src/state/storage.hpp

/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#ifndef __STATE_STORAGE_HPP__
#define __STATE_STORAGE_HPP__

#include <set>
#include <string>

#include <process/future.hpp>

#include <stout/option.hpp>
#include <stout/uuid.hpp>

#include "messages/state.hpp"

namespace mesos {
namespace internal {
namespace state {

class Storage
{
public:
  Storage() {}
  virtual ~Storage() {}

  // Get and set state entries, factored out to allow Storage
  // implementations to be agnostic of Variable. Note that set acts
  // like a "test-and-set" by requiring the existing entry to have the
  // specified UUID.
  virtual process::Future<Option<Entry> > get(const std::string& name) = 0;
  virtual process::Future<bool> set(const Entry& entry, const UUID& uuid) = 0;

  // Returns true if successfully expunged the variable from the state.
  virtual process::Future<bool> expunge(const Entry& entry) = 0;

  // Returns the collection of variable names in the state.
  virtual process::Future<std::set<std::string> > names() = 0;
};

} // namespace state {
} // namespace internal {
} // namespace mesos {

#endif // __STATE_STORAGE_HPP__