blob: 6cf75ba4ebe522519f4967cf0fa0f87549156b5a [file] [log] [blame]
// Copyright (c) 2013 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/simple/simple_index.h"
#include <algorithm>
#include <limits>
#include <string>
#include <utility>
#include "base/bind.h"
#include "base/bind_helpers.h"
#include "base/files/file_enumerator.h"
#include "base/files/file_util.h"
#include "base/logging.h"
#include "base/message_loop/message_loop.h"
#include "base/metrics/field_trial.h"
#include "base/numerics/safe_conversions.h"
#include "base/pickle.h"
#include "base/strings/string_number_conversions.h"
#include "base/strings/string_tokenizer.h"
#include "base/task_runner.h"
#include "base/threading/worker_pool.h"
#include "base/time/time.h"
#include "net/base/net_errors.h"
#include "net/disk_cache/simple/simple_entry_format.h"
#include "net/disk_cache/simple/simple_histogram_macros.h"
#include "net/disk_cache/simple/simple_index_delegate.h"
#include "net/disk_cache/simple/simple_index_file.h"
#include "net/disk_cache/simple/simple_synchronous_entry.h"
#include "net/disk_cache/simple/simple_util.h"
#if defined(OS_POSIX)
#include <sys/stat.h>
#include <sys/time.h>
#endif
namespace {
// How many milliseconds we delay writing the index to disk since the last cache
// operation has happened.
const int kWriteToDiskDelayMSecs = 20000;
const int kWriteToDiskOnBackgroundDelayMSecs = 100;
// Divides the cache space into this amount of parts to evict when only one part
// is left.
const uint32_t kEvictionMarginDivisor = 20;
const uint32_t kBytesInKb = 1024;
// Utility class used for timestamp comparisons in entry metadata while sorting.
class CompareHashesForTimestamp {
typedef disk_cache::SimpleIndex SimpleIndex;
typedef disk_cache::SimpleIndex::EntrySet EntrySet;
public:
explicit CompareHashesForTimestamp(const EntrySet& set);
bool operator()(uint64_t hash1, uint64_t hash2);
private:
const EntrySet& entry_set_;
};
CompareHashesForTimestamp::CompareHashesForTimestamp(const EntrySet& set)
: entry_set_(set) {
}
bool CompareHashesForTimestamp::operator()(uint64_t hash1, uint64_t hash2) {
EntrySet::const_iterator it1 = entry_set_.find(hash1);
DCHECK(it1 != entry_set_.end());
EntrySet::const_iterator it2 = entry_set_.find(hash2);
DCHECK(it2 != entry_set_.end());
return it1->second.GetLastUsedTime() < it2->second.GetLastUsedTime();
}
} // namespace
namespace disk_cache {
EntryMetadata::EntryMetadata()
: last_used_time_seconds_since_epoch_(0),
entry_size_(0) {
}
EntryMetadata::EntryMetadata(base::Time last_used_time,
base::StrictNumeric<uint32_t> entry_size)
: last_used_time_seconds_since_epoch_(0), entry_size_(entry_size) {
SetLastUsedTime(last_used_time);
}
base::Time EntryMetadata::GetLastUsedTime() const {
// Preserve nullity.
if (last_used_time_seconds_since_epoch_ == 0)
return base::Time();
return base::Time::UnixEpoch() +
base::TimeDelta::FromSeconds(last_used_time_seconds_since_epoch_);
}
void EntryMetadata::SetLastUsedTime(const base::Time& last_used_time) {
// Preserve nullity.
if (last_used_time.is_null()) {
last_used_time_seconds_since_epoch_ = 0;
return;
}
last_used_time_seconds_since_epoch_ = base::saturated_cast<uint32_t>(
(last_used_time - base::Time::UnixEpoch()).InSeconds());
// Avoid accidental nullity.
if (last_used_time_seconds_since_epoch_ == 0)
last_used_time_seconds_since_epoch_ = 1;
}
uint32_t EntryMetadata::GetEntrySize() const {
return entry_size_;
}
void EntryMetadata::SetEntrySize(base::StrictNumeric<uint32_t> entry_size) {
entry_size_ = entry_size;
}
void EntryMetadata::Serialize(base::Pickle* pickle) const {
DCHECK(pickle);
int64_t internal_last_used_time = GetLastUsedTime().ToInternalValue();
pickle->WriteInt64(internal_last_used_time);
pickle->WriteUInt64(entry_size_);
}
bool EntryMetadata::Deserialize(base::PickleIterator* it) {
DCHECK(it);
int64_t tmp_last_used_time;
uint64_t tmp_entry_size;
if (!it->ReadInt64(&tmp_last_used_time) || !it->ReadUInt64(&tmp_entry_size) ||
tmp_entry_size > std::numeric_limits<decltype(entry_size_)>::max())
return false;
SetLastUsedTime(base::Time::FromInternalValue(tmp_last_used_time));
entry_size_ = static_cast<uint32_t>(tmp_entry_size);
return true;
}
SimpleIndex::SimpleIndex(
const scoped_refptr<base::SingleThreadTaskRunner>& io_thread,
SimpleIndexDelegate* delegate,
net::CacheType cache_type,
std::unique_ptr<SimpleIndexFile> index_file)
: delegate_(delegate),
cache_type_(cache_type),
cache_size_(0),
max_size_(0),
high_watermark_(0),
low_watermark_(0),
eviction_in_progress_(false),
initialized_(false),
init_method_(INITIALIZE_METHOD_MAX),
index_file_(std::move(index_file)),
io_thread_(io_thread),
// Creating the callback once so it is reused every time
// write_to_disk_timer_.Start() is called.
write_to_disk_cb_(base::Bind(&SimpleIndex::WriteToDisk,
AsWeakPtr(),
INDEX_WRITE_REASON_IDLE)),
app_on_background_(false) {}
SimpleIndex::~SimpleIndex() {
DCHECK(io_thread_checker_.CalledOnValidThread());
// Fail all callbacks waiting for the index to come up.
for (CallbackList::iterator it = to_run_when_initialized_.begin(),
end = to_run_when_initialized_.end(); it != end; ++it) {
it->Run(net::ERR_ABORTED);
}
}
void SimpleIndex::Initialize(base::Time cache_mtime) {
DCHECK(io_thread_checker_.CalledOnValidThread());
#if defined(OS_ANDROID)
if (base::android::IsVMInitialized()) {
app_status_listener_.reset(new base::android::ApplicationStatusListener(
base::Bind(&SimpleIndex::OnApplicationStateChange, AsWeakPtr())));
}
#endif
SimpleIndexLoadResult* load_result = new SimpleIndexLoadResult();
std::unique_ptr<SimpleIndexLoadResult> load_result_scoped(load_result);
base::Closure reply = base::Bind(
&SimpleIndex::MergeInitializingSet,
AsWeakPtr(),
base::Passed(&load_result_scoped));
index_file_->LoadIndexEntries(cache_mtime, reply, load_result);
}
void SimpleIndex::SetMaxSize(uint64_t max_bytes) {
// Zero size means use the default.
if (max_bytes) {
max_size_ = max_bytes;
high_watermark_ = max_size_ - max_size_ / kEvictionMarginDivisor;
low_watermark_ = max_size_ - 2 * (max_size_ / kEvictionMarginDivisor);
}
}
int SimpleIndex::ExecuteWhenReady(const net::CompletionCallback& task) {
DCHECK(io_thread_checker_.CalledOnValidThread());
if (initialized_)
io_thread_->PostTask(FROM_HERE, base::Bind(task, net::OK));
else
to_run_when_initialized_.push_back(task);
return net::ERR_IO_PENDING;
}
std::unique_ptr<SimpleIndex::HashList> SimpleIndex::GetEntriesBetween(
base::Time initial_time,
base::Time end_time) {
DCHECK_EQ(true, initialized_);
if (!initial_time.is_null())
initial_time -= EntryMetadata::GetLowerEpsilonForTimeComparisons();
if (end_time.is_null())
end_time = base::Time::Max();
else
end_time += EntryMetadata::GetUpperEpsilonForTimeComparisons();
const base::Time extended_end_time =
end_time.is_null() ? base::Time::Max() : end_time;
DCHECK(extended_end_time >= initial_time);
std::unique_ptr<HashList> ret_hashes(new HashList());
for (EntrySet::iterator it = entries_set_.begin(), end = entries_set_.end();
it != end; ++it) {
EntryMetadata& metadata = it->second;
base::Time entry_time = metadata.GetLastUsedTime();
if (initial_time <= entry_time && entry_time < extended_end_time)
ret_hashes->push_back(it->first);
}
return ret_hashes;
}
std::unique_ptr<SimpleIndex::HashList> SimpleIndex::GetAllHashes() {
return GetEntriesBetween(base::Time(), base::Time());
}
int32_t SimpleIndex::GetEntryCount() const {
// TODO(pasko): return a meaningful initial estimate before initialized.
return entries_set_.size();
}
uint64_t SimpleIndex::GetCacheSize() const {
DCHECK(initialized_);
return cache_size_;
}
void SimpleIndex::Insert(uint64_t entry_hash) {
DCHECK(io_thread_checker_.CalledOnValidThread());
// Upon insert we don't know yet the size of the entry.
// It will be updated later when the SimpleEntryImpl finishes opening or
// creating the new entry, and then UpdateEntrySize will be called.
InsertInEntrySet(entry_hash, EntryMetadata(base::Time::Now(), 0u),
&entries_set_);
if (!initialized_)
removed_entries_.erase(entry_hash);
PostponeWritingToDisk();
}
void SimpleIndex::Remove(uint64_t entry_hash) {
DCHECK(io_thread_checker_.CalledOnValidThread());
EntrySet::iterator it = entries_set_.find(entry_hash);
if (it != entries_set_.end()) {
UpdateEntryIteratorSize(&it, 0u);
entries_set_.erase(it);
}
if (!initialized_)
removed_entries_.insert(entry_hash);
PostponeWritingToDisk();
}
bool SimpleIndex::Has(uint64_t hash) const {
DCHECK(io_thread_checker_.CalledOnValidThread());
// If not initialized, always return true, forcing it to go to the disk.
return !initialized_ || entries_set_.count(hash) > 0;
}
bool SimpleIndex::UseIfExists(uint64_t entry_hash) {
DCHECK(io_thread_checker_.CalledOnValidThread());
// Always update the last used time, even if it is during initialization.
// It will be merged later.
EntrySet::iterator it = entries_set_.find(entry_hash);
if (it == entries_set_.end())
// If not initialized, always return true, forcing it to go to the disk.
return !initialized_;
it->second.SetLastUsedTime(base::Time::Now());
PostponeWritingToDisk();
return true;
}
void SimpleIndex::StartEvictionIfNeeded() {
DCHECK(io_thread_checker_.CalledOnValidThread());
if (eviction_in_progress_ || cache_size_ <= high_watermark_)
return;
// Take all live key hashes from the index and sort them by time.
eviction_in_progress_ = true;
eviction_start_time_ = base::TimeTicks::Now();
SIMPLE_CACHE_UMA(
MEMORY_KB, "Eviction.CacheSizeOnStart2", cache_type_,
static_cast<base::HistogramBase::Sample>(cache_size_ / kBytesInKb));
SIMPLE_CACHE_UMA(
MEMORY_KB, "Eviction.MaxCacheSizeOnStart2", cache_type_,
static_cast<base::HistogramBase::Sample>(max_size_ / kBytesInKb));
std::vector<uint64_t> entry_hashes;
entry_hashes.reserve(entries_set_.size());
for (EntrySet::const_iterator it = entries_set_.begin(),
end = entries_set_.end(); it != end; ++it) {
entry_hashes.push_back(it->first);
}
std::sort(entry_hashes.begin(), entry_hashes.end(),
CompareHashesForTimestamp(entries_set_));
// Remove as many entries from the index to get below |low_watermark_|.
std::vector<uint64_t>::iterator it = entry_hashes.begin();
uint64_t evicted_so_far_size = 0;
while (evicted_so_far_size < cache_size_ - low_watermark_) {
DCHECK(it != entry_hashes.end());
EntrySet::iterator found_meta = entries_set_.find(*it);
DCHECK(found_meta != entries_set_.end());
evicted_so_far_size += found_meta->second.GetEntrySize();
++it;
}
// Take out the rest of hashes from the eviction list.
entry_hashes.erase(it, entry_hashes.end());
SIMPLE_CACHE_UMA(COUNTS,
"Eviction.EntryCount", cache_type_, entry_hashes.size());
SIMPLE_CACHE_UMA(TIMES,
"Eviction.TimeToSelectEntries", cache_type_,
base::TimeTicks::Now() - eviction_start_time_);
SIMPLE_CACHE_UMA(
MEMORY_KB, "Eviction.SizeOfEvicted2", cache_type_,
static_cast<base::HistogramBase::Sample>(
evicted_so_far_size / kBytesInKb));
delegate_->DoomEntries(&entry_hashes, base::Bind(&SimpleIndex::EvictionDone,
AsWeakPtr()));
}
bool SimpleIndex::UpdateEntrySize(uint64_t entry_hash,
base::StrictNumeric<uint32_t> entry_size) {
DCHECK(io_thread_checker_.CalledOnValidThread());
EntrySet::iterator it = entries_set_.find(entry_hash);
if (it == entries_set_.end())
return false;
UpdateEntryIteratorSize(&it, entry_size);
PostponeWritingToDisk();
StartEvictionIfNeeded();
return true;
}
void SimpleIndex::EvictionDone(int result) {
DCHECK(io_thread_checker_.CalledOnValidThread());
// Ignore the result of eviction. We did our best.
eviction_in_progress_ = false;
SIMPLE_CACHE_UMA(BOOLEAN, "Eviction.Result", cache_type_, result == net::OK);
SIMPLE_CACHE_UMA(TIMES,
"Eviction.TimeToDone", cache_type_,
base::TimeTicks::Now() - eviction_start_time_);
SIMPLE_CACHE_UMA(
MEMORY_KB, "Eviction.SizeWhenDone2", cache_type_,
static_cast<base::HistogramBase::Sample>(cache_size_ / kBytesInKb));
}
// static
void SimpleIndex::InsertInEntrySet(
uint64_t entry_hash,
const disk_cache::EntryMetadata& entry_metadata,
EntrySet* entry_set) {
DCHECK(entry_set);
entry_set->insert(std::make_pair(entry_hash, entry_metadata));
}
void SimpleIndex::PostponeWritingToDisk() {
if (!initialized_)
return;
const int delay = app_on_background_ ? kWriteToDiskOnBackgroundDelayMSecs
: kWriteToDiskDelayMSecs;
// If the timer is already active, Start() will just Reset it, postponing it.
write_to_disk_timer_.Start(
FROM_HERE, base::TimeDelta::FromMilliseconds(delay), write_to_disk_cb_);
}
void SimpleIndex::UpdateEntryIteratorSize(
EntrySet::iterator* it,
base::StrictNumeric<uint32_t> entry_size) {
// Update the total cache size with the new entry size.
DCHECK(io_thread_checker_.CalledOnValidThread());
DCHECK_GE(cache_size_, (*it)->second.GetEntrySize());
cache_size_ -= (*it)->second.GetEntrySize();
cache_size_ += static_cast<uint32_t>(entry_size);
(*it)->second.SetEntrySize(entry_size);
}
void SimpleIndex::MergeInitializingSet(
std::unique_ptr<SimpleIndexLoadResult> load_result) {
DCHECK(io_thread_checker_.CalledOnValidThread());
DCHECK(load_result->did_load);
EntrySet* index_file_entries = &load_result->entries;
for (std::unordered_set<uint64_t>::const_iterator it =
removed_entries_.begin();
it != removed_entries_.end(); ++it) {
index_file_entries->erase(*it);
}
removed_entries_.clear();
for (EntrySet::const_iterator it = entries_set_.begin();
it != entries_set_.end(); ++it) {
const uint64_t entry_hash = it->first;
std::pair<EntrySet::iterator, bool> insert_result =
index_file_entries->insert(EntrySet::value_type(entry_hash,
EntryMetadata()));
EntrySet::iterator& possibly_inserted_entry = insert_result.first;
possibly_inserted_entry->second = it->second;
}
uint64_t merged_cache_size = 0;
for (EntrySet::iterator it = index_file_entries->begin();
it != index_file_entries->end(); ++it) {
merged_cache_size += it->second.GetEntrySize();
}
entries_set_.swap(*index_file_entries);
cache_size_ = merged_cache_size;
initialized_ = true;
init_method_ = load_result->init_method;
// The actual IO is asynchronous, so calling WriteToDisk() shouldn't slow the
// merge down much.
if (load_result->flush_required)
WriteToDisk(INDEX_WRITE_REASON_STARTUP_MERGE);
SIMPLE_CACHE_UMA(CUSTOM_COUNTS,
"IndexInitializationWaiters", cache_type_,
to_run_when_initialized_.size(), 0, 100, 20);
// Run all callbacks waiting for the index to come up.
for (CallbackList::iterator it = to_run_when_initialized_.begin(),
end = to_run_when_initialized_.end(); it != end; ++it) {
io_thread_->PostTask(FROM_HERE, base::Bind((*it), net::OK));
}
to_run_when_initialized_.clear();
}
#if defined(OS_ANDROID)
void SimpleIndex::OnApplicationStateChange(
base::android::ApplicationState state) {
DCHECK(io_thread_checker_.CalledOnValidThread());
// For more info about android activities, see:
// developer.android.com/training/basics/activity-lifecycle/pausing.html
if (state == base::android::APPLICATION_STATE_HAS_RUNNING_ACTIVITIES) {
app_on_background_ = false;
} else if (state ==
base::android::APPLICATION_STATE_HAS_STOPPED_ACTIVITIES) {
app_on_background_ = true;
WriteToDisk(INDEX_WRITE_REASON_ANDROID_STOPPED);
}
}
#endif
void SimpleIndex::WriteToDisk(IndexWriteToDiskReason reason) {
DCHECK(io_thread_checker_.CalledOnValidThread());
if (!initialized_)
return;
SIMPLE_CACHE_UMA(CUSTOM_COUNTS,
"IndexNumEntriesOnWrite", cache_type_,
entries_set_.size(), 0, 100000, 50);
const base::TimeTicks start = base::TimeTicks::Now();
if (!last_write_to_disk_.is_null()) {
if (app_on_background_) {
SIMPLE_CACHE_UMA(MEDIUM_TIMES,
"IndexWriteInterval.Background", cache_type_,
start - last_write_to_disk_);
} else {
SIMPLE_CACHE_UMA(MEDIUM_TIMES,
"IndexWriteInterval.Foreground", cache_type_,
start - last_write_to_disk_);
}
}
last_write_to_disk_ = start;
index_file_->WriteToDisk(reason, entries_set_, cache_size_, start,
app_on_background_, base::Closure());
}
} // namespace disk_cache