blob: 03fbbad099431d2d328581045ea18770fbcd4007 [file] [log] [blame]
// Copyright 2013 The Chromium Authors
// 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/check_op.h"
#include "base/files/file_util.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/task_runner.h"
#include "base/time/time.h"
#include "base/trace_event/memory_usage_estimator.h"
#include "build/build_config.h"
#include "net/base/net_errors.h"
#include "net/disk_cache/backend_cleanup_tracker.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 BUILDFLAG(IS_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;
// This is added to the size of each entry before using the size
// to determine which entries to evict first. It's basically an
// estimate of the filesystem overhead, but it also serves to flatten
// the curve so that 1-byte entries and 2-byte entries are basically
// treated the same.
static const int kEstimatedEntryOverhead = 512;
} // namespace
namespace disk_cache {
EntryMetadata::EntryMetadata()
: last_used_time_seconds_since_epoch_(0),
entry_size_256b_chunks_(0),
in_memory_data_(0) {}
EntryMetadata::EntryMetadata(base::Time last_used_time,
base::StrictNumeric<uint32_t> entry_size)
: last_used_time_seconds_since_epoch_(0),
entry_size_256b_chunks_(0),
in_memory_data_(0) {
SetEntrySize(entry_size); // to round/pack properly.
SetLastUsedTime(last_used_time);
}
EntryMetadata::EntryMetadata(int32_t trailer_prefetch_size,
base::StrictNumeric<uint32_t> entry_size)
: trailer_prefetch_size_(0),
entry_size_256b_chunks_(0),
in_memory_data_(0) {
SetEntrySize(entry_size); // to round/pack properly
SetTrailerPrefetchSize(trailer_prefetch_size);
}
base::Time EntryMetadata::GetLastUsedTime() const {
// Preserve nullity.
if (last_used_time_seconds_since_epoch_ == 0)
return base::Time();
return base::Time::UnixEpoch() +
base::Seconds(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;
}
int32_t EntryMetadata::GetTrailerPrefetchSize() const {
return trailer_prefetch_size_;
}
void EntryMetadata::SetTrailerPrefetchSize(int32_t size) {
if (size <= 0)
return;
trailer_prefetch_size_ = size;
}
uint32_t EntryMetadata::GetEntrySize() const {
return entry_size_256b_chunks_ << 8;
}
void EntryMetadata::SetEntrySize(base::StrictNumeric<uint32_t> entry_size) {
// This should not overflow since we limit entries to 1/8th of the cache.
entry_size_256b_chunks_ = (static_cast<uint32_t>(entry_size) + 255) >> 8;
}
void EntryMetadata::Serialize(net::CacheType cache_type,
base::Pickle* pickle) const {
DCHECK(pickle);
// If you modify the size of the size of the pickle, be sure to update
// kOnDiskSizeBytes.
uint32_t packed_entry_info = (entry_size_256b_chunks_ << 8) | in_memory_data_;
if (cache_type == net::APP_CACHE) {
pickle->WriteInt64(trailer_prefetch_size_);
} else {
int64_t internal_last_used_time = GetLastUsedTime().ToInternalValue();
pickle->WriteInt64(internal_last_used_time);
}
pickle->WriteUInt64(packed_entry_info);
}
bool EntryMetadata::Deserialize(net::CacheType cache_type,
base::PickleIterator* it,
bool has_entry_in_memory_data,
bool app_cache_has_trailer_prefetch_size) {
DCHECK(it);
int64_t tmp_time_or_prefetch_size;
uint64_t tmp_entry_size;
if (!it->ReadInt64(&tmp_time_or_prefetch_size) ||
!it->ReadUInt64(&tmp_entry_size) ||
tmp_entry_size > std::numeric_limits<uint32_t>::max())
return false;
if (cache_type == net::APP_CACHE) {
if (app_cache_has_trailer_prefetch_size) {
int32_t trailer_prefetch_size = 0;
base::CheckedNumeric<int32_t> numeric_size(tmp_time_or_prefetch_size);
if (numeric_size.AssignIfValid(&trailer_prefetch_size)) {
SetTrailerPrefetchSize(trailer_prefetch_size);
}
}
} else {
SetLastUsedTime(base::Time::FromInternalValue(tmp_time_or_prefetch_size));
}
if (has_entry_in_memory_data) {
// tmp_entry_size actually packs entry_size_256b_chunks_ and
// in_memory_data_.
SetEntrySize(static_cast<uint32_t>(tmp_entry_size & 0xFFFFFF00));
SetInMemoryData(static_cast<uint8_t>(tmp_entry_size & 0xFF));
} else {
SetEntrySize(static_cast<uint32_t>(tmp_entry_size));
SetInMemoryData(0);
}
return true;
}
SimpleIndex::SimpleIndex(
const scoped_refptr<base::SequencedTaskRunner>& task_runner,
scoped_refptr<BackendCleanupTracker> cleanup_tracker,
SimpleIndexDelegate* delegate,
net::CacheType cache_type,
std::unique_ptr<SimpleIndexFile> index_file)
: cleanup_tracker_(std::move(cleanup_tracker)),
delegate_(delegate),
cache_type_(cache_type),
index_file_(std::move(index_file)),
task_runner_(task_runner),
// Creating the callback once so it is reused every time
// write_to_disk_timer_.Start() is called.
write_to_disk_cb_(base::BindRepeating(&SimpleIndex::WriteToDisk,
AsWeakPtr(),
INDEX_WRITE_REASON_IDLE)) {}
SimpleIndex::~SimpleIndex() {
DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
// Fail all callbacks waiting for the index to come up.
for (auto& callback : to_run_when_initialized_) {
std::move(callback).Run(net::ERR_ABORTED);
}
}
void SimpleIndex::Initialize(base::Time cache_mtime) {
DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
#if BUILDFLAG(IS_ANDROID)
if (app_status_listener_) {
app_status_listener_->SetCallback(base::BindRepeating(
&SimpleIndex::OnApplicationStateChange, AsWeakPtr()));
} else if (base::android::IsVMInitialized()) {
owned_app_status_listener_ =
base::android::ApplicationStatusListener::New(base::BindRepeating(
&SimpleIndex::OnApplicationStateChange, AsWeakPtr()));
app_status_listener_ = owned_app_status_listener_.get();
}
#endif
auto load_result = std::make_unique<SimpleIndexLoadResult>();
auto* load_result_ptr = load_result.get();
index_file_->LoadIndexEntries(
cache_mtime,
base::BindOnce(&SimpleIndex::MergeInitializingSet, AsWeakPtr(),
std::move(load_result)),
load_result_ptr);
}
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);
}
}
void SimpleIndex::ExecuteWhenReady(net::CompletionOnceCallback task) {
DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
if (initialized_)
task_runner_->PostTask(FROM_HERE, base::BindOnce(std::move(task), net::OK));
else
to_run_when_initialized_.push_back(std::move(task));
}
std::unique_ptr<SimpleIndex::HashList> SimpleIndex::GetEntriesBetween(
base::Time initial_time,
base::Time end_time) {
DCHECK_EQ(true, initialized_);
// The net::APP_CACHE mode does not track access times. Assert that external
// consumers are not relying on access time ranges.
DCHECK(cache_type_ != net::APP_CACHE ||
(initial_time.is_null() && end_time.is_null()));
if (!initial_time.is_null())
initial_time -= EntryMetadata::GetLowerEpsilonForTimeComparisons();
if (end_time.is_null())
end_time = base::Time::Max();
else
end_time += EntryMetadata::GetUpperEpsilonForTimeComparisons();
DCHECK(end_time >= initial_time);
auto ret_hashes = std::make_unique<HashList>();
for (const auto& entry : entries_set_) {
const EntryMetadata& metadata = entry.second;
base::Time entry_time = metadata.GetLastUsedTime();
if (initial_time <= entry_time && entry_time < end_time)
ret_hashes->push_back(entry.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_;
}
uint64_t SimpleIndex::GetCacheSizeBetween(base::Time initial_time,
base::Time end_time) const {
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();
DCHECK(end_time >= initial_time);
uint64_t size = 0;
for (const auto& entry : entries_set_) {
const EntryMetadata& metadata = entry.second;
base::Time entry_time = metadata.GetLastUsedTime();
if (initial_time <= entry_time && entry_time < end_time)
size += metadata.GetEntrySize();
}
return size;
}
base::Time SimpleIndex::GetLastUsedTime(uint64_t entry_hash) {
DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
DCHECK_NE(cache_type_, net::APP_CACHE);
auto it = entries_set_.find(entry_hash);
if (it == entries_set_.end())
return base::Time();
return it->second.GetLastUsedTime();
}
void SimpleIndex::SetLastUsedTimeForTest(uint64_t entry_hash,
const base::Time last_used) {
auto it = entries_set_.find(entry_hash);
DCHECK(it != entries_set_.end());
it->second.SetLastUsedTime(last_used);
}
bool SimpleIndex::HasPendingWrite() const {
return write_to_disk_timer_.IsRunning();
}
void SimpleIndex::Insert(uint64_t entry_hash) {
DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
// 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.
bool inserted = false;
if (cache_type_ == net::APP_CACHE) {
inserted =
InsertInEntrySet(entry_hash, EntryMetadata(-1, 0u), &entries_set_);
} else {
inserted = InsertInEntrySet(
entry_hash, EntryMetadata(base::Time::Now(), 0u), &entries_set_);
}
if (!initialized_)
removed_entries_.erase(entry_hash);
if (inserted)
PostponeWritingToDisk();
}
void SimpleIndex::Remove(uint64_t entry_hash) {
DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
bool need_write = false;
auto it = entries_set_.find(entry_hash);
if (it != entries_set_.end()) {
UpdateEntryIteratorSize(&it, 0u);
entries_set_.erase(it);
need_write = true;
}
if (!initialized_)
removed_entries_.insert(entry_hash);
if (need_write)
PostponeWritingToDisk();
}
bool SimpleIndex::Has(uint64_t hash) const {
DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
// If not initialized, always return true, forcing it to go to the disk.
return !initialized_ || entries_set_.count(hash) > 0;
}
uint8_t SimpleIndex::GetEntryInMemoryData(uint64_t entry_hash) const {
DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
auto it = entries_set_.find(entry_hash);
if (it == entries_set_.end())
return 0;
return it->second.GetInMemoryData();
}
void SimpleIndex::SetEntryInMemoryData(uint64_t entry_hash, uint8_t value) {
DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
auto it = entries_set_.find(entry_hash);
if (it == entries_set_.end())
return;
return it->second.SetInMemoryData(value);
}
bool SimpleIndex::UseIfExists(uint64_t entry_hash) {
DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
// Always update the last used time, even if it is during initialization.
// It will be merged later.
auto 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_;
// We do not need to track access times in APP_CACHE mode.
if (cache_type_ == net::APP_CACHE)
return true;
it->second.SetLastUsedTime(base::Time::Now());
PostponeWritingToDisk();
return true;
}
void SimpleIndex::StartEvictionIfNeeded() {
DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
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();
bool use_size_heuristic =
(cache_type_ != net::GENERATED_BYTE_CODE_CACHE &&
cache_type_ != net::GENERATED_WEBUI_BYTE_CODE_CACHE);
// Flatten for sorting.
std::vector<std::pair<uint64_t, const EntrySet::value_type*>> entries;
entries.reserve(entries_set_.size());
uint32_t now = (base::Time::Now() - base::Time::UnixEpoch()).InSeconds();
for (EntrySet::const_iterator i = entries_set_.begin();
i != entries_set_.end(); ++i) {
uint64_t sort_value = now - i->second.RawTimeForSorting();
// See crbug.com/736437 for context.
//
// Will not overflow since we're multiplying two 32-bit values and storing
// them in a 64-bit variable.
if (use_size_heuristic)
sort_value *= i->second.GetEntrySize() + kEstimatedEntryOverhead;
// Subtract so we don't need a custom comparator.
entries.emplace_back(std::numeric_limits<uint64_t>::max() - sort_value,
&*i);
}
uint64_t evicted_so_far_size = 0;
const uint64_t amount_to_evict = cache_size_ - low_watermark_;
std::vector<uint64_t> entry_hashes;
std::sort(entries.begin(), entries.end());
for (const auto& score_metadata_pair : entries) {
if (evicted_so_far_size >= amount_to_evict)
break;
evicted_so_far_size += score_metadata_pair.second->second.GetEntrySize();
entry_hashes.push_back(score_metadata_pair.second->first);
}
SIMPLE_CACHE_UMA(COUNTS_1M,
"Eviction.EntryCount", cache_type_, entry_hashes.size());
SIMPLE_CACHE_UMA(TIMES,
"Eviction.TimeToSelectEntries", cache_type_,
base::TimeTicks::Now() - eviction_start_time_);
delegate_->DoomEntries(
&entry_hashes, base::BindOnce(&SimpleIndex::EvictionDone, AsWeakPtr()));
}
int32_t SimpleIndex::GetTrailerPrefetchSize(uint64_t entry_hash) const {
DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
DCHECK_EQ(cache_type_, net::APP_CACHE);
auto it = entries_set_.find(entry_hash);
if (it == entries_set_.end())
return -1;
return it->second.GetTrailerPrefetchSize();
}
void SimpleIndex::SetTrailerPrefetchSize(uint64_t entry_hash, int32_t size) {
DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
DCHECK_EQ(cache_type_, net::APP_CACHE);
auto it = entries_set_.find(entry_hash);
if (it == entries_set_.end())
return;
int32_t original_size = it->second.GetTrailerPrefetchSize();
it->second.SetTrailerPrefetchSize(size);
if (original_size != it->second.GetTrailerPrefetchSize())
PostponeWritingToDisk();
}
bool SimpleIndex::UpdateEntrySize(uint64_t entry_hash,
base::StrictNumeric<uint32_t> entry_size) {
DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
auto it = entries_set_.find(entry_hash);
if (it == entries_set_.end())
return false;
// Update the entry size. If there was no change, then there is nothing
// else to do here.
if (!UpdateEntryIteratorSize(&it, entry_size))
return true;
PostponeWritingToDisk();
StartEvictionIfNeeded();
return true;
}
void SimpleIndex::EvictionDone(int result) {
DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
// Ignore the result of eviction. We did our best.
eviction_in_progress_ = false;
SIMPLE_CACHE_UMA(TIMES,
"Eviction.TimeToDone", cache_type_,
base::TimeTicks::Now() - eviction_start_time_);
}
// static
bool SimpleIndex::InsertInEntrySet(
uint64_t entry_hash,
const disk_cache::EntryMetadata& entry_metadata,
EntrySet* entry_set) {
DCHECK(entry_set);
auto result = entry_set->insert(std::make_pair(entry_hash, entry_metadata));
return result.second;
}
void SimpleIndex::InsertEntryForTesting(uint64_t entry_hash,
const EntryMetadata& entry_metadata) {
DCHECK(entries_set_.find(entry_hash) == entries_set_.end());
if (InsertInEntrySet(entry_hash, entry_metadata, &entries_set_))
cache_size_ += entry_metadata.GetEntrySize();
}
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::Milliseconds(delay),
write_to_disk_cb_);
}
bool SimpleIndex::UpdateEntryIteratorSize(
EntrySet::iterator* it,
base::StrictNumeric<uint32_t> entry_size) {
// Update the total cache size with the new entry size.
DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
DCHECK_GE(cache_size_, (*it)->second.GetEntrySize());
uint32_t original_size = (*it)->second.GetEntrySize();
cache_size_ -= (*it)->second.GetEntrySize();
(*it)->second.SetEntrySize(entry_size);
// We use GetEntrySize to get consistent rounding.
cache_size_ += (*it)->second.GetEntrySize();
// Return true if the size of the entry actually changed. Make sure to
// compare the rounded values provided by GetEntrySize().
return original_size != (*it)->second.GetEntrySize();
}
void SimpleIndex::MergeInitializingSet(
std::unique_ptr<SimpleIndexLoadResult> load_result) {
DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
EntrySet* index_file_entries = &load_result->entries;
for (uint64_t removed_entry : removed_entries_) {
index_file_entries->erase(removed_entry);
}
removed_entries_.clear();
for (const auto& it : entries_set_) {
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 (const auto& index_file_entry : *index_file_entries) {
merged_cache_size += index_file_entry.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, "IndexNumEntriesOnInit", cache_type_,
entries_set_.size(), 0, 100000, 50);
SIMPLE_CACHE_UMA(
MEMORY_KB, "CacheSizeOnInit", cache_type_,
static_cast<base::HistogramBase::Sample>(cache_size_ / kBytesInKb));
SIMPLE_CACHE_UMA(
MEMORY_KB, "MaxCacheSizeOnInit", cache_type_,
static_cast<base::HistogramBase::Sample>(max_size_ / kBytesInKb));
// Run all callbacks waiting for the index to come up.
for (auto& callback : to_run_when_initialized_) {
task_runner_->PostTask(FROM_HERE,
base::BindOnce(std::move(callback), net::OK));
}
to_run_when_initialized_.clear();
}
#if BUILDFLAG(IS_ANDROID)
void SimpleIndex::OnApplicationStateChange(
base::android::ApplicationState state) {
DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
// 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_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
if (!initialized_)
return;
// Cancel any pending writes since we are about to write to disk now.
write_to_disk_timer_.AbandonAndStop();
base::OnceClosure after_write;
if (cleanup_tracker_) {
// Make anyone synchronizing with our cleanup wait for the index to be
// written back.
after_write = base::DoNothingWithBoundArgs(cleanup_tracker_);
}
index_file_->WriteToDisk(cache_type_, reason, entries_set_, cache_size_,
std::move(after_write));
}
} // namespace disk_cache