From 5f0d23426dac8b99d74aeda91997811c840b8fcd Mon Sep 17 00:00:00 2001
From: Minghao Li <castermode@gmail.com>
Date: Wed, 1 Jun 2022 13:35:23 +0800
Subject: [PATCH] refactor: snapshotReSend

---
 source/libs/sync/src/syncSnapshot.c | 82 +++++++++++++++--------------
 1 file changed, 42 insertions(+), 40 deletions(-)

diff --git a/source/libs/sync/src/syncSnapshot.c b/source/libs/sync/src/syncSnapshot.c
index 7825a7cd95..38d3dc4995 100644
--- a/source/libs/sync/src/syncSnapshot.c
+++ b/source/libs/sync/src/syncSnapshot.c
@@ -370,50 +370,52 @@ int32_t syncNodeOnSnapshotSendCb(SSyncNode *pSyncNode, SyncSnapshotSend *pMsg) {
 
   // state, term, seq/ack
   if (pSyncNode->state == TAOS_SYNC_STATE_FOLLOWER) {
-    if (pMsg->seq == SYNC_SNAPSHOT_SEQ_BEGIN) {
-      // begin
-      snapshotReceiverStart(pReceiver);
-      pReceiver->ack = pMsg->seq;
-      needRsp = true;
-
-    } else if (pMsg->seq == SYNC_SNAPSHOT_SEQ_END) {
-      // end, finish FSM
-      pSyncNode->pFsm->FpSnapshotDoWrite(pSyncNode->pFsm, pReceiver->pWriter, pMsg->data, pMsg->dataLen);
-      pSyncNode->pFsm->FpSnapshotStopWrite(pSyncNode->pFsm, pReceiver->pWriter, true);
-      snapshotReceiverStop(pReceiver);
-      pReceiver->ack = pMsg->seq;
-      needRsp = true;
-
-    } else if (pMsg->seq == SYNC_SNAPSHOT_SEQ_FORCE_CLOSE) {
-      pSyncNode->pFsm->FpSnapshotStopWrite(pSyncNode->pFsm, pReceiver->pWriter, false);
-      snapshotReceiverStop(pReceiver);
-      needRsp = false;
-
-    } else if (pMsg->seq > SYNC_SNAPSHOT_SEQ_BEGIN && pMsg->seq < SYNC_SNAPSHOT_SEQ_END) {
-      // transfering
-      if (pMsg->seq == pReceiver->ack + 1) {
-        pSyncNode->pFsm->FpSnapshotDoWrite(pSyncNode->pFsm, pReceiver->pWriter, pMsg->data, pMsg->dataLen);
+    if (pMsg->term == pSyncNode->pRaftStore->currentTerm) {
+      if (pMsg->seq == SYNC_SNAPSHOT_SEQ_BEGIN) {
+        // begin
+        snapshotReceiverStart(pReceiver);
         pReceiver->ack = pMsg->seq;
+        needRsp = true;
+
+      } else if (pMsg->seq == SYNC_SNAPSHOT_SEQ_END) {
+        // end, finish FSM
+        pSyncNode->pFsm->FpSnapshotDoWrite(pSyncNode->pFsm, pReceiver->pWriter, pMsg->data, pMsg->dataLen);
+        pSyncNode->pFsm->FpSnapshotStopWrite(pSyncNode->pFsm, pReceiver->pWriter, true);
+        snapshotReceiverStop(pReceiver);
+        pReceiver->ack = pMsg->seq;
+        needRsp = true;
+
+      } else if (pMsg->seq == SYNC_SNAPSHOT_SEQ_FORCE_CLOSE) {
+        pSyncNode->pFsm->FpSnapshotStopWrite(pSyncNode->pFsm, pReceiver->pWriter, false);
+        snapshotReceiverStop(pReceiver);
+        needRsp = false;
+
+      } else if (pMsg->seq > SYNC_SNAPSHOT_SEQ_BEGIN && pMsg->seq < SYNC_SNAPSHOT_SEQ_END) {
+        // transfering
+        if (pMsg->seq == pReceiver->ack + 1) {
+          pSyncNode->pFsm->FpSnapshotDoWrite(pSyncNode->pFsm, pReceiver->pWriter, pMsg->data, pMsg->dataLen);
+          pReceiver->ack = pMsg->seq;
+        }
+        needRsp = true;
+
+      } else {
+        ASSERT(0);
       }
-      needRsp = true;
 
-    } else {
-      ASSERT(0);
-    }
+      if (needRsp) {
+        SyncSnapshotRsp *pRspMsg = syncSnapshotRspBuild(pSyncNode->vgId);
+        pRspMsg->srcId = pSyncNode->myRaftId;
+        pRspMsg->destId = pMsg->srcId;
+        pRspMsg->term = pSyncNode->pRaftStore->currentTerm;
+        pRspMsg->lastIndex = pMsg->lastIndex;
+        pRspMsg->lastTerm = pMsg->lastTerm;
+        pRspMsg->ack = pReceiver->ack;
 
-    if (needRsp) {
-      SyncSnapshotRsp *pRspMsg = syncSnapshotRspBuild(pSyncNode->vgId);
-      pRspMsg->srcId = pSyncNode->myRaftId;
-      pRspMsg->destId = pMsg->srcId;
-      pRspMsg->term = pSyncNode->pRaftStore->currentTerm;
-      pRspMsg->lastIndex = pMsg->lastIndex;
-      pRspMsg->lastTerm = pMsg->lastTerm;
-      pRspMsg->ack = pReceiver->ack;
-
-      SRpcMsg rpcMsg;
-      syncSnapshotRsp2RpcMsg(pRspMsg, &rpcMsg);
-      syncNodeSendMsgById(&(pRspMsg->destId), pSyncNode, &rpcMsg);
-      syncSnapshotRspDestroy(pRspMsg);
+        SRpcMsg rpcMsg;
+        syncSnapshotRsp2RpcMsg(pRspMsg, &rpcMsg);
+        syncNodeSendMsgById(&(pRspMsg->destId), pSyncNode, &rpcMsg);
+        syncSnapshotRspDestroy(pRspMsg);
+      }
     }
   }
   return 0;