enh(query): set the status of stream scan operator.

source/common/src/tmsg.c

@@ -52,6 +52,10 @@ int32_t tGetSubmitMsgNext(SSubmitMsgIter *pIter, SSubmitBlk **pPBlock) {
   if (pIter->len == 0) {
     pIter->len += sizeof(SSubmitReq);
   } else {
+    if (pIter->len >= pIter->totalLen) {
+      ASSERT(0);
+    }
+
     SSubmitBlk *pSubmitBlk = (SSubmitBlk *)POINTER_SHIFT(pIter->pMsg, pIter->len);
     pIter->len += (sizeof(SSubmitBlk) + pSubmitBlk->dataLen + pSubmitBlk->schemaLen);
     ASSERT(pIter->len > 0);

source/libs/executor/src/executor.c

@@ -34,6 +34,8 @@ static int32_t doSetStreamBlock(SOperatorInfo* pOperator, void* input, size_t nu
     pOperator->status = OP_NOT_OPENED;
     return doSetStreamBlock(pOperator->pDownstream[0], input, numOfBlocks, type, id);
   } else {
+    pOperator->status = OP_NOT_OPENED;
+
     SStreamBlockScanInfo* pInfo = pOperator->info;
 
     // the block type can not be changed in the streamscan operators

source/libs/executor/src/executorimpl.c

@@ -4931,6 +4931,10 @@ static SSDataBlock* doProjectOperation(SOperatorInfo* pOperator, bool* newgroup)
 
   SSDataBlock* pRes = pInfo->pRes;
   blockDataCleanup(pRes);
+
+  if (pOperator->status == OP_EXEC_DONE) {
+    return NULL;
+  }
   
 #if 0
   if (pProjectInfo->existDataBlock) {  // TODO refactor

source/libs/executor/src/scanoperator.c

@@ -539,7 +539,7 @@ static SSDataBlock* doStreamBlockScan(SOperatorInfo* pOperator, bool* newgroup)
   SStreamBlockScanInfo* pInfo = pOperator->info;
 
   pTaskInfo->code = pOperator->_openFn(pOperator);
-  if (pTaskInfo->code != TSDB_CODE_SUCCESS) {
+  if (pTaskInfo->code != TSDB_CODE_SUCCESS || pOperator->status == OP_EXEC_DONE) {
     return NULL;
   }
 
@@ -547,6 +547,7 @@ static SSDataBlock* doStreamBlockScan(SOperatorInfo* pOperator, bool* newgroup)
     size_t total = taosArrayGetSize(pInfo->pBlockLists);
     if (pInfo->validBlockIndex >= total) {
       doClearBufferedBlocks(pInfo);
+      pOperator->status = OP_EXEC_DONE;
       return NULL;
     }
 
@@ -560,11 +561,12 @@ static SSDataBlock* doStreamBlockScan(SOperatorInfo* pOperator, bool* newgroup)
       pTaskInfo->code = tqRetrieveDataBlockInfo(pInfo->readerHandle, pBlockInfo);
       if (pTaskInfo->code != TSDB_CODE_SUCCESS) {
         terrno = pTaskInfo->code;
+        pOperator->status = OP_EXEC_DONE;
         return NULL;
       }
 
       if (pBlockInfo->rows == 0) {
-        return NULL;
+        break;
       }
 
       SArray* pCols = tqRetrieveDataBlock(pInfo->readerHandle);
@@ -583,6 +585,7 @@ static SSDataBlock* doStreamBlockScan(SOperatorInfo* pOperator, bool* newgroup)
 
       if (pInfo->pRes->pDataBlock == NULL) {
         // TODO add log
+        pOperator->status = OP_EXEC_DONE;
         pTaskInfo->code = terrno;
         return NULL;
       }
@@ -594,6 +597,10 @@ static SSDataBlock* doStreamBlockScan(SOperatorInfo* pOperator, bool* newgroup)
     pInfo->numOfExec++;
     pInfo->numOfRows += pBlockInfo->rows;
 
+    if (pBlockInfo->rows == 0) {
+      pOperator->status = OP_EXEC_DONE;
+    }
+
     return (pBlockInfo->rows == 0) ? NULL : pInfo->pRes;
   }
 }

source/libs/function/src/builtinsimpl.c

@@ -866,10 +866,6 @@ int32_t firstFunction(SqlFunctionCtx *pCtx) {
 }
 
 int32_t lastFunction(SqlFunctionCtx *pCtx) {
-  if (pCtx->order != TSDB_ORDER_DESC) {
-    return 0;
-  }
-
   int32_t numOfElems = 0;
 
   SResultRowEntryInfo *pResInfo = GET_RES_INFO(pCtx);