optimize session operator reload state

source/libs/executor/src/timewindowoperator.c

@@ -3192,11 +3192,12 @@ SStreamStateCur* getNextSessionWinInfo(SStreamAggSupporter* pAggSup, SSHashObj*
   return pCur;
 }
 
-static void compactSessionWindow(SOperatorInfo* pOperator, SResultWindowInfo* pCurWin, SSHashObj* pStUpdated,
+static int32_t compactSessionWindow(SOperatorInfo* pOperator, SResultWindowInfo* pCurWin, SSHashObj* pStUpdated,
                                  SSHashObj* pStDeleted, bool addGap) {
-  SExprSupp*                     pSup = &pOperator->exprSupp;
-  SExecTaskInfo*                 pTaskInfo = pOperator->pTaskInfo;
-  SStorageAPI* pAPI = &pOperator->pTaskInfo->storageAPI;
+  SExprSupp*     pSup = &pOperator->exprSupp;
+  SExecTaskInfo* pTaskInfo = pOperator->pTaskInfo;
+  SStorageAPI*   pAPI = &pOperator->pTaskInfo->storageAPI;
+  int32_t        winNum = 0;
 
   SStreamSessionAggOperatorInfo* pInfo = pOperator->info;
   SResultRow*                    pCurResult = NULL;
@@ -3230,7 +3231,9 @@ static void compactSessionWindow(SOperatorInfo* pOperator, SResultWindowInfo* pC
     doDeleteSessionWindow(pAggSup, &winInfo.sessionWin);
     pAPI->stateStore.streamStateFreeCur(pCur);
     taosMemoryFree(winInfo.pOutputBuf);
+    winNum++;
   }
+  return winNum;
 }
 
 int32_t saveSessionOutputBuf(SStreamAggSupporter* pAggSup, SResultWindowInfo* pWinInfo) {
@@ -3731,9 +3734,11 @@ void streamSessionReloadState(SOperatorInfo* pOperator) {
   for (int32_t i = 0; i < num; i++) {
     SResultWindowInfo winInfo = {0};
     setSessionOutputBuf(pAggSup, pSeKeyBuf[i].win.skey, pSeKeyBuf[i].win.ekey, pSeKeyBuf[i].groupId, &winInfo);
-    compactSessionWindow(pOperator, &winInfo, pInfo->pStUpdated, pInfo->pStDeleted, true);
-    saveSessionOutputBuf(pAggSup, &winInfo);
-    saveResult(winInfo, pInfo->pStUpdated);
+    int32_t winNum = compactSessionWindow(pOperator, &winInfo, pInfo->pStUpdated, pInfo->pStDeleted, true);
+    if (winNum > 0) {
+      saveSessionOutputBuf(pAggSup, &winInfo);
+      saveResult(winInfo, pInfo->pStUpdated);
+    }
   }
   taosMemoryFree(pBuf);