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

103 lines
4.5 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/>.
*/
#ifndef _TD_LIBS_SYNC_APPEND_ENTRIES_H
#define _TD_LIBS_SYNC_APPEND_ENTRIES_H
#ifdef __cplusplus
extern "C" {
#endif
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include "syncInt.h"
#include "syncMessage.h"
#include "taosdef.h"
// TLA+ Spec
// HandleAppendEntriesRequest(i, j, m) ==
// LET logOk == \/ m.mprevLogIndex = 0
// \/ /\ m.mprevLogIndex > 0
// /\ m.mprevLogIndex <= Len(log[i])
// /\ m.mprevLogTerm = log[i][m.mprevLogIndex].term
// IN /\ m.mterm <= currentTerm[i]
// /\ \/ /\ \* reject request
// \/ m.mterm < currentTerm[i]
// \/ /\ m.mterm = currentTerm[i]
// /\ state[i] = Follower
// /\ \lnot logOk
// /\ Reply([mtype |-> AppendEntriesResponse,
// mterm |-> currentTerm[i],
// msuccess |-> FALSE,
// mmatchIndex |-> 0,
// msource |-> i,
// mdest |-> j],
// m)
// /\ UNCHANGED <<serverVars, logVars>>
// \/ \* return to follower state
// /\ m.mterm = currentTerm[i]
// /\ state[i] = Candidate
// /\ state' = [state EXCEPT ![i] = Follower]
// /\ UNCHANGED <<currentTerm, votedFor, logVars, messages>>
// \/ \* accept request
// /\ m.mterm = currentTerm[i]
// /\ state[i] = Follower
// /\ logOk
// /\ LET index == m.mprevLogIndex + 1
// IN \/ \* already done with request
// /\ \/ m.mentries = << >>
// \/ /\ m.mentries /= << >>
// /\ Len(log[i]) >= index
// /\ log[i][index].term = m.mentries[1].term
// \* This could make our commitIndex decrease (for
// \* example if we process an old, duplicated request),
// \* but that doesn't really affect anything.
// /\ commitIndex' = [commitIndex EXCEPT ![i] =
// m.mcommitIndex]
// /\ Reply([mtype |-> AppendEntriesResponse,
// mterm |-> currentTerm[i],
// msuccess |-> TRUE,
// mmatchIndex |-> m.mprevLogIndex +
// Len(m.mentries),
// msource |-> i,
// mdest |-> j],
// m)
// /\ UNCHANGED <<serverVars, log>>
// \/ \* conflict: remove 1 entry
// /\ m.mentries /= << >>
// /\ Len(log[i]) >= index
// /\ log[i][index].term /= m.mentries[1].term
// /\ LET new == [index2 \in 1..(Len(log[i]) - 1) |->
// log[i][index2]]
// IN log' = [log EXCEPT ![i] = new]
// /\ UNCHANGED <<serverVars, commitIndex, messages>>
// \/ \* no conflict: append entry
// /\ m.mentries /= << >>
// /\ Len(log[i]) = m.mprevLogIndex
// /\ log' = [log EXCEPT ![i] =
// Append(log[i], m.mentries[1])]
// /\ UNCHANGED <<serverVars, commitIndex, messages>>
// /\ UNCHANGED <<candidateVars, leaderVars>>
//
int32_t syncNodeOnAppendEntriesCb(SSyncNode* ths, SyncAppendEntries* pMsg);
int32_t syncNodeOnAppendEntriesSnapshotCb(SSyncNode* ths, SyncAppendEntries* pMsg);
#ifdef __cplusplus
}
#endif
#endif /*_TD_LIBS_SYNC_APPEND_ENTRIES_H*/