diff options
Diffstat (limited to 'chromium/net/disk_cache/v3/backend_worker.cc')
| -rw-r--r-- | chromium/net/disk_cache/v3/backend_worker.cc | 485 |
1 files changed, 485 insertions, 0 deletions
diff --git a/chromium/net/disk_cache/v3/backend_worker.cc b/chromium/net/disk_cache/v3/backend_worker.cc new file mode 100644 index 00000000000..cbccfddb5c6 --- /dev/null +++ b/chromium/net/disk_cache/v3/backend_worker.cc @@ -0,0 +1,485 @@ +// 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; +} + +// ------------------------------------------------------------------------ + +// Sets group for the current experiment. Returns false if the files should be +// discarded. +bool InitExperiment(disk_cache::IndexHeader* header, bool cache_created) { + if (header->experiment == disk_cache::EXPERIMENT_OLD_FILE1 || + header->experiment == disk_cache::EXPERIMENT_OLD_FILE2) { + // Discard current cache. + return false; + } + + if (base::FieldTrialList::FindFullName("SimpleCacheTrial") == + "ExperimentControl") { + if (cache_created) { + header->experiment = disk_cache::EXPERIMENT_SIMPLE_CONTROL; + return true; + } else if (header->experiment != disk_cache::EXPERIMENT_SIMPLE_CONTROL) { + return false; + } + } + + header->experiment = disk_cache::NO_EXPERIMENT; + return true; +} + +} // 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) { +} + +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; +} + +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; +} + +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(); + } +} + +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(); +} + +base::FilePath BackendImpl::GetFileName(Addr address) const { + if (!address.is_separate_file() || !address.is_initialized()) { + NOTREACHED(); + return base::FilePath(); + } + + std::string tmp = base::StringPrintf("f_%06x", address.FileNumber()); + return path_.AppendASCII(tmp); +} + +// We just created a new file so we're going to write the header and set the +// file length to include the hash table (zero filled). +bool BackendImpl::CreateBackingStore(disk_cache::File* file) { + AdjustMaxCacheSize(0); + + IndexHeader header; + header.table_len = DesiredIndexTableLen(max_size_); + + // We need file version 2.1 for the new eviction algorithm. + if (new_eviction_) + header.version = 0x20001; + + header.create_time = Time::Now().ToInternalValue(); + + if (!file->Write(&header, sizeof(header), 0)) + return false; + + return file->SetLength(GetIndexSize(header.table_len)); +} + +bool BackendImpl::InitBackingStore(bool* file_created) { + if (!file_util::CreateDirectory(path_)) + return false; + + base::FilePath index_name = path_.AppendASCII(kIndexName); + + int flags = base::PLATFORM_FILE_READ | + base::PLATFORM_FILE_WRITE | + base::PLATFORM_FILE_OPEN_ALWAYS | + base::PLATFORM_FILE_EXCLUSIVE_WRITE; + scoped_refptr<disk_cache::File> file(new disk_cache::File( + base::CreatePlatformFile(index_name, flags, file_created, NULL))); + + if (!file->IsValid()) + return false; + + bool ret = true; + if (*file_created) + ret = CreateBackingStore(file.get()); + + file = NULL; + if (!ret) + return false; + + index_ = new MappedFile(); + data_ = reinterpret_cast<Index*>(index_->Init(index_name, 0)); + if (!data_) { + LOG(ERROR) << "Unable to map Index file"; + return false; + } + + if (index_->GetLength() < sizeof(Index)) { + // We verify this again on CheckIndex() but it's easier to make sure now + // that the header is there. + LOG(ERROR) << "Corrupt Index file"; + return false; + } + + return true; +} + +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); +} + +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; +} + +} // namespace disk_cache |