refactor(query): do some internal refactor.

source/libs/executor/src/executorimpl.c

@@ -3738,6 +3738,32 @@ static int32_t doSendFetchDataRequest(SExchangeInfo* pExchangeInfo, SExecTaskInf
   return TSDB_CODE_SUCCESS;
 }
 
+// NOTE: sources columns are more than the destination SSDatablock columns.
+static void relocateColumnData(SSDataBlock* pBlock, const SArray* pColMatchInfo, SArray* pCols) {
+  size_t numOfSrcCols = taosArrayGetSize(pCols);
+  ASSERT(numOfSrcCols >= pBlock->info.numOfCols);
+
+  int32_t i = 0, j = 0;
+  while(i < numOfSrcCols && j < taosArrayGetSize(pColMatchInfo)) {
+    SColumnInfoData* p = taosArrayGet(pCols, i);
+    SColMatchInfo*   pmInfo = taosArrayGet(pColMatchInfo, j);
+    if (!pmInfo->output) {
+      j++;
+      continue;
+    }
+
+    if (p->info.colId == pmInfo->colId) {
+      taosArraySet(pBlock->pDataBlock, pmInfo->targetSlotId, p);
+      i++;
+      j++;
+    } else if (p->info.colId < pmInfo->colId) {
+      i++;
+    } else {
+      ASSERT(0);
+    }
+  }
+}
+
 int32_t setSDataBlockFromFetchRsp(SSDataBlock* pRes, SLoadRemoteDataInfo* pLoadInfo, int32_t numOfRows, char* pData,
                                   int32_t compLen, int32_t numOfOutput, int64_t startTs, uint64_t* total,
                                   SArray* pColList) {
@@ -3755,7 +3781,7 @@ int32_t setSDataBlockFromFetchRsp(SSDataBlock* pRes, SLoadRemoteDataInfo* pLoadI
     char* pStart = pData + sizeof(int32_t) * numOfOutput;
     for (int32_t i = 0; i < numOfOutput; ++i) {
       colLen[i] = htonl(colLen[i]);
-      ASSERT(colLen[i] > 0);
+      ASSERT(colLen[i] >= 0);
 
       SColumnInfoData* pColInfoData = taosArrayGet(pRes->pDataBlock, i);
       if (IS_VAR_DATA_TYPE(pColInfoData->info.type)) {
@@ -3765,13 +3791,18 @@ int32_t setSDataBlockFromFetchRsp(SSDataBlock* pRes, SLoadRemoteDataInfo* pLoadI
         memcpy(pColInfoData->varmeta.offset, pStart, sizeof(int32_t) * numOfRows);
         pStart += sizeof(int32_t) * numOfRows;
 
-        pColInfoData->pData = taosMemoryMalloc(colLen[i]);
+        if (colLen[i] > 0) {
+          pColInfoData->pData = taosMemoryMalloc(colLen[i]);
+        }
       } else {
         memcpy(pColInfoData->nullbitmap, pStart, BitmapLen(numOfRows));
         pStart += BitmapLen(numOfRows);
       }
 
-      memcpy(pColInfoData->pData, pStart, colLen[i]);
+      if (colLen[i] > 0) {
+        memcpy(pColInfoData->pData, pStart, colLen[i]);
+      }
+
       //TODO setting this flag to true temporarily so aggregate function on stable will
       //examine NULL value for non-primary key column
       pColInfoData->hasNull = true;
@@ -3784,6 +3815,7 @@ int32_t setSDataBlockFromFetchRsp(SSDataBlock* pRes, SLoadRemoteDataInfo* pLoadI
     int32_t numOfCols = htonl(*(int32_t*)pStart);
     pStart += sizeof(int32_t);
 
+    // todo refactor:extract method
     SSysTableSchema* pSchema = (SSysTableSchema*)pStart;
     for (int32_t i = 0; i < numOfCols; ++i) {
       SSysTableSchema* p = (SSysTableSchema*)pStart;
@@ -3838,19 +3870,7 @@ int32_t setSDataBlockFromFetchRsp(SSDataBlock* pRes, SLoadRemoteDataInfo* pLoadI
     }
 
     // data from mnode
-    for (int32_t i = 0; i < numOfCols; ++i) {
-      SColumnInfoData* pSrc = taosArrayGet(block.pDataBlock, i);
-
-      for (int32_t j = 0; j < numOfOutput; ++j) {
-        int16_t colIndex = *(int16_t*)taosArrayGet(pColList, j);
-
-        if (colIndex - 1 == i) {
-          SColumnInfoData* pColInfoData = taosArrayGet(pRes->pDataBlock, j);
-          colDataAssign(pColInfoData, pSrc, numOfRows);
-          break;
-        }
-      }
-    }
+    relocateColumnData(pRes,  pColList, block.pDataBlock);
   }
 
   pRes->info.rows = numOfRows;
@@ -6422,7 +6442,6 @@ static tsdbReaderT doCreateDataReader(STableScanPhysiNode* pTableScanNode, SRead
 static int32_t doCreateTableGroup(void* metaHandle, int32_t tableType, uint64_t tableUid, STableGroupInfo* pGroupInfo,
                                   uint64_t queryId, uint64_t taskId);
 static SArray* extractTableIdList(const STableGroupInfo* pTableGroupInfo);
-static SArray* extractScanColumnId(SNodeList* pNodeList);
 static SArray* extractColumnInfo(SNodeList* pNodeList);
 static SArray* extractColMatchInfo(SNodeList* pNodeList, SDataBlockDescNode* pOutputNodeList, int32_t* numOfOutputCols);
 
@@ -6493,8 +6512,9 @@ SOperatorInfo* createOperatorTree(SPhysiNode* pPhyNode, SExecTaskInfo* pTaskInfo
       SScanPhysiNode* pScanNode = &pSysScanPhyNode->scan;
 
       SSDataBlock* pResBlock = createResDataBlock(pScanNode->node.pOutputDataBlockDesc);
-      SArray* colList = extractScanColumnId(pScanNode->pScanCols);
 
+      int32_t numOfOutputCols = 0;
+      SArray* colList = extractColMatchInfo(pScanNode->pScanCols, pScanNode->node.pOutputDataBlockDesc, &numOfOutputCols);
       SOperatorInfo* pOperator = createSysTableScanOperatorInfo(
           pHandle, pResBlock, &pScanNode->tableName, pScanNode->node.pConditions, pSysScanPhyNode->mgmtEpSet,
           colList, pTaskInfo, pSysScanPhyNode->showRewrite, pSysScanPhyNode->accountId);
@@ -6657,28 +6677,6 @@ static  int32_t initQueryTableDataCond(SQueryTableDataCond* pCond, const STableS
   return TSDB_CODE_SUCCESS;
 }
 
-SArray* extractScanColumnId(SNodeList* pNodeList) {
-  size_t  numOfCols = LIST_LENGTH(pNodeList);
-  SArray* pList = taosArrayInit(numOfCols, sizeof(int16_t));
-  if (pList == NULL) {
-    terrno = TSDB_CODE_OUT_OF_MEMORY;
-    return NULL;
-  }
-
-  for (int32_t i = 0; i < numOfCols; ++i) {
-    for (int32_t j = 0; j < numOfCols; ++j) {
-      STargetNode* pNode = (STargetNode*)nodesListGetNode(pNodeList, j);
-      if (pNode->slotId == i) {
-        SColumnNode* pColNode = (SColumnNode*)pNode->pExpr;
-        taosArrayPush(pList, &pColNode->colId);
-        break;
-      }
-    }
-  }
-
-  return pList;
-}
-
 SArray* extractColumnInfo(SNodeList* pNodeList) {
   size_t  numOfCols = LIST_LENGTH(pNodeList);
   SArray* pList = taosArrayInit(numOfCols, sizeof(SColumn));
@@ -6814,9 +6812,9 @@ SArray* extractColMatchInfo(SNodeList* pNodeList, SDataBlockDescNode* pOutputNod
     SColumnNode* pColNode = (SColumnNode*)pNode->pExpr;
 
     SColMatchInfo c = {0};
+    c.output = true;
     c.colId = pColNode->colId;
     c.targetSlotId = pNode->slotId;
-    c.output = true;
     taosArrayPush(pList, &c);
   }
 
@@ -6824,8 +6822,10 @@ SArray* extractColMatchInfo(SNodeList* pNodeList, SDataBlockDescNode* pOutputNod
   int32_t num = LIST_LENGTH(pOutputNodeList->pSlots);
   for (int32_t i = 0; i < num; ++i) {
     SSlotDescNode* pNode = (SSlotDescNode*)nodesListGetNode(pOutputNodeList->pSlots, i);
+
     // todo: add reserve flag check
-    if (pNode->slotId >= numOfCols) {  // it is a column reserved for the arithmetic expression calculation
+    // it is a column reserved for the arithmetic expression calculation
+    if (pNode->slotId >= numOfCols) {
       (*numOfOutputCols) += 1;
       continue;
     }