1
0
Fork 0
arangodb/arangod/Agency/Agent.h

170 lines
3.7 KiB
C++

////////////////////////////////////////////////////////////////////////////////
/// DISCLAIMER
///
/// Copyright 2014-2016 ArangoDB GmbH, Cologne, Germany
/// Copyright 2004-2014 triAGENS GmbH, Cologne, Germany
///
/// Licensed 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.
///
/// Copyright holder is ArangoDB GmbH, Cologne, Germany
///
/// @author Kaveh Vahedipour
////////////////////////////////////////////////////////////////////////////////
#ifndef __ARANGODB_CONSENSUS_AGENT__
#define __ARANGODB_CONSENSUS_AGENT__
#include "AgencyCommon.h"
#include "AgentCallback.h"
#include "Constituent.h"
#include "State.h"
#include "Store.h"
#include <boost/property_tree/ptree.hpp>
namespace arangodb {
namespace consensus {
class Agent : public arangodb::Thread {
// We need to asynchroneously append entries
public:
/**
* @brief Default ctor
*/
Agent ();
/**
* @brief Construct with program options
*/
Agent (config_t const&);
/**
* @brief Clean up
*/
virtual ~Agent();
/**
* @brief Get current term
*/
term_t term() const;
/**
* @brief Get current term
*/
id_t id() const;
/**
* @brief Vote request
*/
query_t requestVote(term_t , id_t, index_t, index_t);
/**
* @brief Provide configuration
*/
Config<double> const& config () const;
/**
* @brief Start thread
*/
void start ();
/**
* @brief Verbose print of myself
*/
void print (arangodb::LoggerStream&) const;
/**
* @brief Are we fit to run?
*/
bool fitness () const;
/**
* @brief
*/
void report (status_t);
/**
* @brief Leader ID
*/
id_t leaderID () const;
/**
* @brief Attempt write
*/
write_ret_t write (query_t const&);
/**
* @brief Read from agency
*/
read_ret_t read (query_t const&) const;
/**
* @brief Invoked by leader to replicate log entries (§5.3);
* also used as heartbeat (§5.2).
*/
append_entries_t appendEntries (term_t, id_t, index_t, term_t, index_t,
query_t const&);
/**
* @brief 1. Deal with appendEntries to slaves.
* 2. Report success of write processes.
*/
void run ();
/**
* @brief Report appended entries from AgentCallback
*/
void reportIn (id_t id, std::vector<index_t> idx);
/**
* @brief Wait for slaves to confirm appended entries
*/
bool waitFor (std::vector<index_t> entries, std::chrono::duration timeout=2.0);
private:
Constituent _constituent; /**< @brief Leader election delegate */
State _state; /**< @brief Log replica */
config_t _config; /**< @brief Command line arguments */
std::atomic<index_t> _last_commit_index;
index_t _last_commit_index_tmp;
arangodb::Mutex _uncommitedLock;
store<std::string> _spear_head;
store<std::string> _read_db;
AgentCallback _agent_callback;
arangodb::basics::ConditionVariable _cv; // agency callbacks
arangodb::basics::ConditionVariable _cv_rest; // rest handler
std::atomic<bool> _stopping;
std::vector<index_t> _confirmed;
};
}
LoggerStream& operator<< (LoggerStream&, arangodb::consensus::Agent const&);
}
#endif