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// Copyright 2016 The Fuchsia 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 <lib/fit/function.h>
#include <functional>
#include <map>
#include <memory>
#include <string>
#include "src/ledger/bin/storage/impl/page_storage_impl.h"
#include "src/ledger/bin/storage/public/commit.h"
#include "src/ledger/bin/storage/public/journal.h"
#include "src/ledger/bin/storage/public/types.h"
#include "src/lib/fxl/macros.h"
namespace storage {
// A |JournalImpl| represents an in-memory |Journal|. As such, if not committed,
// (e.g. because of an unexpected shutdown) its entries will be lost. Instances
// of |JournalImpl| are valid as long as |Commit| has not been called. When no
// longer valid, it is an error to try to call any further methods on that
// object. A journal that is not commited before destruction, will be rolled
// back.
class JournalImpl : public Journal {
// Passkey idiom to restrict access to the constructor to static factories.
class Token;
JournalImpl(Token token, ledger::Environment* environment,
PageStorageImpl* page_storage,
std::unique_ptr<const Commit> base);
~JournalImpl() override;
// Creates a new Journal for a simple commit.
static std::unique_ptr<Journal> Simple(ledger::Environment* environment,
PageStorageImpl* page_storage,
std::unique_ptr<const Commit> base);
// Creates a new Journal for a merge commit.
static std::unique_ptr<Journal> Merge(ledger::Environment* environment,
PageStorageImpl* page_storage,
std::unique_ptr<const Commit> base,
std::unique_ptr<const Commit> other);
// Commits the changes of this |Journal|. Trying to update entries or rollback
// will fail after a successful commit. The callback will be called with the
// returned status and:
// - the new commit if a new commit object has been created.
// - a null commit if the operation is a no-op.
// This Journal object should not be deleted before |callback| is called.
void Commit(
fit::function<void(Status, std::unique_ptr<const storage::Commit>)>
// Journal:
void Put(convert::ExtendedStringView key, ObjectIdentifier object_identifier,
KeyPriority priority) override;
void Delete(convert::ExtendedStringView key) override;
void Clear() override;
class Token {
Token() {}
friend JournalImpl;
// Creates a new commit. The commit parents are |parents|. The content of the
// commit is built by executing |changes| over the content pointed by
// |root_identifier|.
void CreateCommitFromChanges(
std::vector<std::unique_ptr<const storage::Commit>> parents,
ObjectIdentifier root_identifier, std::vector<EntryChange> changes,
fit::function<void(Status, std::unique_ptr<const storage::Commit>)>
void GetObjectsToSync(
fit::function<void(Status status,
std::vector<ObjectIdentifier> objects_to_sync)>
ledger::Environment* const environment_;
PageStorageImpl* const page_storage_;
std::unique_ptr<const storage::Commit> base_;
std::unique_ptr<const storage::Commit> other_;
JournalContainsClearOperation cleared_ = JournalContainsClearOperation::NO;
std::map<std::string, EntryChange> journal_entries_;
// After |Commit| has been called, no further mutations are allowed on the
// journal.
bool committed_;
} // namespace storage