refactor(sync): add leader transfer callback

source/dnode/mnode/impl/src/mndMain.c

@@ -371,13 +371,15 @@ void mndPreClose(SMnode *pMnode) {
     atomic_store_8(&(pMnode->syncMgmt.leaderTransferFinish), 0);
     syncLeaderTransfer(pMnode->syncMgmt.sync);
 
-    mDebug("vgId:1, mnode start leader transfer");
-    // wait for leader transfer finish
-    while (!atomic_load_8(&(pMnode->syncMgmt.leaderTransferFinish))) {
-      taosMsleep(10);
-      mDebug("vgId:1, mnode waiting for leader transfer");
-    }
-    mDebug("vgId:1, mnode finish leader transfer");
+    /*
+        mDebug("vgId:1, mnode start leader transfer");
+        // wait for leader transfer finish
+        while (!atomic_load_8(&(pMnode->syncMgmt.leaderTransferFinish))) {
+          taosMsleep(10);
+          mDebug("vgId:1, mnode waiting for leader transfer");
+        }
+        mDebug("vgId:1, mnode finish leader transfer");
+    */
   }
 }
 

source/libs/sync/inc/syncInt.h

@@ -253,6 +253,7 @@ bool syncNodeCheckNewConfig(SSyncNode* pSyncNode, const SSyncCfg* pNewCfg);
 
 int32_t syncNodeLeaderTransfer(SSyncNode* pSyncNode);
 int32_t syncNodeLeaderTransferTo(SSyncNode* pSyncNode, SNodeInfo newLeader);
+int32_t syncDoLeaderTransfer(SSyncNode* ths, SRpcMsg* pRpcMsg, SSyncRaftEntry* pEntry);
 
 // for debug --------------
 void syncNodePrint(SSyncNode* pObj);

source/libs/sync/src/syncAppendEntries.c

@@ -477,6 +477,13 @@ static int32_t syncNodeDoMakeLogSame(SSyncNode* ths, SyncIndex FromIndex) {
 static int32_t syncNodePreCommit(SSyncNode* ths, SSyncRaftEntry* pEntry) {
   SRpcMsg rpcMsg;
   syncEntry2OriginalRpc(pEntry, &rpcMsg);
+
+  // leader transfer
+  if (pEntry->originalRpcType == TDMT_SYNC_LEADER_TRANSFER) {
+    int32_t code = syncDoLeaderTransfer(ths, &rpcMsg, pEntry);
+    ASSERT(code == 0);
+  }
+
   if (ths->pFsm != NULL) {
     if (ths->pFsm->FpPreCommitCb != NULL && syncUtilUserPreCommit(pEntry->originalRpcType)) {
       SFsmCbMeta cbMeta = {0};

source/libs/sync/src/syncMain.c

@@ -2598,7 +2598,7 @@ const char* syncStr(ESyncState state) {
   }
 }
 
-static int32_t syncDoLeaderTransfer(SSyncNode* ths, SRpcMsg* pRpcMsg, SSyncRaftEntry* pEntry) {
+int32_t syncDoLeaderTransfer(SSyncNode* ths, SRpcMsg* pRpcMsg, SSyncRaftEntry* pEntry) {
   SyncLeaderTransfer* pSyncLeaderTransfer = syncLeaderTransferFromRpcMsg2(pRpcMsg);
 
   syncNodeEventLog(ths, "do leader transfer");
@@ -2811,11 +2811,14 @@ int32_t syncNodeCommit(SSyncNode* ths, SyncIndex beginIndex, SyncIndex endIndex,
           ASSERT(code == 0);
         }
 
+#if 0
+        // execute in pre-commit
         // leader transfer
         if (pEntry->originalRpcType == TDMT_SYNC_LEADER_TRANSFER) {
           code = syncDoLeaderTransfer(ths, &rpcMsg, pEntry);
           ASSERT(code == 0);
         }
+#endif
 
         // restore finish
         // if only snapshot, a noop entry will be append, so syncLogLastIndex is always ok