * 2)
58 return kBaseTableLen * 2;
59 if (storage_size <= k64kEntriesStore * 4)
60 return kBaseTableLen * 4;
61 if (storage_size <= k64kEntriesStore * 8)
62 return kBaseTableLen * 8;
63
64 // The biggest storage_size for int32 requires a 4 MB table.
65 return kBaseTableLen * 16;
66 }
67
68 int MaxStorageSizeForTable(int table_len) {
69 return table_len * (k64kEntriesStore / kBaseTableLen);
70 }
71
72 size_t GetIndexSize(int table_len) {
73 size_t table_size = sizeof(disk_cache::CacheAddr) * table_len;
74 return sizeof(disk_cache::IndexHeader) + table_size;
75 }
76
77 // ------------------------------------------------------------------------
78
79 // Sets group for the current experiment. Returns false if the files should be
80 // discarded.
81 bool InitExperiment(disk_cache::IndexHeader* header, bool cache_created) {
82 if (header->experiment == disk_cache::EXPERIMENT_OLD_FILE1 ||
83 header->experiment == disk_cache::EXPERIMENT_OLD_FILE2) {
84 // Discard current cache.
85 return false;
86 }
87
88 if (base::FieldTrialList::FindFullName("SimpleCacheTrial") ==
89 "ExperimentControl") {
90 if (cache_created) {
91 header->experiment = disk_cache::EXPERIMENT_SIMPLE_CONTROL;
92 return true;
93 }
94 return header->experiment == disk_cache::EXPERIMENT_SIMPLE_CONTROL;
95 }
96
97 header->experiment = disk_cache::NO_EXPERIMENT;
98 return true;
99 }
100
101 // A callback to perform final cleanup on the background thread.
102 void FinalCleanupCallback(disk_cache::BackendImpl* backend) {
103 backend->CleanupCache();
104 }
105
106 } // namespace
107
108 // ------------------------------------------------------------------------
109
110 namespace disk_cache {
111
112 BackendImpl::BackendImpl(
113 const base::FilePath& path,
114 const scoped_refptr<base::SingleThreadTaskRunner>& cache_thread,
115 net::NetLog* net_log)
116 : background_queue_(this, cache_thread),
117 path_(path),
118 block_files_(path),
119 mask_(0),
120 max_size_(0),
121 up_ticks_(0),
122 cache_type_(net::DISK_CACHE),
123 uma_report_(0),
124 user_flags_(0),
125 init_(false),
126 restarted_(false),
127 unit_test_(false),
128 read_only_(false),
129 disabled_(false),
130 new_eviction_(false),
131 first_timer_(true),
132 user_load_(false),
133 net_log_(net_log),
134 done_(true, false),
135 ptr_factory_(this) {
136 }
137
138 BackendImpl::BackendImpl(
139 const base::FilePath& path,
140 uint32 mask,
141 const scoped_refptr<base::SingleThreadTaskRunner>& cache_thread,
142 net::NetLog* net_log)
143 : background_queue_(this, cache_thread),
144 path_(path),
145 block_files_(path),
146 mask_(mask),
147 max_size_(0),
148 up_ticks_(0),
149 cache_type_(net::DISK_CACHE),
150 uma_report_(0),
151 user_flags_(kMask),
152 init_(false),
153 restarted_(false),
154 unit_test_(false),
155 read_only_(false),
156 disabled_(false),
157 new_eviction_(false),
158 first_timer_(true),
159 user_load_(false),
160 net_log_(net_log),
161 done_(true, false),
162 ptr_factory_(this) {
163 }
164
165 BackendImpl::~BackendImpl() {
166 if (user_flags_ & kNoRandom) {
167 // This is a unit test, so we want to be strict about not leaking entries
168 // and completing all the work.
169 background_queue_.WaitForPendingIO();
170 } else {
171 // This is most likely not a test, so we want to do as little work as
172 // possible at this time, at the price of leaving dirty entries behind.
173 background_queue_.DropPendingIO();
174 }
175
176 if (background_queue_.BackgroundIsCurrentThread()) {
177 // Unit tests may use the same thread for everything.
178 CleanupCache();
179 } else {
180 background_queue_.background_thread()->PostTask(
181 FROM_HERE, base::Bind(&FinalCleanupCallback, base::Unretained(this)));
182 // http://crbug.com/74623
183 base::ThreadRestrictions::ScopedAllowWait allow_wait;
184 done_.Wait();
185 }
186 }
187
188 int BackendImpl::Init(const CompletionCallback& callback) {
189 background_queue_.Init(callback);
190 return net::ERR_IO_PENDING;
191 }
192
193 int BackendImpl::SyncInit() {
194 #if defined(NET_BUILD_STRESS_CACHE)
195 // Start evictions right away.
196 up_ticks_ = kTrimDelay * 2;
197 #endif
198 DCHECK(!init_);
199 if (init_)
200 return net::ERR_FAILED;
201
202 bool create_files = false;
203 if (!InitBackingStore(&create_files)) {
204 ReportError(ERR_STORAGE_ERROR);
205 return net::ERR_FAILED;
206 }
207
208 num_refs_ = num_pending_io_ = max_refs_ = 0;
209 entry_count_ = byte_count_ = 0;
210
211 bool should_create_timer = false;
212 if (!restarted_) {
213 buffer_bytes_ = 0;
214 trace_object_ = TraceObject::GetTraceObject();
215 should_create_timer = true;
216 }
217
218 init_ = true;
219 Trace("Init");
220
221 if (data_->header.experiment != NO_EXPERIMENT &&
222 cache_type_ != net::DISK_CACHE) {
223 // No experiment for other caches.
224 return net::ERR_FAILED;
225 }
226
227 if (!(user_flags_ & kNoRandom)) {
228 // The unit test controls directly what to test.
229 new_eviction_ = (cache_type_ == net::DISK_CACHE);
230 }
231
232 if (!CheckIndex()) {
233 ReportError(ERR_INIT_FAILED);
234 return net::ERR_FAILED;
235 }
236
237 if (!restarted_ && (create_files || !data_->header.num_entries))
238 ReportError(ERR_CACHE_CREATED);
239
240 if (!(user_flags_ & kNoRandom) && cache_type_ == net::DISK_CACHE &&
241 !InitExperiment(&data_->header, create_files)) {
242 return net::ERR_FAILED;
243 }
244
245 // We don't care if the value overflows. The only thing we care about is that
246 // the id cannot be zero, because that value is used as "not dirty".
247 // Increasing the value once per second gives us many years before we start
248 // having collisions.
249 data_->header.this_id++;
250 if (!data_->header.this_id)
251 data_->header.this_id++;
252
253 bool previous_crash = (data_->header.crash != 0);
254 data_->header.crash = 1;
255
256 if (!block_files_.Init(create_files))
257 return net::ERR_FAILED;
258
259 // We want to minimize the changes to cache for an AppCache.
260 if (cache_type() == net::APP_CACHE) {
261 DCHECK(!new_eviction_);
262 read_only_ = true;
263 } else if (cache_type() == net::SHADER_CACHE) {
264 DCHECK(!new_eviction_);
265 }
266
267 eviction_.Init(this);
268
269 // stats_ and rankings_ may end up calling back to us so we better be enabled.
270 disabled_ = false;
271 if (!InitStats())
272 return net::ERR_FAILED;
273
274 disabled_ = !rankings_.Init(this, new_eviction_);
275
276 #if defined(STRESS_CACHE_EXTENDED_VALIDATION)
277 trace_object_->EnableTracing(false);
278 int sc = SelfCheck();
279 if (sc < 0 && sc != ERR_NUM_ENTRIES_MISMATCH)
280 NOTREACHED();
281 trace_object_->EnableTracing(true);
282 #endif
283
284 if (previous_crash) {
285 ReportError(ERR_PREVIOUS_CRASH);
286 } else if (!restarted_) {
287 ReportError(ERR_NO_ERROR);
288 }
289
290 FlushIndex();
291
292 if (!disabled_ && should_create_timer) {
293 // Create a recurrent timer of 30 secs.
294 int timer_delay = unit_test_ ? 1000 : 30000;
295 timer_.reset(new base::RepeatingTimer<BackendImpl>());
296 timer_->Start(FROM_HERE, TimeDelta::FromMilliseconds(timer_delay), this,
297 &BackendImpl::OnStatsTimer);
298 }
299
300 return disabled_ ? net::ERR_FAILED : net::OK;
301 }
302
303 void BackendImpl::CleanupCache() {
304 Trace("Backend Cleanup");
305 eviction_.Stop();
306 timer_.reset();
307
308 if (init_) {
309 StoreStats();
310 if (data_)
311 data_->header.crash = 0;
312
313 if (user_flags_ & kNoRandom) {
314 // This is a net_unittest, verify that we are not 'leaking' entries.
315 File::WaitForPendingIO(&num_pending_io_);
316 DCHECK(!num_refs_);
317 } else {
318 File::DropPendingIO();
319 }
320 }
321 block_files_.CloseFiles();
322 FlushIndex();
323 index_ = NULL;
324 ptr_factory_.InvalidateWeakPtrs();
325 done_.Signal();
326 }
327
328 // ------------------------------------------------------------------------
329
330 int BackendImpl::SyncOpenEntry(const std::string& key, Entry** entry) {
331 DCHECK(entry);
332 *entry = OpenEntryImpl(key);
333 return (*entry) ? net::OK : net::ERR_FAILED;
334 }
335
336 int BackendImpl::SyncCreateEntry(const std::string& key, Entry** entry) {
337 DCHECK(entry);
338 *entry = CreateEntryImpl(key);
339 return (*entry) ? net::OK : net::ERR_FAILED;
340 }
341
342 int BackendImpl::SyncDoomEntry(const std::string& key) {
343 if (disabled_)
344 return net::ERR_FAILED;
345
346 EntryImpl* entry = OpenEntryImpl(key);
347 if (!entry)
348 return net::ERR_FAILED;
349
350 entry->DoomImpl();
351 entry->Release();
352 return net::OK;
353 }
354
355 int BackendImpl::SyncDoomAllEntries() {
356 // This is not really an error, but it is an interesting condition.
357 ReportError(ERR_CACHE_DOOMED);
358 stats_.OnEvent(Stats::DOOM_CACHE);
359 if (!num_refs_) {
360 RestartCache(false);
361 return disabled_ ? net::ERR_FAILED : net::OK;
362 } else {
363 if (disabled_)
364 return net::ERR_FAILED;
365
366 eviction_.TrimCache(true);
367 return net::OK;
368 }
369 }
370
371 int BackendImpl::SyncDoomEntriesBetween(const base::Time initial_time,
372 const base::Time end_time) {
373 DCHECK_NE(net::APP_CACHE, cache_type_);
374 if (end_time.is_null())
375 return SyncDoomEntriesSince(initial_time);
376
377 DCHECK(end_time >= initial_time);
378
379 if (disabled_)
380 return net::ERR_FAILED;
381
382 EntryImpl* node;
383 scoped_ptr<Rankings::Iterator> iterator(new Rankings::Iterator());
384 EntryImpl* next = OpenNextEntryImpl(iterator.get());
385 if (!next)
386 return net::OK;
387
388 while (next) {
389 node = next;
390 next = OpenNextEntryImpl(iterator.get());
391
392 if (node->GetLastUsed() >= initial_time &&
393 node->GetLastUsed() < end_time) {
394 node->DoomImpl();
395 } else if (node->GetLastUsed() < initial_time) {
396 if (next)
397 next->Release();
398 next = NULL;
399 SyncEndEnumeration(iterator.Pass());
400 }
401
402 node->Release();
403 }
404
405 return net::OK;
406 }
407
408 // We use OpenNextEntryImpl to retrieve elements from the cache, until we get
409 // entries that are too old.
410 int BackendImpl::SyncDoomEntriesSince(const base::Time initial_time) {
411 DCHECK_NE(net::APP_CACHE, cache_type_);
412 if (disabled_)
413 return net::ERR_FAILED;
414
415 stats_.OnEvent(Stats::DOOM_RECENT);
416 for (;;) {
417 scoped_ptr<Rankings::Iterator> iterator(new Rankings::Iterator());
418 EntryImpl* entry = OpenNextEntryImpl(iterator.get());
419 if (!entry)
420 return net::OK;
421
422 if (initial_time > entry->GetLastUsed()) {
423 entry->Release();
424 SyncEndEnumeration(iterator.Pass());
425 return net::OK;
426 }
427
428 entry->DoomImpl();
429 entry->Release();
430 SyncEndEnumeration(iterator.Pass()); // The doom invalidated the iterator.
431 }
432 }
433
434 int BackendImpl::SyncOpenNextEntry(Rankings::Iterator* iterator,
435 Entry** next_entry) {
436 *next_entry = OpenNextEntryImpl(iterator);
437 return (*next_entry) ? net::OK : net::ERR_FAILED;
438 }
439
440 void BackendImpl::SyncEndEnumeration(scoped_ptr<Rankings::Iterator> iterator) {
441 iterator->Reset();
442 }
443
444 void BackendImpl::SyncOnExternalCacheHit(const std::string& key) {
445 if (disabled_)
446 return;
447
448 uint32 hash = base::Hash(key);
449 bool error;
450 EntryImpl* cache_entry = MatchEntry(key, hash, false, Addr(), &error);
451 if (cache_entry) {
452 if (ENTRY_NORMAL == cache_entry->entry()->Data()->state) {
453 UpdateRank(cache_entry, cache_type() == net::SHADER_CACHE);
454 }
455 cache_entry->Release();
456 }
457 }
458
459 EntryImpl* BackendImpl::OpenEntryImpl(const std::string& key) {
460 if (disabled_)
461 return NULL;
462
463 TimeTicks start = TimeTicks::Now();
464 uint32 hash = base::Hash(key);
465 Trace("Open hash 0x%x", hash);
466
467 bool error;
468 EntryImpl* cache_entry = MatchEntry(key, hash, false, Addr(), &error);
469 if (cache_entry && ENTRY_NORMAL != cache_entry->entry()->Data()->state) {
470 // The entry was already evicted.
471 cache_entry->Release();
472 cache_entry = NULL;
473 web_fonts_histogram::RecordEvictedEntry(key);
474 } else if (!cache_entry) {
475 web_fonts_histogram::RecordCacheMiss(key);
476 }
477
478 int current_size = data_->header.num_bytes / (1024 * 1024);
479 int64 total_hours = stats_.GetCounter(Stats::TIMER) / 120;
480 int64 no_use_hours = stats_.GetCounter(Stats::LAST_REPORT_TIMER) / 120;
481 int64 use_hours = total_hours - no_use_hours;
482
483 if (!cache_entry) {
484 CACHE_UMA(AGE_MS, "OpenTime.Miss", 0, start);
485 CACHE_UMA(COUNTS_10000, "AllOpenBySize.Miss", 0, current_size);
486 CACHE_UMA(HOURS, "AllOpenByTotalHours.Miss", 0,
487 static_cast<base::HistogramBase::Sample>(total_hours));
488 CACHE_UMA(HOURS, "AllOpenByUseHours.Miss", 0,
489 static_cast<base::HistogramBase::Sample>(use_hours));
490 stats_.OnEvent(Stats::OPEN_MISS);
491 return NULL;
492 }
493
494 eviction_.OnOpenEntry(cache_entry);
495 entry_count_++;
496
497 Trace("Open hash 0x%x end: 0x%x", hash,
498 cache_entry->entry()->address().value());
499 CACHE_UMA(AGE_MS, "OpenTime", 0, start);
500 CACHE_UMA(COUNTS_10000, "AllOpenBySize.Hit", 0, current_size);
501 CACHE_UMA(HOURS, "AllOpenByTotalHours.Hit", 0,
502 static_cast<base::HistogramBase::Sample>(total_hours));
503 CACHE_UMA(HOURS, "AllOpenByUseHours.Hit", 0,
504 static_cast<base::HistogramBase::Sample>(use_hours));
505 stats_.OnEvent(Stats::OPEN_HIT);
506 web_fonts_histogram::RecordCacheHit(cache_entry);
507 return cache_entry;
508 }
509
510 EntryImpl* BackendImpl::CreateEntryImpl(const std::string& key) {
511 if (disabled_ || key.empty())
512 return NULL;
513
514 TimeTicks start = TimeTicks::Now();
515 uint32 hash = base::Hash(key);
516 Trace("Create hash 0x%x", hash);
517
518 scoped_refptr<EntryImpl> parent;
519 Addr entry_address(data_->table[hash & mask_]);
520 if (entry_address.is_initialized()) {
521 // We have an entry already. It could be the one we are looking for, or just
522 // a hash conflict.
523 bool error;
524 EntryImpl* old_entry = MatchEntry(key, hash, false, Addr(), &error);
525 if (old_entry)
526 return ResurrectEntry(old_entry);
527
528 EntryImpl* parent_entry = MatchEntry(key, hash, true, Addr(), &error);
529 DCHECK(!error);
530 if (parent_entry) {
531 parent.swap(&parent_entry);
532 } else if (data_->table[hash & mask_]) {
533 // We should have corrected the problem.
534 NOTREACHED();
535 return NULL;
536 }
537 }
538
539 // The general flow is to allocate disk space and initialize the entry data,
540 // followed by saving that to disk, then linking the entry though the index
541 // and finally through the lists. If there is a crash in this process, we may
542 // end up with:
543 // a. Used, unreferenced empty blocks on disk (basically just garbage).
544 // b. Used, unreferenced but meaningful data on disk (more garbage).
545 // c. A fully formed entry, reachable only through the index.
546 // d. A fully formed entry, also reachable through the lists, but still dirty.
547 //
548 // Anything after (b) can be automatically cleaned up. We may consider saving
549 // the current operation (as we do while manipulating the lists) so that we
550 // can detect and cleanup (a) and (b).
551
552 int num_blocks = EntryImpl::NumBlocksForEntry(key.size());
553 if (!block_files_.CreateBlock(BLOCK_256, num_blocks, &entry_address)) {
554 LOG(ERROR) << "Create entry failed " << key.c_str();
555 stats_.OnEvent(Stats::CREATE_ERROR);
556 return NULL;
557 }
558
559 Addr node_address(0);
560 if (!block_files_.CreateBlock(RANKINGS, 1, &node_address)) {
561 block_files_.DeleteBlock(entry_address, false);
562 LOG(ERROR) << "Create entry failed " << key.c_str();
563 stats_.OnEvent(Stats::CREATE_ERROR);
564 return NULL;
565 }
566
567 scoped_refptr<EntryImpl> cache_entry(
568 new EntryImpl(this, entry_address, false));
569 IncreaseNumRefs();
570
571 if (!cache_entry->CreateEntry(node_address, key, hash)) {
572 block_files_.DeleteBlock(entry_address, false);
573 block_files_.DeleteBlock(node_address, false);
574 LOG(ERROR) << "Create entry failed " << key.c_str();
575 stats_.OnEvent(Stats::CREATE_ERROR);
576 return NULL;
577 }
578
579 cache_entry->BeginLogging(net_log_, true);
580
581 // We are not failing the operation; let's add this to the map.
582 open_entries_[entry_address.value()] = cache_entry.get();
583
584 // Save the entry.
585 cache_entry->entry()->Store();
586 cache_entry->rankings()->Store();
587 IncreaseNumEntries();
588 entry_count_++;
589
590 // Link this entry through the index.
591 if (parent.get()) {
592 parent->SetNextAddress(entry_address);
593 } else {
594 data_->table[hash & mask_] = entry_address.value();
595 }
596
597 // Link this entry through the lists.
598 eviction_.OnCreateEntry(cache_entry.get());
599
600 CACHE_UMA(AGE_MS, "CreateTime", 0, start);
601 stats_.OnEvent(Stats::CREATE_HIT);
602 Trace("create entry hit ");
603 FlushIndex();
604 cache_entry->AddRef();
605 return cache_entry.get();
606 }
607
608 EntryImpl* BackendImpl::OpenNextEntryImpl(Rankings::Iterator* iterator) {
609 if (disabled_)
610 return NULL;
611
612 const int kListsToSearch = 3;
613 scoped_refptr<EntryImpl> entries[kListsToSearch];
614 if (!iterator->my_rankings) {
615 iterator->my_rankings = &rankings_;
616 bool ret = false;
617
618 // Get an entry from each list.
619 for (int i = 0; i < kListsToSearch; i++) {
620 EntryImpl* temp = NULL;
621 ret |= OpenFollowingEntryFromList(static_cast<Rankings::List>(i),
622 &iterator->nodes[i], &temp);
623 entries[i].swap(&temp); // The entry was already addref'd.
624 }
625 if (!ret) {
626 iterator->Reset();
627 return NULL;
628 }
629 } else {
630 // Get the next entry from the last list, and the actual entries for the
631 // elements on the other lists.
632 for (int i = 0; i < kListsToSearch; i++) {
633 EntryImpl* temp = NULL;
634 if (iterator->list == i) {
635 OpenFollowingEntryFromList(
636 iterator->list, &iterator->nodes[i], &temp);
637 } else {
638 temp = GetEnumeratedEntry(iterator->nodes[i],
639 static_cast<Rankings::List>(i));
640 }
641
642 entries[i].swap(&temp); // The entry was already addref'd.
643 }
644 }
645
646 int newest = -1;
647 int oldest = -1;
648 Time access_times[kListsToSearch];
649 for (int i = 0; i < kListsToSearch; i++) {
650 if (entries[i].get()) {
651 access_times[i] = entries[i]->GetLastUsed();
652 if (newest < 0) {
653 DCHECK_LT(oldest, 0);
654 newest = oldest = i;
655 continue;
656 }
657 if (access_times[i] > access_times[newest])
658 newest = i;
659 if (access_times[i] < access_times[oldest])
660 oldest = i;
661 }
662 }
663
664 if (newest < 0 || oldest < 0) {
665 iterator->Reset();
666 return NULL;
667 }
668
669 EntryImpl* next_entry;
670 next_entry = entries[newest].get();
671 iterator->list = static_cast<Rankings::List>(newest);
672 next_entry->AddRef();
673 return next_entry;
674 }
675
676 bool BackendImpl::SetMaxSize(int max_bytes) {
677 static_assert(sizeof(max_bytes) == sizeof(max_size_),
678 "unsupported int model");
679 if (max_bytes < 0)
680 return false;
681
682 // Zero size means use the default.
683 if (!max_bytes)
684 return true;
685
686 // Avoid a DCHECK later on.
687 if (max_bytes >= kint32max - kint32max / 10)
688 max_bytes = kint32max - kint32max / 10 - 1;
689
690 user_flags_ |= kMaxSize;
691 max_size_ = max_bytes;
692 return true;
693 }
694
695 void BackendImpl::SetType(net::CacheType type) {
696 DCHECK_NE(net::MEMORY_CACHE, type);
697 cache_type_ = type;
698 }
699
700 base::FilePath BackendImpl::GetFileName(Addr address) const {
701 if (!address.is_separate_file() || !address.is_initialized()) {
702 NOTREACHED();
703 return base::FilePath();
704 }
705
706 std::string tmp = base::StringPrintf("f_%06x", address.FileNumber());
707 return path_.AppendASCII(tmp);
708 }
709
710 MappedFile* BackendImpl::File(Addr address) {
711 if (disabled_)
712 return NULL;
713 return block_files_.GetFile(address);
714 }
715
716 base::WeakPtr<InFlightBackendIO> BackendImpl::GetBackgroundQueue() {
717 return background_queue_.GetWeakPtr();
718 }
719
720 bool BackendImpl::CreateExternalFile(Addr* address) {
721 int file_number = data_->header.last_file + 1;
722 Addr file_address(0);
723 bool success = false;
724 for (int i = 0; i < 0x0fffffff; i++, file_number++) {
725 if (!file_address.SetFileNumber(file_number)) {
726 file_number = 1;
727 continue;
728 }
729 base::FilePath name = GetFileName(file_address);
730 int flags = base::File::FLAG_READ | base::File::FLAG_WRITE |
731 base::File::FLAG_CREATE | base::File::FLAG_EXCLUSIVE_WRITE;
732 base::File file(name, flags);
733 if (!file.IsValid()) {
734 base::File::Error error = file.error_details();
735 if (error != base::File::FILE_ERROR_EXISTS) {
736 LOG(ERROR) << "Unable to create file: " << error;
737 return false;
738 }
739 continue;
740 }
741
742 success = true;
743 break;
744 }
745
746 DCHECK(success);
747 if (!success)
748 return false;
749
750 data_->header.last_file = file_number;
751 address->set_value(file_address.value());
752 return true;
753 }
754
755 bool BackendImpl::CreateBlock(FileType block_type, int block_count,
756 Addr* block_address) {
757 return block_files_.CreateBlock(block_type, block_count, block_address);
758 }
759
760 void BackendImpl::DeleteBlock(Addr block_address, bool deep) {
761 block_files_.DeleteBlock(block_address, deep);
762 }
763
764 LruData* BackendImpl::GetLruData() {
765 return &data_->header.lru;
766 }
767
768 void BackendImpl::UpdateRank(EntryImpl* entry, bool modified) {
769 if (read_only_ || (!modified && cache_type() == net::SHADER_CACHE))
770 return;
771 eviction_.UpdateRank(entry, modified);
772 }
773
774 void BackendImpl::RecoveredEntry(CacheRankingsBlock* rankings) {
775 Addr address(rankings->Data()->contents);
776 EntryImpl* cache_entry = NULL;
777 if (NewEntry(address, &cache_entry)) {
778 STRESS_NOTREACHED();
779 return;
780 }
781
782 uint32 hash = cache_entry->GetHash();
783 cache_entry->Release();
784
785 // Anything on the table means that this entry is there.
786 if (data_->table[hash & mask_])
787 return;
788
789 data_->table[hash & mask_] = address.value();
790 FlushIndex();
791 }
792
793 void BackendImpl::InternalDoomEntry(EntryImpl* entry) {
794 uint32 hash = entry->GetHash();
795 std::string key = entry->GetKey();
796 Addr entry_addr = entry->entry()->address();
797 bool error;
798 EntryImpl* parent_entry = MatchEntry(key, hash, true, entry_addr, &error);
799 CacheAddr child(entry->GetNextAddress());
800
801 Trace("Doom entry 0x%p", entry);
802
803 if (!entry->doomed()) {
804 // We may have doomed this entry from within MatchEntry.
805 eviction_.OnDoomEntry(entry);
806 entry->InternalDoom();
807 if (!new_eviction_) {
808 DecreaseNumEntries();
809 }
810 stats_.OnEvent(Stats::DOOM_ENTRY);
811 }
812
813 if (parent_entry) {
814 parent_entry->SetNextAddress(Addr(child));
815 parent_entry->Release();
816 } else if (!error) {
817 data_->table[hash & mask_] = child;
818 }
819
820 FlushIndex();
821 }
822
823 #if defined(NET_BUILD_STRESS_CACHE)
824
825 CacheAddr BackendImpl::GetNextAddr(Addr address) {
826 EntriesMap::iterator it = open_entries_.find(address.value());
827 if (it != open_entries_.end()) {
828 EntryImpl* this_entry = it->second;
829 return this_entry->GetNextAddress();
830 }
831 DCHECK(block_files_.IsValid(address));
832 DCHECK(!address.is_separate_file() && address.file_type() == BLOCK_256);
833
834 CacheEntryBlock entry(File(address), address);
835 CHECK(entry.Load());
836 return entry.Data()->next;
837 }
838
839 void BackendImpl::NotLinked(EntryImpl* entry) {
840 Addr entry_addr = entry->entry()->address();
841 uint32 i = entry->GetHash() & mask_;
842 Addr address(data_->table[i]);
843 if (!address.is_initialized())
844 return;
845
846 for (;;) {
847 DCHECK(entry_addr.value() != address.value());
848 address.set_value(GetNextAddr(address));
849 if (!address.is_initialized())
850 break;
851 }
852 }
853 #endif // NET_BUILD_STRESS_CACHE
854
855 // An entry may be linked on the DELETED list for a while after being doomed.
856 // This function is called when we want to remove it.
857 void BackendImpl::RemoveEntry(EntryImpl* entry) {
858 #if defined(NET_BUILD_STRESS_CACHE)
859 NotLinked(entry);
860 #endif
861 if (!new_eviction_)
862 return;
863
864 DCHECK_NE(ENTRY_NORMAL, entry->entry()->Data()->state);
865
866 Trace("Remove entry 0x%p", entry);
867 eviction_.OnDestroyEntry(entry);
868 DecreaseNumEntries();
869 }
870
871 void BackendImpl::OnEntryDestroyBegin(Addr address) {
872 EntriesMap::iterator it = open_entries_.find(address.value());
873 if (it != open_entries_.end())
874 open_entries_.erase(it);
875 }
876
877 void BackendImpl::OnEntryDestroyEnd() {
878 DecreaseNumRefs();
879 if (data_->header.num_bytes > max_size_ && !read_only_ &&
880 (up_ticks_ > kTrimDelay || user_flags_ & kNoRandom))
881 eviction_.TrimCache(false);
882 }
883
884 EntryImpl* BackendImpl::GetOpenEntry(CacheRankingsBlock* rankings) const {
885 DCHECK(rankings->HasData());
886 EntriesMap::const_iterator it =
887 open_entries_.find(rankings->Data()->contents);
888 if (it != open_entries_.end()) {
889 // We have this entry in memory.
890 return it->second;
891 }
892
893 return NULL;
894 }
895
896 int32 BackendImpl::GetCurrentEntryId() const {
897 return data_->header.this_id;
898 }
899
900 int BackendImpl::MaxFileSize() const {
901 return cache_type() == net::PNACL_CACHE ? max_size_ : max_size_ / 8;
902 }
903
904 void BackendImpl::ModifyStorageSize(int32 old_size, int32 new_size) {
905 if (disabled_ || old_size == new_size)
906 return;
907 if (old_size > new_size)
908 SubstractStorageSize(old_size - new_size);
909 else
910 AddStorageSize(new_size - old_size);
911
912 FlushIndex();
913
914 // Update the usage statistics.
915 stats_.ModifyStorageStats(old_size, new_size);
916 }
917
918 void BackendImpl::TooMuchStorageRequested(int32 size) {
919 stats_.ModifyStorageStats(0, size);
920 }
921
922 bool BackendImpl::IsAllocAllowed(int current_size, int new_size) {
923 DCHECK_GT(new_size, current_size);
924 if (user_flags_ & kNoBuffering)
925 return false;
926
927 int to_add = new_size - current_size;
928 if (buffer_bytes_ + to_add > MaxBuffersSize())
929 return false;
930
931 buffer_bytes_ += to_add;
932 CACHE_UMA(COUNTS_50000, "BufferBytes", 0, buffer_bytes_ / 1024);
933 return true;
934 }
935
936 void BackendImpl::BufferDeleted(int size) {
937 buffer_bytes_ -= size;
938 DCHECK_GE(size, 0);
939 }
940
941 bool BackendImpl::IsLoaded() const {
942 CACHE_UMA(COUNTS, "PendingIO", 0, num_pending_io_);
943 if (user_flags_ & kNoLoadProtection)
944 return false;
945
946 return (num_pending_io_ > 5 || user_load_);
947 }
948
949 std::string BackendImpl::HistogramName(const char* name, int experiment) const {
950 if (!experiment)
951 return base::StringPrintf("DiskCache.%d.%s", cache_type_, name);
952 return base::StringPrintf("DiskCache.%d.%s_%d", cache_type_,
953 name, experiment);
954 }
955
956 base::WeakPtr<BackendImpl> BackendImpl::GetWeakPtr() {
957 return ptr_factory_.GetWeakPtr();
958 }
959
960 // We want to remove biases from some histograms so we only send data once per
961 // week.
962 bool BackendImpl::ShouldReportAgain() {
963 if (uma_report_)
964 return uma_report_ == 2;
965
966 uma_report_++;
967 int64 last_report = stats_.GetCounter(Stats::LAST_REPORT);
968 Time last_time = Time::FromInternalValue(last_report);
969 if (!last_report || (Time::Now() - last_time).InDays() >= 7) {
970 stats_.SetCounter(Stats::LAST_REPORT, Time::Now().ToInternalValue());
971 uma_report_++;
972 return true;
973 }
974 return false;
975 }
976
977 void BackendImpl::FirstEviction() {
978 DCHECK(data_->header.create_time);
979 if (!GetEntryCount())
980 return; // This is just for unit tests.
981
982 Time create_time = Time::FromInternalValue(data_->header.create_time);
983 CACHE_UMA(AGE, "FillupAge", 0, create_time);
984
985 int64 use_time = stats_.GetCounter(Stats::TIMER);
986 CACHE_UMA(HOURS, "FillupTime", 0, static_cast<int>(use_time / 120));
987 CACHE_UMA(PERCENTAGE, "FirstHitRatio", 0, stats_.GetHitRatio());
988
989 if (!use_time)
990 use_time = 1;
991 CACHE_UMA(COUNTS_10000, "FirstEntryAccessRate", 0,
992 static_cast<int>(data_->header.num_entries / use_time));
993 CACHE_UMA(COUNTS, "FirstByteIORate", 0,
994 static_cast<int>((data_->header.num_bytes / 1024) / use_time));
995
996 int avg_size = data_->header.num_bytes / GetEntryCount();
997 CACHE_UMA(COUNTS, "FirstEntrySize", 0, avg_size);
998
999 int large_entries_bytes = stats_.GetLargeEntriesSize();
1000 int large_ratio = large_entries_bytes * 100 / data_->header.num_bytes;
1001 CACHE_UMA(PERCENTAGE, "FirstLargeEntriesRatio", 0, large_ratio);
1002
1003 if (new_eviction_) {
1004 CACHE_UMA(PERCENTAGE, "FirstResurrectRatio", 0, stats_.GetResurrectRatio());
1005 CACHE_UMA(PERCENTAGE, "FirstNoUseRatio", 0,
1006 data_->header.lru.sizes[0] * 100 / data_->header.num_entries);
1007 CACHE_UMA(PERCENTAGE, "FirstLowUseRatio", 0,
1008 data_->header.lru.sizes[1] * 100 / data_->header.num_entries);
1009 CACHE_UMA(PERCENTAGE, "FirstHighUseRatio", 0,
1010 data_->header.lru.sizes[2] * 100 / data_->header.num_entries);
1011 }
1012
1013 stats_.ResetRatios();
1014 }
1015
1016 void BackendImpl::CriticalError(int error) {
1017 STRESS_NOTREACHED();
1018 LOG(ERROR) << "Critical error found " << error;
1019 if (disabled_)
1020 return;
1021
1022 stats_.OnEvent(Stats::FATAL_ERROR);
1023 LogStats();
1024 ReportError(error);
1025
1026 // Setting the index table length to an invalid value will force re-creation
1027 // of the cache files.
1028 data_->header.table_len = 1;
1029 disabled_ = true;
1030
1031 if (!num_refs_)
1032 base::MessageLoop::current()->PostTask(
1033 FROM_HERE, base::Bind(&BackendImpl::RestartCache, GetWeakPtr(), true));
1034 }
1035
1036 void BackendImpl::ReportError(int error) {
1037 STRESS_DCHECK(!error || error == ERR_PREVIOUS_CRASH ||
1038 error == ERR_CACHE_CREATED);
1039
1040 // We transmit positive numbers, instead of direct error codes.
1041 DCHECK_LE(error, 0);
1042 CACHE_UMA(CACHE_ERROR, "Error", 0, error * -1);
1043 }
1044
1045 void BackendImpl::OnEvent(Stats::Counters an_event) {
1046 stats_.OnEvent(an_event);
1047 }
1048
1049 void BackendImpl::OnRead(int32 bytes) {
1050 DCHECK_GE(bytes, 0);
1051 byte_count_ += bytes;
1052 if (byte_count_ < 0)
1053 byte_count_ = kint32max;
1054 }
1055
1056 void BackendImpl::OnWrite(int32 bytes) {
1057 // We use the same implementation as OnRead... just log the number of bytes.
1058 OnRead(bytes);
1059 }
1060
1061 void BackendImpl::OnStatsTimer() {
1062 if (disabled_)
1063 return;
1064
1065 stats_.OnEvent(Stats::TIMER);
1066 int64 time = stats_.GetCounter(Stats::TIMER);
1067 int64 current = stats_.GetCounter(Stats::OPEN_ENTRIES);
1068
1069 // OPEN_ENTRIES is a sampled average of the number of open entries, avoiding
1070 // the bias towards 0.
1071 if (num_refs_ && (current != num_refs_)) {
1072 int64 diff = (num_refs_ - current) / 50;
1073 if (!diff)
1074 diff = num_refs_ > current ? 1 : -1;
1075 current = current + diff;
1076 stats_.SetCounter(Stats::OPEN_ENTRIES, current);
1077 stats_.SetCounter(Stats::MAX_ENTRIES, max_refs_);
1078 }
1079
1080 CACHE_UMA(COUNTS, "NumberOfReferences", 0, num_refs_);
1081
1082 CACHE_UMA(COUNTS_10000, "EntryAccessRate", 0, entry_count_);
1083 CACHE_UMA(COUNTS, "ByteIORate", 0, byte_count_ / 1024);
1084
1085 // These values cover about 99.5% of the population (Oct 2011).
1086 user_load_ = (entry_count_ > 300 || byte_count_ > 7 * 1024 * 1024);
1087 entry_count_ = 0;
1088 byte_count_ = 0;
1089 up_ticks_++;
1090
1091 if (!data_)
1092 first_timer_ = false;
1093 if (first_timer_) {
1094 first_timer_ = false;
1095 if (ShouldReportAgain())
1096 ReportStats();
1097 }
1098
1099 // Save stats to disk at 5 min intervals.
1100 if (time % 10 == 0)
1101 StoreStats();
1102 }
1103
1104 void BackendImpl::IncrementIoCount() {
1105 num_pending_io_++;
1106 }
1107
1108 void BackendImpl::DecrementIoCount() {
1109 num_pending_io_--;
1110 }
1111
1112 void BackendImpl::SetUnitTestMode() {
1113 user_flags_ |= kUnitTestMode;
1114 unit_test_ = true;
1115 }
1116
1117 void BackendImpl::SetUpgradeMode() {
1118 user_flags_ |= kUpgradeMode;
1119 read_only_ = true;
1120 }
1121
1122 void BackendImpl::SetNewEviction() {
1123 user_flags_ |= kNewEviction;
1124 new_eviction_ = true;
1125 }
1126
1127 void BackendImpl::SetFlags(uint32 flags) {
1128 user_flags_ |= flags;
1129 }
1130
1131 void BackendImpl::ClearRefCountForTest() {
1132 num_refs_ = 0;
1133 }
1134
1135 int BackendImpl::FlushQueueForTest(const CompletionCallback& callback) {
1136 background_queue_.FlushQueue(callback);
1137 return net::ERR_IO_PENDING;
1138 }
1139
1140 int BackendImpl::RunTaskForTest(const base::Closure& task,
1141 const CompletionCallback& callback) {
1142 background_queue_.RunTask(task, callback);
1143 return net::ERR_IO_PENDING;
1144 }
1145
1146 void BackendImpl::TrimForTest(bool empty) {
1147 eviction_.SetTestMode();
1148 eviction_.TrimCache(empty);
1149 }
1150
1151 void BackendImpl::TrimDeletedListForTest(bool empty) {
1152 eviction_.SetTestMode();
1153 eviction_.TrimDeletedList(empty);
1154 }
1155
1156 base::RepeatingTimer<BackendImpl>* BackendImpl::GetTimerForTest() {
1157 return timer_.get();
1158 }
1159
1160 int BackendImpl::SelfCheck() {
1161 if (!init_) {
1162 LOG(ERROR) << "Init failed";
1163 return ERR_INIT_FAILED;
1164 }
1165
1166 int num_entries = rankings_.SelfCheck();
1167 if (num_entries < 0) {
1168 LOG(ERROR) << "Invalid rankings list, error " << num_entries;
1169 #if !defined(NET_BUILD_STRESS_CACHE)
1170 return num_entries;
1171 #endif
1172 }
1173
1174 if (num_entries != data_->header.num_entries) {
1175 LOG(ERROR) << "Number of entries mismatch";
1176 #if !defined(NET_BUILD_STRESS_CACHE)
1177 return ERR_NUM_ENTRIES_MISMATCH;
1178 #endif
1179 }
1180
1181 return CheckAllEntries();
1182 }
1183
1184 void BackendImpl::FlushIndex() {
1185 if (index_.get() && !disabled_)
1186 index_->Flush();
1187 }
1188
1189 // ------------------------------------------------------------------------
1190
1191 net::CacheType BackendImpl::GetCacheType() const {
1192 return cache_type_;
1193 }
1194
1195 int32 BackendImpl::GetEntryCount() const {
1196 if (!index_.get() || disabled_)
1197 return 0;
1198 // num_entries includes entries already evicted.
1199 int32 not_deleted = data_->header.num_entries -
1200 data_->header.lru.sizes[Rankings::DELETED];
1201
1202 if (not_deleted < 0) {
1203 NOTREACHED();
1204 not_deleted = 0;
1205 }
1206
1207 return not_deleted;
1208 }
1209
1210 int BackendImpl::OpenEntry(const std::string& key, Entry** entry,
1211 const CompletionCallback& callback) {
1212 DCHECK(!callback.is_null());
1213 background_queue_.OpenEntry(key, entry, callback);
1214 return net::ERR_IO_PENDING;
1215 }
1216
1217 int BackendImpl::CreateEntry(const std::string& key, Entry** entry,
1218 const CompletionCallback& callback) {
1219 DCHECK(!callback.is_null());
1220 background_queue_.CreateEntry(key, entry, callback);
1221 return net::ERR_IO_PENDING;
1222 }
1223
1224 int BackendImpl::DoomEntry(const std::string& key,
1225 const CompletionCallback& callback) {
1226 DCHECK(!callback.is_null());
1227 background_queue_.DoomEntry(key, callback);
1228 return net::ERR_IO_PENDING;
1229 }
1230
1231 int BackendImpl::DoomAllEntries(const CompletionCallback& callback) {
1232 DCHECK(!callback.is_null());
1233 background_queue_.DoomAllEntries(callback);
1234 return net::ERR_IO_PENDING;
1235 }
1236
1237 int BackendImpl::DoomEntriesBetween(const base::Time initial_time,
1238 const base::Time end_time,
1239 const CompletionCallback& callback) {
1240 DCHECK(!callback.is_null());
1241 background_queue_.DoomEntriesBetween(initial_time, end_time, callback);
1242 return net::ERR_IO_PENDING;
1243 }
1244
1245 int BackendImpl::DoomEntriesSince(const base::Time initial_time,
1246 const CompletionCallback& callback) {
1247 DCHECK(!callback.is_null());
1248 background_queue_.DoomEntriesSince(initial_time, callback);
1249 return net::ERR_IO_PENDING;
1250 }
1251
1252 class BackendImpl::IteratorImpl : public Backend::Iterator {
1253 public:
1254 explicit IteratorImpl(base::WeakPtr<InFlightBackendIO> background_queue)
1255 : background_queue_(background_queue),
1256 iterator_(new Rankings::Iterator()) {
1257 }
1258
1259 ~IteratorImpl() override {
1260 if (background_queue_)
1261 background_queue_->EndEnumeration(iterator_.Pass());
1262 }
1263
1264 int OpenNextEntry(Entry** next_entry,
1265 const net::CompletionCallback& callback) override {
1266 if (!background_queue_)
1267 return net::ERR_FAILED;
1268 background_queue_->OpenNextEntry(iterator_.get(), next_entry, callback);
1269 return net::ERR_IO_PENDING;
1270 }
1271
1272 private:
1273 const base::WeakPtr<InFlightBackendIO> background_queue_;
1274 scoped_ptr<Rankings::Iterator> iterator_;
1275 };
1276
1277 scoped_ptr<Backend::Iterator> BackendImpl::CreateIterator() {
1278 return scoped_ptr<Backend::Iterator>(new IteratorImpl(GetBackgroundQueue()));
1279 }
1280
1281 void BackendImpl::GetStats(StatsItems* stats) {
1282 if (disabled_)
1283 return;
1284
1285 std::pair<std::string, std::string> item;
1286
1287 item.first = "Entries";
1288 item.second = base::StringPrintf("%d", data_->header.num_entries);
1289 stats->push_back(item);
1290
1291 item.first = "Pending IO";
1292 item.second = base::StringPrintf("%d", num_pending_io_);
1293 stats->push_back(item);
1294
1295 item.first = "Max size";
1296 item.second = base::StringPrintf("%d", max_size_);
1297 stats->push_back(item);
1298
1299 item.first = "Current size";
1300 item.second = base::StringPrintf("%d", data_->header.num_bytes);
1301 stats->push_back(item);
1302
1303 item.first = "Cache type";
1304 item.second = "Blockfile Cache";
1305 stats->push_back(item);
1306
1307 stats_.GetItems(stats);
1308 }
1309
1310 void BackendImpl::OnExternalCacheHit(const std::string& key) {
1311 background_queue_.OnExternalCacheHit(key);
1312 }
1313
1314 // ------------------------------------------------------------------------
1315
1316 // We just created a new file so we're going to write the header and set the
1317 // file length to include the hash table (zero filled).
1318 bool BackendImpl::CreateBackingStore(disk_cache::File* file) {
1319 AdjustMaxCacheSize(0);
1320
1321 IndexHeader header;
1322 header.table_len = DesiredIndexTableLen(max_size_);
1323
1324 // We need file version 2.1 for the new eviction algorithm.
1325 if (new_eviction_)
1326 header.version = 0x20001;
1327
1328 header.create_time = Time::Now().ToInternalValue();
1329
1330 if (!file->Write(&header, sizeof(header), 0))
1331 return false;
1332
1333 return file->SetLength(GetIndexSize(header.table_len));
1334 }
1335
1336 bool BackendImpl::InitBackingStore(bool* file_created) {
1337 if (!base::CreateDirectory(path_))
1338 return false;
1339
1340 base::FilePath index_name = path_.AppendASCII(kIndexName);
1341
1342 int flags = base::File::FLAG_READ | base::File::FLAG_WRITE |
1343 base::File::FLAG_OPEN_ALWAYS | base::File::FLAG_EXCLUSIVE_WRITE;
1344 base::File base_file(index_name, flags);
1345 if (!base_file.IsValid())
1346 return false;
1347
1348 bool ret = true;
1349 *file_created = base_file.created();
1350
1351 scoped_refptr<disk_cache::File> file(new disk_cache::File(base_file.Pass()));
1352 if (*file_created)
1353 ret = CreateBackingStore(file.get());
1354
1355 file = NULL;
1356 if (!ret)
1357 return false;
1358
1359 index_ = new MappedFile();
1360 data_ = static_cast<Index*>(index_->Init(index_name, 0));
1361 if (!data_) {
1362 LOG(ERROR) << "Unable to map Index file";
1363 return false;
1364 }
1365
1366 if (index_->GetLength() < sizeof(Index)) {
1367 // We verify this again on CheckIndex() but it's easier to make sure now
1368 // that the header is there.
1369 LOG(ERROR) << "Corrupt Index file";
1370 return false;
1371 }
1372
1373 return true;
1374 }
1375
1376 // The maximum cache size will be either set explicitly by the caller, or
1377 // calculated by this code.
1378 void BackendImpl::AdjustMaxCacheSize(int table_len) {
1379 if (max_size_)
1380 return;
1381
1382 // If table_len is provided, the index file exists.
1383 DCHECK(!table_len || data_->header.magic);
1384
1385 // The user is not setting the size, let's figure it out.
1386 int64 available = base::SysInfo::AmountOfFreeDiskSpace(path_);
1387 if (available < 0) {
1388 max_size_ = kDefaultCacheSize;
1389 return;
1390 }
1391
1392 if (table_len)
1393 available += data_->header.num_bytes;
1394
1395 max_size_ = PreferredCacheSize(available);
1396
1397 if (!table_len)
1398 return;
1399
1400 // If we already have a table, adjust the size to it.
1401 int current_max_size = MaxStorageSizeForTable(table_len);
1402 if (max_size_ > current_max_size)
1403 max_size_= current_max_size;
1404 }
1405
1406 bool BackendImpl::InitStats() {
1407 Addr address(data_->header.stats);
1408 int size = stats_.StorageSize();
1409
1410 if (!address.is_initialized()) {
1411 FileType file_type = Addr::RequiredFileType(size);
1412 DCHECK_NE(file_type, EXTERNAL);
1413 int num_blocks = Addr::RequiredBlocks(size, file_type);
1414
1415 if (!CreateBlock(file_type, num_blocks, &address))
1416 return false;
1417
1418 data_->header.stats = address.value();
1419 return stats_.Init(NULL, 0, address);
1420 }
1421
1422 if (!address.is_block_file()) {
1423 NOTREACHED();
1424 return false;
1425 }
1426
1427 // Load the required data.
1428 size = address.num_blocks() * address.BlockSize();
1429 MappedFile* file = File(address);
1430 if (!file)
1431 return false;
1432
1433 scoped_ptr<char[]> data(new char[size]);
1434 size_t offset = address.start_block() * address.BlockSize() +
1435 kBlockHeaderSize;
1436 if (!file->Read(data.get(), size, offset))
1437 return false;
1438
1439 if (!stats_.Init(data.get(), size, address))
1440 return false;
1441 if (cache_type_ == net::DISK_CACHE && ShouldReportAgain())
1442 stats_.InitSizeHistogram();
1443 return true;
1444 }
1445
1446 void BackendImpl::StoreStats() {
1447 int size = stats_.StorageSize();
1448 scoped_ptr<char[]> data(new char[size]);
1449 Addr address;
1450 size = stats_.SerializeStats(data.get(), size, &address);
1451 DCHECK(size);
1452 if (!address.is_initialized())
1453 return;
1454
1455 MappedFile* file = File(address);
1456 if (!file)
1457 return;
1458
1459 size_t offset = address.start_block() * address.BlockSize() +
1460 kBlockHeaderSize;
1461 file->Write(data.get(), size, offset); // ignore result.
1462 }
1463
1464 void BackendImpl::RestartCache(bool failure) {
1465 int64 errors = stats_.GetCounter(Stats::FATAL_ERROR);
1466 int64 full_dooms = stats_.GetCounter(Stats::DOOM_CACHE);
1467 int64 partial_dooms = stats_.GetCounter(Stats::DOOM_RECENT);
1468 int64 last_report = stats_.GetCounter(Stats::LAST_REPORT);
1469
1470 PrepareForRestart();
1471 if (failure) {
1472 DCHECK(!num_refs_);
1473 DCHECK(!open_entries_.size());
1474 DelayedCacheCleanup(path_);
1475 } else {
1476 DeleteCache(path_, false);
1477 }
1478
1479 // Don't call Init() if directed by the unit test: we are simulating a failure
1480 // trying to re-enable the cache.
1481 if (unit_test_)
1482 init_ = true; // Let the destructor do proper cleanup.
1483 else if (SyncInit() == net::OK) {
1484 stats_.SetCounter(Stats::FATAL_ERROR, errors);
1485 stats_.SetCounter(Stats::DOOM_CACHE, full_dooms);
1486 stats_.SetCounter(Stats::DOOM_RECENT, partial_dooms);
1487 stats_.SetCounter(Stats::LAST_REPORT, last_report);
1488 }
1489 }
1490
1491 void BackendImpl::PrepareForRestart() {
1492 // Reset the mask_ if it was not given by the user.
1493 if (!(user_flags_ & kMask))
1494 mask_ = 0;
1495
1496 if (!(user_flags_ & kNewEviction))
1497 new_eviction_ = false;
1498
1499 disabled_ = true;
1500 data_->header.crash = 0;
1501 index_->Flush();
1502 index_ = NULL;
1503 data_ = NULL;
1504 block_files_.CloseFiles();
1505 rankings_.Reset();
1506 init_ = false;
1507 restarted_ = true;
1508 }
1509
1510 int BackendImpl::NewEntry(Addr address, EntryImpl** entry) {
1511 EntriesMap::iterator it = open_entries_.find(address.value());
1512 if (it != open_entries_.end()) {
1513 // Easy job. This entry is already in memory.
1514 EntryImpl* this_entry = it->second;
1515 this_entry->AddRef();
1516 *entry = this_entry;
1517 return 0;
1518 }
1519
1520 STRESS_DCHECK(block_files_.IsValid(address));
1521
1522 if (!address.SanityCheckForEntryV2()) {
1523 LOG(WARNING) << "Wrong entry address.";
1524 STRESS_NOTREACHED();
1525 return ERR_INVALID_ADDRESS;
1526 }
1527
1528 scoped_refptr<EntryImpl> cache_entry(
1529 new EntryImpl(this, address, read_only_));
1530 IncreaseNumRefs();
1531 *entry = NULL;
1532
1533 TimeTicks start = TimeTicks::Now();
1534 if (!cache_entry->entry()->Load())
1535 return ERR_READ_FAILURE;
1536
1537 if (IsLoaded()) {
1538 CACHE_UMA(AGE_MS, "LoadTime", 0, start);
1539 }
1540
1541 if (!cache_entry->SanityCheck()) {
1542 LOG(WARNING) << "Messed up entry found.";
1543 STRESS_NOTREACHED();
1544 return ERR_INVALID_ENTRY;
1545 }
1546
1547 STRESS_DCHECK(block_files_.IsValid(
1548 Addr(cache_entry->entry()->Data()->rankings_node)));
1549
1550 if (!cache_entry->LoadNodeAddress())
1551 return ERR_READ_FAILURE;
1552
1553 if (!rankings_.SanityCheck(cache_entry->rankings(), false)) {
1554 STRESS_NOTREACHED();
1555 cache_entry->SetDirtyFlag(0);
1556 // Don't remove this from the list (it is not linked properly). Instead,
1557 // break the link back to the entry because it is going away, and leave the
1558 // rankings node to be deleted if we find it through a list.
1559 rankings_.SetContents(cache_entry->rankings(), 0);
1560 } else if (!rankings_.DataSanityCheck(cache_entry->rankings(), false)) {
1561 STRESS_NOTREACHED();
1562 cache_entry->SetDirtyFlag(0);
1563 rankings_.SetContents(cache_entry->rankings(), address.value());
1564 }
1565
1566 if (!cache_entry->DataSanityCheck()) {
1567 LOG(WARNING) << "Messed up entry found.";
1568 cache_entry->SetDirtyFlag(0);
1569 cache_entry->FixForDelete();
1570 }
1571
1572 // Prevent overwriting the dirty flag on the destructor.
1573 cache_entry->SetDirtyFlag(GetCurrentEntryId());
1574
1575 if (cache_entry->dirty()) {
1576 Trace("Dirty entry 0x%p 0x%x", reinterpret_cast<void*>(cache_entry.get()),
1577 address.value());
1578 }
1579
1580 open_entries_[address.value()] = cache_entry.get();
1581
1582 cache_entry->BeginLogging(net_log_, false);
1583 cache_entry.swap(entry);
1584 return 0;
1585 }
1586
1587 EntryImpl* BackendImpl::MatchEntry(const std::string& key, uint32 hash,
1588 bool find_parent, Addr entry_addr,
1589 bool* match_error) {
1590 Addr address(data_->table[hash & mask_]);
1591 scoped_refptr<EntryImpl> cache_entry, parent_entry;
1592 EntryImpl* tmp = NULL;
1593 bool found = false;
1594 std::set<CacheAddr> visited;
1595 *match_error = false;
1596
1597 for (;;) {
1598 if (disabled_)
1599 break;
1600
1601 if (visited.find(address.value()) != visited.end()) {
1602 // It's possible for a buggy version of the code to write a loop. Just
1603 // break it.
1604 Trace("Hash collision loop 0x%x", address.value());
1605 address.set_value(0);
1606 parent_entry->SetNextAddress(address);
1607 }
1608 visited.insert(address.value());
1609
1610 if (!address.is_initialized()) {
1611 if (find_parent)
1612 found = true;
1613 break;
1614 }
1615
1616 int error = NewEntry(address, &tmp);
1617 cache_entry.swap(&tmp);
1618
1619 if (error || cache_entry->dirty()) {
1620 // This entry is dirty on disk (it was not properly closed): we cannot
1621 // trust it.
1622 Addr child(0);
1623 if (!error)
1624 child.set_value(cache_entry->GetNextAddress());
1625
1626 if (parent_entry.get()) {
1627 parent_entry->SetNextAddress(child);
1628 parent_entry = NULL;
1629 } else {
1630 data_->table[hash & mask_] = child.value();
1631 }
1632
1633 Trace("MatchEntry dirty %d 0x%x 0x%x", find_parent, entry_addr.value(),
1634 address.value());
1635
1636 if (!error) {
1637 // It is important to call DestroyInvalidEntry after removing this
1638 // entry from the table.
1639 DestroyInvalidEntry(cache_entry.get());
1640 cache_entry = NULL;
1641 } else {
1642 Trace("NewEntry failed on MatchEntry 0x%x", address.value());
1643 }
1644
1645 // Restart the search.
1646 address.set_value(data_->table[hash & mask_]);
1647 visited.clear();
1648 continue;
1649 }
1650
1651 DCHECK_EQ(hash & mask_, cache_entry->entry()->Data()->hash & mask_);
1652 if (cache_entry->IsSameEntry(key, hash)) {
1653 if (!cache_entry->Update())
1654 cache_entry = NULL;
1655 found = true;
1656 if (find_parent && entry_addr.value() != address.value()) {
1657 Trace("Entry not on the index 0x%x", address.value());
1658 *match_error = true;
1659 parent_entry = NULL;
1660 }
1661 break;
1662 }
1663 if (!cache_entry->Update())
1664 cache_entry = NULL;
1665 parent_entry = cache_entry;
1666 cache_entry = NULL;
1667 if (!parent_entry.get())
1668 break;
1669
1670 address.set_value(parent_entry->GetNextAddress());
1671 }
1672
1673 if (parent_entry.get() && (!find_parent || !found))
1674 parent_entry = NULL;
1675
1676 if (find_parent && entry_addr.is_initialized() && !cache_entry.get()) {
1677 *match_error = true;
1678 parent_entry = NULL;
1679 }
1680
1681 if (cache_entry.get() && (find_parent || !found))
1682 cache_entry = NULL;
1683
1684 find_parent ? parent_entry.swap(&tmp) : cache_entry.swap(&tmp);
1685 FlushIndex();
1686 return tmp;
1687 }
1688
1689 bool BackendImpl::OpenFollowingEntryFromList(Rankings::List list,
1690 CacheRankingsBlock** from_entry,
1691 EntryImpl** next_entry) {
1692 if (disabled_)
1693 return false;
1694
1695 if (!new_eviction_ && Rankings::NO_USE != list)
1696 return false;
1697
1698 Rankings::ScopedRankingsBlock rankings(&rankings_, *from_entry);
1699 CacheRankingsBlock* next_block = rankings_.GetNext(rankings.get(), list);
1700 Rankings::ScopedRankingsBlock next(&rankings_, next_block);
1701 *from_entry = NULL;
1702
1703 *next_entry = GetEnumeratedEntry(next.get(), list);
1704 if (!*next_entry)
1705 return false;
1706
1707 *from_entry = next.release();
1708 return true;
1709 }
1710
1711 EntryImpl* BackendImpl::GetEnumeratedEntry(CacheRankingsBlock* next,
1712 Rankings::List list) {
1713 if (!next || disabled_)
1714 return NULL;
1715
1716 EntryImpl* entry;
1717 int rv = NewEntry(Addr(next->Data()->contents), &entry);
1718 if (rv) {
1719 STRESS_NOTREACHED();
1720 rankings_.Remove(next, list, false);
1721 if (rv == ERR_INVALID_ADDRESS) {
1722 // There is nothing linked from the index. Delete the rankings node.
1723 DeleteBlock(next->address(), true);
1724 }
1725 return NULL;
1726 }
1727
1728 if (entry->dirty()) {
1729 // We cannot trust this entry.
1730 InternalDoomEntry(entry);
1731 entry->Release();
1732 return NULL;
1733 }
1734
1735 if (!entry->Update()) {
1736 STRESS_NOTREACHED();
1737 entry->Release();
1738 return NULL;
1739 }
1740
1741 // Note that it is unfortunate (but possible) for this entry to be clean, but
1742 // not actually the real entry. In other words, we could have lost this entry
1743 // from the index, and it could have been replaced with a newer one. It's not
1744 // worth checking that this entry is "the real one", so we just return it and
1745 // let the enumeration continue; this entry will be evicted at some point, and
1746 // the regular path will work with the real entry. With time, this problem
1747 // will disasappear because this scenario is just a bug.
1748
1749 // Make sure that we save the key for later.
1750 entry->GetKey();
1751
1752 return entry;
1753 }
1754
1755 EntryImpl* BackendImpl::ResurrectEntry(EntryImpl* deleted_entry) {
1756 if (ENTRY_NORMAL == deleted_entry->entry()->Data()->state) {
1757 deleted_entry->Release();
1758 stats_.OnEvent(Stats::CREATE_MISS);
1759 Trace("create entry miss ");
1760 return NULL;
1761 }
1762
1763 // We are attempting to create an entry and found out that the entry was
1764 // previously deleted.
1765
1766 eviction_.OnCreateEntry(deleted_entry);
1767 entry_count_++;
1768
1769 stats_.OnEvent(Stats::RESURRECT_HIT);
1770 Trace("Resurrect entry hit ");
1771 return deleted_entry;
1772 }
1773
1774 void BackendImpl::DestroyInvalidEntry(EntryImpl* entry) {
1775 LOG(WARNING) << "Destroying invalid entry.";
1776 Trace("Destroying invalid entry 0x%p", entry);
1777
1778 entry->SetPointerForInvalidEntry(GetCurrentEntryId());
1779
1780 eviction_.OnDoomEntry(entry);
1781 entry->InternalDoom();
1782
1783 if (!new_eviction_)
1784 DecreaseNumEntries();
1785 stats_.OnEvent(Stats::INVALID_ENTRY);
1786 }
1787
1788 void BackendImpl::AddStorageSize(int32 bytes) {
1789 data_->header.num_bytes += bytes;
1790 DCHECK_GE(data_->header.num_bytes, 0);
1791 }
1792
1793 void BackendImpl::SubstractStorageSize(int32 bytes) {
1794 data_->header.num_bytes -= bytes;
1795 DCHECK_GE(data_->header.num_bytes, 0);
1796 }
1797
1798 void BackendImpl::IncreaseNumRefs() {
1799 num_refs_++;
1800 if (max_refs_ < num_refs_)
1801 max_refs_ = num_refs_;
1802 }
1803
1804 void BackendImpl::DecreaseNumRefs() {
1805 DCHECK(num_refs_);
1806 num_refs_--;
1807
1808 if (!num_refs_ && disabled_)
1809 base::MessageLoop::current()->PostTask(
1810 FROM_HERE, base::Bind(&BackendImpl::RestartCache, GetWeakPtr(), true));
1811 }
1812
1813 void BackendImpl::IncreaseNumEntries() {
1814 data_->header.num_entries++;
1815 DCHECK_GT(data_->header.num_entries, 0);
1816 }
1817
1818 void BackendImpl::DecreaseNumEntries() {
1819 data_->header.num_entries--;
1820 if (data_->header.num_entries < 0) {
1821 NOTREACHED();
1822 data_->header.num_entries = 0;
1823 }
1824 }
1825
1826 void BackendImpl::LogStats() {
1827 StatsItems stats;
1828 GetStats(&stats);
1829
1830 for (size_t index = 0; index < stats.size(); index++)
1831 VLOG(1) << stats[index].first << ": " << stats[index].second;
1832 }
1833
1834 void BackendImpl::ReportStats() {
1835 CACHE_UMA(COUNTS, "Entries", 0, data_->header.num_entries);
1836
1837 int current_size = data_->header.num_bytes / (1024 * 1024);
1838 int max_size = max_size_ / (1024 * 1024);
1839 int hit_ratio_as_percentage = stats_.GetHitRatio();
1840
1841 CACHE_UMA(COUNTS_10000, "Size2", 0, current_size);
1842 // For any bin in HitRatioBySize2, the hit ratio of caches of that size is the
1843 // ratio of that bin's total count to the count in the same bin in the Size2
1844 // histogram.
1845 if (base::RandInt(0, 99) < hit_ratio_as_percentage)
1846 CACHE_UMA(COUNTS_10000, "HitRatioBySize2", 0, current_size);
1847 CACHE_UMA(COUNTS_10000, "MaxSize2", 0, max_size);
1848 if (!max_size)
1849 max_size++;
1850 CACHE_UMA(PERCENTAGE, "UsedSpace", 0, current_size * 100 / max_size);
1851
1852 CACHE_UMA(COUNTS_10000, "AverageOpenEntries2", 0,
1853 static_cast<int>(stats_.GetCounter(Stats::OPEN_ENTRIES)));
1854 CACHE_UMA(COUNTS_10000, "MaxOpenEntries2", 0,
1855 static_cast<int>(stats_.GetCounter(Stats::MAX_ENTRIES)));
1856 stats_.SetCounter(Stats::MAX_ENTRIES, 0);
1857
1858 CACHE_UMA(COUNTS_10000, "TotalFatalErrors", 0,
1859 static_cast<int>(stats_.GetCounter(Stats::FATAL_ERROR)));
1860 CACHE_UMA(COUNTS_10000, "TotalDoomCache", 0,
1861 static_cast<int>(stats_.GetCounter(Stats::DOOM_CACHE)));
1862 CACHE_UMA(COUNTS_10000, "TotalDoomRecentEntries", 0,
1863 static_cast<int>(stats_.GetCounter(Stats::DOOM_RECENT)));
1864 stats_.SetCounter(Stats::FATAL_ERROR, 0);
1865 stats_.SetCounter(Stats::DOOM_CACHE, 0);
1866 stats_.SetCounter(Stats::DOOM_RECENT, 0);
1867
1868 int age = (Time::Now() -
1869 Time::FromInternalValue(data_->header.create_time)).InHours();
1870 if (age)
1871 CACHE_UMA(HOURS, "FilesAge", 0, age);
1872
1873 int64 total_hours = stats_.GetCounter(Stats::TIMER) / 120;
1874 if (!data_->header.create_time || !data_->header.lru.filled) {
1875 int cause = data_->header.create_time ? 0 : 1;
1876 if (!data_->header.lru.filled)
1877 cause |= 2;
1878 CACHE_UMA(CACHE_ERROR, "ShortReport", 0, cause);
1879 CACHE_UMA(HOURS, "TotalTimeNotFull", 0, static_cast<int>(total_hours));
1880 return;
1881 }
1882
1883 // This is an up to date client that will report FirstEviction() data. After
1884 // that event, start reporting this:
1885
1886 CACHE_UMA(HOURS, "TotalTime", 0, static_cast<int>(total_hours));
1887 // For any bin in HitRatioByTotalTime, the hit ratio of caches of that total
1888 // time is the ratio of that bin's total count to the count in the same bin in
1889 // the TotalTime histogram.
1890 if (base::RandInt(0, 99) < hit_ratio_as_percentage)
1891 CACHE_UMA(HOURS, "HitRatioByTotalTime", 0, static_cast<int>(total_hours));
1892
1893 int64 use_hours = stats_.GetCounter(Stats::LAST_REPORT_TIMER) / 120;
1894 stats_.SetCounter(Stats::LAST_REPORT_TIMER, stats_.GetCounter(Stats::TIMER));
1895
1896 // We may see users with no use_hours at this point if this is the first time
1897 // we are running this code.
1898 if (use_hours)
1899 use_hours = total_hours - use_hours;
1900
1901 if (!use_hours || !GetEntryCount() || !data_->header.num_bytes)
1902 return;
1903
1904 CACHE_UMA(HOURS, "UseTime", 0, static_cast<int>(use_hours));
1905 // For any bin in HitRatioByUseTime, the hit ratio of caches of that use time
1906 // is the ratio of that bin's total count to the count in the same bin in the
1907 // UseTime histogram.
1908 if (base::RandInt(0, 99) < hit_ratio_as_percentage)
1909 CACHE_UMA(HOURS, "HitRatioByUseTime", 0, static_cast<int>(use_hours));
1910 CACHE_UMA(PERCENTAGE, "HitRatio", 0, hit_ratio_as_percentage);
1911
1912 int64 trim_rate = stats_.GetCounter(Stats::TRIM_ENTRY) / use_hours;
1913 CACHE_UMA(COUNTS, "TrimRate", 0, static_cast<int>(trim_rate));
1914
1915 int avg_size = data_->header.num_bytes / GetEntryCount();
1916 CACHE_UMA(COUNTS, "EntrySize", 0, avg_size);
1917 CACHE_UMA(COUNTS, "EntriesFull", 0, data_->header.num_entries);
1918
1919 CACHE_UMA(PERCENTAGE, "IndexLoad", 0,
1920 data_->header.num_entries * 100 / (mask_ + 1));
1921
1922 int large_entries_bytes = stats_.GetLargeEntriesSize();
1923 int large_ratio = large_entries_bytes * 100 / data_->header.num_bytes;
1924 CACHE_UMA(PERCENTAGE, "LargeEntriesRatio", 0, large_ratio);
1925
1926 if (new_eviction_) {
1927 CACHE_UMA(PERCENTAGE, "ResurrectRatio", 0, stats_.GetResurrectRatio());
1928 CACHE_UMA(PERCENTAGE, "NoUseRatio", 0,
1929 data_->header.lru.sizes[0] * 100 / data_->header.num_entries);
1930 CACHE_UMA(PERCENTAGE, "LowUseRatio", 0,
1931 data_->header.lru.sizes[1] * 100 / data_->header.num_entries);
1932 CACHE_UMA(PERCENTAGE, "HighUseRatio", 0,
1933 data_->header.lru.sizes[2] * 100 / data_->header.num_entries);
1934 CACHE_UMA(PERCENTAGE, "DeletedRatio", 0,
1935 data_->header.lru.sizes[4] * 100 / data_->header.num_entries);
1936 }
1937
1938 stats_.ResetRatios();
1939 stats_.SetCounter(Stats::TRIM_ENTRY, 0);
1940
1941 if (cache_type_ == net::DISK_CACHE)
1942 block_files_.ReportStats();
1943 }
1944
1945 void BackendImpl::UpgradeTo2_1() {
1946 // 2.1 is basically the same as 2.0, except that new fields are actually
1947 // updated by the new eviction algorithm.
1948 DCHECK(0x20000 == data_->header.version);
1949 data_->header.version = 0x20001;
1950 data_->header.lru.sizes[Rankings::NO_USE] = data_->header.num_entries;
1951 }
1952
1953 bool BackendImpl::CheckIndex() {
1954 DCHECK(data_);
1955
1956 size_t current_size = index_->GetLength();
1957 if (current_size < sizeof(Index)) {
1958 LOG(ERROR) << "Corrupt Index file";
1959 return false;
1960 }
1961
1962 if (new_eviction_) {
1963 // We support versions 2.0 and 2.1, upgrading 2.0 to 2.1.
1964 if (kIndexMagic != data_->header.magic ||
1965 kCurrentVersion >> 16 != data_->header.version >> 16) {
1966 LOG(ERROR) << "Invalid file version or magic";
1967 return false;
1968 }
1969 if (kCurrentVersion == data_->header.version) {
1970 // We need file version 2.1 for the new eviction algorithm.
1971 UpgradeTo2_1();
1972 }
1973 } else {
1974 if (kIndexMagic != data_->header.magic ||
1975 kCurrentVersion != data_->header.version) {
1976 LOG(ERROR) << "Invalid file version or magic";
1977 return false;
1978 }
1979 }
1980
1981 if (!data_->header.table_len) {
1982 LOG(ERROR) << "Invalid table size";
1983 return false;
1984 }
1985
1986 if (current_size < GetIndexSize(data_->header.table_len) ||
1987 data_->header.table_len & (kBaseTableLen - 1)) {
1988 LOG(ERROR) << "Corrupt Index file";
1989 return false;
1990 }
1991
1992 AdjustMaxCacheSize(data_->header.table_len);
1993
1994 #if !defined(NET_BUILD_STRESS_CACHE)
1995 if (data_->header.num_bytes < 0 ||
1996 (max_size_ < kint32max - kDefaultCacheSize &&
1997 data_->header.num_bytes > max_size_ + kDefaultCacheSize)) {
1998 LOG(ERROR) << "Invalid cache (current) size";
1999 return false;
2000 }
2001 #endif
2002
2003 if (data_->header.num_entries < 0) {
2004 LOG(ERROR) << "Invalid number of entries";
2005 return false;
2006 }
2007
2008 if (!mask_)
2009 mask_ = data_->header.table_len - 1;
2010
2011 // Load the table into memory.
2012 return index_->Preload();
2013 }
2014
2015 int BackendImpl::CheckAllEntries() {
2016 int num_dirty = 0;
2017 int num_entries = 0;
2018 DCHECK(mask_ < kuint32max);
2019 for (unsigned int i = 0; i <= mask_; i++) {
2020 Addr address(data_->table[i]);
2021 if (!address.is_initialized())
2022 continue;
2023 for (;;) {
2024 EntryImpl* tmp;
2025 int ret = NewEntry(address, &tmp);
2026 if (ret) {
2027 STRESS_NOTREACHED();
2028 return ret;
2029 }
2030 scoped_refptr<EntryImpl> cache_entry;
2031 cache_entry.swap(&tmp);
2032
2033 if (cache_entry->dirty())
2034 num_dirty++;
2035 else if (CheckEntry(cache_entry.get()))
2036 num_entries++;
2037 else
2038 return ERR_INVALID_ENTRY;
2039
2040 DCHECK_EQ(i, cache_entry->entry()->Data()->hash & mask_);
2041 address.set_value(cache_entry->GetNextAddress());
2042 if (!address.is_initialized())
2043 break;
2044 }
2045 }
2046
2047 Trace("CheckAllEntries End");
2048 if (num_entries + num_dirty != data_->header.num_entries) {
2049 LOG(ERROR) << "Number of entries " << num_entries << " " << num_dirty <<
2050 " " << data_->header.num_entries;
2051 DCHECK_LT(num_entries, data_->header.num_entries);
2052 return ERR_NUM_ENTRIES_MISMATCH;
2053 }
2054
2055 return num_dirty;
2056 }
2057
2058 bool BackendImpl::CheckEntry(EntryImpl* cache_entry) {
2059 bool ok = block_files_.IsValid(cache_entry->entry()->address());
2060 ok = ok && block_files_.IsValid(cache_entry->rankings()->address());
2061 EntryStore* data = cache_entry->entry()->Data();
2062 for (size_t i = 0; i < arraysize(data->data_addr); i++) {
2063 if (data->data_addr[i]) {
2064 Addr address(data->data_addr[i]);
2065 if (address.is_block_file())
2066 ok = ok && block_files_.IsValid(address);
2067 }
2068 }
2069
2070 return ok && cache_entry->rankings()->VerifyHash();
2071 }
2072
2073 int BackendImpl::MaxBuffersSize() {
2074 static int64 total_memory = base::SysInfo::AmountOfPhysicalMemory();
2075 static bool done = false;
2076
2077 if (!done) {
2078 const int kMaxBuffersSize = 30 * 1024 * 1024;
2079
2080 // We want to use up to 2% of the computer's memory.
2081 total_memory = total_memory * 2 / 100;
2082 if (total_memory > kMaxBuffersSize || total_memory <= 0)
2083 total_memory = kMaxBuffersSize;
2084
2085 done = true;
2086 }
2087
2088 return static_cast<int>(total_memory);
2089 }
2090
2091 } // namespace disk_cache
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