homework-jianmu/source/libs/sync/src/syncRequestVoteReply.c

98 lines
3.2 KiB
C

/*
* Copyright (c) 2019 TAOS Data, Inc. <jhtao@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/>.
*/
#define _DEFAULT_SOURCE
#include "syncRequestVoteReply.h"
#include "syncMessage.h"
#include "syncRaftStore.h"
#include "syncUtil.h"
#include "syncVoteMgr.h"
// TLA+ Spec
// HandleRequestVoteResponse(i, j, m) ==
// \* This tallies votes even when the current state is not Candidate, but
// \* they won't be looked at, so it doesn't matter.
// /\ m.mterm = currentTerm[i]
// /\ votesResponded' = [votesResponded EXCEPT ![i] =
// votesResponded[i] \cup {j}]
// /\ \/ /\ m.mvoteGranted
// /\ votesGranted' = [votesGranted EXCEPT ![i] =
// votesGranted[i] \cup {j}]
// /\ voterLog' = [voterLog EXCEPT ![i] =
// voterLog[i] @@ (j :> m.mlog)]
// \/ /\ ~m.mvoteGranted
// /\ UNCHANGED <<votesGranted, voterLog>>
// /\ Discard(m)
// /\ UNCHANGED <<serverVars, votedFor, leaderVars, logVars>>
//
int32_t syncNodeOnRequestVoteReply(SSyncNode* ths, const SRpcMsg* pRpcMsg) {
int32_t ret = 0;
SyncRequestVoteReply* pMsg = pRpcMsg->pCont;
// if already drop replica, do not process
if (!syncNodeInRaftGroup(ths, &(pMsg->srcId))) {
syncLogRecvRequestVoteReply(ths, pMsg, "not in my config");
return -1;
}
SyncTerm currentTerm = raftStoreGetTerm(ths);
// drop stale response
if (pMsg->term < currentTerm) {
syncLogRecvRequestVoteReply(ths, pMsg, "drop stale response");
return -1;
}
if (pMsg->term > currentTerm) {
syncLogRecvRequestVoteReply(ths, pMsg, "error term");
syncNodeStepDown(ths, pMsg->term);
return -1;
}
syncLogRecvRequestVoteReply(ths, pMsg, "");
ASSERT(pMsg->term == currentTerm);
// This tallies votes even when the current state is not Candidate,
// but they won't be looked at, so it doesn't matter.
if (ths->state == TAOS_SYNC_STATE_CANDIDATE) {
if (ths->pVotesRespond->term != pMsg->term) {
sNError(ths, "vote respond error vote-respond-mgr term:%" PRIu64 ", msg term:%" PRIu64 "",
ths->pVotesRespond->term, pMsg->term);
return -1;
}
votesRespondAdd(ths->pVotesRespond, pMsg);
if (pMsg->voteGranted) {
// add vote
voteGrantedVote(ths->pVotesGranted, pMsg);
// maybe to leader
if (voteGrantedMajority(ths->pVotesGranted)) {
if (!ths->pVotesGranted->toLeader) {
syncNodeCandidate2Leader(ths);
// prevent to leader again!
ths->pVotesGranted->toLeader = true;
}
}
} else {
;
// do nothing
// UNCHANGED <<votesGranted, voterLog>>
}
}
return 0;
}