| // Copyright 2016 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 "content/browser/leveldb_wrapper_impl.h" |
| |
| #include "base/bind.h" |
| #include "base/metrics/histogram_macros.h" |
| #include "base/threading/thread_task_runner_handle.h" |
| #include "components/leveldb/public/cpp/util.h" |
| #include "content/public/browser/browser_thread.h" |
| |
| namespace content { |
| |
| void LevelDBWrapperImpl::Delegate::MigrateData( |
| base::OnceCallback<void(std::unique_ptr<ValueMap>)> callback) { |
| std::move(callback).Run(nullptr); |
| } |
| |
| void LevelDBWrapperImpl::Delegate::OnMapLoaded(leveldb::mojom::DatabaseError) {} |
| |
| bool LevelDBWrapperImpl::s_aggressive_flushing_enabled_ = false; |
| |
| LevelDBWrapperImpl::RateLimiter::RateLimiter(size_t desired_rate, |
| base::TimeDelta time_quantum) |
| : rate_(desired_rate), samples_(0), time_quantum_(time_quantum) { |
| DCHECK_GT(desired_rate, 0ul); |
| } |
| |
| base::TimeDelta LevelDBWrapperImpl::RateLimiter::ComputeTimeNeeded() const { |
| return time_quantum_ * (samples_ / rate_); |
| } |
| |
| base::TimeDelta LevelDBWrapperImpl::RateLimiter::ComputeDelayNeeded( |
| const base::TimeDelta elapsed_time) const { |
| base::TimeDelta time_needed = ComputeTimeNeeded(); |
| if (time_needed > elapsed_time) |
| return time_needed - elapsed_time; |
| return base::TimeDelta(); |
| } |
| |
| LevelDBWrapperImpl::CommitBatch::CommitBatch() : clear_all_first(false) {} |
| LevelDBWrapperImpl::CommitBatch::~CommitBatch() {} |
| |
| LevelDBWrapperImpl::LevelDBWrapperImpl( |
| leveldb::mojom::LevelDBDatabase* database, |
| const std::string& prefix, |
| size_t max_size, |
| base::TimeDelta default_commit_delay, |
| int max_bytes_per_hour, |
| int max_commits_per_hour, |
| Delegate* delegate) |
| : prefix_(leveldb::StdStringToUint8Vector(prefix)), |
| delegate_(delegate), |
| database_(database), |
| bytes_used_(0), |
| max_size_(max_size), |
| start_time_(base::TimeTicks::Now()), |
| default_commit_delay_(default_commit_delay), |
| data_rate_limiter_(max_bytes_per_hour, base::TimeDelta::FromHours(1)), |
| commit_rate_limiter_(max_commits_per_hour, base::TimeDelta::FromHours(1)), |
| weak_ptr_factory_(this) { |
| bindings_.set_connection_error_handler(base::Bind( |
| &LevelDBWrapperImpl::OnConnectionError, base::Unretained(this))); |
| } |
| |
| LevelDBWrapperImpl::~LevelDBWrapperImpl() { |
| if (commit_batch_) |
| CommitChanges(); |
| } |
| |
| void LevelDBWrapperImpl::Bind(mojom::LevelDBWrapperRequest request) { |
| bindings_.AddBinding(this, std::move(request)); |
| } |
| |
| void LevelDBWrapperImpl::EnableAggressiveCommitDelay() { |
| s_aggressive_flushing_enabled_ = true; |
| } |
| |
| void LevelDBWrapperImpl::ScheduleImmediateCommit() { |
| if (!on_load_complete_tasks_.empty()) { |
| LoadMap(base::Bind(&LevelDBWrapperImpl::ScheduleImmediateCommit, |
| base::Unretained(this))); |
| return; |
| } |
| |
| if (!database_ || !commit_batch_) |
| return; |
| CommitChanges(); |
| } |
| |
| void LevelDBWrapperImpl::PurgeMemory() { |
| if (!map_ || // We're not using any memory. |
| commit_batch_ || // We leave things alone with changes pending. |
| !database_) { // Don't purge anything if we're not backed by a database. |
| return; |
| } |
| |
| map_.reset(); |
| } |
| |
| void LevelDBWrapperImpl::AddObserver( |
| mojom::LevelDBObserverAssociatedPtrInfo observer) { |
| mojom::LevelDBObserverAssociatedPtr observer_ptr; |
| observer_ptr.Bind(std::move(observer)); |
| observers_.AddPtr(std::move(observer_ptr)); |
| } |
| |
| void LevelDBWrapperImpl::Put(const std::vector<uint8_t>& key, |
| const std::vector<uint8_t>& value, |
| const std::string& source, |
| PutCallback callback) { |
| if (!map_) { |
| LoadMap(base::Bind(&LevelDBWrapperImpl::Put, base::Unretained(this), key, |
| value, source, base::Passed(&callback))); |
| return; |
| } |
| |
| bool has_old_item = false; |
| size_t old_item_size = 0; |
| auto found = map_->find(key); |
| if (found != map_->end()) { |
| if (found->second == value) { |
| std::move(callback).Run(true); // Key already has this value. |
| return; |
| } |
| old_item_size = key.size() + found->second.size(); |
| has_old_item = true; |
| } |
| size_t new_item_size = key.size() + value.size(); |
| size_t new_bytes_used = bytes_used_ - old_item_size + new_item_size; |
| |
| // Only check quota if the size is increasing, this allows |
| // shrinking changes to pre-existing maps that are over budget. |
| if (new_item_size > old_item_size && new_bytes_used > max_size_) { |
| std::move(callback).Run(false); |
| return; |
| } |
| |
| if (database_) { |
| CreateCommitBatchIfNeeded(); |
| commit_batch_->changed_keys.insert(key); |
| } |
| |
| std::vector<uint8_t> old_value; |
| if (has_old_item) { |
| old_value.swap((*map_)[key]); |
| } |
| (*map_)[key] = value; |
| bytes_used_ = new_bytes_used; |
| if (!has_old_item) { |
| // We added a new key/value pair. |
| observers_.ForAllPtrs( |
| [&key, &value, &source](mojom::LevelDBObserver* observer) { |
| observer->KeyAdded(key, value, source); |
| }); |
| } else { |
| // We changed the value for an existing key. |
| observers_.ForAllPtrs( |
| [&key, &value, &source, &old_value](mojom::LevelDBObserver* observer) { |
| observer->KeyChanged(key, value, old_value, source); |
| }); |
| } |
| std::move(callback).Run(true); |
| } |
| |
| void LevelDBWrapperImpl::Delete(const std::vector<uint8_t>& key, |
| const std::string& source, |
| DeleteCallback callback) { |
| if (!map_) { |
| LoadMap(base::Bind(&LevelDBWrapperImpl::Delete, base::Unretained(this), key, |
| source, base::Passed(&callback))); |
| return; |
| } |
| |
| auto found = map_->find(key); |
| if (found == map_->end()) { |
| std::move(callback).Run(true); |
| return; |
| } |
| |
| if (database_) { |
| CreateCommitBatchIfNeeded(); |
| commit_batch_->changed_keys.insert(std::move(found->first)); |
| } |
| |
| std::vector<uint8_t> old_value(std::move(found->second)); |
| map_->erase(found); |
| bytes_used_ -= key.size() + old_value.size(); |
| observers_.ForAllPtrs( |
| [&key, &source, &old_value](mojom::LevelDBObserver* observer) { |
| observer->KeyDeleted(key, old_value, source); |
| }); |
| std::move(callback).Run(true); |
| } |
| |
| void LevelDBWrapperImpl::DeleteAll(const std::string& source, |
| DeleteAllCallback callback) { |
| if (!map_) { |
| LoadMap(base::Bind(&LevelDBWrapperImpl::DeleteAll, base::Unretained(this), |
| source, base::Passed(&callback))); |
| return; |
| } |
| |
| if (map_->empty()) { |
| std::move(callback).Run(true); |
| return; |
| } |
| |
| if (database_) { |
| CreateCommitBatchIfNeeded(); |
| commit_batch_->clear_all_first = true; |
| commit_batch_->changed_keys.clear(); |
| } |
| |
| map_->clear(); |
| bytes_used_ = 0; |
| observers_.ForAllPtrs( |
| [&source](mojom::LevelDBObserver* observer) { |
| observer->AllDeleted(source); |
| }); |
| std::move(callback).Run(true); |
| } |
| |
| void LevelDBWrapperImpl::Get(const std::vector<uint8_t>& key, |
| GetCallback callback) { |
| if (!map_) { |
| LoadMap(base::Bind(&LevelDBWrapperImpl::Get, base::Unretained(this), key, |
| base::Passed(&callback))); |
| return; |
| } |
| |
| auto found = map_->find(key); |
| if (found == map_->end()) { |
| std::move(callback).Run(false, std::vector<uint8_t>()); |
| return; |
| } |
| std::move(callback).Run(true, found->second); |
| } |
| |
| void LevelDBWrapperImpl::GetAll( |
| mojom::LevelDBWrapperGetAllCallbackAssociatedPtrInfo complete_callback, |
| GetAllCallback callback) { |
| if (!map_) { |
| LoadMap(base::Bind(&LevelDBWrapperImpl::GetAll, base::Unretained(this), |
| base::Passed(&complete_callback), |
| base::Passed(&callback))); |
| return; |
| } |
| |
| std::vector<mojom::KeyValuePtr> all; |
| for (const auto& it : (*map_)) { |
| mojom::KeyValuePtr kv = mojom::KeyValue::New(); |
| kv->key = it.first; |
| kv->value = it.second; |
| all.push_back(std::move(kv)); |
| } |
| std::move(callback).Run(leveldb::mojom::DatabaseError::OK, std::move(all)); |
| if (complete_callback.is_valid()) { |
| mojom::LevelDBWrapperGetAllCallbackAssociatedPtr complete_ptr; |
| complete_ptr.Bind(std::move(complete_callback)); |
| complete_ptr->Complete(true); |
| } |
| } |
| |
| void LevelDBWrapperImpl::OnConnectionError() { |
| if (!bindings_.empty()) |
| return; |
| // If any tasks are waiting for load to complete, delay calling the |
| // no_bindings_callback_ until all those tasks have completed. |
| if (!on_load_complete_tasks_.empty()) |
| return; |
| delegate_->OnNoBindings(); |
| } |
| |
| void LevelDBWrapperImpl::LoadMap(const base::Closure& completion_callback) { |
| DCHECK(!map_); |
| on_load_complete_tasks_.push_back(completion_callback); |
| if (on_load_complete_tasks_.size() > 1) |
| return; |
| |
| if (!database_) { |
| OnMapLoaded(leveldb::mojom::DatabaseError::IO_ERROR, |
| std::vector<leveldb::mojom::KeyValuePtr>()); |
| return; |
| } |
| |
| database_->GetPrefixed(prefix_, base::Bind(&LevelDBWrapperImpl::OnMapLoaded, |
| weak_ptr_factory_.GetWeakPtr())); |
| } |
| |
| void LevelDBWrapperImpl::OnMapLoaded( |
| leveldb::mojom::DatabaseError status, |
| std::vector<leveldb::mojom::KeyValuePtr> data) { |
| DCHECK(!map_); |
| |
| if (data.empty() && status == leveldb::mojom::DatabaseError::OK) { |
| delegate_->MigrateData( |
| base::BindOnce(&LevelDBWrapperImpl::OnGotMigrationData, |
| weak_ptr_factory_.GetWeakPtr())); |
| return; |
| } |
| |
| map_.reset(new ValueMap); |
| bytes_used_ = 0; |
| for (auto& it : data) { |
| DCHECK_GE(it->key.size(), prefix_.size()); |
| (*map_)[std::vector<uint8_t>(it->key.begin() + prefix_.size(), |
| it->key.end())] = it->value; |
| bytes_used_ += it->key.size() - prefix_.size() + it->value.size(); |
| } |
| |
| // We proceed without using a backing store, nothing will be persisted but the |
| // class is functional for the lifetime of the object. |
| delegate_->OnMapLoaded(status); |
| if (status != leveldb::mojom::DatabaseError::OK) |
| database_ = nullptr; |
| |
| OnLoadComplete(); |
| } |
| |
| void LevelDBWrapperImpl::OnGotMigrationData(std::unique_ptr<ValueMap> data) { |
| map_ = data ? std::move(data) : base::MakeUnique<ValueMap>(); |
| bytes_used_ = 0; |
| for (const auto& it : *map_) |
| bytes_used_ += it.first.size() + it.second.size(); |
| |
| if (database_ && !empty()) { |
| CreateCommitBatchIfNeeded(); |
| for (const auto& it : *map_) |
| commit_batch_->changed_keys.insert(it.first); |
| CommitChanges(); |
| } |
| |
| OnLoadComplete(); |
| } |
| |
| void LevelDBWrapperImpl::OnLoadComplete() { |
| std::vector<base::Closure> tasks; |
| on_load_complete_tasks_.swap(tasks); |
| for (auto& task : tasks) |
| task.Run(); |
| |
| // We might need to call the no_bindings_callback_ here if bindings became |
| // empty while waiting for load to complete. |
| if (bindings_.empty()) |
| delegate_->OnNoBindings(); |
| } |
| |
| void LevelDBWrapperImpl::CreateCommitBatchIfNeeded() { |
| if (commit_batch_) |
| return; |
| |
| commit_batch_.reset(new CommitBatch()); |
| BrowserThread::PostAfterStartupTask( |
| FROM_HERE, base::ThreadTaskRunnerHandle::Get(), |
| base::Bind(&LevelDBWrapperImpl::StartCommitTimer, |
| weak_ptr_factory_.GetWeakPtr())); |
| } |
| |
| void LevelDBWrapperImpl::StartCommitTimer() { |
| if (!commit_batch_) |
| return; |
| |
| // Start a timer to commit any changes that accrue in the batch, but only if |
| // no commits are currently in flight. In that case the timer will be |
| // started after the commits have happened. |
| if (commit_batches_in_flight_) |
| return; |
| |
| base::ThreadTaskRunnerHandle::Get()->PostDelayedTask( |
| FROM_HERE, base::Bind(&LevelDBWrapperImpl::CommitChanges, |
| weak_ptr_factory_.GetWeakPtr()), |
| ComputeCommitDelay()); |
| } |
| |
| base::TimeDelta LevelDBWrapperImpl::ComputeCommitDelay() const { |
| if (s_aggressive_flushing_enabled_) |
| return base::TimeDelta::FromSeconds(1); |
| |
| base::TimeDelta elapsed_time = base::TimeTicks::Now() - start_time_; |
| base::TimeDelta delay = std::max( |
| default_commit_delay_, |
| std::max(commit_rate_limiter_.ComputeDelayNeeded(elapsed_time), |
| data_rate_limiter_.ComputeDelayNeeded(elapsed_time))); |
| UMA_HISTOGRAM_LONG_TIMES("LevelDBWrapper.CommitDelay", delay); |
| return delay; |
| } |
| |
| void LevelDBWrapperImpl::CommitChanges() { |
| DCHECK(database_); |
| DCHECK(map_); |
| if (!commit_batch_) |
| return; |
| |
| commit_rate_limiter_.add_samples(1); |
| |
| // Commit all our changes in a single batch. |
| std::vector<leveldb::mojom::BatchedOperationPtr> operations = |
| delegate_->PrepareToCommit(); |
| if (commit_batch_->clear_all_first) { |
| leveldb::mojom::BatchedOperationPtr item = |
| leveldb::mojom::BatchedOperation::New(); |
| item->type = leveldb::mojom::BatchOperationType::DELETE_PREFIXED_KEY; |
| item->key = prefix_; |
| operations.push_back(std::move(item)); |
| } |
| size_t data_size = 0; |
| for (const auto& key: commit_batch_->changed_keys) { |
| data_size += key.size(); |
| leveldb::mojom::BatchedOperationPtr item = |
| leveldb::mojom::BatchedOperation::New(); |
| item->key.reserve(prefix_.size() + key.size()); |
| item->key.insert(item->key.end(), prefix_.begin(), prefix_.end()); |
| item->key.insert(item->key.end(), key.begin(), key.end()); |
| auto it = map_->find(key); |
| if (it == map_->end()) { |
| item->type = leveldb::mojom::BatchOperationType::DELETE_KEY; |
| } else { |
| item->type = leveldb::mojom::BatchOperationType::PUT_KEY; |
| item->value = it->second; |
| data_size += it->second.size(); |
| } |
| operations.push_back(std::move(item)); |
| } |
| commit_batch_.reset(); |
| |
| data_rate_limiter_.add_samples(data_size); |
| |
| ++commit_batches_in_flight_; |
| |
| // TODO(michaeln): Currently there is no guarantee LevelDBDatabaseImp::Write |
| // will run during a clean shutdown. We need that to avoid dataloss. |
| database_->Write(std::move(operations), |
| base::Bind(&LevelDBWrapperImpl::OnCommitComplete, |
| weak_ptr_factory_.GetWeakPtr())); |
| } |
| |
| void LevelDBWrapperImpl::OnCommitComplete(leveldb::mojom::DatabaseError error) { |
| --commit_batches_in_flight_; |
| StartCommitTimer(); |
| delegate_->DidCommit(error); |
| } |
| |
| } // namespace content |