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arangodb/arangod/Agency/State.h

136 lines
3.4 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_STATE__
#define __ARANGODB_CONSENSUS_STATE__
#include "AgencyCommon.h"
#include "State.h"
#include <Basics/Thread.h>
#include <Cluster/ClusterComm.h>
#include <velocypack/vpack.h>
#include <cstdint>
#include <functional>
//using namespace arangodb::velocypack;
class Slice {};
namespace arangodb {
namespace consensus {
class Agent;
/**
* @brief State replica
*/
class State {
public:
/// @brief Default constructor
State (std::string const& end_point = "tcp://localhost:8529");
/// @brief Default Destructor
virtual ~State();
/// @brief Append log entry
void append (query_t const& query);
/// @brief Log entries (leader)
std::vector<index_t> log (query_t const& query, std::vector<bool> const& indices, term_t term, id_t lid);
/// @brief Log entries (followers)
bool log (query_t const& queries, term_t term, id_t leaderId, index_t prevLogIndex, term_t prevLogTerm);
/// @brief Find entry at index with term
bool findit (index_t index, term_t term);
/// @brief Collect all from index on
collect_ret_t collectFrom (index_t index);
std::vector<log_t> get (
index_t = 0, index_t = std::numeric_limits<uint64_t>::max()) const;
std::vector<VPackSlice> slices (
index_t = 0, index_t = std::numeric_limits<uint64_t>::max()) const;
/// @brief log entry at index i
log_t const& operator[](index_t) const;
/// @brief last log entry
log_t const& lastLog () const;
/// @brief Set endpoint
bool setEndPoint (std::string const&);
/// @brief Load persisted data from above or start with empty log
bool load ();
friend std::ostream& operator<< (std::ostream& os, State const& s) {
for (auto const& i : s._log)
LOG(INFO) << "index(" << i.index <<") term(" << i.term << ") leader: ("
<< i.leaderId << ") query("
<< VPackSlice(i.entry->data()).toJson() << ")";
return os;
}
private:
/// @brief Save currentTerm, votedFor, log entries
bool save (arangodb::velocypack::Slice const&, index_t, term_t,
double timeout = 0.0);
bool loadCollection (std::string const& name);
bool checkDBs();
bool checkDB(std::string const& name);
bool createCollection(std::string const& name);
mutable arangodb::Mutex _logLock; /**< @brief Mutex for modifying _log */
std::vector<log_t> _log; /**< @brief State entries */
std::string _end_point; /**< @brief persistence end point */
bool _dbs_checked;
};
}}
#endif