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content / browser / indexed_db / instance / leveldb_tombstone_sweeper.cc [blame]
// Copyright 2017 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "content/browser/indexed_db/instance/leveldb_tombstone_sweeper.h"
#include <string>
#include <string_view>
#include "base/not_fatal_until.h"
#include "base/rand_util.h"
#include "base/strings/string_number_conversions.h"
#include "base/task/sequenced_task_runner.h"
#include "components/services/storage/indexed_db/scopes/varint_coding.h"
#include "third_party/blink/public/common/indexeddb/indexeddb_key.h"
#include "third_party/blink/public/common/indexeddb/indexeddb_metadata.h"
#include "third_party/leveldatabase/env_chromium.h"
#include "third_party/leveldatabase/src/include/leveldb/db.h"
#include "third_party/leveldatabase/src/include/leveldb/iterator.h"
namespace content::indexed_db {
namespace {
using blink::IndexedDBDatabaseMetadata;
using blink::IndexedDBIndexMetadata;
using blink::IndexedDBKey;
using blink::IndexedDBObjectStoreMetadata;
} // namespace
template <typename T>
WrappingIterator<T>::WrappingIterator() {}
template <typename T>
WrappingIterator<T>::WrappingIterator(const T* container,
size_t start_position) {
container_ = container;
valid_ = true;
iterations_done_ = 0;
DCHECK_LT(start_position, container_->size());
inner_ = container_->begin();
std::advance(inner_, start_position);
CHECK(inner_ != container_->end(), base::NotFatalUntil::M130);
}
template <typename T>
WrappingIterator<T>::~WrappingIterator() {}
template <typename T>
void WrappingIterator<T>::Next() {
DCHECK(valid_);
iterations_done_++;
if (iterations_done_ >= container_->size()) {
valid_ = false;
return;
}
inner_++;
if (inner_ == container_->end()) {
inner_ = container_->begin();
}
}
template <typename T>
const typename T::value_type& WrappingIterator<T>::Value() const {
CHECK(valid_);
return *inner_;
}
LevelDbTombstoneSweeper::LevelDbTombstoneSweeper(int round_iterations,
int max_iterations,
leveldb::DB* database)
: BackingStorePreCloseTaskQueue::PreCloseTask(database),
max_round_iterations_(round_iterations),
max_iterations_(max_iterations) {
sweep_state_.start_database_seed = static_cast<size_t>(base::RandUint64());
sweep_state_.start_object_store_seed =
static_cast<size_t>(base::RandUint64());
sweep_state_.start_index_seed = static_cast<size_t>(base::RandUint64());
}
LevelDbTombstoneSweeper::~LevelDbTombstoneSweeper() {}
bool LevelDbTombstoneSweeper::RequiresMetadata() const {
return true;
}
void LevelDbTombstoneSweeper::SetMetadata(
const std::vector<IndexedDBDatabaseMetadata>* metadata) {
database_metadata_ = metadata;
total_indices_ = 0;
for (const auto& db : *metadata) {
for (const auto& os_pair : db.object_stores) {
total_indices_ += os_pair.second.indexes.size();
}
}
}
LevelDbTombstoneSweeper::SweepState::SweepState() = default;
LevelDbTombstoneSweeper::SweepState::~SweepState() = default;
bool LevelDbTombstoneSweeper::RunRound() {
DCHECK(database_metadata_);
if (database_metadata_->empty()) {
return true;
}
Status s;
SweepStatus status = DoSweep(&s);
if (status != SweepStatus::DONE_ERROR) {
s = FlushDeletions();
if (!s.ok()) {
status = SweepStatus::DONE_ERROR;
}
}
return status != SweepStatus::SWEEPING;
}
Status LevelDbTombstoneSweeper::FlushDeletions() {
if (!has_writes_) {
return Status::OK();
}
Status status(
database()->Write(leveldb::WriteOptions(), &round_deletion_batch_));
round_deletion_batch_.Clear();
has_writes_ = false;
return status;
}
bool LevelDbTombstoneSweeper::ShouldContinueIteration(
LevelDbTombstoneSweeper::SweepStatus* sweep_status,
Status* leveldb_status,
int* round_iterations) {
++num_iterations_;
++(*round_iterations);
if (!iterator_->Valid()) {
*leveldb_status = iterator_->status();
if (!leveldb_status->ok()) {
*sweep_status = SweepStatus::DONE_ERROR;
return false;
}
*sweep_status = SweepStatus::SWEEPING;
return true;
}
if (*round_iterations >= max_round_iterations_) {
*sweep_status = SweepStatus::SWEEPING;
return false;
}
if (num_iterations_ >= max_iterations_) {
*sweep_status = SweepStatus::DONE;
return false;
}
return true;
}
LevelDbTombstoneSweeper::SweepStatus LevelDbTombstoneSweeper::DoSweep(
Status* leveldb_status) {
int round_iterations = 0;
SweepStatus sweep_status;
if (database_metadata_->empty()) {
return SweepStatus::DONE;
}
if (!iterator_) {
leveldb::ReadOptions iterator_options;
iterator_options.fill_cache = false;
iterator_options.verify_checksums = true;
iterator_.reset(database()->NewIterator(iterator_options));
}
if (!sweep_state_.database_it) {
size_t start_database_idx = static_cast<size_t>(
sweep_state_.start_database_seed % database_metadata_->size());
sweep_state_.database_it =
WrappingIterator<IndexedDBDatabaseMetadataVector>(
database_metadata_.get(), start_database_idx);
}
// Loop conditions facilitate starting at random index.
for (; sweep_state_.database_it.value().IsValid();
sweep_state_.database_it.value().Next()) {
const IndexedDBDatabaseMetadata& database =
sweep_state_.database_it.value().Value();
if (database.object_stores.empty()) {
continue;
}
if (!sweep_state_.object_store_it) {
size_t start_object_store_idx = static_cast<size_t>(
sweep_state_.start_object_store_seed % database.object_stores.size());
sweep_state_.object_store_it = WrappingIterator<ObjectStoreMetadataMap>(
&database.object_stores, start_object_store_idx);
}
// Loop conditions facilitate starting at random index.
for (; sweep_state_.object_store_it.value().IsValid();
sweep_state_.object_store_it.value().Next()) {
const IndexedDBObjectStoreMetadata& object_store =
sweep_state_.object_store_it.value().Value().second;
if (object_store.indexes.empty()) {
continue;
}
if (!sweep_state_.index_it) {
size_t start_index_idx = static_cast<size_t>(
sweep_state_.start_index_seed % object_store.indexes.size());
sweep_state_.index_it = WrappingIterator<IndexMetadataMap>(
&object_store.indexes, start_index_idx);
}
// Loop conditions facilitate starting at random index.
for (; sweep_state_.index_it.value().IsValid();
sweep_state_.index_it.value().Next()) {
const IndexedDBIndexMetadata& index =
sweep_state_.index_it.value().Value().second;
bool can_continue =
IterateIndex(database.id, object_store.id, index, &sweep_status,
leveldb_status, &round_iterations);
if (!can_continue) {
return sweep_status;
}
}
sweep_state_.index_it = std::nullopt;
}
sweep_state_.object_store_it = std::nullopt;
}
return SweepStatus::DONE;
}
bool LevelDbTombstoneSweeper::IterateIndex(
int64_t database_id,
int64_t object_store_id,
const IndexedDBIndexMetadata& index,
LevelDbTombstoneSweeper::SweepStatus* sweep_status,
Status* leveldb_status,
int* round_iterations) {
// If the sweeper exited early from an index scan, continue where it left off.
if (sweep_state_.index_it_key) {
iterator_->Seek(sweep_state_.index_it_key.value().Encode());
if (!ShouldContinueIteration(sweep_status, leveldb_status,
round_iterations)) {
return false;
}
// Start at the first unvisited value.
iterator_->Next();
if (!ShouldContinueIteration(sweep_status, leveldb_status,
round_iterations)) {
return false;
}
} else {
iterator_->Seek(
IndexDataKey::EncodeMinKey(database_id, object_store_id, index.id));
if (!ShouldContinueIteration(sweep_status, leveldb_status,
round_iterations)) {
return false;
}
}
while (iterator_->Valid()) {
leveldb::Slice key_slice = iterator_->key();
std::string_view index_key_str = leveldb_env::MakeStringView(key_slice);
std::string_view index_value_str =
leveldb_env::MakeStringView(iterator_->value());
// See if we've reached the end of the current index or all indexes.
sweep_state_.index_it_key.emplace(IndexDataKey());
if (!IndexDataKey::Decode(&index_key_str,
&sweep_state_.index_it_key.value()) ||
sweep_state_.index_it_key.value().IndexId() != index.id) {
break;
}
int64_t index_data_version;
std::unique_ptr<IndexedDBKey> primary_key;
if (!DecodeVarInt(&index_value_str, &index_data_version)) {
iterator_->Next();
if (!ShouldContinueIteration(sweep_status, leveldb_status,
round_iterations)) {
return false;
}
continue;
}
std::string encoded_primary_key(index_value_str);
std::string exists_key = ExistsEntryKey::Encode(
database_id, object_store_id, encoded_primary_key);
std::string exists_value;
Status s(
database()->Get(leveldb::ReadOptions(), exists_key, &exists_value));
if (!s.ok()) {
iterator_->Next();
if (!ShouldContinueIteration(sweep_status, leveldb_status,
round_iterations)) {
return false;
}
continue;
}
std::string_view exists_value_piece(exists_value);
int64_t decoded_exists_version;
if (!DecodeInt(&exists_value_piece, &decoded_exists_version) ||
!exists_value_piece.empty()) {
iterator_->Next();
if (!ShouldContinueIteration(sweep_status, leveldb_status,
round_iterations)) {
return false;
}
continue;
}
if (decoded_exists_version != index_data_version) {
has_writes_ = true;
round_deletion_batch_.Delete(key_slice);
}
iterator_->Next();
if (!ShouldContinueIteration(sweep_status, leveldb_status,
round_iterations)) {
return false;
}
}
++indices_scanned_;
sweep_state_.index_it_key = std::nullopt;
return true;
}
} // namespace content::indexed_db