scalar.c

#include "function.h"
#include "functionMgt.h"
#include "nodes.h"
#include "querynodes.h"
#include "sclInt.h"
#include "sclvector.h"
#include "tcommon.h"
#include "tdatablock.h"
#include "scalar.h"

int32_t scalarGetOperatorParamNum(EOperatorType type) {
  if (OP_TYPE_IS_NULL == type || OP_TYPE_IS_NOT_NULL == type || OP_TYPE_IS_TRUE == type || OP_TYPE_IS_NOT_TRUE == type 
   || OP_TYPE_IS_FALSE == type || OP_TYPE_IS_NOT_FALSE == type || OP_TYPE_IS_UNKNOWN == type || OP_TYPE_IS_NOT_UNKNOWN == type
   || OP_TYPE_MINUS == type) {
    return 1;
  }

  return 2;
}

SColumnInfoData* createColumnInfoData(SDataType* pType, int32_t numOfRows) {
  SColumnInfoData* pColumnData = taosMemoryCalloc(1, sizeof(SColumnInfoData));
  if (pColumnData == NULL) {
    terrno = TSDB_CODE_OUT_OF_MEMORY;
    return NULL;
  }

  pColumnData->info.type      = pType->type;
  pColumnData->info.bytes     = pType->bytes;
  pColumnData->info.scale     = pType->scale;
  pColumnData->info.precision = pType->precision;

  int32_t code = colInfoDataEnsureCapacity(pColumnData, 0, numOfRows);
  if (code != TSDB_CODE_SUCCESS) {
    terrno = TSDB_CODE_OUT_OF_MEMORY;
    taosMemoryFree(pColumnData);
    return NULL;
  } else {
    return pColumnData;
  }
}

int32_t doConvertDataType(SValueNode* pValueNode, SScalarParam* out) {
  SScalarParam in = {.numOfRows = 1};
  in.columnData = createColumnInfoData(&pValueNode->node.resType, 1);
  colDataAppend(in.columnData, 0, nodesGetValueFromNode(pValueNode), false);

  colInfoDataEnsureCapacity(out->columnData, 0, 1);
  int32_t code = vectorConvertImpl(&in, out);
  sclFreeParam(&in);

  return code;
}

int32_t scalarGenerateSetFromList(void **data, void *pNode, uint32_t type) {
  SHashObj *pObj = taosHashInit(256, taosGetDefaultHashFunction(type), true, false);
  if (NULL == pObj) {
    sclError("taosHashInit failed, size:%d", 256);
    SCL_ERR_RET(TSDB_CODE_QRY_OUT_OF_MEMORY);
  }

  taosHashSetEqualFp(pObj, taosGetDefaultEqualFunction(type)); 

  int32_t code = 0;
  SNodeListNode *nodeList = (SNodeListNode *)pNode;
  SListCell *cell = nodeList->pNodeList->pHead;
  SScalarParam out = {.columnData = taosMemoryCalloc(1, sizeof(SColumnInfoData))};

  int32_t len = 0;
  void *buf = NULL;
  
  for (int32_t i = 0; i < nodeList->pNodeList->length; ++i) {
    SValueNode *valueNode = (SValueNode *)cell->pNode;

    if (valueNode->node.resType.type != type) {
      out.columnData->info.type = type;
      out.columnData->info.bytes = tDataTypes[type].bytes;

      code = doConvertDataType(valueNode, &out);
      if (code != TSDB_CODE_SUCCESS) {
//        sclError("convert data from %d to %d failed", in.type, out.type);
        SCL_ERR_JRET(code);
      }

      if (IS_VAR_DATA_TYPE(type)) {
        len = varDataLen(out.columnData->pData);
        buf = varDataVal(out.columnData->pData);
      } else {
        len = tDataTypes[type].bytes;
        buf = out.columnData->pData;
      }
    } else {
      buf = nodesGetValueFromNode(valueNode);
      if (IS_VAR_DATA_TYPE(type)) {
        len = varDataLen(buf);
        buf = varDataVal(buf);
      } else {
        len = valueNode->node.resType.bytes;
      }
    }
    
    if (taosHashPut(pObj, buf, (size_t)len, NULL, 0)) {
      sclError("taosHashPut failed");
      SCL_ERR_JRET(TSDB_CODE_QRY_OUT_OF_MEMORY);
    }

    cell = cell->pNext;
  }

  *data = pObj;
  return TSDB_CODE_SUCCESS;

_return:
  taosHashCleanup(pObj);
  SCL_RET(code);
}

void sclFreeRes(SHashObj *res) {
  SScalarParam *p = NULL;
  void *pIter = taosHashIterate(res, NULL);
  while (pIter) {
    p = (SScalarParam *)pIter;

    if (p) {
      sclFreeParam(p);
    }
    pIter = taosHashIterate(res, pIter);
  }
  taosHashCleanup(res);
}

void sclFreeParam(SScalarParam *param) {
  if (param->columnData != NULL) {
    colDataDestroy(param->columnData);
    taosMemoryFree(param->columnData);
  }

  if (param->pHashFilter != NULL) {
    taosHashCleanup(param->pHashFilter);
  }
}

int32_t sclCopyValueNodeValue(SValueNode *pNode, void **res) {
  if (TSDB_DATA_TYPE_NULL == pNode->node.resType.type) {
    return TSDB_CODE_SUCCESS;
  }
  
  *res = taosMemoryMalloc(pNode->node.resType.bytes);
  if (NULL == (*res)) {
    sclError("malloc %d failed", pNode->node.resType.bytes);
    SCL_ERR_RET(TSDB_CODE_QRY_OUT_OF_MEMORY);
  }

  memcpy(*res, nodesGetValueFromNode(pNode), pNode->node.resType.bytes);
  return TSDB_CODE_SUCCESS;
}

int32_t sclInitParam(SNode* node, SScalarParam *param, SScalarCtx *ctx, int32_t *rowNum) {
  switch (nodeType(node)) {
    case QUERY_NODE_VALUE: {
      SValueNode *valueNode = (SValueNode *)node;

      param->numOfRows = 1;
      param->columnData = createColumnInfoData(&valueNode->node.resType, 1);
      if (TSDB_DATA_TYPE_NULL == valueNode->node.resType.type) {
        colDataAppendNULL(param->columnData, 0);
      } else {
        colDataAppend(param->columnData, 0, nodesGetValueFromNode(valueNode), false);
      }
      break;
    }
    case QUERY_NODE_NODE_LIST: {
      SNodeListNode *nodeList = (SNodeListNode *)node;
      if (LIST_LENGTH(nodeList->pNodeList) <= 0) {
        sclError("invalid length in nodeList, length:%d", LIST_LENGTH(nodeList->pNodeList));
        SCL_RET(TSDB_CODE_QRY_INVALID_INPUT);
      }

      SCL_ERR_RET(scalarGenerateSetFromList((void**) &param->pHashFilter, node, nodeList->dataType.type));
      if (taosHashPut(ctx->pRes, &node, POINTER_BYTES, param, sizeof(*param))) {
        taosHashCleanup(param->pHashFilter);
        sclError("taosHashPut nodeList failed, size:%d", (int32_t)sizeof(*param));
        return TSDB_CODE_QRY_OUT_OF_MEMORY;
      }   
      break;
    }
    case QUERY_NODE_COLUMN: {
      if (NULL == ctx->pBlockList) {
        sclError("invalid node type for constant calculating, type:%d, src:%p", nodeType(node), ctx->pBlockList);
        SCL_ERR_RET(TSDB_CODE_QRY_APP_ERROR);
      }
      
      SColumnNode *ref = (SColumnNode *)node;

      int32_t index = -1;
      for(int32_t i = 0; i < taosArrayGetSize(ctx->pBlockList); ++i) {
        SSDataBlock* pb = taosArrayGetP(ctx->pBlockList, i);
        if (pb->info.blockId == ref->dataBlockId) {
          index = i;
          break;
        }
      }

      if (index == -1) {
        sclError("column tupleId is too big, tupleId:%d, dataBlockNum:%d", ref->dataBlockId, (int32_t)taosArrayGetSize(ctx->pBlockList));
        SCL_ERR_RET(TSDB_CODE_QRY_INVALID_INPUT);
      }

      SSDataBlock *block = *(SSDataBlock **)taosArrayGet(ctx->pBlockList, index);
      if (NULL == block || ref->slotId >= block->info.numOfCols) {
        sclError("column slotId is too big, slodId:%d, dataBlockSize:%d", ref->slotId, (int32_t)taosArrayGetSize(block->pDataBlock));
        SCL_ERR_RET(TSDB_CODE_QRY_INVALID_INPUT);
      }

      SColumnInfoData *columnData = (SColumnInfoData *)taosArrayGet(block->pDataBlock, ref->slotId);
      param->numOfRows = block->info.rows;
      param->columnData = columnData;
      break;
    }
    case QUERY_NODE_FUNCTION:
    case QUERY_NODE_OPERATOR:
    case QUERY_NODE_LOGIC_CONDITION: {
      SScalarParam *res = (SScalarParam *)taosHashGet(ctx->pRes, &node, POINTER_BYTES);
      if (NULL == res) {
        sclError("no result for node, type:%d, node:%p", nodeType(node), node);
        SCL_ERR_RET(TSDB_CODE_QRY_APP_ERROR);
      }
      *param = *res;
      break;
    }
    default:
      break;
  }

  if (param->numOfRows > *rowNum) {
    if ((1 != param->numOfRows) && (1 < *rowNum)) {
      sclError("different row nums, rowNum:%d, newRowNum:%d", *rowNum, param->numOfRows);
      SCL_ERR_RET(TSDB_CODE_QRY_INVALID_INPUT);
    }
    
    *rowNum = param->numOfRows;
  }

  return TSDB_CODE_SUCCESS;
}

int32_t sclInitParamList(SScalarParam **pParams, SNodeList* pParamList, SScalarCtx *ctx, int32_t *paramNum, int32_t *rowNum) {  
  int32_t code = 0;
  if (NULL == pParamList) {
    if (ctx->pBlockList) {
      SSDataBlock *pBlock = taosArrayGet(ctx->pBlockList, 0);
      *rowNum = pBlock->info.rows;
    } else {
      *rowNum = 1;
    }

    *paramNum = 1;
  } else {
    *paramNum = pParamList->length;
  }

  SScalarParam *paramList = taosMemoryCalloc(*paramNum, sizeof(SScalarParam));
  if (NULL == paramList) {
    sclError("calloc %d failed", (int32_t)((*paramNum) * sizeof(SScalarParam)));
    SCL_ERR_RET(TSDB_CODE_QRY_OUT_OF_MEMORY);
  }

  if (pParamList) {
    SNode *tnode = NULL;
    int32_t i = 0;
    if (SCL_IS_CONST_CALC(ctx)) {
      WHERE_EACH (tnode, pParamList) { 
        if (!SCL_IS_CONST_NODE(tnode)) {
          WHERE_NEXT;
        } else {
          SCL_ERR_JRET(sclInitParam(tnode, &paramList[i], ctx, rowNum));
          ERASE_NODE(pParamList);
        }
        
        ++i;
      }
    } else {
      FOREACH(tnode, pParamList) { 
        SCL_ERR_JRET(sclInitParam(tnode, &paramList[i], ctx, rowNum));
        ++i;
      }
    }
  } else {
    paramList[0].numOfRows = *rowNum;
  }

  if (0 == *rowNum) {
    taosMemoryFreeClear(paramList);    
  }

  *pParams = paramList;
  return TSDB_CODE_SUCCESS;

_return:
  taosMemoryFreeClear(paramList);
  SCL_RET(code);
}

int32_t sclInitOperatorParams(SScalarParam **pParams, SOperatorNode *node, SScalarCtx *ctx, int32_t *rowNum) {
  int32_t code = 0;
  int32_t paramNum = scalarGetOperatorParamNum(node->opType);
  if (NULL == node->pLeft || (paramNum == 2 && NULL == node->pRight)) {
    sclError("invalid operation node, left:%p, right:%p", node->pLeft, node->pRight);
    SCL_ERR_RET(TSDB_CODE_QRY_INVALID_INPUT);
  }
  
  SScalarParam *paramList = taosMemoryCalloc(paramNum, sizeof(SScalarParam));
  if (NULL == paramList) {
    sclError("calloc %d failed", (int32_t)(paramNum * sizeof(SScalarParam)));
    SCL_ERR_RET(TSDB_CODE_QRY_OUT_OF_MEMORY);
  }

  SCL_ERR_JRET(sclInitParam(node->pLeft, &paramList[0], ctx, rowNum));
  if (paramNum > 1) {
    SCL_ERR_JRET(sclInitParam(node->pRight, &paramList[1], ctx, rowNum));
  }

  *pParams = paramList;
  return TSDB_CODE_SUCCESS;

_return:
  taosMemoryFreeClear(paramList);
  SCL_RET(code);
}

int32_t sclExecFunction(SFunctionNode *node, SScalarCtx *ctx, SScalarParam *output) {
  SScalarFuncExecFuncs ffpSet = {0};
  int32_t code = fmGetScalarFuncExecFuncs(node->funcId, &ffpSet);
  if (code) {
    sclError("fmGetFuncExecFuncs failed, funcId:%d, code:%s", node->funcId, tstrerror(code));
    SCL_ERR_RET(code);
  }

  SScalarParam *params = NULL;
  int32_t rowNum = 0;
  int32_t paramNum = 0;
  SCL_ERR_RET(sclInitParamList(&params, node->pParameterList, ctx, &paramNum, &rowNum));

  output->columnData = createColumnInfoData(&node->node.resType, rowNum);
  if (output->columnData == NULL) {
    sclError("calloc %d failed", (int32_t)(rowNum * output->columnData->info.bytes));
    SCL_ERR_JRET(TSDB_CODE_QRY_OUT_OF_MEMORY);
  }

  code = (*ffpSet.process)(params, paramNum, output);
  if (code) {
    sclError("scalar function exec failed, funcId:%d, code:%s", node->funcId, tstrerror(code));
    SCL_ERR_JRET(code);
  }

_return:

  for (int32_t i = 0; i < paramNum; ++i) {
//    sclFreeParamNoData(params + i);
  }

  taosMemoryFreeClear(params);
  SCL_RET(code);
}

int32_t sclExecLogic(SLogicConditionNode *node, SScalarCtx *ctx, SScalarParam *output) {
  if (NULL == node->pParameterList || node->pParameterList->length <= 0) {
    sclError("invalid logic parameter list, list:%p, paramNum:%d", node->pParameterList, node->pParameterList ? node->pParameterList->length : 0);
    SCL_ERR_RET(TSDB_CODE_QRY_INVALID_INPUT);
  }

  if (TSDB_DATA_TYPE_BOOL != node->node.resType.type) {
    sclError("invalid logic resType, type:%d", node->node.resType.type);
    SCL_ERR_RET(TSDB_CODE_QRY_INVALID_INPUT);
  }

  if (LOGIC_COND_TYPE_NOT == node->condType && node->pParameterList->length > 1) {
    sclError("invalid NOT operation parameter number, paramNum:%d", node->pParameterList->length);
    SCL_ERR_RET(TSDB_CODE_QRY_INVALID_INPUT);
  }

  SScalarParam *params = NULL;
  int32_t rowNum = 0;
  int32_t paramNum = 0;
  int32_t code = 0;
  SCL_ERR_RET(sclInitParamList(&params, node->pParameterList, ctx, &paramNum, &rowNum));
  if (NULL == params) {
    output->numOfRows = 0;
    return TSDB_CODE_SUCCESS;
  }

  int32_t type = node->node.resType.type;
  output->numOfRows = rowNum;

  SDataType t = {.type = type, .bytes = tDataTypes[type].bytes};
  output->columnData = createColumnInfoData(&t, rowNum);
  if (output->columnData == NULL) {
    sclError("calloc %d failed", (int32_t)(rowNum * sizeof(bool)));
    SCL_ERR_JRET(TSDB_CODE_QRY_OUT_OF_MEMORY);
  }

  bool value = false;
  bool complete = true;
  for (int32_t i = 0; i < rowNum; ++i) {
    complete = true;
    for (int32_t m = 0; m < paramNum; ++m) {
      if (NULL == params[m].columnData) {
        complete = false;
        continue;
      }
      char* p = colDataGetData(params[m].columnData, i);
      GET_TYPED_DATA(value, bool, params[m].columnData->info.type, p);

      if (LOGIC_COND_TYPE_AND == node->condType && (false == value)) {
        complete = true;
        break;
      } else if (LOGIC_COND_TYPE_OR == node->condType && value) {
        complete = true;
        break;
      } else if (LOGIC_COND_TYPE_NOT == node->condType) {
        value = !value;
      }
    }

    if (complete) {
      colDataAppend(output->columnData, i, (char*) &value, false);
    }
  }

  if (SCL_IS_CONST_CALC(ctx) && (false == complete)) {
    sclFreeParam(output);
    output->numOfRows = 0;
  }

_return:

  for (int32_t i = 0; i < paramNum; ++i) {
//    sclFreeParamNoData(params + i);
  }

  taosMemoryFreeClear(params);
  SCL_RET(code);
}

int32_t sclExecOperator(SOperatorNode *node, SScalarCtx *ctx, SScalarParam *output) {
  SScalarParam *params = NULL;
  int32_t rowNum = 0;
  int32_t code = 0;

  SCL_ERR_RET(sclInitOperatorParams(&params, node, ctx, &rowNum));
  output->columnData = createColumnInfoData(&node->node.resType, rowNum);
  if (output->columnData == NULL) {
    sclError("calloc failed, size:%d", (int32_t)rowNum * node->node.resType.bytes);
    SCL_ERR_JRET(TSDB_CODE_QRY_OUT_OF_MEMORY);
  }

  _bin_scalar_fn_t OperatorFn = getBinScalarOperatorFn(node->opType);

  int32_t paramNum = scalarGetOperatorParamNum(node->opType);
  SScalarParam* pLeft = &params[0];
  SScalarParam* pRight = paramNum > 1 ? &params[1] : NULL;

  OperatorFn(pLeft, pRight, output, TSDB_ORDER_ASC);

_return:
  for (int32_t i = 0; i < paramNum; ++i) {
//    sclFreeParam(&params[i]);
  }

  taosMemoryFreeClear(params);
  SCL_RET(code);
}

EDealRes sclRewriteFunction(SNode** pNode, SScalarCtx *ctx) {
  SFunctionNode *node = (SFunctionNode *)*pNode;
  SNode* tnode = NULL;
  if (fmIsUserDefinedFunc(node->funcId)) {
    return DEAL_RES_CONTINUE;
  }
  
  FOREACH(tnode, node->pParameterList) {
    if (!SCL_IS_CONST_NODE(tnode)) {
      return DEAL_RES_CONTINUE;
    }
  }

  SScalarParam output = {0};

  ctx->code = sclExecFunction(node, ctx, &output);
  if (ctx->code) {
    return DEAL_RES_ERROR;
  }

  SValueNode *res = (SValueNode *)nodesMakeNode(QUERY_NODE_VALUE);
  if (NULL == res) {
    sclError("make value node failed");
    sclFreeParam(&output);
    ctx->code = TSDB_CODE_QRY_OUT_OF_MEMORY;
    return DEAL_RES_ERROR;
  }

  if (colDataIsNull_s(output.columnData, 0)) {
    res->node.resType.type = TSDB_DATA_TYPE_NULL;
  } else {
    res->node.resType = node->node.resType;
    int32_t type = output.columnData->info.type;
    if (IS_VAR_DATA_TYPE(type)) {
      res->datum.p = output.columnData->pData;
      output.columnData->pData = NULL;
    } else {
      memcpy(nodesGetValueFromNode(res), output.columnData->pData, tDataTypes[type].bytes);
    }
  }

  nodesDestroyNode(*pNode);
  *pNode = (SNode*)res;

  sclFreeParam(&output);
  return DEAL_RES_CONTINUE;
}

EDealRes sclRewriteLogic(SNode** pNode, SScalarCtx *ctx) {
  SLogicConditionNode *node = (SLogicConditionNode *)*pNode;

  SScalarParam output = {0};
  ctx->code = sclExecLogic(node, ctx, &output);
  if (ctx->code) {
    return DEAL_RES_ERROR;
  }

  if (0 == output.numOfRows) {
    return DEAL_RES_CONTINUE;
  }

  SValueNode *res = (SValueNode *)nodesMakeNode(QUERY_NODE_VALUE);
  if (NULL == res) {
    sclError("make value node failed");
    sclFreeParam(&output);
    ctx->code = TSDB_CODE_QRY_OUT_OF_MEMORY;
    return DEAL_RES_ERROR;
  }

  res->node.resType = node->node.resType;

  int32_t type = output.columnData->info.type;
  if (IS_VAR_DATA_TYPE(type)) {
    res->datum.p = output.columnData->pData;
    output.columnData->pData = NULL;
  } else {
    memcpy(nodesGetValueFromNode(res), output.columnData->pData, tDataTypes[type].bytes);
  }

  nodesDestroyNode(*pNode);
  *pNode = (SNode*)res;

  sclFreeParam(&output);
  return DEAL_RES_CONTINUE;
}

EDealRes sclRewriteOperator(SNode** pNode, SScalarCtx *ctx) {
  SOperatorNode *node = (SOperatorNode *)*pNode;

  if (!SCL_IS_CONST_NODE(node->pLeft)) {
    return DEAL_RES_CONTINUE;
  }

  if (!SCL_IS_CONST_NODE(node->pRight)) {
    return DEAL_RES_CONTINUE;
  }

  SScalarParam output = {.columnData = taosMemoryCalloc(1, sizeof(SColumnInfoData))};
  ctx->code = sclExecOperator(node, ctx, &output);
  if (ctx->code) {
    return DEAL_RES_ERROR;
  }

  SValueNode *res = (SValueNode *)nodesMakeNode(QUERY_NODE_VALUE);
  if (NULL == res) {
    sclError("make value node failed");    
    sclFreeParam(&output);    
    ctx->code = TSDB_CODE_QRY_OUT_OF_MEMORY;
    return DEAL_RES_ERROR;
  }

  res->node.resType = node->node.resType;

  int32_t type = output.columnData->info.type;
  if (IS_VAR_DATA_TYPE(type)) {  // todo refactor
    res->datum.p = output.columnData->pData;
    output.columnData->pData = NULL;
  } else {
    memcpy(nodesGetValueFromNode(res), output.columnData->pData, tDataTypes[type].bytes);
  }

  nodesDestroyNode(*pNode);
  *pNode = (SNode*)res;

  sclFreeParam(&output);
  return DEAL_RES_CONTINUE;
}

EDealRes sclConstantsRewriter(SNode** pNode, void* pContext) {
  if (QUERY_NODE_VALUE == nodeType(*pNode) || QUERY_NODE_COLUMN == nodeType(*pNode) || QUERY_NODE_NODE_LIST == nodeType(*pNode)) {
    return DEAL_RES_CONTINUE;
  }

  SScalarCtx *ctx = (SScalarCtx *)pContext;

  if (QUERY_NODE_FUNCTION == nodeType(*pNode)) {
    return sclRewriteFunction(pNode, ctx);
  }

  if (QUERY_NODE_LOGIC_CONDITION == nodeType(*pNode)) {
    return sclRewriteLogic(pNode, ctx);
  }

  if (QUERY_NODE_OPERATOR == nodeType(*pNode)) {
    return sclRewriteOperator(pNode, ctx);
  }  
  
  sclError("invalid node type for calculating constants, type:%d", nodeType(*pNode));
  ctx->code = TSDB_CODE_QRY_INVALID_INPUT;
  return DEAL_RES_ERROR;
}

EDealRes sclWalkFunction(SNode* pNode, SScalarCtx *ctx) {
  SFunctionNode *node = (SFunctionNode *)pNode;
  SScalarParam output = {0};
  
  ctx->code = sclExecFunction(node, ctx, &output);
  if (ctx->code) {
    return DEAL_RES_ERROR;
  }

  if (taosHashPut(ctx->pRes, &pNode, POINTER_BYTES, &output, sizeof(output))) {
    ctx->code = TSDB_CODE_QRY_OUT_OF_MEMORY;
    return DEAL_RES_ERROR;
  }

  return DEAL_RES_CONTINUE;
}

EDealRes sclWalkLogic(SNode* pNode, SScalarCtx *ctx) {
  SLogicConditionNode *node = (SLogicConditionNode *)pNode;
  SScalarParam output = {0};
  
  ctx->code = sclExecLogic(node, ctx, &output);
  if (ctx->code) {
    return DEAL_RES_ERROR;
  }

  if (taosHashPut(ctx->pRes, &pNode, POINTER_BYTES, &output, sizeof(output))) {
    ctx->code = TSDB_CODE_QRY_OUT_OF_MEMORY;
    return DEAL_RES_ERROR;
  }

  return DEAL_RES_CONTINUE;
}

EDealRes sclWalkOperator(SNode* pNode, SScalarCtx *ctx) {
  SOperatorNode *node = (SOperatorNode *)pNode;
  SScalarParam output = {0};
  
  ctx->code = sclExecOperator(node, ctx, &output);
  if (ctx->code) {
    return DEAL_RES_ERROR;
  }

  if (taosHashPut(ctx->pRes, &pNode, POINTER_BYTES, &output, sizeof(output))) {
    ctx->code = TSDB_CODE_QRY_OUT_OF_MEMORY;
    return DEAL_RES_ERROR;
  }

  return DEAL_RES_CONTINUE;
}

EDealRes sclWalkTarget(SNode* pNode, SScalarCtx *ctx) {
  STargetNode *target = (STargetNode *)pNode;

  if (target->dataBlockId >= taosArrayGetSize(ctx->pBlockList)) {
    sclError("target tupleId is too big, tupleId:%d, dataBlockNum:%d", target->dataBlockId, (int32_t)taosArrayGetSize(ctx->pBlockList));
    ctx->code = TSDB_CODE_QRY_INVALID_INPUT;
    return DEAL_RES_ERROR;
  }

  int32_t index = -1;
  for(int32_t i = 0; i < taosArrayGetSize(ctx->pBlockList); ++i) {
    SSDataBlock* pb = taosArrayGetP(ctx->pBlockList, i);
    if (pb->info.blockId == target->dataBlockId) {
      index = i;
      break;
    }
  }

  if (index == -1) {
    sclError("column tupleId is too big, tupleId:%d, dataBlockNum:%d", target->dataBlockId, (int32_t)taosArrayGetSize(ctx->pBlockList));
    ctx->code = TSDB_CODE_QRY_INVALID_INPUT;
    return DEAL_RES_ERROR;
  }

  SSDataBlock *block = *(SSDataBlock **)taosArrayGet(ctx->pBlockList, index);

  if (target->slotId >= taosArrayGetSize(block->pDataBlock)) {
    sclError("target slot not exist, dataBlockId:%d, slotId:%d, dataBlockNum:%d", target->dataBlockId, target->slotId, (int32_t)taosArrayGetSize(block->pDataBlock));
    ctx->code = TSDB_CODE_QRY_INVALID_INPUT;
    return DEAL_RES_ERROR;
  }

  // if block->pDataBlock is not enough, there are problems if target->slotId bigger than the size of block->pDataBlock,
  SColumnInfoData *col = taosArrayGet(block->pDataBlock, target->slotId);

  SScalarParam *res = (SScalarParam *)taosHashGet(ctx->pRes, (void *)&target->pExpr, POINTER_BYTES);
  if (NULL == res) {
    sclError("no valid res in hash, node:%p, type:%d", target->pExpr, nodeType(target->pExpr));
    ctx->code = TSDB_CODE_QRY_APP_ERROR;
    return DEAL_RES_ERROR;
  }

  colDataAssign(col, res->columnData, res->numOfRows);
  block->info.rows = res->numOfRows;

  sclFreeParam(res);
  taosHashRemove(ctx->pRes, (void *)&target->pExpr, POINTER_BYTES);
  return DEAL_RES_CONTINUE;
}

EDealRes sclCalcWalker(SNode* pNode, void* pContext) {
  if (QUERY_NODE_VALUE == nodeType(pNode) || QUERY_NODE_NODE_LIST == nodeType(pNode) || QUERY_NODE_COLUMN == nodeType(pNode)) {
    return DEAL_RES_CONTINUE;
  }

  SScalarCtx *ctx = (SScalarCtx *)pContext;
  if (QUERY_NODE_FUNCTION == nodeType(pNode)) {
    return sclWalkFunction(pNode, ctx);
  }

  if (QUERY_NODE_LOGIC_CONDITION == nodeType(pNode)) {
    return sclWalkLogic(pNode, ctx);
  }

  if (QUERY_NODE_OPERATOR == nodeType(pNode)) {
    return sclWalkOperator(pNode, ctx);
  }

  if (QUERY_NODE_TARGET == nodeType(pNode)) {
    return sclWalkTarget(pNode, ctx);
  }

  sclError("invalid node type for scalar calculating, type:%d", nodeType(pNode));
  ctx->code = TSDB_CODE_QRY_INVALID_INPUT;
  return DEAL_RES_ERROR;
}

int32_t scalarCalculateConstants(SNode *pNode, SNode **pRes) {
  if (NULL == pNode) {
    SCL_ERR_RET(TSDB_CODE_QRY_INVALID_INPUT);
  }

  int32_t code = 0;
  SScalarCtx ctx = {0};
  ctx.pRes = taosHashInit(SCL_DEFAULT_OP_NUM, taosGetDefaultHashFunction(TSDB_DATA_TYPE_BIGINT), false, HASH_NO_LOCK);
  if (NULL == ctx.pRes) {
    sclError("taosHashInit failed, num:%d", SCL_DEFAULT_OP_NUM);
    SCL_ERR_RET(TSDB_CODE_QRY_OUT_OF_MEMORY);
  }
  
  nodesRewriteExprPostOrder(&pNode, sclConstantsRewriter, (void *)&ctx);
  SCL_ERR_JRET(ctx.code);
  *pRes = pNode;

_return:
  sclFreeRes(ctx.pRes);
  return code;
}

int32_t scalarCalculate(SNode *pNode, SArray *pBlockList, SScalarParam *pDst) {
  if (NULL == pNode || NULL == pBlockList) {
    SCL_ERR_RET(TSDB_CODE_QRY_INVALID_INPUT);
  }

  int32_t code = 0;
  SScalarCtx ctx = {.code = 0, .pBlockList = pBlockList};

  // TODO: OPT performance
  ctx.pRes = taosHashInit(SCL_DEFAULT_OP_NUM, taosGetDefaultHashFunction(TSDB_DATA_TYPE_BIGINT), false, HASH_NO_LOCK);
  if (NULL == ctx.pRes) {
    sclError("taosHashInit failed, num:%d", SCL_DEFAULT_OP_NUM);
    SCL_ERR_RET(TSDB_CODE_QRY_OUT_OF_MEMORY);
  }
  
  nodesWalkExprPostOrder(pNode, sclCalcWalker, (void *)&ctx);
  SCL_ERR_JRET(ctx.code);

  if (pDst) {
    SScalarParam *res = (SScalarParam *)taosHashGet(ctx.pRes, (void *)&pNode, POINTER_BYTES);
    if (NULL == res) {
      sclError("no valid res in hash, node:%p, type:%d", pNode, nodeType(pNode));
      SCL_ERR_JRET(TSDB_CODE_QRY_APP_ERROR);
    }
    
    colDataAssign(pDst->columnData, res->columnData, res->numOfRows);
    pDst->numOfRows = res->numOfRows;
    taosHashRemove(ctx.pRes, (void *)&pNode, POINTER_BYTES);
  }

_return:
  //nodesDestroyNode(pNode);
  sclFreeRes(ctx.pRes);
  return code;
}