homework-jianmu/source/libs/sync/inc/raft.h

143 lines
3.7 KiB
C

/*
* Copyright (c) 2019 TAOS Data, Inc. <cli@taosdata.com>
*
* This program is free software: you can use, redistribute, and/or modify
* it under the terms of the GNU Affero General Public License, version 3
* or later ("AGPL"), as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef _TD_LIBS_SYNC_RAFT_H
#define _TD_LIBS_SYNC_RAFT_H
#include "sync.h"
#include "sync_type.h"
#include "raft_message.h"
typedef struct SSyncRaftProgress SSyncRaftProgress;
typedef struct RaftLeaderState {
int nProgress;
SSyncRaftProgress* progress;
} RaftLeaderState;
typedef struct RaftCandidateState {
/* votes results */
SyncRaftVoteRespType votes[TSDB_MAX_REPLICA];
/* true if in pre-vote phase */
bool inPreVote;
} RaftCandidateState;
typedef struct SSyncRaftIOMethods {
// send SSyncMessage to node
int (*send)(const SSyncMessage* pMsg, const SNodeInfo* pNode);
} SSyncRaftIOMethods;
typedef int (*SyncRaftStepFp)(SSyncRaft* pRaft, const SSyncMessage* pMsg);
typedef void (*SyncRaftTickFp)(SSyncRaft* pRaft);
struct SSyncRaft {
// owner sync node
SSyncNode* pNode;
int maxMsgSize;
SSyncFSM fsm;
SSyncLogStore logStore;
SStateManager stateManager;
SyncTerm term;
SyncNodeId voteFor;
SyncNodeId selfId;
SyncGroupId selfGroupId;
/**
* the leader id
**/
SyncNodeId leaderId;
/**
* leadTransferee is id of the leader transfer target when its value is not zero.
* Follow the procedure defined in raft thesis 3.10.
**/
SyncNodeId leadTransferee;
/**
* New configuration is ignored if there exists unapplied configuration.
**/
bool hasPendingConf;
SSyncCluster cluster;
ESyncRole state;
/**
* number of ticks since it reached last electionTimeout when it is leader
* or candidate.
* number of ticks since it reached last electionTimeout or received a
* valid message from current leader when it is a follower.
**/
uint16_t electionElapsed;
/**
* number of ticks since it reached last heartbeatTimeout.
* only leader keeps heartbeatElapsed.
**/
uint16_t heartbeatElapsed;
// current tick count since start up
uint32_t currentTick;
// election timeout tick(random in [3:6] tick)
uint16_t electionTimeoutTick;
// heartbeat timeout tick(default: 1 tick)
uint16_t heartbeatTimeoutTick;
bool preVote;
bool checkQuorum;
SSyncRaftIOMethods io;
// union different state data
union {
RaftLeaderState leaderState;
RaftCandidateState candidateState;
};
SSyncRaftLog *log;
SyncRaftStepFp stepFp;
SyncRaftTickFp tickFp;
};
int32_t syncRaftStart(SSyncRaft* pRaft, const SSyncInfo* pInfo);
int32_t syncRaftStep(SSyncRaft* pRaft, const SSyncMessage* pMsg);
int32_t syncRaftTick(SSyncRaft* pRaft);
void syncRaftBecomeFollower(SSyncRaft* pRaft, SyncTerm term, SyncNodeId leaderId);
void syncRaftBecomePreCandidate(SSyncRaft* pRaft);
void syncRaftBecomeCandidate(SSyncRaft* pRaft);
void syncRaftBecomeLeader(SSyncRaft* pRaft);
void syncRaftStartElection(SSyncRaft* pRaft, SyncRaftElectionType cType);
void syncRaftTriggerHeartbeat(SSyncRaft* pRaft);
void syncRaftRandomizedElectionTimeout(SSyncRaft* pRaft);
bool syncRaftIsPromotable(SSyncRaft* pRaft);
bool syncRaftIsPastElectionTimeout(SSyncRaft* pRaft);
int syncRaftQuorum(SSyncRaft* pRaft);
int syncRaftNumOfGranted(SSyncRaft* pRaft, SyncNodeId id,
bool preVote, bool accept, int* rejectNum);
#endif /* _TD_LIBS_SYNC_RAFT_H */