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// Copyright 2014 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.
#ifndef COMPONENTS_LEVELDB_PROTO_PROTO_DATABASE_H_
#define COMPONENTS_LEVELDB_PROTO_PROTO_DATABASE_H_
#include <memory>
#include <string>
#include <utility>
#include <vector>
#include "base/callback_forward.h"
#include "components/leveldb_proto/options.h"
namespace base {
class FilePath;
}
namespace leveldb_proto {
// Interface for classes providing persistent storage of Protocol Buffer
// entries (T must be a Proto type extending MessageLite).
template <typename T>
class ProtoDatabase {
public:
using InitCallback = base::Callback<void(bool success)>;
using UpdateCallback = base::Callback<void(bool success)>;
using LoadCallback =
base::Callback<void(bool success, std::unique_ptr<std::vector<T>>)>;
using LoadKeysCallback =
base::Callback<void(bool success,
std::unique_ptr<std::vector<std::string>>)>;
using GetCallback = base::Callback<void(bool success, std::unique_ptr<T>)>;
using DestroyCallback = base::Callback<void(bool success)>;
// A list of key-value (string, T) tuples.
using KeyEntryVector = std::vector<std::pair<std::string, T>>;
virtual ~ProtoDatabase() {}
// Asynchronously initializes the object with default options. |callback| will
// be invoked on the calling thread when complete.
void Init(const char* client_name,
const base::FilePath& database_dir,
const InitCallback& callback) {
InitWithOptions(client_name, Options(database_dir), callback);
}
// Similar to Init, but takes additional options.
virtual void InitWithOptions(const char* client_name,
const Options& options,
const InitCallback& callback) = 0;
// Asynchronously saves |entries_to_save| and deletes entries from
// |keys_to_remove| from the database. |callback| will be invoked on the
// calling thread when complete.
virtual void UpdateEntries(
std::unique_ptr<KeyEntryVector> entries_to_save,
std::unique_ptr<std::vector<std::string>> keys_to_remove,
const UpdateCallback& callback) = 0;
// Asynchronously loads all entries from the database and invokes |callback|
// when complete.
virtual void LoadEntries(const LoadCallback& callback) = 0;
// Asynchronously loads all keys from the database and invokes |callback| with
// those keys when complete.
virtual void LoadKeys(const LoadKeysCallback& callback) = 0;
// Asynchronously loads a single entry, identified by |key|, from the database
// and invokes |callback| when complete. If no entry with |key| is found,
// a nullptr is passed to the callback, but the success flag is still true.
virtual void GetEntry(const std::string& key,
const GetCallback& callback) = 0;
// Asynchronously destroys the database.
virtual void Destroy(const DestroyCallback& callback) = 0;
};
} // namespace leveldb_proto
#endif // COMPONENTS_LEVELDB_PROTO_PROTO_DATABASE_H_
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