enh(query): support event window.

source/libs/executor/src/eventwindowoperator.c

@@ -172,7 +172,9 @@ static SSDataBlock* eventWindowAggregate(SOperatorInfo* pOperator) {
   SExprSupp* pSup = &pOperator->exprSupp;
   int32_t    order = TSDB_ORDER_ASC;
 
-  blockDataCleanup(pInfo->binfo.pRes);
+  SSDataBlock* pRes = pInfo->binfo.pRes;
+
+  blockDataCleanup(pRes);
 
   SOperatorInfo* downstream = pOperator->pDownstream[0];
   while (1) {
@@ -194,9 +196,12 @@ static SSDataBlock* eventWindowAggregate(SOperatorInfo* pOperator) {
     }
 
     eventWindowAggImpl(pOperator, pInfo, pBlock);
+    if (pRes->info.rows >= pOperator->resultInfo.threshold) {
+      return pRes;
+    }
   }
 
-  return pInfo->binfo.pRes->info.rows == 0 ? NULL : pInfo->binfo.pRes;
+  return pRes->info.rows == 0 ? NULL : pRes;
 }
 
 static int32_t setSingleOutputTupleBufv1(SResultRowInfo* pResultRowInfo, STimeWindow* win, SResultRow** pResult,
@@ -236,6 +241,7 @@ void eventWindowAggImpl(SOperatorInfo* pOperator, SEventWindowOperatorInfo* pInf
   SExecTaskInfo* pTaskInfo = pOperator->pTaskInfo;
   SExprSupp*     pSup = &pOperator->exprSupp;
 
+  SSDataBlock* pRes = pInfo->binfo.pRes;
   int64_t gid = pBlock->info.id.groupId;
 
   SColumnInfoData* pColInfoData = taosArrayGet(pBlock->pDataBlock, pInfo->tsSlotId);
@@ -272,13 +278,18 @@ void eventWindowAggImpl(SOperatorInfo* pOperator, SEventWindowOperatorInfo* pInf
       if (rowIndex < pBlock->info.rows) {
         doEventWindowAggImpl(pInfo, pSup, startIndex, rowIndex, pBlock, tsList, pTaskInfo);
 
-        // todo check if pblock buffer is enough
         doUpdateNumOfRows(pSup->pCtx, pInfo->pRow, pSup->numOfExprs, pSup->rowEntryInfoOffset);
 
-        copyResultrowToDataBlock(pSup->pExprInfo, pSup->numOfExprs, pInfo->pRow, pSup->pCtx, pInfo->binfo.pRes,
+        // check buffer size
+        if (pRes->info.rows + pInfo->pRow->numOfRows >= pRes->info.capacity) {
+          int32_t newSize = pRes->info.rows + pInfo->pRow->numOfRows;
+          blockDataEnsureCapacity(pRes, newSize);
+        }
+
+        copyResultrowToDataBlock(pSup->pExprInfo, pSup->numOfExprs, pInfo->pRow, pSup->pCtx, pRes,
                                  pSup->rowEntryInfoOffset, pTaskInfo);
 
-        pInfo->binfo.pRes->info.rows += pInfo->pRow->numOfRows;
+        pRes->info.rows += pInfo->pRow->numOfRows;
 
         pInfo->inWindow = false;
         rowIndex += 1;