enhance: code refactor and operator full implement slimit

source/libs/executor/src/scanoperator.c

@@ -2512,9 +2512,11 @@ _error:
   return NULL;
 }
 
-static void doTagScanOneTable(SOperatorInfo* pOperator, const SExecTaskInfo* pTaskInfo, STagScanInfo* pInfo,
-                              const SExprInfo* pExprInfo, const SSDataBlock* pRes, int32_t size, const char* str,
-                              int32_t* count, SMetaReader* mr) {
+static void doTagScanOneTable(SOperatorInfo* pOperator, const SSDataBlock* pRes, int32_t count, SMetaReader* mr) {
+  SExecTaskInfo* pTaskInfo = pOperator->pTaskInfo;
+  STagScanInfo* pInfo = pOperator->info;
+  SExprInfo*    pExprInfo = &pOperator->exprSupp.pExprInfo[0];
+
   STableKeyInfo* item = tableListGetInfo(pInfo->pTableListInfo, pInfo->curPos);
   int32_t        code = metaGetTableEntryByUid(mr, item->uid);
   tDecoderClear(&(*mr).coder);
@@ -2525,13 +2527,14 @@ static void doTagScanOneTable(SOperatorInfo* pOperator, const SExecTaskInfo* pTa
     T_LONG_JMP(pTaskInfo->env, terrno);
   }
 
+  char str[512];
   for (int32_t j = 0; j < pOperator->exprSupp.numOfExprs; ++j) {
     SColumnInfoData* pDst = taosArrayGet(pRes->pDataBlock, pExprInfo[j].base.resSchema.slotId);
 
     // refactor later
     if (fmIsScanPseudoColumnFunc(pExprInfo[j].pExpr->_function.functionId)) {
       STR_TO_VARSTR(str, (*mr).me.name);
-      colDataSetVal(pDst, (*count), str, false);
+      colDataSetVal(pDst, (count), str, false);
     } else {  // it is a tag value
       STagVal val = {0};
       val.cid = pExprInfo[j].base.pParam[0].pCol->colId;
@@ -2543,7 +2546,7 @@ static void doTagScanOneTable(SOperatorInfo* pOperator, const SExecTaskInfo* pTa
       } else {
         data = (char*)p;
       }
-      colDataSetVal(pDst, (*count), data,
+      colDataSetVal(pDst, (count), data,
                     (data == NULL) || (pDst->info.type == TSDB_DATA_TYPE_JSON && tTagIsJsonNull(data)));
 
       if (pDst->info.type != TSDB_DATA_TYPE_JSON && p != NULL && IS_VAR_DATA_TYPE(((const STagVal*)p)->type) &&
@@ -2552,11 +2555,6 @@ static void doTagScanOneTable(SOperatorInfo* pOperator, const SExecTaskInfo* pTa
       }
     }
   }
-
-  (*count) += 1;
-  if (++pInfo->curPos >= size) {
-    setOperatorCompleted(pOperator);
-  }
 }
 
 static SSDataBlock* doTagScan(SOperatorInfo* pOperator) {
@@ -2583,9 +2581,20 @@ static SSDataBlock* doTagScan(SOperatorInfo* pOperator) {
   metaReaderInit(&mr, pInfo->readHandle.meta, 0);
 
   while (pInfo->curPos < size && count < pOperator->resultInfo.capacity) {
-    doTagScanOneTable(pOperator, pTaskInfo, pInfo, pExprInfo, pRes, size, str, &count, &mr);
+    doTagScanOneTable(pOperator, pRes, count, &mr);
+    ++count;
+    if (++pInfo->curPos >= size) {
+      setOperatorCompleted(pOperator);
+    }
+    // each table with tbname is a group, hence its own block, but only group when slimit exists for performance reason.
     if (pInfo->pSlimit != NULL) {
+      if (pInfo->curPos < pInfo->pSlimit->offset) {
+        continue;
+      }
       pInfo->pRes->info.id.groupId = calcGroupId(mr.me.name, strlen(mr.me.name));
+      if (pInfo->curPos >= (pInfo->pSlimit->offset + pInfo->pSlimit->limit) - 1) {
+        setOperatorCompleted(pOperator);
+      }
       break;
     }
   }

source/libs/planner/src/planOptimizer.c

@@ -2442,6 +2442,8 @@ static void tagScanOptCloneAncestorSlimit(SLogicNode* pTableScanNode) {
   if (NULL != pNode) {
     //TODO: only set the slimit now. push down slimit later
     pTableScanNode->pSlimit = nodesCloneNode(pNode->pSlimit);
+    ((SLimitNode*)pTableScanNode->pSlimit)->limit += ((SLimitNode*)pTableScanNode->pSlimit)->offset;
+    ((SLimitNode*)pTableScanNode->pSlimit)->offset = 0;
   }
   return;
 }