diff options
Diffstat (limited to 'chromium/net/disk_cache/v3/backend_impl_v3.cc')
| -rw-r--r-- | chromium/net/disk_cache/v3/backend_impl_v3.cc | 1640 |
1 files changed, 1640 insertions, 0 deletions
diff --git a/chromium/net/disk_cache/v3/backend_impl_v3.cc b/chromium/net/disk_cache/v3/backend_impl_v3.cc new file mode 100644 index 00000000000..92ea272226b --- /dev/null +++ b/chromium/net/disk_cache/v3/backend_impl_v3.cc @@ -0,0 +1,1640 @@ +// Copyright (c) 2012 The Chromium Authors. All rights reserved. +// Use of this source code is governed by a BSD-style license that can be +// found in the LICENSE file. + +#include "net/disk_cache/backend_impl.h" + +#include "base/bind.h" +#include "base/bind_helpers.h" +#include "base/file_util.h" +#include "base/files/file_path.h" +#include "base/hash.h" +#include "base/message_loop/message_loop.h" +#include "base/metrics/field_trial.h" +#include "base/metrics/histogram.h" +#include "base/metrics/stats_counters.h" +#include "base/rand_util.h" +#include "base/strings/string_util.h" +#include "base/strings/stringprintf.h" +#include "base/sys_info.h" +#include "base/threading/thread_restrictions.h" +#include "base/time/time.h" +#include "base/timer/timer.h" +#include "net/base/net_errors.h" +#include "net/disk_cache/cache_util.h" +#include "net/disk_cache/entry_impl.h" +#include "net/disk_cache/errors.h" +#include "net/disk_cache/experiments.h" +#include "net/disk_cache/file.h" + +// This has to be defined before including histogram_macros.h from this file. +#define NET_DISK_CACHE_BACKEND_IMPL_CC_ +#include "net/disk_cache/histogram_macros.h" + +using base::Time; +using base::TimeDelta; +using base::TimeTicks; + +namespace { + +const char* kIndexName = "index"; + +// Seems like ~240 MB correspond to less than 50k entries for 99% of the people. +// Note that the actual target is to keep the index table load factor under 55% +// for most users. +const int k64kEntriesStore = 240 * 1000 * 1000; +const int kBaseTableLen = 64 * 1024; +const int kDefaultCacheSize = 80 * 1024 * 1024; + +// Avoid trimming the cache for the first 5 minutes (10 timer ticks). +const int kTrimDelay = 10; + +int DesiredIndexTableLen(int32 storage_size) { + if (storage_size <= k64kEntriesStore) + return kBaseTableLen; + if (storage_size <= k64kEntriesStore * 2) + return kBaseTableLen * 2; + if (storage_size <= k64kEntriesStore * 4) + return kBaseTableLen * 4; + if (storage_size <= k64kEntriesStore * 8) + return kBaseTableLen * 8; + + // The biggest storage_size for int32 requires a 4 MB table. + return kBaseTableLen * 16; +} + +int MaxStorageSizeForTable(int table_len) { + return table_len * (k64kEntriesStore / kBaseTableLen); +} + +size_t GetIndexSize(int table_len) { + size_t table_size = sizeof(disk_cache::CacheAddr) * table_len; + return sizeof(disk_cache::IndexHeader) + table_size; +} + +} // namespace + +// ------------------------------------------------------------------------ + +namespace disk_cache { + +BackendImpl::BackendImpl(const base::FilePath& path, + base::MessageLoopProxy* cache_thread, + net::NetLog* net_log) + : background_queue_(this, cache_thread), + path_(path), + block_files_(path), + mask_(0), + max_size_(0), + up_ticks_(0), + cache_type_(net::DISK_CACHE), + uma_report_(0), + user_flags_(0), + init_(false), + restarted_(false), + unit_test_(false), + read_only_(false), + disabled_(false), + new_eviction_(false), + first_timer_(true), + user_load_(false), + net_log_(net_log), + done_(true, false), + ptr_factory_(this) { +} + +BackendImpl::BackendImpl(const base::FilePath& path, + uint32 mask, + base::MessageLoopProxy* cache_thread, + net::NetLog* net_log) + : background_queue_(this, cache_thread), + path_(path), + block_files_(path), + mask_(mask), + max_size_(0), + up_ticks_(0), + cache_type_(net::DISK_CACHE), + uma_report_(0), + user_flags_(kMask), + init_(false), + restarted_(false), + unit_test_(false), + read_only_(false), + disabled_(false), + new_eviction_(false), + first_timer_(true), + user_load_(false), + net_log_(net_log), + done_(true, false), + ptr_factory_(this) { +} + +BackendImpl::~BackendImpl() { + if (user_flags_ & kNoRandom) { + // This is a unit test, so we want to be strict about not leaking entries + // and completing all the work. + background_queue_.WaitForPendingIO(); + } else { + // This is most likely not a test, so we want to do as little work as + // possible at this time, at the price of leaving dirty entries behind. + background_queue_.DropPendingIO(); + } + + if (background_queue_.BackgroundIsCurrentThread()) { + // Unit tests may use the same thread for everything. + CleanupCache(); + } else { + background_queue_.background_thread()->PostTask( + FROM_HERE, base::Bind(&FinalCleanupCallback, base::Unretained(this))); + // http://crbug.com/74623 + base::ThreadRestrictions::ScopedAllowWait allow_wait; + done_.Wait(); + } +} + +int BackendImpl::Init(const CompletionCallback& callback) { + background_queue_.Init(callback); + return net::ERR_IO_PENDING; +} + +// ------------------------------------------------------------------------ + +int BackendImpl::OpenPrevEntry(void** iter, Entry** prev_entry, + const CompletionCallback& callback) { + DCHECK(!callback.is_null()); + background_queue_.OpenPrevEntry(iter, prev_entry, callback); + return net::ERR_IO_PENDING; +} + +bool BackendImpl::SetMaxSize(int max_bytes) { + COMPILE_ASSERT(sizeof(max_bytes) == sizeof(max_size_), unsupported_int_model); + if (max_bytes < 0) + return false; + + // Zero size means use the default. + if (!max_bytes) + return true; + + // Avoid a DCHECK later on. + if (max_bytes >= kint32max - kint32max / 10) + max_bytes = kint32max - kint32max / 10 - 1; + + user_flags_ |= kMaxSize; + max_size_ = max_bytes; + return true; +} + +void BackendImpl::SetType(net::CacheType type) { + DCHECK_NE(net::MEMORY_CACHE, type); + cache_type_ = type; +} + +bool BackendImpl::CreateBlock(FileType block_type, int block_count, + Addr* block_address) { + return block_files_.CreateBlock(block_type, block_count, block_address); +} + +void BackendImpl::UpdateRank(EntryImpl* entry, bool modified) { + if (read_only_ || (!modified && cache_type() == net::SHADER_CACHE)) + return; + eviction_.UpdateRank(entry, modified); +} + +void BackendImpl::InternalDoomEntry(EntryImpl* entry) { + uint32 hash = entry->GetHash(); + std::string key = entry->GetKey(); + Addr entry_addr = entry->entry()->address(); + bool error; + EntryImpl* parent_entry = MatchEntry(key, hash, true, entry_addr, &error); + CacheAddr child(entry->GetNextAddress()); + + Trace("Doom entry 0x%p", entry); + + if (!entry->doomed()) { + // We may have doomed this entry from within MatchEntry. + eviction_.OnDoomEntry(entry); + entry->InternalDoom(); + if (!new_eviction_) { + DecreaseNumEntries(); + } + stats_.OnEvent(Stats::DOOM_ENTRY); + } + + if (parent_entry) { + parent_entry->SetNextAddress(Addr(child)); + parent_entry->Release(); + } else if (!error) { + data_->table[hash & mask_] = child; + } + + FlushIndex(); +} + +void BackendImpl::OnEntryDestroyBegin(Addr address) { + EntriesMap::iterator it = open_entries_.find(address.value()); + if (it != open_entries_.end()) + open_entries_.erase(it); +} + +void BackendImpl::OnEntryDestroyEnd() { + DecreaseNumRefs(); + if (data_->header.num_bytes > max_size_ && !read_only_ && + (up_ticks_ > kTrimDelay || user_flags_ & kNoRandom)) + eviction_.TrimCache(false); +} + +EntryImpl* BackendImpl::GetOpenEntry(CacheRankingsBlock* rankings) const { + DCHECK(rankings->HasData()); + EntriesMap::const_iterator it = + open_entries_.find(rankings->Data()->contents); + if (it != open_entries_.end()) { + // We have this entry in memory. + return it->second; + } + + return NULL; +} + +int BackendImpl::MaxFileSize() const { + return max_size_ / 8; +} + +void BackendImpl::ModifyStorageSize(int32 old_size, int32 new_size) { + if (disabled_ || old_size == new_size) + return; + if (old_size > new_size) + SubstractStorageSize(old_size - new_size); + else + AddStorageSize(new_size - old_size); + + FlushIndex(); + + // Update the usage statistics. + stats_.ModifyStorageStats(old_size, new_size); +} + +void BackendImpl::TooMuchStorageRequested(int32 size) { + stats_.ModifyStorageStats(0, size); +} + +bool BackendImpl::IsAllocAllowed(int current_size, int new_size) { + DCHECK_GT(new_size, current_size); + if (user_flags_ & kNoBuffering) + return false; + + int to_add = new_size - current_size; + if (buffer_bytes_ + to_add > MaxBuffersSize()) + return false; + + buffer_bytes_ += to_add; + CACHE_UMA(COUNTS_50000, "BufferBytes", 0, buffer_bytes_ / 1024); + return true; +} + +void BackendImpl::BufferDeleted(int size) { + buffer_bytes_ -= size; + DCHECK_GE(size, 0); +} + +bool BackendImpl::IsLoaded() const { + CACHE_UMA(COUNTS, "PendingIO", 0, num_pending_io_); + if (user_flags_ & kNoLoadProtection) + return false; + + return (num_pending_io_ > 5 || user_load_); +} + +std::string BackendImpl::HistogramName(const char* name, int experiment) const { + if (!experiment) + return base::StringPrintf("DiskCache.%d.%s", cache_type_, name); + return base::StringPrintf("DiskCache.%d.%s_%d", cache_type_, + name, experiment); +} + +base::WeakPtr<BackendImpl> BackendImpl::GetWeakPtr() { + return ptr_factory_.GetWeakPtr(); +} + +// We want to remove biases from some histograms so we only send data once per +// week. +bool BackendImpl::ShouldReportAgain() { + if (uma_report_) + return uma_report_ == 2; + + uma_report_++; + int64 last_report = stats_.GetCounter(Stats::LAST_REPORT); + Time last_time = Time::FromInternalValue(last_report); + if (!last_report || (Time::Now() - last_time).InDays() >= 7) { + stats_.SetCounter(Stats::LAST_REPORT, Time::Now().ToInternalValue()); + uma_report_++; + return true; + } + return false; +} + +void BackendImpl::FirstEviction() { + DCHECK(data_->header.create_time); + if (!GetEntryCount()) + return; // This is just for unit tests. + + Time create_time = Time::FromInternalValue(data_->header.create_time); + CACHE_UMA(AGE, "FillupAge", 0, create_time); + + int64 use_time = stats_.GetCounter(Stats::TIMER); + CACHE_UMA(HOURS, "FillupTime", 0, static_cast<int>(use_time / 120)); + CACHE_UMA(PERCENTAGE, "FirstHitRatio", 0, stats_.GetHitRatio()); + + if (!use_time) + use_time = 1; + CACHE_UMA(COUNTS_10000, "FirstEntryAccessRate", 0, + static_cast<int>(data_->header.num_entries / use_time)); + CACHE_UMA(COUNTS, "FirstByteIORate", 0, + static_cast<int>((data_->header.num_bytes / 1024) / use_time)); + + int avg_size = data_->header.num_bytes / GetEntryCount(); + CACHE_UMA(COUNTS, "FirstEntrySize", 0, avg_size); + + int large_entries_bytes = stats_.GetLargeEntriesSize(); + int large_ratio = large_entries_bytes * 100 / data_->header.num_bytes; + CACHE_UMA(PERCENTAGE, "FirstLargeEntriesRatio", 0, large_ratio); + + if (new_eviction_) { + CACHE_UMA(PERCENTAGE, "FirstResurrectRatio", 0, stats_.GetResurrectRatio()); + CACHE_UMA(PERCENTAGE, "FirstNoUseRatio", 0, + data_->header.lru.sizes[0] * 100 / data_->header.num_entries); + CACHE_UMA(PERCENTAGE, "FirstLowUseRatio", 0, + data_->header.lru.sizes[1] * 100 / data_->header.num_entries); + CACHE_UMA(PERCENTAGE, "FirstHighUseRatio", 0, + data_->header.lru.sizes[2] * 100 / data_->header.num_entries); + } + + stats_.ResetRatios(); +} + +void BackendImpl::OnEvent(Stats::Counters an_event) { + stats_.OnEvent(an_event); +} + +void BackendImpl::OnRead(int32 bytes) { + DCHECK_GE(bytes, 0); + byte_count_ += bytes; + if (byte_count_ < 0) + byte_count_ = kint32max; +} + +void BackendImpl::OnWrite(int32 bytes) { + // We use the same implementation as OnRead... just log the number of bytes. + OnRead(bytes); +} + +void BackendImpl::OnStatsTimer() { + stats_.OnEvent(Stats::TIMER); + int64 time = stats_.GetCounter(Stats::TIMER); + int64 current = stats_.GetCounter(Stats::OPEN_ENTRIES); + + // OPEN_ENTRIES is a sampled average of the number of open entries, avoiding + // the bias towards 0. + if (num_refs_ && (current != num_refs_)) { + int64 diff = (num_refs_ - current) / 50; + if (!diff) + diff = num_refs_ > current ? 1 : -1; + current = current + diff; + stats_.SetCounter(Stats::OPEN_ENTRIES, current); + stats_.SetCounter(Stats::MAX_ENTRIES, max_refs_); + } + + CACHE_UMA(COUNTS, "NumberOfReferences", 0, num_refs_); + + CACHE_UMA(COUNTS_10000, "EntryAccessRate", 0, entry_count_); + CACHE_UMA(COUNTS, "ByteIORate", 0, byte_count_ / 1024); + + // These values cover about 99.5% of the population (Oct 2011). + user_load_ = (entry_count_ > 300 || byte_count_ > 7 * 1024 * 1024); + entry_count_ = 0; + byte_count_ = 0; + up_ticks_++; + + if (!data_) + first_timer_ = false; + if (first_timer_) { + first_timer_ = false; + if (ShouldReportAgain()) + ReportStats(); + } + + // Save stats to disk at 5 min intervals. + if (time % 10 == 0) + StoreStats(); +} + +void BackendImpl::SetUnitTestMode() { + user_flags_ |= kUnitTestMode; + unit_test_ = true; +} + +void BackendImpl::SetUpgradeMode() { + user_flags_ |= kUpgradeMode; + read_only_ = true; +} + +void BackendImpl::SetNewEviction() { + user_flags_ |= kNewEviction; + new_eviction_ = true; +} + +void BackendImpl::SetFlags(uint32 flags) { + user_flags_ |= flags; +} + +int BackendImpl::FlushQueueForTest(const CompletionCallback& callback) { + background_queue_.FlushQueue(callback); + return net::ERR_IO_PENDING; +} + +void BackendImpl::TrimForTest(bool empty) { + eviction_.SetTestMode(); + eviction_.TrimCache(empty); +} + +void BackendImpl::TrimDeletedListForTest(bool empty) { + eviction_.SetTestMode(); + eviction_.TrimDeletedList(empty); +} + +int BackendImpl::SelfCheck() { + if (!init_) { + LOG(ERROR) << "Init failed"; + return ERR_INIT_FAILED; + } + + int num_entries = rankings_.SelfCheck(); + if (num_entries < 0) { + LOG(ERROR) << "Invalid rankings list, error " << num_entries; +#if !defined(NET_BUILD_STRESS_CACHE) + return num_entries; +#endif + } + + if (num_entries != data_->header.num_entries) { + LOG(ERROR) << "Number of entries mismatch"; +#if !defined(NET_BUILD_STRESS_CACHE) + return ERR_NUM_ENTRIES_MISMATCH; +#endif + } + + return CheckAllEntries(); +} + +// ------------------------------------------------------------------------ + +net::CacheType BackendImpl::GetCacheType() const { + return cache_type_; +} + +int32 BackendImpl::GetEntryCount() const { + if (!index_.get() || disabled_) + return 0; + // num_entries includes entries already evicted. + int32 not_deleted = data_->header.num_entries - + data_->header.lru.sizes[Rankings::DELETED]; + + if (not_deleted < 0) { + NOTREACHED(); + not_deleted = 0; + } + + return not_deleted; +} + +EntryImpl* BackendImpl::OpenEntryImpl(const std::string& key) { + if (disabled_) + return NULL; + + TimeTicks start = TimeTicks::Now(); + uint32 hash = base::Hash(key); + Trace("Open hash 0x%x", hash); + + bool error; + EntryImpl* cache_entry = MatchEntry(key, hash, false, Addr(), &error); + if (cache_entry && ENTRY_NORMAL != cache_entry->entry()->Data()->state) { + // The entry was already evicted. + cache_entry->Release(); + cache_entry = NULL; + } + + int current_size = data_->header.num_bytes / (1024 * 1024); + int64 total_hours = stats_.GetCounter(Stats::TIMER) / 120; + int64 no_use_hours = stats_.GetCounter(Stats::LAST_REPORT_TIMER) / 120; + int64 use_hours = total_hours - no_use_hours; + + if (!cache_entry) { + CACHE_UMA(AGE_MS, "OpenTime.Miss", 0, start); + CACHE_UMA(COUNTS_10000, "AllOpenBySize.Miss", 0, current_size); + CACHE_UMA(HOURS, "AllOpenByTotalHours.Miss", 0, total_hours); + CACHE_UMA(HOURS, "AllOpenByUseHours.Miss", 0, use_hours); + stats_.OnEvent(Stats::OPEN_MISS); + return NULL; + } + + eviction_.OnOpenEntry(cache_entry); + entry_count_++; + + Trace("Open hash 0x%x end: 0x%x", hash, + cache_entry->entry()->address().value()); + CACHE_UMA(AGE_MS, "OpenTime", 0, start); + CACHE_UMA(COUNTS_10000, "AllOpenBySize.Hit", 0, current_size); + CACHE_UMA(HOURS, "AllOpenByTotalHours.Hit", 0, total_hours); + CACHE_UMA(HOURS, "AllOpenByUseHours.Hit", 0, use_hours); + stats_.OnEvent(Stats::OPEN_HIT); + SIMPLE_STATS_COUNTER("disk_cache.hit"); + return cache_entry; +} + +EntryImpl* BackendImpl::CreateEntryImpl(const std::string& key) { + if (disabled_ || key.empty()) + return NULL; + + TimeTicks start = TimeTicks::Now(); + Trace("Create hash 0x%x", hash); + + scoped_refptr<EntryImpl> parent; + Addr entry_address(data_->table[hash & mask_]); + if (entry_address.is_initialized()) { + // We have an entry already. It could be the one we are looking for, or just + // a hash conflict. + bool error; + EntryImpl* old_entry = MatchEntry(key, hash, false, Addr(), &error); + if (old_entry) + return ResurrectEntry(old_entry); + + EntryImpl* parent_entry = MatchEntry(key, hash, true, Addr(), &error); + DCHECK(!error); + if (parent_entry) { + parent.swap(&parent_entry); + } else if (data_->table[hash & mask_]) { + // We should have corrected the problem. + NOTREACHED(); + return NULL; + } + } + + // The general flow is to allocate disk space and initialize the entry data, + // followed by saving that to disk, then linking the entry though the index + // and finally through the lists. If there is a crash in this process, we may + // end up with: + // a. Used, unreferenced empty blocks on disk (basically just garbage). + // b. Used, unreferenced but meaningful data on disk (more garbage). + // c. A fully formed entry, reachable only through the index. + // d. A fully formed entry, also reachable through the lists, but still dirty. + // + // Anything after (b) can be automatically cleaned up. We may consider saving + // the current operation (as we do while manipulating the lists) so that we + // can detect and cleanup (a) and (b). + + int num_blocks = EntryImpl::NumBlocksForEntry(key.size()); + if (!block_files_.CreateBlock(BLOCK_256, num_blocks, &entry_address)) { + LOG(ERROR) << "Create entry failed " << key.c_str(); + stats_.OnEvent(Stats::CREATE_ERROR); + return NULL; + } + + Addr node_address(0); + if (!block_files_.CreateBlock(RANKINGS, 1, &node_address)) { + block_files_.DeleteBlock(entry_address, false); + LOG(ERROR) << "Create entry failed " << key.c_str(); + stats_.OnEvent(Stats::CREATE_ERROR); + return NULL; + } + + scoped_refptr<EntryImpl> cache_entry( + new EntryImpl(this, entry_address, false)); + IncreaseNumRefs(); + + if (!cache_entry->CreateEntry(node_address, key, hash)) { + block_files_.DeleteBlock(entry_address, false); + block_files_.DeleteBlock(node_address, false); + LOG(ERROR) << "Create entry failed " << key.c_str(); + stats_.OnEvent(Stats::CREATE_ERROR); + return NULL; + } + + cache_entry->BeginLogging(net_log_, true); + + // We are not failing the operation; let's add this to the map. + open_entries_[entry_address.value()] = cache_entry.get(); + + // Save the entry. + cache_entry->entry()->Store(); + cache_entry->rankings()->Store(); + IncreaseNumEntries(); + entry_count_++; + + // Link this entry through the index. + if (parent.get()) { + parent->SetNextAddress(entry_address); + } else { + data_->table[hash & mask_] = entry_address.value(); + } + + // Link this entry through the lists. + eviction_.OnCreateEntry(cache_entry.get()); + + CACHE_UMA(AGE_MS, "CreateTime", 0, start); + stats_.OnEvent(Stats::CREATE_HIT); + SIMPLE_STATS_COUNTER("disk_cache.miss"); + Trace("create entry hit "); + FlushIndex(); + cache_entry->AddRef(); + return cache_entry.get(); +} + +int BackendImpl::SyncDoomEntry(const std::string& key) { + if (disabled_) + return net::ERR_FAILED; + + EntryImpl* entry = OpenEntryImpl(key); + if (!entry) + return net::ERR_FAILED; + + entry->DoomImpl(); + entry->Release(); + return net::OK; +} + +int BackendImpl::SyncDoomAllEntries() { + // This is not really an error, but it is an interesting condition. + ReportError(ERR_CACHE_DOOMED); + stats_.OnEvent(Stats::DOOM_CACHE); + if (!num_refs_) { + RestartCache(false); + return disabled_ ? net::ERR_FAILED : net::OK; + } else { + if (disabled_) + return net::ERR_FAILED; + + eviction_.TrimCache(true); + return net::OK; + } +} + +int BackendImpl::SyncDoomEntriesBetween(const base::Time initial_time, + const base::Time end_time) { + DCHECK_NE(net::APP_CACHE, cache_type_); + if (end_time.is_null()) + return SyncDoomEntriesSince(initial_time); + + DCHECK(end_time >= initial_time); + + if (disabled_) + return net::ERR_FAILED; + + EntryImpl* node; + void* iter = NULL; + EntryImpl* next = OpenNextEntryImpl(&iter); + if (!next) + return net::OK; + + while (next) { + node = next; + next = OpenNextEntryImpl(&iter); + + if (node->GetLastUsed() >= initial_time && + node->GetLastUsed() < end_time) { + node->DoomImpl(); + } else if (node->GetLastUsed() < initial_time) { + if (next) + next->Release(); + next = NULL; + SyncEndEnumeration(iter); + } + + node->Release(); + } + + return net::OK; +} + +// We use OpenNextEntryImpl to retrieve elements from the cache, until we get +// entries that are too old. +int BackendImpl::SyncDoomEntriesSince(const base::Time initial_time) { + DCHECK_NE(net::APP_CACHE, cache_type_); + if (disabled_) + return net::ERR_FAILED; + + stats_.OnEvent(Stats::DOOM_RECENT); + for (;;) { + void* iter = NULL; + EntryImpl* entry = OpenNextEntryImpl(&iter); + if (!entry) + return net::OK; + + if (initial_time > entry->GetLastUsed()) { + entry->Release(); + SyncEndEnumeration(iter); + return net::OK; + } + + entry->DoomImpl(); + entry->Release(); + SyncEndEnumeration(iter); // Dooming the entry invalidates the iterator. + } +} + +int BackendImpl::OpenNextEntry(void** iter, Entry** next_entry, + const CompletionCallback& callback) { + DCHECK(!callback.is_null()); + background_queue_.OpenNextEntry(iter, next_entry, callback); + return net::ERR_IO_PENDING; +} + +void BackendImpl::EndEnumeration(void** iter) { + background_queue_.EndEnumeration(*iter); + *iter = NULL; +} + +void BackendImpl::GetStats(StatsItems* stats) { + if (disabled_) + return; + + std::pair<std::string, std::string> item; + + item.first = "Entries"; + item.second = base::StringPrintf("%d", data_->header.num_entries); + stats->push_back(item); + + item.first = "Pending IO"; + item.second = base::StringPrintf("%d", num_pending_io_); + stats->push_back(item); + + item.first = "Max size"; + item.second = base::StringPrintf("%d", max_size_); + stats->push_back(item); + + item.first = "Current size"; + item.second = base::StringPrintf("%d", data_->header.num_bytes); + stats->push_back(item); + + item.first = "Cache type"; + item.second = "Blockfile Cache"; + stats->push_back(item); + + stats_.GetItems(stats); +} + +void BackendImpl::SyncOnExternalCacheHit(const std::string& key) { + if (disabled_) + return; + + uint32 hash = base::Hash(key); + bool error; + EntryImpl* cache_entry = MatchEntry(key, hash, false, Addr(), &error); + if (cache_entry) { + if (ENTRY_NORMAL == cache_entry->entry()->Data()->state) { + UpdateRank(cache_entry, cache_type() == net::SHADER_CACHE); + } + cache_entry->Release(); + } +} + +// ------------------------------------------------------------------------ + +// The maximum cache size will be either set explicitly by the caller, or +// calculated by this code. +void BackendImpl::AdjustMaxCacheSize(int table_len) { + if (max_size_) + return; + + // If table_len is provided, the index file exists. + DCHECK(!table_len || data_->header.magic); + + // The user is not setting the size, let's figure it out. + int64 available = base::SysInfo::AmountOfFreeDiskSpace(path_); + if (available < 0) { + max_size_ = kDefaultCacheSize; + return; + } + + if (table_len) + available += data_->header.num_bytes; + + max_size_ = PreferedCacheSize(available); + + // Let's not use more than the default size while we tune-up the performance + // of bigger caches. TODO(rvargas): remove this limit. + if (max_size_ > kDefaultCacheSize * 4) + max_size_ = kDefaultCacheSize * 4; + + if (!table_len) + return; + + // If we already have a table, adjust the size to it. + int current_max_size = MaxStorageSizeForTable(table_len); + if (max_size_ > current_max_size) + max_size_= current_max_size; +} + +bool BackendImpl::InitStats() { + Addr address(data_->header.stats); + int size = stats_.StorageSize(); + + if (!address.is_initialized()) { + FileType file_type = Addr::RequiredFileType(size); + DCHECK_NE(file_type, EXTERNAL); + int num_blocks = Addr::RequiredBlocks(size, file_type); + + if (!CreateBlock(file_type, num_blocks, &address)) + return false; + return stats_.Init(NULL, 0, address); + } + + if (!address.is_block_file()) { + NOTREACHED(); + return false; + } + + // Load the required data. + size = address.num_blocks() * address.BlockSize(); + MappedFile* file = File(address); + if (!file) + return false; + + scoped_ptr<char[]> data(new char[size]); + size_t offset = address.start_block() * address.BlockSize() + + kBlockHeaderSize; + if (!file->Read(data.get(), size, offset)) + return false; + + if (!stats_.Init(data.get(), size, address)) + return false; + if (cache_type_ == net::DISK_CACHE && ShouldReportAgain()) + stats_.InitSizeHistogram(); + return true; +} + +void BackendImpl::StoreStats() { + int size = stats_.StorageSize(); + scoped_ptr<char[]> data(new char[size]); + Addr address; + size = stats_.SerializeStats(data.get(), size, &address); + DCHECK(size); + if (!address.is_initialized()) + return; + + MappedFile* file = File(address); + if (!file) + return; + + size_t offset = address.start_block() * address.BlockSize() + + kBlockHeaderSize; + file->Write(data.get(), size, offset); // ignore result. +} + +void BackendImpl::RestartCache(bool failure) { + int64 errors = stats_.GetCounter(Stats::FATAL_ERROR); + int64 full_dooms = stats_.GetCounter(Stats::DOOM_CACHE); + int64 partial_dooms = stats_.GetCounter(Stats::DOOM_RECENT); + int64 last_report = stats_.GetCounter(Stats::LAST_REPORT); + + PrepareForRestart(); + if (failure) { + DCHECK(!num_refs_); + DCHECK(!open_entries_.size()); + DelayedCacheCleanup(path_); + } else { + DeleteCache(path_, false); + } + + // Don't call Init() if directed by the unit test: we are simulating a failure + // trying to re-enable the cache. + if (unit_test_) + init_ = true; // Let the destructor do proper cleanup. + else if (SyncInit() == net::OK) { + stats_.SetCounter(Stats::FATAL_ERROR, errors); + stats_.SetCounter(Stats::DOOM_CACHE, full_dooms); + stats_.SetCounter(Stats::DOOM_RECENT, partial_dooms); + stats_.SetCounter(Stats::LAST_REPORT, last_report); + } +} + +void BackendImpl::PrepareForRestart() { + // Reset the mask_ if it was not given by the user. + if (!(user_flags_ & kMask)) + mask_ = 0; + + if (!(user_flags_ & kNewEviction)) + new_eviction_ = false; + + disabled_ = true; + data_->header.crash = 0; + index_->Flush(); + index_ = NULL; + data_ = NULL; + block_files_.CloseFiles(); + rankings_.Reset(); + init_ = false; + restarted_ = true; +} + +void BackendImpl::CleanupCache() { + Trace("Backend Cleanup"); + eviction_.Stop(); + timer_.reset(); + + if (init_) { + StoreStats(); + if (data_) + data_->header.crash = 0; + + if (user_flags_ & kNoRandom) { + // This is a net_unittest, verify that we are not 'leaking' entries. + File::WaitForPendingIO(&num_pending_io_); + DCHECK(!num_refs_); + } else { + File::DropPendingIO(); + } + } + block_files_.CloseFiles(); + FlushIndex(); + index_ = NULL; + ptr_factory_.InvalidateWeakPtrs(); + done_.Signal(); +} + +int BackendImpl::NewEntry(Addr address, EntryImpl** entry) { + EntriesMap::iterator it = open_entries_.find(address.value()); + if (it != open_entries_.end()) { + // Easy job. This entry is already in memory. + EntryImpl* this_entry = it->second; + this_entry->AddRef(); + *entry = this_entry; + return 0; + } + + STRESS_DCHECK(block_files_.IsValid(address)); + + if (!address.SanityCheckForEntry()) { + LOG(WARNING) << "Wrong entry address."; + STRESS_NOTREACHED(); + return ERR_INVALID_ADDRESS; + } + + scoped_refptr<EntryImpl> cache_entry( + new EntryImpl(this, address, read_only_)); + IncreaseNumRefs(); + *entry = NULL; + + TimeTicks start = TimeTicks::Now(); + if (!cache_entry->entry()->Load()) + return ERR_READ_FAILURE; + + if (IsLoaded()) { + CACHE_UMA(AGE_MS, "LoadTime", 0, start); + } + + if (!cache_entry->SanityCheck()) { + LOG(WARNING) << "Messed up entry found."; + STRESS_NOTREACHED(); + return ERR_INVALID_ENTRY; + } + + STRESS_DCHECK(block_files_.IsValid( + Addr(cache_entry->entry()->Data()->rankings_node))); + + if (!cache_entry->LoadNodeAddress()) + return ERR_READ_FAILURE; + + if (!rankings_.SanityCheck(cache_entry->rankings(), false)) { + STRESS_NOTREACHED(); + cache_entry->SetDirtyFlag(0); + // Don't remove this from the list (it is not linked properly). Instead, + // break the link back to the entry because it is going away, and leave the + // rankings node to be deleted if we find it through a list. + rankings_.SetContents(cache_entry->rankings(), 0); + } else if (!rankings_.DataSanityCheck(cache_entry->rankings(), false)) { + STRESS_NOTREACHED(); + cache_entry->SetDirtyFlag(0); + rankings_.SetContents(cache_entry->rankings(), address.value()); + } + + if (!cache_entry->DataSanityCheck()) { + LOG(WARNING) << "Messed up entry found."; + cache_entry->SetDirtyFlag(0); + cache_entry->FixForDelete(); + } + + // Prevent overwriting the dirty flag on the destructor. + cache_entry->SetDirtyFlag(GetCurrentEntryId()); + + if (cache_entry->dirty()) { + Trace("Dirty entry 0x%p 0x%x", reinterpret_cast<void*>(cache_entry.get()), + address.value()); + } + + open_entries_[address.value()] = cache_entry.get(); + + cache_entry->BeginLogging(net_log_, false); + cache_entry.swap(entry); + return 0; +} + +// This is the actual implementation for OpenNextEntry and OpenPrevEntry. +EntryImpl* BackendImpl::OpenFollowingEntry(bool forward, void** iter) { + if (disabled_) + return NULL; + + DCHECK(iter); + + const int kListsToSearch = 3; + scoped_refptr<EntryImpl> entries[kListsToSearch]; + scoped_ptr<Rankings::Iterator> iterator( + reinterpret_cast<Rankings::Iterator*>(*iter)); + *iter = NULL; + + if (!iterator.get()) { + iterator.reset(new Rankings::Iterator(&rankings_)); + bool ret = false; + + // Get an entry from each list. + for (int i = 0; i < kListsToSearch; i++) { + EntryImpl* temp = NULL; + ret |= OpenFollowingEntryFromList(forward, static_cast<Rankings::List>(i), + &iterator->nodes[i], &temp); + entries[i].swap(&temp); // The entry was already addref'd. + } + if (!ret) + return NULL; + } else { + // Get the next entry from the last list, and the actual entries for the + // elements on the other lists. + for (int i = 0; i < kListsToSearch; i++) { + EntryImpl* temp = NULL; + if (iterator->list == i) { + OpenFollowingEntryFromList(forward, iterator->list, + &iterator->nodes[i], &temp); + } else { + temp = GetEnumeratedEntry(iterator->nodes[i], + static_cast<Rankings::List>(i)); + } + + entries[i].swap(&temp); // The entry was already addref'd. + } + } + + int newest = -1; + int oldest = -1; + Time access_times[kListsToSearch]; + for (int i = 0; i < kListsToSearch; i++) { + if (entries[i].get()) { + access_times[i] = entries[i]->GetLastUsed(); + if (newest < 0) { + DCHECK_LT(oldest, 0); + newest = oldest = i; + continue; + } + if (access_times[i] > access_times[newest]) + newest = i; + if (access_times[i] < access_times[oldest]) + oldest = i; + } + } + + if (newest < 0 || oldest < 0) + return NULL; + + EntryImpl* next_entry; + if (forward) { + next_entry = entries[newest].get(); + iterator->list = static_cast<Rankings::List>(newest); + } else { + next_entry = entries[oldest].get(); + iterator->list = static_cast<Rankings::List>(oldest); + } + + *iter = iterator.release(); + next_entry->AddRef(); + return next_entry; +} + +void BackendImpl::AddStorageSize(int32 bytes) { + data_->header.num_bytes += bytes; + DCHECK_GE(data_->header.num_bytes, 0); +} + +void BackendImpl::SubstractStorageSize(int32 bytes) { + data_->header.num_bytes -= bytes; + DCHECK_GE(data_->header.num_bytes, 0); +} + +void BackendImpl::IncreaseNumRefs() { + num_refs_++; + if (max_refs_ < num_refs_) + max_refs_ = num_refs_; +} + +void BackendImpl::DecreaseNumRefs() { + DCHECK(num_refs_); + num_refs_--; + + if (!num_refs_ && disabled_) + base::MessageLoop::current()->PostTask( + FROM_HERE, base::Bind(&BackendImpl::RestartCache, GetWeakPtr(), true)); +} + +void BackendImpl::IncreaseNumEntries() { + data_->header.num_entries++; + DCHECK_GT(data_->header.num_entries, 0); +} + +void BackendImpl::DecreaseNumEntries() { + data_->header.num_entries--; + if (data_->header.num_entries < 0) { + NOTREACHED(); + data_->header.num_entries = 0; + } +} + +int BackendImpl::SyncInit() { +#if defined(NET_BUILD_STRESS_CACHE) + // Start evictions right away. + up_ticks_ = kTrimDelay * 2; +#endif + DCHECK(!init_); + if (init_) + return net::ERR_FAILED; + + bool create_files = false; + if (!InitBackingStore(&create_files)) { + ReportError(ERR_STORAGE_ERROR); + return net::ERR_FAILED; + } + + num_refs_ = num_pending_io_ = max_refs_ = 0; + entry_count_ = byte_count_ = 0; + + if (!restarted_) { + buffer_bytes_ = 0; + trace_object_ = TraceObject::GetTraceObject(); + // Create a recurrent timer of 30 secs. + int timer_delay = unit_test_ ? 1000 : 30000; + timer_.reset(new base::RepeatingTimer<BackendImpl>()); + timer_->Start(FROM_HERE, TimeDelta::FromMilliseconds(timer_delay), this, + &BackendImpl::OnStatsTimer); + } + + init_ = true; + Trace("Init"); + + if (data_->header.experiment != NO_EXPERIMENT && + cache_type_ != net::DISK_CACHE) { + // No experiment for other caches. + return net::ERR_FAILED; + } + + if (!(user_flags_ & kNoRandom)) { + // The unit test controls directly what to test. + new_eviction_ = (cache_type_ == net::DISK_CACHE); + } + + if (!CheckIndex()) { + ReportError(ERR_INIT_FAILED); + return net::ERR_FAILED; + } + + if (!restarted_ && (create_files || !data_->header.num_entries)) + ReportError(ERR_CACHE_CREATED); + + if (!(user_flags_ & kNoRandom) && cache_type_ == net::DISK_CACHE && + !InitExperiment(&data_->header, create_files)) { + return net::ERR_FAILED; + } + + // We don't care if the value overflows. The only thing we care about is that + // the id cannot be zero, because that value is used as "not dirty". + // Increasing the value once per second gives us many years before we start + // having collisions. + data_->header.this_id++; + if (!data_->header.this_id) + data_->header.this_id++; + + bool previous_crash = (data_->header.crash != 0); + data_->header.crash = 1; + + if (!block_files_.Init(create_files)) + return net::ERR_FAILED; + + // We want to minimize the changes to cache for an AppCache. + if (cache_type() == net::APP_CACHE) { + DCHECK(!new_eviction_); + read_only_ = true; + } else if (cache_type() == net::SHADER_CACHE) { + DCHECK(!new_eviction_); + } + + eviction_.Init(this); + + // stats_ and rankings_ may end up calling back to us so we better be enabled. + disabled_ = false; + if (!InitStats()) + return net::ERR_FAILED; + + disabled_ = !rankings_.Init(this, new_eviction_); + +#if defined(STRESS_CACHE_EXTENDED_VALIDATION) + trace_object_->EnableTracing(false); + int sc = SelfCheck(); + if (sc < 0 && sc != ERR_NUM_ENTRIES_MISMATCH) + NOTREACHED(); + trace_object_->EnableTracing(true); +#endif + + if (previous_crash) { + ReportError(ERR_PREVIOUS_CRASH); + } else if (!restarted_) { + ReportError(ERR_NO_ERROR); + } + + FlushIndex(); + + return disabled_ ? net::ERR_FAILED : net::OK; +} + +EntryImpl* BackendImpl::ResurrectEntry(EntryImpl* deleted_entry) { + if (ENTRY_NORMAL == deleted_entry->entry()->Data()->state) { + deleted_entry->Release(); + stats_.OnEvent(Stats::CREATE_MISS); + Trace("create entry miss "); + return NULL; + } + + // We are attempting to create an entry and found out that the entry was + // previously deleted. + + eviction_.OnCreateEntry(deleted_entry); + entry_count_++; + + stats_.OnEvent(Stats::RESURRECT_HIT); + Trace("Resurrect entry hit "); + return deleted_entry; +} + +EntryImpl* BackendImpl::CreateEntryImpl(const std::string& key) { + if (disabled_ || key.empty()) + return NULL; + + TimeTicks start = TimeTicks::Now(); + Trace("Create hash 0x%x", hash); + + scoped_refptr<EntryImpl> parent; + Addr entry_address(data_->table[hash & mask_]); + if (entry_address.is_initialized()) { + // We have an entry already. It could be the one we are looking for, or just + // a hash conflict. + bool error; + EntryImpl* old_entry = MatchEntry(key, hash, false, Addr(), &error); + if (old_entry) + return ResurrectEntry(old_entry); + + EntryImpl* parent_entry = MatchEntry(key, hash, true, Addr(), &error); + DCHECK(!error); + if (parent_entry) { + parent.swap(&parent_entry); + } else if (data_->table[hash & mask_]) { + // We should have corrected the problem. + NOTREACHED(); + return NULL; + } + } + + // The general flow is to allocate disk space and initialize the entry data, + // followed by saving that to disk, then linking the entry though the index + // and finally through the lists. If there is a crash in this process, we may + // end up with: + // a. Used, unreferenced empty blocks on disk (basically just garbage). + // b. Used, unreferenced but meaningful data on disk (more garbage). + // c. A fully formed entry, reachable only through the index. + // d. A fully formed entry, also reachable through the lists, but still dirty. + // + // Anything after (b) can be automatically cleaned up. We may consider saving + // the current operation (as we do while manipulating the lists) so that we + // can detect and cleanup (a) and (b). + + int num_blocks = EntryImpl::NumBlocksForEntry(key.size()); + if (!block_files_.CreateBlock(BLOCK_256, num_blocks, &entry_address)) { + LOG(ERROR) << "Create entry failed " << key.c_str(); + stats_.OnEvent(Stats::CREATE_ERROR); + return NULL; + } + + Addr node_address(0); + if (!block_files_.CreateBlock(RANKINGS, 1, &node_address)) { + block_files_.DeleteBlock(entry_address, false); + LOG(ERROR) << "Create entry failed " << key.c_str(); + stats_.OnEvent(Stats::CREATE_ERROR); + return NULL; + } + + scoped_refptr<EntryImpl> cache_entry( + new EntryImpl(this, entry_address, false)); + IncreaseNumRefs(); + + if (!cache_entry->CreateEntry(node_address, key, hash)) { + block_files_.DeleteBlock(entry_address, false); + block_files_.DeleteBlock(node_address, false); + LOG(ERROR) << "Create entry failed " << key.c_str(); + stats_.OnEvent(Stats::CREATE_ERROR); + return NULL; + } + + cache_entry->BeginLogging(net_log_, true); + + // We are not failing the operation; let's add this to the map. + open_entries_[entry_address.value()] = cache_entry; + + // Save the entry. + cache_entry->entry()->Store(); + cache_entry->rankings()->Store(); + IncreaseNumEntries(); + entry_count_++; + + // Link this entry through the index. + if (parent.get()) { + parent->SetNextAddress(entry_address); + } else { + data_->table[hash & mask_] = entry_address.value(); + } + + // Link this entry through the lists. + eviction_.OnCreateEntry(cache_entry); + + CACHE_UMA(AGE_MS, "CreateTime", 0, start); + stats_.OnEvent(Stats::CREATE_HIT); + SIMPLE_STATS_COUNTER("disk_cache.miss"); + Trace("create entry hit "); + FlushIndex(); + cache_entry->AddRef(); + return cache_entry.get(); +} + +void BackendImpl::LogStats() { + StatsItems stats; + GetStats(&stats); + + for (size_t index = 0; index < stats.size(); index++) + VLOG(1) << stats[index].first << ": " << stats[index].second; +} + +void BackendImpl::ReportStats() { + CACHE_UMA(COUNTS, "Entries", 0, data_->header.num_entries); + + int current_size = data_->header.num_bytes / (1024 * 1024); + int max_size = max_size_ / (1024 * 1024); + int hit_ratio_as_percentage = stats_.GetHitRatio(); + + CACHE_UMA(COUNTS_10000, "Size2", 0, current_size); + // For any bin in HitRatioBySize2, the hit ratio of caches of that size is the + // ratio of that bin's total count to the count in the same bin in the Size2 + // histogram. + if (base::RandInt(0, 99) < hit_ratio_as_percentage) + CACHE_UMA(COUNTS_10000, "HitRatioBySize2", 0, current_size); + CACHE_UMA(COUNTS_10000, "MaxSize2", 0, max_size); + if (!max_size) + max_size++; + CACHE_UMA(PERCENTAGE, "UsedSpace", 0, current_size * 100 / max_size); + + CACHE_UMA(COUNTS_10000, "AverageOpenEntries2", 0, + static_cast<int>(stats_.GetCounter(Stats::OPEN_ENTRIES))); + CACHE_UMA(COUNTS_10000, "MaxOpenEntries2", 0, + static_cast<int>(stats_.GetCounter(Stats::MAX_ENTRIES))); + stats_.SetCounter(Stats::MAX_ENTRIES, 0); + + CACHE_UMA(COUNTS_10000, "TotalFatalErrors", 0, + static_cast<int>(stats_.GetCounter(Stats::FATAL_ERROR))); + CACHE_UMA(COUNTS_10000, "TotalDoomCache", 0, + static_cast<int>(stats_.GetCounter(Stats::DOOM_CACHE))); + CACHE_UMA(COUNTS_10000, "TotalDoomRecentEntries", 0, + static_cast<int>(stats_.GetCounter(Stats::DOOM_RECENT))); + stats_.SetCounter(Stats::FATAL_ERROR, 0); + stats_.SetCounter(Stats::DOOM_CACHE, 0); + stats_.SetCounter(Stats::DOOM_RECENT, 0); + + int64 total_hours = stats_.GetCounter(Stats::TIMER) / 120; + if (!data_->header.create_time || !data_->header.lru.filled) { + int cause = data_->header.create_time ? 0 : 1; + if (!data_->header.lru.filled) + cause |= 2; + CACHE_UMA(CACHE_ERROR, "ShortReport", 0, cause); + CACHE_UMA(HOURS, "TotalTimeNotFull", 0, static_cast<int>(total_hours)); + return; + } + + // This is an up to date client that will report FirstEviction() data. After + // that event, start reporting this: + + CACHE_UMA(HOURS, "TotalTime", 0, static_cast<int>(total_hours)); + // For any bin in HitRatioByTotalTime, the hit ratio of caches of that total + // time is the ratio of that bin's total count to the count in the same bin in + // the TotalTime histogram. + if (base::RandInt(0, 99) < hit_ratio_as_percentage) + CACHE_UMA(HOURS, "HitRatioByTotalTime", 0, implicit_cast<int>(total_hours)); + + int64 use_hours = stats_.GetCounter(Stats::LAST_REPORT_TIMER) / 120; + stats_.SetCounter(Stats::LAST_REPORT_TIMER, stats_.GetCounter(Stats::TIMER)); + + // We may see users with no use_hours at this point if this is the first time + // we are running this code. + if (use_hours) + use_hours = total_hours - use_hours; + + if (!use_hours || !GetEntryCount() || !data_->header.num_bytes) + return; + + CACHE_UMA(HOURS, "UseTime", 0, static_cast<int>(use_hours)); + // For any bin in HitRatioByUseTime, the hit ratio of caches of that use time + // is the ratio of that bin's total count to the count in the same bin in the + // UseTime histogram. + if (base::RandInt(0, 99) < hit_ratio_as_percentage) + CACHE_UMA(HOURS, "HitRatioByUseTime", 0, implicit_cast<int>(use_hours)); + CACHE_UMA(PERCENTAGE, "HitRatio", 0, hit_ratio_as_percentage); + + int64 trim_rate = stats_.GetCounter(Stats::TRIM_ENTRY) / use_hours; + CACHE_UMA(COUNTS, "TrimRate", 0, static_cast<int>(trim_rate)); + + int avg_size = data_->header.num_bytes / GetEntryCount(); + CACHE_UMA(COUNTS, "EntrySize", 0, avg_size); + CACHE_UMA(COUNTS, "EntriesFull", 0, data_->header.num_entries); + + CACHE_UMA(PERCENTAGE, "IndexLoad", 0, + data_->header.num_entries * 100 / (mask_ + 1)); + + int large_entries_bytes = stats_.GetLargeEntriesSize(); + int large_ratio = large_entries_bytes * 100 / data_->header.num_bytes; + CACHE_UMA(PERCENTAGE, "LargeEntriesRatio", 0, large_ratio); + + if (new_eviction_) { + CACHE_UMA(PERCENTAGE, "ResurrectRatio", 0, stats_.GetResurrectRatio()); + CACHE_UMA(PERCENTAGE, "NoUseRatio", 0, + data_->header.lru.sizes[0] * 100 / data_->header.num_entries); + CACHE_UMA(PERCENTAGE, "LowUseRatio", 0, + data_->header.lru.sizes[1] * 100 / data_->header.num_entries); + CACHE_UMA(PERCENTAGE, "HighUseRatio", 0, + data_->header.lru.sizes[2] * 100 / data_->header.num_entries); + CACHE_UMA(PERCENTAGE, "DeletedRatio", 0, + data_->header.lru.sizes[4] * 100 / data_->header.num_entries); + } + + stats_.ResetRatios(); + stats_.SetCounter(Stats::TRIM_ENTRY, 0); + + if (cache_type_ == net::DISK_CACHE) + block_files_.ReportStats(); +} + +void BackendImpl::ReportError(int error) { + STRESS_DCHECK(!error || error == ERR_PREVIOUS_CRASH || + error == ERR_CACHE_CREATED); + + // We transmit positive numbers, instead of direct error codes. + DCHECK_LE(error, 0); + CACHE_UMA(CACHE_ERROR, "Error", 0, error * -1); +} + +bool BackendImpl::CheckIndex() { + DCHECK(data_); + + size_t current_size = index_->GetLength(); + if (current_size < sizeof(Index)) { + LOG(ERROR) << "Corrupt Index file"; + return false; + } + + if (new_eviction_) { + // We support versions 2.0 and 2.1, upgrading 2.0 to 2.1. + if (kIndexMagic != data_->header.magic || + kCurrentVersion >> 16 != data_->header.version >> 16) { + LOG(ERROR) << "Invalid file version or magic"; + return false; + } + if (kCurrentVersion == data_->header.version) { + // We need file version 2.1 for the new eviction algorithm. + UpgradeTo2_1(); + } + } else { + if (kIndexMagic != data_->header.magic || + kCurrentVersion != data_->header.version) { + LOG(ERROR) << "Invalid file version or magic"; + return false; + } + } + + if (!data_->header.table_len) { + LOG(ERROR) << "Invalid table size"; + return false; + } + + if (current_size < GetIndexSize(data_->header.table_len) || + data_->header.table_len & (kBaseTableLen - 1)) { + LOG(ERROR) << "Corrupt Index file"; + return false; + } + + AdjustMaxCacheSize(data_->header.table_len); + +#if !defined(NET_BUILD_STRESS_CACHE) + if (data_->header.num_bytes < 0 || + (max_size_ < kint32max - kDefaultCacheSize && + data_->header.num_bytes > max_size_ + kDefaultCacheSize)) { + LOG(ERROR) << "Invalid cache (current) size"; + return false; + } +#endif + + if (data_->header.num_entries < 0) { + LOG(ERROR) << "Invalid number of entries"; + return false; + } + + if (!mask_) + mask_ = data_->header.table_len - 1; + + // Load the table into memory with a single read. + scoped_ptr<char[]> buf(new char[current_size]); + return index_->Read(buf.get(), current_size, 0); +} + +int BackendImpl::CheckAllEntries() { + int num_dirty = 0; + int num_entries = 0; + DCHECK(mask_ < kuint32max); + for (unsigned int i = 0; i <= mask_; i++) { + Addr address(data_->table[i]); + if (!address.is_initialized()) + continue; + for (;;) { + EntryImpl* tmp; + int ret = NewEntry(address, &tmp); + if (ret) { + STRESS_NOTREACHED(); + return ret; + } + scoped_refptr<EntryImpl> cache_entry; + cache_entry.swap(&tmp); + + if (cache_entry->dirty()) + num_dirty++; + else if (CheckEntry(cache_entry.get())) + num_entries++; + else + return ERR_INVALID_ENTRY; + + DCHECK_EQ(i, cache_entry->entry()->Data()->hash & mask_); + address.set_value(cache_entry->GetNextAddress()); + if (!address.is_initialized()) + break; + } + } + + Trace("CheckAllEntries End"); + if (num_entries + num_dirty != data_->header.num_entries) { + LOG(ERROR) << "Number of entries " << num_entries << " " << num_dirty << + " " << data_->header.num_entries; + DCHECK_LT(num_entries, data_->header.num_entries); + return ERR_NUM_ENTRIES_MISMATCH; + } + + return num_dirty; +} + +bool BackendImpl::CheckEntry(EntryImpl* cache_entry) { + bool ok = block_files_.IsValid(cache_entry->entry()->address()); + ok = ok && block_files_.IsValid(cache_entry->rankings()->address()); + EntryStore* data = cache_entry->entry()->Data(); + for (size_t i = 0; i < arraysize(data->data_addr); i++) { + if (data->data_addr[i]) { + Addr address(data->data_addr[i]); + if (address.is_block_file()) + ok = ok && block_files_.IsValid(address); + } + } + + return ok && cache_entry->rankings()->VerifyHash(); +} + +int BackendImpl::MaxBuffersSize() { + static int64 total_memory = base::SysInfo::AmountOfPhysicalMemory(); + static bool done = false; + + if (!done) { + const int kMaxBuffersSize = 30 * 1024 * 1024; + + // We want to use up to 2% of the computer's memory. + total_memory = total_memory * 2 / 100; + if (total_memory > kMaxBuffersSize || total_memory <= 0) + total_memory = kMaxBuffersSize; + + done = true; + } + + return static_cast<int>(total_memory); +} + +} // namespace disk_cache |