enh(query): enable twa function in select clause.

include/common/tmsg.h

@@ -571,13 +571,6 @@ int32_t tSerializeSGetUserAuthRsp(void* buf, int32_t bufLen, SGetUserAuthRsp* pR
 int32_t tDeserializeSGetUserAuthRsp(void* buf, int32_t bufLen, SGetUserAuthRsp* pRsp);
 void    tFreeSGetUserAuthRsp(SGetUserAuthRsp* pRsp);
 
-typedef struct {
-  int16_t colId;     // column id
-  int16_t colIndex;  // column index in colList if it is a normal column or index in tagColList if a tag
-  int16_t flag;      // denote if it is a tag or a normal column
-  char    name[TSDB_DB_FNAME_LEN];
-} SColIndex;
-
 typedef struct {
   int16_t lowerRelOptr;
   int16_t upperRelOptr;

include/libs/executor/executor.h

@@ -156,18 +156,6 @@ int64_t qGetQueriedTableUid(qTaskInfo_t tinfo);
  */
 int32_t qGetQualifiedTableIdList(void* pTableList, const char* tagCond, int32_t tagCondLen, SArray* pTableIdList);
 
-/**
- * Create the table group according to the group by tags info
- * @param pTableIdList
- * @param skey
- * @param groupInfo
- * @param groupByIndex
- * @param numOfIndex
- * @return
- */
-// int32_t qCreateTableGroupByGroupExpr(SArray* pTableIdList, TSKEY skey, STableGroupInfo groupInfo, SColIndex*
-// groupByIndex, int32_t numOfIndex);
-
 /**
  * Update the table id list of a given query.
  * @param uid   child table uid

include/libs/function/function.h

@@ -67,50 +67,6 @@ typedef struct SFileBlockInfo {
 #define TOP_BOTTOM_QUERY_LIMIT    100
 #define FUNCTIONS_NAME_MAX_LENGTH 16
 
-#define FUNCTION_INVALID_ID  -1
-#define FUNCTION_COUNT        0
-#define FUNCTION_SUM          1
-#define FUNCTION_AVG          2
-#define FUNCTION_MIN          3
-#define FUNCTION_MAX          4
-#define FUNCTION_STDDEV       5
-#define FUNCTION_PERCT        6
-#define FUNCTION_APERCT       7
-#define FUNCTION_FIRST        8
-#define FUNCTION_LAST         9
-#define FUNCTION_LAST_ROW     10
-#define FUNCTION_TOP          11
-#define FUNCTION_BOTTOM       12
-#define FUNCTION_SPREAD       13
-#define FUNCTION_TWA          14
-#define FUNCTION_LEASTSQR     15
-
-#define FUNCTION_TS           16
-#define FUNCTION_TS_DUMMY     17
-#define FUNCTION_TAG_DUMMY    18
-#define FUNCTION_TS_COMP      19
-
-#define FUNCTION_TAG          20
-#define FUNCTION_PRJ          21
-
-#define FUNCTION_TAGPRJ       22
-#define FUNCTION_ARITHM       23
-#define FUNCTION_DIFF         24
-
-#define FUNCTION_FIRST_DST    25
-#define FUNCTION_LAST_DST     26
-#define FUNCTION_STDDEV_DST   27
-#define FUNCTION_INTERP       28
-
-#define FUNCTION_RATE         29
-#define FUNCTION_IRATE        30
-#define FUNCTION_TID_TAG      31
-#define FUNCTION_DERIVATIVE   32
-#define FUNCTION_BLKINFO      33
-
-
-#define FUNCTION_COV          38
-
 typedef struct SResultRowEntryInfo {
   bool     initialized:1;     // output buffer has been initialized
   bool     complete:1;        // query has completed
@@ -180,10 +136,9 @@ typedef struct SqlFunctionCtx {
   char                  *pOutput;       // final result output buffer, point to sdata->data
   int32_t                numOfParams;
   SFunctParam           *param;         // input parameter, e.g., top(k, 20), the number of results for top query is kept in param
-  int64_t               *ptsList;       // corresponding timestamp array list
+  int64_t               *ptsList;       // corresponding timestamp array list, todo remove it
   SColumnInfoData       *pTsOutput;     // corresponding output buffer for timestamp of each result, e.g., top/bottom*/
   int32_t                offset;
-  SVariant               tag;
   struct  SResultRowEntryInfo *resultInfo;
   SSubsidiaryResInfo     subsidiaries;
   SPoint1                start;

include/util/tlist.h

@@ -229,7 +229,7 @@ int32_t    tdListAppend(SList *list, void *data);
 SListNode *tdListPopHead(SList *list);
 SListNode *tdListPopTail(SList *list);
 SListNode *tdListGetHead(SList *list);
-SListNode *tsListGetTail(SList *list);
+SListNode *tdListGetTail(SList *list);
 SListNode *tdListPopNode(SList *list, SListNode *node);
 void       tdListMove(SList *src, SList *dst);
 void       tdListDiscard(SList *list);

source/libs/executor/inc/executil.h

@@ -75,6 +75,7 @@ typedef struct SResultRowInfo {
   int32_t      size;       // number of result set
   int32_t      capacity;   // max capacity
   SResultRowPosition cur;
+  SList*       openWindow;
 } SResultRowInfo;
 
 struct SqlFunctionCtx;

source/libs/executor/inc/executorimpl.h

@@ -451,15 +451,15 @@ typedef struct SIntervalAggOperatorInfo {
   int32_t            primaryTsIndex;     // primary time stamp slot id from result of downstream operator.
   STimeWindow        win;                // query time range
   bool               timeWindowInterpo;  // interpolation needed or not
-  char**             pRow;               // previous row/tuple of already processed datablock
+  SArray*            pInterpCols;        // interpolation columns
   SAggSupporter      aggSup;             // aggregate supporter
   STableQueryInfo*   pCurrent;           // current tableQueryInfo struct
   int32_t            order;              // current SSDataBlock scan order
   EOPTR_EXEC_MODEL   execModel;          // operator execution model [batch model|stream model]
   SArray*            pUpdatedWindow;     // updated time window due to the input data block from the downstream operator.
   STimeWindowAggSupp twAggSup;
-  struct SFillInfo*  pFillInfo;          // fill info
   bool               invertible;
+  SArray*            pPrevValues;        //  SArray<SGroupKeys> used to keep the previous not null value for interpolation.
 } SIntervalAggOperatorInfo;
 
 typedef struct SStreamFinalIntervalOperatorInfo {
@@ -802,7 +802,7 @@ int32_t binarySearchForKey(char* pValue, int num, TSKEY key, int order);
 int32_t initCacheSupporter(SCatchSupporter* pCatchSup, size_t rowSize, const char* pKey,
     const char* pDir);
 int32_t initStreamAggSupporter(SStreamAggSupporter* pSup, const char* pKey);
-SResultRow* getNewResultRow_rv(SDiskbasedBuf* pResultBuf, int64_t tableGroupId, int32_t interBufSize);
+SResultRow* getNewResultRow(SDiskbasedBuf* pResultBuf, int64_t tableGroupId, int32_t interBufSize);
 SResultWindowInfo* getSessionTimeWindow(SArray* pWinInfos, TSKEY ts, int64_t gap,
     int32_t* pIndex);
 int32_t updateSessionWindowInfo(SResultWindowInfo* pWinInfo, TSKEY* pTs, int32_t rows,

source/libs/executor/src/executil.c

@@ -258,32 +258,6 @@ int32_t getNumOfTotalRes(SGroupResInfo* pGroupResInfo) {
   return (int32_t) taosArrayGetSize(pGroupResInfo->pRows);
 }
 
-static int64_t getNumOfResultWindowRes(STaskRuntimeEnv* pRuntimeEnv, SResultRowPosition *pos, int32_t* rowCellInfoOffset) {
-  STaskAttr* pQueryAttr = pRuntimeEnv->pQueryAttr;
-  ASSERT(0);
-
-  for (int32_t j = 0; j < pQueryAttr->numOfOutput; ++j) {
-    int32_t functionId = 0;//pQueryAttr->pExpr1[j].base.functionId;
-
-    /*
-     * ts, tag, tagprj function can not decide the output number of current query
-     * the number of output result is decided by main output
-     */
-    if (functionId == FUNCTION_TS || functionId == FUNCTION_TAG || functionId == FUNCTION_TAGPRJ) {
-      continue;
-    }
-
-//    SResultRowEntryInfo *pResultInfo = getResultCell(pResultRow, j, rowCellInfoOffset);
-//    assert(pResultInfo != NULL);
-//
-//    if (pResultInfo->numOfRes > 0) {
-//      return pResultInfo->numOfRes;
-//    }
-  }
-
-  return 0;
-}
-
 static int32_t tableResultComparFn(const void *pLeft, const void *pRight, void *param) {
   int32_t left  = *(int32_t *)pLeft;
   int32_t right = *(int32_t *)pRight;
@@ -381,7 +355,7 @@ static int32_t mergeIntoGroupResultImplRv(STaskRuntimeEnv *pRuntimeEnv, SGroupRe
     }
 
 
-    int64_t num = getNumOfResultWindowRes(pRuntimeEnv, &pResultRowCell->pos, rowCellInfoOffset);
+    int64_t num = 0;//getNumOfResultWindowRes(pRuntimeEnv, &pResultRowCell->pos, rowCellInfoOffset);
     if (num <= 0) {
       continue;
     }

source/libs/executor/src/executorimpl.c

@@ -239,36 +239,6 @@ static bool hasNull(SColumn* pColumn, SColumnDataAgg* pStatis) {
   return true;
 }
 
-static void prepareResultListBuffer(SResultRowInfo* pResultRowInfo, jmp_buf env) {
-  int64_t newCapacity = 0;
-
-  // more than the capacity, reallocate the resources
-  if (pResultRowInfo->size < pResultRowInfo->capacity) {
-    return;
-  }
-
-  if (pResultRowInfo->capacity > 10000) {
-    newCapacity = (int64_t)(pResultRowInfo->capacity * 1.25);
-  } else {
-    newCapacity = (int64_t)(pResultRowInfo->capacity * 1.5);
-  }
-
-  if (newCapacity <= pResultRowInfo->capacity) {
-    newCapacity += 4;
-  }
-
-  char* p = taosMemoryRealloc(pResultRowInfo->pPosition, newCapacity * sizeof(SResultRowPosition));
-  if (p == NULL) {
-    longjmp(env, TSDB_CODE_OUT_OF_MEMORY);
-  }
-
-  pResultRowInfo->pPosition = (SResultRowPosition*)p;
-
-  int32_t inc = (int32_t)newCapacity - pResultRowInfo->capacity;
-  memset(&pResultRowInfo->pPosition[pResultRowInfo->capacity], 0, sizeof(SResultRowPosition) * inc);
-  pResultRowInfo->capacity = (int32_t)newCapacity;
-}
-
 static bool chkResultRowFromKey(STaskRuntimeEnv* pRuntimeEnv, SResultRowInfo* pResultRowInfo, char* pData,
                                 int16_t bytes, bool masterscan, uint64_t uid) {
   bool existed = false;
@@ -306,7 +276,7 @@ static bool chkResultRowFromKey(STaskRuntimeEnv* pRuntimeEnv, SResultRowInfo* pR
   return p1 != NULL;
 }
 
-SResultRow* getNewResultRow_rv(SDiskbasedBuf* pResultBuf, int64_t tableGroupId, int32_t interBufSize) {
+SResultRow* getNewResultRow(SDiskbasedBuf* pResultBuf, int64_t tableGroupId, int32_t interBufSize) {
   SFilePage* pData = NULL;
 
   // in the first scan, new space needed for results
@@ -392,25 +362,22 @@ SResultRow* doSetResultOutBufByKey(SDiskbasedBuf* pResultBuf, SResultRowInfo* pR
   }
 
   // allocate a new buffer page
-  prepareResultListBuffer(pResultRowInfo, pTaskInfo->env);
   if (pResult == NULL) {
     ASSERT(pSup->resultRowSize > 0);
-    pResult = getNewResultRow_rv(pResultBuf, groupId, pSup->resultRowSize);
+    pResult = getNewResultRow(pResultBuf, groupId, pSup->resultRowSize);
+
     initResultRow(pResult);
 
     // add a new result set for a new group
     SResultRowPosition pos = {.pageId = pResult->pageId, .offset = pResult->offset};
-    taosHashPut(pSup->pResultRowHashTable, pSup->keyBuf, GET_RES_WINDOW_KEY_LEN(bytes), &pos,
-                sizeof(SResultRowPosition));
+    taosHashPut(pSup->pResultRowHashTable, pSup->keyBuf, GET_RES_WINDOW_KEY_LEN(bytes), &pos, sizeof(SResultRowPosition));
   }
 
   // 2. set the new time window to be the new active time window
-  pResultRowInfo->pPosition[pResultRowInfo->size++] =
-      (SResultRowPosition){.pageId = pResult->pageId, .offset = pResult->offset};
   pResultRowInfo->cur = (SResultRowPosition){.pageId = pResult->pageId, .offset = pResult->offset};
 
   // too many time window in query
-  if (pResultRowInfo->size > MAX_INTERVAL_TIME_WINDOW) {
+  if (taosHashGetSize(pSup->pResultRowHashTable) > MAX_INTERVAL_TIME_WINDOW) {
     longjmp(pTaskInfo->env, TSDB_CODE_QRY_TOO_MANY_TIMEWINDOW);
   }
 
@@ -1218,7 +1185,6 @@ static void* destroySqlFunctionCtx(SqlFunctionCtx* pCtx, int32_t numOfOutput) {
       taosVariantDestroy(&pCtx[i].param[j].param);
     }
 
-    taosVariantDestroy(&pCtx[i].tag);
     taosMemoryFreeClear(pCtx[i].subsidiaries.pCtx);
     taosMemoryFree(pCtx[i].input.pData);
     taosMemoryFree(pCtx[i].input.pColumnDataAgg);
@@ -1248,9 +1214,9 @@ void setTaskKilled(SExecTaskInfo* pTaskInfo) { pTaskInfo->code = TSDB_CODE_TSC_Q
 static bool isCachedLastQuery(STaskAttr* pQueryAttr) {
   for (int32_t i = 0; i < pQueryAttr->numOfOutput; ++i) {
     int32_t functionId = getExprFunctionId(&pQueryAttr->pExpr1[i]);
-    if (functionId == FUNCTION_LAST || functionId == FUNCTION_LAST_DST) {
-      continue;
-    }
+//    if (functionId == FUNCTION_LAST || functionId == FUNCTION_LAST_DST) {
+//      continue;
+//    }
 
     return false;
   }
@@ -1300,7 +1266,7 @@ static int32_t updateBlockLoadStatus(STaskAttr* pQuery, int32_t status) {
 
   for (int32_t i = 0; i < pQuery->numOfOutput; ++i) {
     int32_t functionId = getExprFunctionId(&pQuery->pExpr1[i]);
-
+#if 0
     if (functionId == FUNCTION_TS || functionId == FUNCTION_TS_DUMMY || functionId == FUNCTION_TAG ||
         functionId == FUNCTION_TAG_DUMMY) {
       continue;
@@ -1311,6 +1277,8 @@ static int32_t updateBlockLoadStatus(STaskAttr* pQuery, int32_t status) {
     } else {
       hasOtherFunc = true;
     }
+#endif
+
   }
 
   if (hasFirstLastFunc && status == BLK_DATA_NOT_LOAD) {
@@ -1786,41 +1754,13 @@ void updateOutputBuf(SOptrBasicInfo* pBInfo, int32_t* bufCapacity, int32_t numOf
 
     // set the correct pointer after the memory buffer reallocated.
     int32_t functionId = pBInfo->pCtx[i].functionId;
-
+#if 0
     if (functionId == FUNCTION_TOP || functionId == FUNCTION_BOTTOM || functionId == FUNCTION_DIFF ||
         functionId == FUNCTION_DERIVATIVE) {
       //      if (i > 0) pBInfo->pCtx[i].pTsOutput = pBInfo->pCtx[i - 1].pOutput;
     }
-  }
-}
-
-void copyTsColoum(SSDataBlock* pRes, SqlFunctionCtx* pCtx, int32_t numOfOutput) {
-  bool    needCopyTs = false;
-  int32_t tsNum = 0;
-  char*   src = NULL;
-  for (int32_t i = 0; i < numOfOutput; i++) {
-    int32_t functionId = pCtx[i].functionId;
-    if (functionId == FUNCTION_DIFF || functionId == FUNCTION_DERIVATIVE) {
-      needCopyTs = true;
-      if (i > 0 && pCtx[i - 1].functionId == FUNCTION_TS_DUMMY) {
-        SColumnInfoData* pColRes = taosArrayGet(pRes->pDataBlock, i - 1);  // find ts data
-        src = pColRes->pData;
-      }
-    } else if (functionId == FUNCTION_TS_DUMMY) {
-      tsNum++;
-    }
-  }
-
-  if (!needCopyTs) return;
-  if (tsNum < 2) return;
-  if (src == NULL) return;
+#endif
 
-  for (int32_t i = 0; i < numOfOutput; i++) {
-    int32_t functionId = pCtx[i].functionId;
-    if (functionId == FUNCTION_TS_DUMMY) {
-      SColumnInfoData* pColRes = taosArrayGet(pRes->pDataBlock, i);
-      memcpy(pColRes->pData, src, pColRes->info.bytes * pRes->info.rows);
-    }
   }
 }
 
@@ -3569,7 +3509,7 @@ bool aggDecodeResultRow(SOperatorInfo* pOperator, SAggSupporter* pSup, SOptrBasi
     offset += sizeof(int32_t);
 
     uint64_t    tableGroupId = *(uint64_t*)(result + offset);
-    SResultRow* resultRow = getNewResultRow_rv(pSup->pResultBuf, tableGroupId, pSup->resultRowSize);
+    SResultRow* resultRow = getNewResultRow(pSup->pResultBuf, tableGroupId, pSup->resultRowSize);
     if (!resultRow) {
       longjmp(pOperator->pTaskInfo->env, TSDB_CODE_TSC_INVALID_INPUT);
     }
@@ -3592,10 +3532,6 @@ bool aggDecodeResultRow(SOperatorInfo* pOperator, SAggSupporter* pSup, SOptrBasi
     offset += valueLen;
 
     initResultRow(resultRow);
-    prepareResultListBuffer(&pInfo->resultRowInfo, pOperator->pTaskInfo->env);
-    //    pInfo->resultRowInfo.cur = pInfo->resultRowInfo.size;
-    //    pInfo->resultRowInfo.pPosition[pInfo->resultRowInfo.size++] =
-    //        (SResultRowPosition){.pageId = resultRow->pageId, .offset = resultRow->offset};
     pInfo->resultRowInfo.cur = (SResultRowPosition){.pageId = resultRow->pageId, .offset = resultRow->offset};
   }
 
@@ -3887,18 +3823,6 @@ static SSDataBlock* doFill(SOperatorInfo* pOperator) {
   }
 }
 
-// todo set the attribute of query scan count
-static int32_t getNumOfScanTimes(STaskAttr* pQueryAttr) {
-  for (int32_t i = 0; i < pQueryAttr->numOfOutput; ++i) {
-    int32_t functionId = getExprFunctionId(&pQueryAttr->pExpr1[i]);
-    if (functionId == FUNCTION_STDDEV || functionId == FUNCTION_PERCT) {
-      return 2;
-    }
-  }
-
-  return 1;
-}
-
 static void destroyOperatorInfo(SOperatorInfo* pOperator) {
   if (pOperator == NULL) {
     return;

source/libs/executor/src/groupoperator.c

@@ -110,9 +110,11 @@ static bool groupKeyCompare(SArray* pGroupCols, SArray* pGroupColVals, SSDataBlo
   return true;
 }
 
-static void recordNewGroupKeys(SArray* pGroupCols, SArray* pGroupColVals, SSDataBlock* pBlock, int32_t rowIndex, int32_t numOfGroupCols) {
+static void recordNewGroupKeys(SArray* pGroupCols, SArray* pGroupColVals, SSDataBlock* pBlock, int32_t rowIndex) {
   SColumnDataAgg* pColAgg = NULL;
 
+  size_t numOfGroupCols = taosArrayGetSize(pGroupCols);
+
   for (int32_t i = 0; i < numOfGroupCols; ++i) {
     SColumn*         pCol = taosArrayGet(pGroupCols, i);
     SColumnInfoData* pColInfoData = taosArrayGet(pBlock->pDataBlock, pCol->slotId);
@@ -208,7 +210,7 @@ static void doHashGroupbyAgg(SOperatorInfo* pOperator, SSDataBlock* pBlock) {
   for (int32_t j = 0; j < pBlock->info.rows; ++j) {
     // Compare with the previous row of this column, and do not set the output buffer again if they are identical.
     if (!pInfo->isInit) {
-      recordNewGroupKeys(pInfo->pGroupCols, pInfo->pGroupColVals, pBlock, j, numOfGroupCols);
+      recordNewGroupKeys(pInfo->pGroupCols, pInfo->pGroupColVals, pBlock, j);
       pInfo->isInit = true;
       num++;
       continue;
@@ -223,7 +225,7 @@ static void doHashGroupbyAgg(SOperatorInfo* pOperator, SSDataBlock* pBlock) {
     // The first row of a new block does not belongs to the previous existed group
     if (j == 0) {
       num++;
-      recordNewGroupKeys(pInfo->pGroupCols, pInfo->pGroupColVals, pBlock, j, numOfGroupCols);
+      recordNewGroupKeys(pInfo->pGroupCols, pInfo->pGroupColVals, pBlock, j);
       continue;
     }
 
@@ -238,7 +240,7 @@ static void doHashGroupbyAgg(SOperatorInfo* pOperator, SSDataBlock* pBlock) {
 
     // assign the group keys or user input constant values if required
     doAssignGroupKeys(pCtx, pOperator->numOfExprs, pBlock->info.rows, rowIndex);
-    recordNewGroupKeys(pInfo->pGroupCols, pInfo->pGroupColVals, pBlock, j, numOfGroupCols);
+    recordNewGroupKeys(pInfo->pGroupCols, pInfo->pGroupColVals, pBlock, j);
     num = 1;
   }
 
@@ -396,7 +398,7 @@ static void doHashPartition(SOperatorInfo* pOperator, SSDataBlock* pBlock) {
 
   int32_t numOfGroupCols = taosArrayGetSize(pInfo->pGroupCols);
   for (int32_t j = 0; j < pBlock->info.rows; ++j) {
-    recordNewGroupKeys(pInfo->pGroupCols, pInfo->pGroupColVals, pBlock, j, numOfGroupCols);
+    recordNewGroupKeys(pInfo->pGroupCols, pInfo->pGroupColVals, pBlock, j);
     int32_t len = buildGroupKeys(pInfo->keyBuf, pInfo->pGroupColVals);
 
     SDataGroupInfo* pGInfo = NULL;

source/libs/executor/src/scanoperator.c

@@ -534,8 +534,8 @@ SOperatorInfo* createTableScanOperatorInfo(STableScanPhysiNode* pTableScanNode,
     pInfo->pPseudoCtx = createSqlFunctionCtx(pInfo->pPseudoExpr, pInfo->numOfPseudoExpr, &pInfo->rowCellInfoOffset);
   }
 
-  pInfo->scanInfo = (SScanInfo){.numOfAsc = pTableScanNode->scanSeq[0], .numOfDesc = pTableScanNode->scanSeq[1]};
-  //  pInfo->scanInfo = (SScanInfo){.numOfAsc = 0, .numOfDesc = 1}; // for debug purpose
+//  pInfo->scanInfo = (SScanInfo){.numOfAsc = pTableScanNode->scanSeq[0], .numOfDesc = pTableScanNode->scanSeq[1]};
+    pInfo->scanInfo = (SScanInfo){.numOfAsc = 0, .numOfDesc = 1}; // for debug purpose
 
   pInfo->readHandle = *readHandle;
   pInfo->interval = extractIntervalInfo(pTableScanNode);

source/libs/function/inc/builtinsimpl.h

@@ -140,6 +140,10 @@ bool uniqueFunctionSetup(SqlFunctionCtx *pCtx, SResultRowEntryInfo* pResultInfo)
 int32_t uniqueFunction(SqlFunctionCtx *pCtx);
 //int32_t uniqueFinalize(SqlFunctionCtx* pCtx, SSDataBlock* pBlock);
 
+bool getTwaFuncEnv(struct SFunctionNode* pFunc, SFuncExecEnv* pEnv);
+bool twaFunctionSetup(SqlFunctionCtx *pCtx, SResultRowEntryInfo* pResultInfo);
+int32_t twaFunction(SqlFunctionCtx *pCtx);
+int32_t twaFinalize(struct SqlFunctionCtx *pCtx, SSDataBlock* pBlock);
 
 bool getSelectivityFuncEnv(SFunctionNode* pFunc, SFuncExecEnv* pEnv);
 

source/libs/function/inc/taggfunction.h

@@ -52,13 +52,6 @@ typedef struct SInterpInfoDetail {
   int8_t primaryCol;
 } SInterpInfoDetail;
 
-typedef struct STwaInfo {
-  int8_t      hasResult;  // flag to denote has value
-  double      dOutput;
-  SPoint1     p;
-  STimeWindow win;
-} STwaInfo;
-
 bool topbot_datablock_filter(SqlFunctionCtx *pCtx, const char *minval, const char *maxval);
 
 /**

source/libs/function/src/builtins.c

@@ -18,7 +18,6 @@
 #include "querynodes.h"
 #include "scalar.h"
 #include "taoserror.h"
-#include "tdatablock.h"
 
 static int32_t buildFuncErrMsg(char* pErrBuf, int32_t len, int32_t errCode, const char* pFormat, ...) {
   va_list vArgList;
@@ -314,7 +313,7 @@ static int32_t translateElapsed(SFunctionNode* pFunc, char* pErrBuf, int32_t len
 
     pValue->notReserved = true;
 
-    uint8_t paraType = ((SExprNode*)nodesListGetNode(pFunc->pParameterList, 1))->resType.type;
+    paraType = ((SExprNode*)nodesListGetNode(pFunc->pParameterList, 1))->resType.type;
     if (!IS_INTEGER_TYPE(paraType)) {
       return invaildFuncParaTypeErrMsg(pErrBuf, len, pFunc->functionName);
     }
@@ -1119,6 +1118,16 @@ const SBuiltinFuncDefinition funcMgtBuiltins[] = {
     .finalizeFunc = firstLastFinalize,
     .combineFunc  = lastCombine,
   },
+  {
+    .name = "twa",
+    .type = FUNCTION_TYPE_TWA,
+    .classification = FUNC_MGT_AGG_FUNC | FUNC_MGT_TIMELINE_FUNC,
+    .translateFunc = translateInNumOutDou,
+    .getEnvFunc    = getTwaFuncEnv,
+    .initFunc      = twaFunctionSetup,
+    .processFunc   = twaFunction,
+    .finalizeFunc  = twaFinalize
+  },
   {
     .name = "histogram",
     .type = FUNCTION_TYPE_HISTOGRAM,

source/libs/function/src/builtinsimpl.c

@@ -225,7 +225,6 @@ typedef struct SUniqueInfo {
   int32_t   numOfPoints;
   uint8_t   colType;
   int16_t   colBytes;
-  bool      hasNull; //null is not hashable, handle separately
   SHashObj  *pHash;
   char      pItems[];
 } SUniqueInfo;
@@ -300,7 +299,7 @@ int32_t functionFinalize(SqlFunctionCtx* pCtx, SSDataBlock* pBlock) {
   SColumnInfoData* pCol = taosArrayGet(pBlock->pDataBlock, slotId);
 
   SResultRowEntryInfo* pResInfo = GET_RES_INFO(pCtx);
-  //pResInfo->isNullRes = (pResInfo->numOfRes == 0) ? 1 : 0;
+  pResInfo->isNullRes = (pResInfo->numOfRes == 0) ? 1 : 0;
 
   char* in = GET_ROWCELL_INTERBUF(pResInfo);
   colDataAppend(pCol, pBlock->info.rows, in, pResInfo->isNullRes);
@@ -829,8 +828,10 @@ int32_t avgCombine(SqlFunctionCtx* pDestCtx, SqlFunctionCtx* pSourceCtx) {
 
 int32_t avgFinalize(SqlFunctionCtx* pCtx, SSDataBlock* pBlock) {
   SInputColumnInfoData* pInput = &pCtx->input;
-  int32_t               type = pInput->pData[0]->info.type;
-  SAvgRes*              pAvgRes = GET_ROWCELL_INTERBUF(GET_RES_INFO(pCtx));
+
+  int32_t type = pInput->pData[0]->info.type;
+  SAvgRes* pAvgRes = GET_ROWCELL_INTERBUF(GET_RES_INFO(pCtx));
+
   if (IS_INTEGER_TYPE(type)) {
     pAvgRes->result = pAvgRes->sum.isum / ((double)pAvgRes->count);
   } else {
@@ -1827,7 +1828,7 @@ bool percentileFunctionSetup(SqlFunctionCtx* pCtx, SResultRowEntryInfo* pResultI
 }
 
 int32_t percentileFunction(SqlFunctionCtx* pCtx) {
-  int32_t              notNullElems = 0;
+  int32_t              numOfElems = 0;
   SResultRowEntryInfo* pResInfo = GET_RES_INFO(pCtx);
 
   SInputColumnInfoData* pInput = &pCtx->input;
@@ -1905,11 +1906,11 @@ int32_t percentileFunction(SqlFunctionCtx* pCtx) {
       }
 
       char* data = colDataGetData(pCol, i);
-      notNullElems += 1;
+      numOfElems += 1;
       tMemBucketPut(pInfo->pMemBucket, data, 1);
     }
 
-    SET_VAL(pResInfo, notNullElems, 1);
+    SET_VAL(pResInfo, numOfElems, 1);
   }
 
   return TSDB_CODE_SUCCESS;
@@ -1983,7 +1984,7 @@ bool apercentileFunctionSetup(SqlFunctionCtx* pCtx, SResultRowEntryInfo* pResult
 }
 
 int32_t apercentileFunction(SqlFunctionCtx* pCtx) {
-  int32_t              notNullElems = 0;
+  int32_t              numOfElems = 0;
   SResultRowEntryInfo* pResInfo = GET_RES_INFO(pCtx);
 
   SInputColumnInfoData* pInput = &pCtx->input;
@@ -2000,7 +2001,7 @@ int32_t apercentileFunction(SqlFunctionCtx* pCtx) {
       if (colDataIsNull_f(pCol->nullbitmap, i)) {
         continue;
       }
-      notNullElems += 1;
+      numOfElems += 1;
       char* data = colDataGetData(pCol, i);
 
       double v = 0; // value
@@ -2013,7 +2014,7 @@ int32_t apercentileFunction(SqlFunctionCtx* pCtx) {
       if (colDataIsNull_f(pCol->nullbitmap, i)) {
         continue;
       }
-      notNullElems += 1;
+      numOfElems += 1;
       char* data = colDataGetData(pCol, i);
 
       double v = 0;
@@ -2022,7 +2023,7 @@ int32_t apercentileFunction(SqlFunctionCtx* pCtx) {
     }
   }
 
-  SET_VAL(pResInfo, notNullElems, 1);
+  SET_VAL(pResInfo, numOfElems, 1);
   return TSDB_CODE_SUCCESS;
 }
 
@@ -3690,7 +3691,6 @@ int32_t sampleFunction(SqlFunctionCtx* pCtx) {
   TSKEY* tsList = (int64_t*)pInput->pPTS->pData;
 
   SColumnInfoData* pInputCol = pInput->pData[0];
-  SColumnInfoData* pTsOutput = pCtx->pTsOutput;
   SColumnInfoData* pOutput = (SColumnInfoData*)pCtx->pOutput;
 
   int32_t startOffset = pCtx->offset;
@@ -3713,24 +3713,6 @@ int32_t sampleFunction(SqlFunctionCtx* pCtx) {
   return pInfo->numSampled;
 }
 
-//int32_t sampleFinalize(SqlFunctionCtx* pCtx, SSDataBlock* pBlock) {
-//  SResultRowEntryInfo* pResInfo = GET_RES_INFO(pCtx);
-//  SSampleInfo* pInfo = GET_ROWCELL_INTERBUF(GET_RES_INFO(pCtx));
-//  int32_t        slotId = pCtx->pExpr->base.resSchema.slotId;
-//  SColumnInfoData* pCol = taosArrayGet(pBlock->pDataBlock, slotId);
-//
-//  //int32_t currentRow = pBlock->info.rows;
-//  pResInfo->numOfRes = pInfo->numSampled;
-//
-//  for (int32_t i = 0; i < pInfo->numSampled; ++i) {
-//    colDataAppend(pCol, i, pInfo->data + i * pInfo->colBytes, false);
-//    //TODO: handle ts output
-//  }
-//
-//  return pResInfo->numOfRes;
-//}
-
-
 bool getTailFuncEnv(SFunctionNode* pFunc, SFuncExecEnv* pEnv) {
   SColumnNode* pCol = (SColumnNode*)nodesListGetNode(pFunc->pParameterList, 0);
   SValueNode*  pVal = (SValueNode*)nodesListGetNode(pFunc->pParameterList, 1);
@@ -3806,7 +3788,6 @@ int32_t tailFunction(SqlFunctionCtx* pCtx) {
   TSKEY* tsList = (int64_t*)pInput->pPTS->pData;
 
   SColumnInfoData* pInputCol = pInput->pData[0];
-  SColumnInfoData* pTsOutput = pCtx->pTsOutput;
   SColumnInfoData* pOutput = (SColumnInfoData*)pCtx->pOutput;
 
   int32_t startOffset = pCtx->offset;
@@ -3873,7 +3854,6 @@ bool uniqueFunctionSetup(SqlFunctionCtx* pCtx, SResultRowEntryInfo* pResInfo) {
   pInfo->numOfPoints = 0;
   pInfo->colType = pCtx->resDataInfo.type;
   pInfo->colBytes = pCtx->resDataInfo.bytes;
-  pInfo->hasNull = false;
   if (pInfo->pHash != NULL) {
     taosHashClear(pInfo->pHash);
   } else {
@@ -3887,11 +3867,10 @@ static void doUniqueAdd(SUniqueInfo* pInfo, char *data, TSKEY ts, bool isNull) {
   if (isNull == true) {
     int32_t size = sizeof(SUniqueItem) + pInfo->colBytes;
     SUniqueItem *pItem = (SUniqueItem *)(pInfo->pItems + pInfo->numOfPoints * size);
-    if (pInfo->hasNull == false && pItem->isNull == false) {
+    if (pItem->isNull == false) {
       pItem->timestamp = ts;
       pItem->isNull = true;
       pInfo->numOfPoints++;
-      pInfo->hasNull = true;
     } else if (pItem->timestamp > ts && pItem->isNull == true) {
       pItem->timestamp = ts;
     }
@@ -3911,8 +3890,6 @@ static void doUniqueAdd(SUniqueInfo* pInfo, char *data, TSKEY ts, bool isNull) {
   } else if (pHashItem->timestamp > ts) {
     pHashItem->timestamp = ts;
   }
-
-  return;
 }
 
 int32_t uniqueFunction(SqlFunctionCtx* pCtx) {
@@ -3954,7 +3931,7 @@ int32_t uniqueFunction(SqlFunctionCtx* pCtx) {
 
 int32_t uniqueFinalize(SqlFunctionCtx* pCtx, SSDataBlock* pBlock) {
   SResultRowEntryInfo* pResInfo = GET_RES_INFO(pCtx);
-  SUniqueInfo*    pInfo = GET_ROWCELL_INTERBUF(GET_RES_INFO(pCtx));
+  SUniqueInfo*    pInfo = GET_ROWCELL_INTERBUF(pResInfo);
   int32_t        slotId = pCtx->pExpr->base.resSchema.slotId;
   SColumnInfoData* pCol = taosArrayGet(pBlock->pDataBlock, slotId);
 
@@ -3967,3 +3944,325 @@ int32_t uniqueFinalize(SqlFunctionCtx* pCtx, SSDataBlock* pBlock) {
   return pResInfo->numOfRes;
 }
 
+typedef struct STwaInfo {
+  double      dOutput;
+  int8_t      hasResult;  // flag to denote has value
+  SPoint1     p;
+  STimeWindow win;
+} STwaInfo;
+
+bool getTwaFuncEnv(struct SFunctionNode* pFunc, SFuncExecEnv* pEnv) {
+  pEnv->calcMemSize = sizeof(STwaInfo);
+  return true;
+}
+
+bool twaFunctionSetup(SqlFunctionCtx *pCtx, SResultRowEntryInfo* pResultInfo) {
+  if (!functionSetup(pCtx, pResultInfo)) {
+    return false;
+  }
+
+  STwaInfo *pInfo = GET_ROWCELL_INTERBUF(GET_RES_INFO(pCtx));
+  pInfo->p.key    = INT64_MIN;
+  pInfo->win      = TSWINDOW_INITIALIZER;
+  return true;
+}
+
+static double twa_get_area(SPoint1 s, SPoint1 e) {
+  if ((s.val >= 0 && e.val >= 0)|| (s.val <=0 && e.val <= 0)) {
+    return (s.val + e.val) * (e.key - s.key) / 2;
+  }
+
+  double x = (s.key * e.val - e.key * s.val)/(e.val - s.val);
+  double val = (s.val * (x - s.key) + e.val * (e.key - x)) / 2;
+  return val;
+}
+
+int32_t twaFunction(SqlFunctionCtx* pCtx) {
+  SInputColumnInfoData* pInput = &pCtx->input;
+  SColumnInfoData* pInputCol = pInput->pData[0];
+
+  int32_t numOfElems = 0;
+
+  TSKEY* tsList = (int64_t*)pInput->pPTS->pData;
+
+  SResultRowEntryInfo *pResInfo = GET_RES_INFO(pCtx);
+
+  STwaInfo *pInfo = GET_ROWCELL_INTERBUF(pResInfo);
+
+  SPoint1* last = &pInfo->p;
+
+  int32_t step = 1;//GET_FORWARD_DIRECTION_FACTOR(pCtx->order);
+  int32_t i = pInput->startRowIndex;
+  for (i = pInput->startRowIndex; i < pInput->numOfRows + pInput->startRowIndex; i += step) {
+    if (!colDataIsNull_f(pInputCol->nullbitmap, i)) {
+      break;
+    }
+  }
+
+  if (pCtx->start.key != INT64_MIN) {
+    ASSERT((pCtx->start.key < tsList[i] && pCtx->order == TSDB_ORDER_ASC) ||
+           (pCtx->start.key > tsList[i] && pCtx->order == TSDB_ORDER_DESC));
+
+    ASSERT(last->key == INT64_MIN);
+    last->key = tsList[i];
+
+    GET_TYPED_DATA(last->val, double, pInputCol->info.type, colDataGetData(pInputCol, i));
+
+    pInfo->dOutput += twa_get_area(pCtx->start, *last);
+
+    pInfo->hasResult = DATA_SET_FLAG;
+    pInfo->win.skey = pCtx->start.key;
+    numOfElems++;
+    i += step;
+  } else if (pInfo->p.key == INT64_MIN) {
+    last->key = tsList[i];
+    GET_TYPED_DATA(last->val, double, pInputCol->info.type, colDataGetData(pInputCol, i));
+
+    pInfo->hasResult = DATA_SET_FLAG;
+    pInfo->win.skey = last->key;
+    numOfElems++;
+    i += step;
+  }
+
+  // calculate the value of
+  switch(pInputCol->info.type) {
+    case TSDB_DATA_TYPE_TINYINT: {
+      int8_t *val = (int8_t*) colDataGetData(pInputCol, 0);
+      for (; i < pInput->numOfRows + pInput->startRowIndex; i += step) {
+        if (colDataIsNull_f(pInputCol->nullbitmap, i)) {
+          continue;
+        }
+
+#ifndef _TD_NINGSI_60
+        SPoint1 st = {.key = tsList[i], .val = val[i]};
+#else
+        SPoint1 st;
+        st.key = tsList[i];
+        st.val = val[i];
+#endif
+        pInfo->dOutput += twa_get_area(pInfo->p, st);
+        pInfo->p = st;
+      }
+      break;
+    }
+
+    case TSDB_DATA_TYPE_SMALLINT: {
+      int16_t *val = (int16_t*) colDataGetData(pInputCol, 0);
+      for (; i < pInput->numOfRows + pInput->startRowIndex; i += step) {
+        if (colDataIsNull_f(pInputCol->nullbitmap, i)) {
+          continue;
+        }
+
+#ifndef _TD_NINGSI_60
+        SPoint1 st = {.key = tsList[i], .val = val[i]};
+#else
+        SPoint1 st;
+        st.key = tsList[i];
+        st.val = val[i];
+#endif
+        pInfo->dOutput += twa_get_area(pInfo->p, st);
+        pInfo->p = st;
+      }
+      break;
+    }
+    case TSDB_DATA_TYPE_INT: {
+      int32_t *val = (int32_t*) colDataGetData(pInputCol, 0);
+      for (; i < pInput->numOfRows + pInput->startRowIndex; i += step) {
+        if (colDataIsNull_f(pInputCol->nullbitmap, i)) {
+          continue;
+        }
+
+#ifndef _TD_NINGSI_60
+        SPoint1 st = {.key = tsList[i], .val = val[i]};
+#else
+        SPoint1 st;
+        st.key = tsList[i];
+        st.val = val[i];
+#endif
+        pInfo->dOutput += twa_get_area(pInfo->p, st);
+        pInfo->p = st;
+      }
+      break;
+    }
+    case TSDB_DATA_TYPE_BIGINT: {
+      int64_t *val = (int64_t*) colDataGetData(pInputCol, 0);
+      for (; i < pInput->numOfRows + pInput->startRowIndex; i += step) {
+        if (colDataIsNull_f(pInputCol->nullbitmap, i)) {
+          continue;
+        }
+
+#ifndef _TD_NINGSI_60
+        SPoint1 st = {.key = tsList[i], .val = (double) val[i]};
+#else
+        SPoint1 st;
+        st.key = tsList[i];
+        st.val = (double)val[i];
+#endif
+        pInfo->dOutput += twa_get_area(pInfo->p, st);
+        pInfo->p = st;
+      }
+      break;
+    }
+    case TSDB_DATA_TYPE_FLOAT: {
+      float *val = (float*) colDataGetData(pInputCol, 0);
+      for (; i < pInput->numOfRows + pInput->startRowIndex; i += step) {
+        if (colDataIsNull_f(pInputCol->nullbitmap, i)) {
+          continue;
+        }
+
+#ifndef _TD_NINGSI_60
+        SPoint1 st = {.key = tsList[i], .val = val[i]};
+#else
+        SPoint1 st;
+        st.key = tsList[i];
+        st.val = (double)val[i];
+#endif
+        pInfo->dOutput += twa_get_area(pInfo->p, st);
+        pInfo->p = st;
+      }
+      break;
+    }
+    case TSDB_DATA_TYPE_DOUBLE: {
+      double *val = (double*) colDataGetData(pInputCol, 0);
+      for (; i < pInput->numOfRows + pInput->startRowIndex; i += step) {
+        if (colDataIsNull_f(pInputCol->nullbitmap, i)) {
+          continue;
+        }
+
+#ifndef _TD_NINGSI_60
+        SPoint1 st = {.key = tsList[i], .val = val[i]};
+#else
+        SPoint1 st;
+        st.key = tsList[i];
+        st.val = val[i];
+#endif
+        pInfo->dOutput += twa_get_area(pInfo->p, st);
+        pInfo->p = st;
+      }
+      break;
+    }
+    case TSDB_DATA_TYPE_UTINYINT: {
+      uint8_t *val = (uint8_t*) colDataGetData(pInputCol, 0);
+      for (; i < pInput->numOfRows + pInput->startRowIndex; i += step) {
+        if (colDataIsNull_f(pInputCol->nullbitmap, i)) {
+          continue;
+        }
+
+#ifndef _TD_NINGSI_60
+        SPoint1 st = {.key = tsList[i], .val = val[i]};
+#else
+        SPoint1 st;
+        st.key = tsList[i];
+        st.val = val[i];
+#endif
+        pInfo->dOutput += twa_get_area(pInfo->p, st);
+        pInfo->p = st;
+      }
+      break;
+    }
+    case TSDB_DATA_TYPE_USMALLINT: {
+      uint16_t *val = (uint16_t*) colDataGetData(pInputCol, 0);
+      for (; i < pInput->numOfRows + pInput->startRowIndex; i += step) {
+        if (colDataIsNull_f(pInputCol->nullbitmap, i)) {
+          continue;
+        }
+
+#ifndef _TD_NINGSI_60
+        SPoint1 st = {.key = tsList[i], .val = val[i]};
+#else
+        SPoint1 st;
+        st.key = tsList[i];
+        st.val = val[i];
+#endif
+        pInfo->dOutput += twa_get_area(pInfo->p, st);
+        pInfo->p = st;
+      }
+      break;
+    }
+    case TSDB_DATA_TYPE_UINT: {
+      uint32_t *val = (uint32_t*) colDataGetData(pInputCol, 0);
+      for (; i < pInput->numOfRows + pInput->startRowIndex; i += step) {
+        if (colDataIsNull_f(pInputCol->nullbitmap, i)) {
+          continue;
+        }
+
+#ifndef _TD_NINGSI_60
+        SPoint1 st = {.key = tsList[i], .val = val[i]};
+#else
+        SPoint1 st;
+        st.key = tsList[i];
+        st.val = val[i];
+#endif
+        pInfo->dOutput += twa_get_area(pInfo->p, st);
+        pInfo->p = st;
+      }
+      break;
+    }
+    case TSDB_DATA_TYPE_UBIGINT: {
+      uint64_t *val = (uint64_t*) colDataGetData(pInputCol, 0);
+      for (; i < pInput->numOfRows + pInput->startRowIndex; i += step) {
+        if (colDataIsNull_f(pInputCol->nullbitmap, i)) {
+          continue;
+        }
+
+#ifndef _TD_NINGSI_60
+        SPoint1 st = {.key = tsList[i], .val = (double) val[i]};
+#else
+        SPoint1 st;
+        st.key = tsList[i];
+        st.val = (double) val[i];
+#endif
+        pInfo->dOutput += twa_get_area(pInfo->p, st);
+        pInfo->p = st;
+      }
+      break;
+    }
+
+    default: assert(0);
+  }
+
+  // the last interpolated time window value
+  if (pCtx->end.key != INT64_MIN) {
+    pInfo->dOutput  += twa_get_area(pInfo->p, pCtx->end);
+    pInfo->p = pCtx->end;
+  }
+
+  pInfo->win.ekey  = pInfo->p.key;
+
+  SET_VAL(GET_RES_INFO(pCtx), numOfElems, 1);
+  return TSDB_CODE_SUCCESS;
+}
+
+/*
+ * To copy the input to interResBuf to avoid the input buffer space be over writen
+ * by next input data. The TWA function only applies to each table, so no merge procedure
+ * is required, we simply copy to the resut ot interResBuffer.
+ */
+//void twa_function_copy(SQLFunctionCtx *pCtx) {
+//  assert(pCtx->inputType == TSDB_DATA_TYPE_BINARY);
+//  SResultRowEntryInfo *pResInfo = GET_RES_INFO(pCtx);
+//
+//  memcpy(GET_ROWCELL_INTERBUF(pResInfo), pCtx->pInput, (size_t)pCtx->inputBytes);
+//  pResInfo->hasResult = ((STwaInfo *)pCtx->pInput)->hasResult;
+//}
+
+int32_t twaFinalize(struct SqlFunctionCtx *pCtx, SSDataBlock* pBlock) {
+  SResultRowEntryInfo *pResInfo = GET_RES_INFO(pCtx);
+
+  STwaInfo *pInfo = (STwaInfo *)GET_ROWCELL_INTERBUF(pResInfo);
+  if (pInfo->hasResult != DATA_SET_FLAG) {
+    pResInfo->isNullRes = 1;
+  } else {
+    //  assert(pInfo->win.ekey == pInfo->p.key && pInfo->hasResult == pResInfo->hasResult);
+    if (pInfo->win.ekey == pInfo->win.skey) {
+      pInfo->dOutput = pInfo->p.val;
+    } else {
+      pInfo->dOutput = pInfo->dOutput / (pInfo->win.ekey - pInfo->win.skey);
+    }
+
+    pResInfo->numOfRes = 1;
+  }
+
+  return functionFinalize(pCtx, pBlock);
+}
+

source/libs/function/src/taggfunction.c

@@ -236,7 +236,7 @@ bool isRowEntryCompleted(struct SResultRowEntryInfo* pEntry) {
 bool isRowEntryInitialized(struct SResultRowEntryInfo* pEntry) {
   return pEntry->initialized;
 }
-
+#if 0
 int32_t getResultDataInfo(int32_t dataType, int32_t dataBytes, int32_t functionId, int32_t param, SResultDataInfo* pInfo, int16_t extLength,
     bool isSuperTable/*, SUdfInfo* pUdfInfo*/) {
   if (!isValidDataType(dataType)) {
@@ -470,6 +470,7 @@ int32_t getResultDataInfo(int32_t dataType, int32_t dataBytes, int32_t functionI
   
   return TSDB_CODE_SUCCESS;
 }
+#endif
 
 static bool function_setup(SqlFunctionCtx *pCtx, SResultRowEntryInfo* pResultInfo) {
   if (pResultInfo->initialized) {

source/util/src/tlist.c

@@ -95,7 +95,7 @@ SListNode *tdListPopTail(SList *list) {
 
 SListNode *tdListGetHead(SList *list) { return TD_DLIST_HEAD(list); }
 
-SListNode *tsListGetTail(SList *list) { return TD_DLIST_TAIL(list); }
+SListNode *tdListGetTail(SList *list) { return TD_DLIST_TAIL(list); }
 
 SListNode *tdListPopNode(SList *list, SListNode *node) {
   TD_DLIST_POP(list, node);