feat: support case when clause

include/libs/function/function.h

@@ -176,7 +176,7 @@ struct SScalarParam {
   SColumnInfoData *columnData;
   SHashObj        *pHashFilter;
   int32_t          hashValueType;
-  void            *param; // other parameter, such as meta handle from vnode, to extract table name/tag value
+  void            *param;          // other parameter, such as meta handle from vnode, to extract table name/tag value
   int32_t          numOfRows;
   int32_t          numOfQualified; // number of qualified elements in the final results
 };

source/libs/scalar/src/scalar.c

@@ -177,7 +177,7 @@ void sclFreeRes(SHashObj *res) {
 }
 
 void sclFreeParam(SScalarParam *param) {
-  if (!param->colAlloced) {
+  if (NULL == param || !param->colAlloced) {
     return;
   }
   
@@ -378,7 +378,8 @@ int32_t sclInitParam(SNode* node, SScalarParam *param, SScalarCtx *ctx, int32_t
     }
     case QUERY_NODE_FUNCTION:
     case QUERY_NODE_OPERATOR:
-    case QUERY_NODE_LOGIC_CONDITION: {
+    case QUERY_NODE_LOGIC_CONDITION:
+    case QUERY_NODE_CASE_WHEN: {
       SScalarParam *res = (SScalarParam *)taosHashGet(ctx->pRes, &node, POINTER_BYTES);
       if (NULL == res) {
         sclError("no result for node, type:%d, node:%p", nodeType(node), node);
@@ -532,10 +533,100 @@ _return:
   SCL_RET(code);
 }
 
-int32_t sclGetNodeRes(SNode* node, SArray* pBlockList, SScalarParam **res) {
+int32_t sclGetNodeRes(SNode* node, SScalarCtx *ctx, SScalarParam **res) {
+  if (NULL == node) {
+    return TSDB_CODE_SUCCESS;
+  }
+
+  int32_t rowNum = 0;
+  *res = taosMemoryCalloc(1, sizeof(**res));
+  if (NULL == *res) {
+    SCL_ERR_RET(TSDB_CODE_OUT_OF_MEMORY);
+  }
+  
+  SCL_ERR_RET(sclInitParam(node, *res, ctx, &rowNum));
+
+  return TSDB_CODE_SUCCESS;
+}
+
+int32_t sclWalkCaseWhenList(SScalarCtx *ctx, SNodeList* pList, struct SListCell* pCell, SScalarParam *pCase, SScalarParam *pElse, SScalarParam *pComp, SScalarParam *output, int32_t rowIdx) {
+  SNode *node = NULL;
+  SWhenThenNode* pWhenThen = NULL;
+  SScalarParam *pWhen = NULL;
+  SScalarParam *pThen = NULL;
+
+  for (SListCell* cell = pCell; (NULL != cell ? (node = cell->pNode, true) : (node = NULL, false)); cell = cell->pNext) {
+    pWhenThen = (SWhenThenNode*)node;
+    
+    SCL_ERR_RET(sclGetNodeRes(pWhenThen->pWhen, ctx, &pWhen));
+    SCL_ERR_RET(sclGetNodeRes(pWhenThen->pThen, ctx, &pThen));
+    
+    doVectorCompare(pCase, pWhen, pComp, rowIdx, 1, TSDB_ORDER_ASC, OP_TYPE_EQUAL);
+    
+    bool *equal = colDataGetData(pComp->columnData, rowIdx);
+    if (*equal) {
+      colDataAppend(output->columnData, rowIdx, colDataGetData(pThen, (pThen->numOfRows > 1 ? rowIdx : 0)), colDataIsNull_s(pThen, (pThen->numOfRows > 1 ? rowIdx : 0)));
+      
+      return TSDB_CODE_SUCCESS;
+    }
+  }
+
+  if (pElse) {
+    colDataAppend(output->columnData, rowIdx, colDataGetData(pElse, (pElse->numOfRows > 1 ? rowIdx : 0)), colDataIsNull_s(pElse, (pElse->numOfRows > 1 ? rowIdx : 0)));
+    
+    return TSDB_CODE_SUCCESS;
+  }
+
+  colDataAppend(output->columnData, rowIdx, NULL, true);
+
+  return TSDB_CODE_SUCCESS;
+}
+
+int32_t sclWalkWhenList(SScalarCtx *ctx, SNodeList* pList, struct SListCell* pCell, SScalarParam *pElse, SScalarParam *output, int32_t rowIdx) {
+  SNode *node = NULL;
+  SWhenThenNode* pWhenThen = NULL;
+  SScalarParam *pWhen = NULL;
+  SScalarParam *pThen = NULL;
+  int32_t code = 0;
+
+  for (SListCell* cell = pCell; (NULL != cell ? (node = cell->pNode, true) : (node = NULL, false)); cell = cell->pNext) {
+    pWhenThen = (SWhenThenNode*)node;
+    pWhen = NULL;
+    pThen = NULL;
+    
+    SCL_ERR_JRET(sclGetNodeRes(pWhenThen->pWhen, ctx, &pWhen));
+    SCL_ERR_JRET(sclGetNodeRes(pWhenThen->pThen, ctx, &pThen));
+
+    bool *whenValue = colDataGetData(pWhen->columnData, (pWhen->numOfRows > 1 ? rowIdx : 0));
+    
+    if (*whenValue) {
+      colDataAppend(output->columnData, rowIdx, colDataGetData(pThen, (pThen->numOfRows > 1 ? rowIdx : 0)), colDataIsNull_s(pThen, (pThen->numOfRows > 1 ? rowIdx : 0)));
+
+      goto _return;
+    }
+
+    sclFreeParam(pWhen);
+    sclFreeParam(pThen);
+  }
+
+  if (pElse) {
+    colDataAppend(output->columnData, rowIdx, colDataGetData(pElse, (pElse->numOfRows > 1 ? rowIdx : 0)), colDataIsNull_s(pElse, (pElse->numOfRows > 1 ? rowIdx : 0)));
+    
+    goto _return;
+  }
+
+  colDataAppend(output->columnData, rowIdx, NULL, true);
 
+_return:
+
+  sclFreeParam(pWhen);
+  sclFreeParam(pThen);
+
+  SCL_RET(code);
 }
 
+
+
 int32_t sclExecFunction(SFunctionNode *node, SScalarCtx *ctx, SScalarParam *output) {
   SScalarParam *params = NULL;
   int32_t rowNum = 0;
@@ -693,42 +784,80 @@ _return:
 }
 
 int32_t sclExecCaseWhen(SCaseWhenNode *node, SScalarCtx *ctx, SScalarParam *output) {
-  int32_t rowNum = 0;
   int32_t code = 0;
   SScalarParam *pCase = NULL;
   SScalarParam *pElse = NULL;
-  
-  if (node->pCase) {
-    SCL_ERR_RET(sclGetNodeRes(node->pCase, ctx->pBlockList, &pCase));
+  SScalarParam *pWhen = NULL;
+  SScalarParam *pThen = NULL;
+  SScalarParam *pComp = NULL;
+  int32_t rowNum = 1;
+
+  if (NULL == node->pWhenThenList || node->pWhenThenList->length <= 0) {
+    sclError("invalid whenThen list");
+    SCL_ERR_RET(TSDB_CODE_INVALID_PARA);
   }
+
+  if (ctx->pBlockList) {
+    SSDataBlock* pb = taosArrayGetP(ctx->pBlockList, 0);
+    rowNum = pb->info.rows;
+  }
+
+  SCL_ERR_JRET(sclCreateColumnInfoData(&node->node.resType, rowNum, output));
+  
+  SCL_ERR_JRET(sclGetNodeRes(node->pCase, ctx, &pCase));
+  SCL_ERR_JRET(sclGetNodeRes(node->pElse, ctx, &pElse));
+
+  SDataType compType = {0};
+  compType.type = TSDB_DATA_TYPE_BOOL;
+  compType.bytes = tDataTypes[compType.type].bytes;
   
+  SCL_ERR_JRET(sclCreateColumnInfoData(&compType, rowNum, pComp));
+
   SNode* tnode = NULL;
-  FOREACH(tnode, node->pWhenThenList) {
-    if (QUERY_NODE_VALUE == tnode->type) {
-      return DEAL_RES_CONTINUE;
+  SWhenThenNode* pWhenThen = (SWhenThenNode*)node->pWhenThenList->pHead->pNode;
+
+  SCL_ERR_JRET(sclGetNodeRes(pWhenThen->pWhen, ctx, &pWhen));
+  SCL_ERR_JRET(sclGetNodeRes(pWhenThen->pThen, ctx, &pThen));
+
+  if (pCase) {
+    vectorCompare(pCase, pWhen, pComp, TSDB_ORDER_ASC, OP_TYPE_EQUAL);
+    
+    for (int32_t i = 0; i < rowNum; ++i) {
+      bool *equal = colDataGetData(pComp->columnData, i);
+      if (*equal) {
+        colDataAppend(output->columnData, i, colDataGetData(pThen, (pThen->numOfRows > 1 ? i : 0)), colDataIsNull_s(pThen, (pThen->numOfRows > 1 ? i : 0)));
+      } else {
+        SCL_ERR_JRET(sclWalkCaseWhenList(ctx, node->pWhenThenList, node->pWhenThenList->pHead->pNext, pCase, pElse, pComp, output, i));
+      }
     }
-  }  
-
-  if (output->columnData == NULL) {
-    code = sclCreateColumnInfoData(&node->node.resType, rowNum, output);
-    if (code != TSDB_CODE_SUCCESS) {
-      SCL_ERR_JRET(code);
+  } else {
+    for (int32_t i = 0; i < rowNum; ++i) {
+      bool *equal = colDataGetData(pWhen->columnData, i);
+      if (*equal) {
+        colDataAppend(output->columnData, i, colDataGetData(pThen, (pThen->numOfRows > 1 ? i : 0)), colDataIsNull_s(pThen, (pThen->numOfRows > 1 ? i : 0)));
+      } else {
+        SCL_ERR_JRET(sclWalkWhenList(ctx, node->pWhenThenList, node->pWhenThenList->pHead->pNext, pElse, output, i));
+      }
     }
   }
 
-  _bin_scalar_fn_t OperatorFn = getBinScalarOperatorFn(node->opType);
+  sclFreeParam(pCase);
+  sclFreeParam(pElse);
+  sclFreeParam(pComp);
+  sclFreeParam(pWhen);
+  sclFreeParam(pThen);
 
-  int32_t paramNum = scalarGetOperatorParamNum(node->opType);
-  SScalarParam* pLeft = &params[0];
-  SScalarParam* pRight = paramNum > 1 ? &params[1] : NULL;
-
-  terrno = TSDB_CODE_SUCCESS;
-  OperatorFn(pLeft, pRight, output, TSDB_ORDER_ASC);
-  code = terrno;
+  return TSDB_CODE_SUCCESS;
 
 _return:
 
-  sclFreeParamList(params, paramNum);
+  sclFreeParam(pCase);
+  sclFreeParam(pElse);
+  sclFreeParam(pComp);
+  sclFreeParam(pWhen);
+  sclFreeParam(pThen);
+  sclFreeParam(output);
+
   SCL_RET(code);
 }
 

source/libs/scalar/src/sclvector.c

@@ -1646,8 +1646,8 @@ void vectorBitOr(SScalarParam* pLeft, SScalarParam* pRight, SScalarParam *pOut,
   doReleaseVec(pRightCol, rightConvert);
 }
 
-int32_t doVectorCompareImpl(int32_t numOfRows, SScalarParam *pOut, int32_t startIndex, int32_t step, __compar_fn_t fp,
-                         SScalarParam *pLeft, SScalarParam *pRight, int32_t optr) {
+int32_t doVectorCompareImpl(SScalarParam *pLeft, SScalarParam *pRight, SScalarParam *pOut, int32_t startIndex, int32_t numOfRows, 
+                             int32_t step, __compar_fn_t fp, int32_t optr) {
   int32_t num = 0;
 
   for (int32_t i = startIndex; i < numOfRows && i >= 0; i += step) {
@@ -1700,12 +1700,14 @@ int32_t doVectorCompareImpl(int32_t numOfRows, SScalarParam *pOut, int32_t start
   return num;
 }
 
-void vectorCompareImpl(SScalarParam* pLeft, SScalarParam* pRight, SScalarParam *pOut, int32_t _ord, int32_t optr) {
-  int32_t       i = ((_ord) == TSDB_ORDER_ASC) ? 0 : TMAX(pLeft->numOfRows, pRight->numOfRows) - 1;
+void doVectorCompare(SScalarParam* pLeft, SScalarParam* pRight, SScalarParam *pOut, int32_t startIndex, int32_t numOfRows, 
+                          int32_t _ord, int32_t optr) {
+  int32_t       i = 0;
   int32_t       step = ((_ord) == TSDB_ORDER_ASC) ? 1 : -1;
   int32_t       lType = GET_PARAM_TYPE(pLeft);
   int32_t       rType = GET_PARAM_TYPE(pRight);
   __compar_fn_t fp = NULL;
+  int32_t       compRows = 0;
   
   if (lType == rType) {
     fp = filterGetCompFunc(lType, optr);
@@ -1715,6 +1717,14 @@ void vectorCompareImpl(SScalarParam* pLeft, SScalarParam* pRight, SScalarParam *
 
   pOut->numOfRows = TMAX(pLeft->numOfRows, pRight->numOfRows);
 
+  if (startIndex < 0) {
+    i = ((_ord) == TSDB_ORDER_ASC) ? 0 : TMAX(pLeft->numOfRows, pRight->numOfRows) - 1;
+    compRows = pOut->numOfRows;
+  } else {
+    compRows = startIndex + numOfRows;
+    i = startIndex;
+  }
+
   if (pRight->pHashFilter != NULL) {
     for (; i >= 0 && i < pLeft->numOfRows; i += step) {
       if (IS_HELPER_NULL(pLeft->columnData, i)) {
@@ -1731,7 +1741,7 @@ void vectorCompareImpl(SScalarParam* pLeft, SScalarParam* pRight, SScalarParam *
       }
     }
   } else {  // normal compare
-    pOut->numOfQualified = doVectorCompareImpl(pOut->numOfRows, pOut, i, step, fp, pLeft, pRight, optr);
+    pOut->numOfQualified = doVectorCompareImpl(pLeft, pRight, pOut, i, compRows, step, fp, optr);
   }
 }
 
@@ -1760,7 +1770,8 @@ void vectorCompare(SScalarParam* pLeft, SScalarParam* pRight, SScalarParam *pOut
     }
   }
 
-  vectorCompareImpl(param1, param2, pOut, _ord, optr);
+  doVectorCompare(param1, param2, pOut, -1, -1, _ord, optr);
+  
   sclFreeParam(&pLeftOut);
   sclFreeParam(&pRightOut);  
 }