[td-13039] add first/last query.

include/libs/function/function.h

@@ -163,7 +163,7 @@ typedef struct SInputColumnInfoData {
 typedef struct SqlFunctionCtx {
   SInputColumnInfoData input;
   SResultDataInfo      resDataInfo;
-  uint32_t             order;  // asc|desc
+  uint32_t             order;  // data block scanner order: asc|desc
   ////////////////////////////////////////////////////////////////
   int32_t          startRow;   // start row index
   int32_t          size;       // handled processed row number

source/libs/function/inc/builtinsimpl.h

@@ -37,6 +37,10 @@ bool getMinmaxFuncEnv(SFunctionNode* pFunc, SFuncExecEnv* pEnv);
 void minFunction(SqlFunctionCtx* pCtx);
 void maxFunction(SqlFunctionCtx *pCtx);
 
+bool getFirstLastFuncEnv(SFunctionNode* pFunc, SFuncExecEnv* pEnv);
+void firstFunction(SqlFunctionCtx *pCtx);
+void lastFunction(SqlFunctionCtx *pCtx);
+
 #ifdef __cplusplus
 }
 #endif

source/libs/function/src/builtins.c

@@ -61,6 +61,26 @@ const SBuiltinFuncDefinition funcMgtBuiltins[] = {
     .processFunc  = maxFunction,
     .finalizeFunc = functionFinalizer
   },
+  {
+    .name = "first",
+    .type = FUNCTION_TYPE_FIRST,
+    .classification = FUNC_MGT_AGG_FUNC,
+    .checkFunc    = stubCheckAndGetResultType,
+    .getEnvFunc   = getFirstLastFuncEnv,
+    .initFunc     = functionSetup,
+    .processFunc  = firstFunction,
+    .finalizeFunc = functionFinalizer
+  },
+  {
+    .name = "last",
+    .type = FUNCTION_TYPE_LAST,
+    .classification = FUNC_MGT_AGG_FUNC,
+    .checkFunc    = stubCheckAndGetResultType,
+    .getEnvFunc   = getFirstLastFuncEnv,
+    .initFunc     = functionSetup,
+    .processFunc  = lastFunction,
+    .finalizeFunc = functionFinalizer
+  },
   {
     .name = "concat",
     .type = FUNCTION_TYPE_CONCAT,
@@ -98,6 +118,8 @@ int32_t stubCheckAndGetResultType(SFunctionNode* pFunc) {
       pFunc->node.resType = (SDataType) { .bytes = tDataTypes[resType].bytes, .type = resType };
       break;
     }
+    case FUNCTION_TYPE_FIRST:
+    case FUNCTION_TYPE_LAST:
     case FUNCTION_TYPE_MIN:
     case FUNCTION_TYPE_MAX: {
       SColumnNode* pParam = nodesListGetNode(pFunc->pParameterList, 0);

source/libs/function/src/builtinsimpl.c

@@ -72,13 +72,12 @@ void countFunction(SqlFunctionCtx *pCtx) {
   int32_t numOfElem = 0;
 
   /*
-   * 1. column data missing (schema modified) causes pCtx->hasNull == true. pCtx->isAggSet == true;
-   * 2. for general non-primary key columns, pCtx->hasNull may be true or false, pCtx->isAggSet == true;
-   * 3. for primary key column, pCtx->hasNull always be false, pCtx->isAggSet == false;
+   * 1. column data missing (schema modified) causes pInputCol->hasNull == true. pInput->colDataAggIsSet == true;
+   * 2. for general non-primary key columns, pInputCol->hasNull may be true or false, pInput->colDataAggIsSet == true;
+   * 3. for primary key column, pInputCol->hasNull always be false, pInput->colDataAggIsSet == false;
    */
   SInputColumnInfoData* pInput = &pCtx->input;
   SColumnInfoData* pInputCol = pInput->pData[0];
-
   if (pInput->colDataAggIsSet && pInput->totalRows == pInput->numOfRows) {
     numOfElem = pInput->numOfRows - pInput->pColumnDataAgg[0]->numOfNull;
     ASSERT(numOfElem >= 0);
@@ -173,7 +172,7 @@ void sumFunction(SqlFunctionCtx *pCtx) {
   SET_VAL(GET_RES_INFO(pCtx), numOfElem, 1);
 }
 
-bool getSumFuncEnv(SFunctionNode* pFunc, SFuncExecEnv* pEnv) {
+bool getSumFuncEnv(SFunctionNode* UNUSED_PARAM(pFunc), SFuncExecEnv* pEnv) {
   pEnv->calcMemSize = sizeof(SSumRes);
   return true;
 }
@@ -265,8 +264,7 @@ bool minFunctionSetup(SqlFunctionCtx *pCtx, SResultRowEntryInfo* pResultInfo) {
   return true;
 }
 
-bool getMinmaxFuncEnv(SFunctionNode* pFunc, SFuncExecEnv* pEnv) {
-  SNode* pNode = nodesListGetNode(pFunc->pParameterList, 0);
+bool getMinmaxFuncEnv(SFunctionNode* UNUSED_PARAM(pFunc), SFuncExecEnv* pEnv) {
   pEnv->calcMemSize = sizeof(int64_t);
   return true;
 }
@@ -305,7 +303,7 @@ bool getMinmaxFuncEnv(SFunctionNode* pFunc, SFuncExecEnv* pEnv) {
 
 #define LOOPCHECK_N(val, _col, ctx, _t, _nrow, _start, sign, num)        \
   do {                                                                   \
-    _t* d = (_t*)((_col)->pData);                                        \
+    _t *d = (_t *)((_col)->pData);                                       \
     for (int32_t i = (_start); i < (_nrow) + (_start); ++i) {            \
       if (((_col)->hasNull) && colDataIsNull_f((_col)->nullbitmap, i)) { \
         continue;                                                        \
@@ -446,3 +444,117 @@ void maxFunction(SqlFunctionCtx *pCtx) {
   int32_t numOfElems = doMinMaxHelper(pCtx, 0);
   SET_VAL(GET_RES_INFO(pCtx), numOfElems, 1);
 }
+
+bool getFirstLastFuncEnv(SFunctionNode* pFunc, SFuncExecEnv* pEnv) {
+  SColumnNode* pNode = nodesListGetNode(pFunc->pParameterList, 0);
+  pEnv->calcMemSize = pNode->node.resType.bytes;
+  return true;
+}
+
+// TODO fix this
+// This ordinary first function only handle the data block in ascending order
+void firstFunction(SqlFunctionCtx *pCtx) {
+  if (pCtx->order == TSDB_ORDER_DESC) {
+    return;
+  }
+
+  int32_t numOfElems = 0;
+
+  struct SResultRowEntryInfo *pResInfo = GET_RES_INFO(pCtx);
+  char* buf = GET_ROWCELL_INTERBUF(pResInfo);
+
+  SInputColumnInfoData* pInput = &pCtx->input;
+
+  SColumnInfoData* pInputCol = pInput->pData[0];
+
+  // All null data column, return directly.
+  if (pInput->pColumnDataAgg[0]->numOfNull == pInput->totalRows) {
+    ASSERT(pInputCol->hasNull == true);
+    return;
+  }
+
+  // Check for the first not null data
+  for (int32_t i = pInput->startRowIndex; i < pInput->numOfRows + pInput->startRowIndex; ++i) {
+    if (pInputCol->hasNull && colDataIsNull(pInputCol, pInput->totalRows, i, NULL)) {
+      continue;
+    }
+
+    char* data = colDataGetData(pInputCol, i);
+    memcpy(buf, data, pInputCol->info.bytes);
+    // TODO handle the subsidary value
+//    if (pCtx->ptsList != NULL) {
+//      TSKEY k = GET_TS_DATA(pCtx, i);
+//      DO_UPDATE_TAG_COLUMNS(pCtx, k);
+//    }
+
+    pResInfo->hasResult = DATA_SET_FLAG;
+    pResInfo->complete = true;
+
+    numOfElems++;
+    break;
+  }
+
+  SET_VAL(pResInfo, numOfElems, 1);
+}
+
+void lastFunction(SqlFunctionCtx *pCtx) {
+  if (pCtx->order != TSDB_ORDER_DESC) {
+    return;
+  }
+
+  int32_t numOfElems = 0;
+
+  struct SResultRowEntryInfo *pResInfo = GET_RES_INFO(pCtx);
+  char* buf = GET_ROWCELL_INTERBUF(pResInfo);
+
+  SInputColumnInfoData* pInput = &pCtx->input;
+
+  SColumnInfoData* pInputCol = pInput->pData[0];
+
+  // All null data column, return directly.
+  if (pInput->pColumnDataAgg[0]->numOfNull == pInput->totalRows) {
+    ASSERT(pInputCol->hasNull == true);
+    return;
+  }
+
+  if (pCtx->order == TSDB_ORDER_DESC) {
+    for (int32_t i = pInput->numOfRows + pInput->startRowIndex - 1; i >= pInput->startRowIndex; --i) {
+      if (pInputCol->hasNull && colDataIsNull(pInputCol, pInput->totalRows, i, NULL)) {
+        continue;
+      }
+
+      char* data = colDataGetData(pInputCol, i);
+      memcpy(buf, data, pInputCol->info.bytes);
+
+//      TSKEY ts = pCtx->ptsList ? GET_TS_DATA(pCtx, i) : 0;
+//      DO_UPDATE_TAG_COLUMNS(pCtx, ts);
+
+      pResInfo->hasResult = DATA_SET_FLAG;
+      pResInfo->complete = true;  // set query completed on this column
+      numOfElems++;
+      break;
+    }
+  } else {  // ascending order
+    for (int32_t i = pInput->startRowIndex; i < pInput->numOfRows + pInput->startRowIndex; ++i) {
+      if (pInputCol->hasNull && colDataIsNull(pInputCol, pInput->totalRows, i, NULL)) {
+        continue;
+      }
+
+      char* data = colDataGetData(pInputCol, i);
+      TSKEY ts = pCtx->ptsList ? GET_TS_DATA(pCtx, i) : 0;
+
+      if (pResInfo->hasResult != DATA_SET_FLAG || (*(TSKEY*)buf) < ts) {
+        pResInfo->hasResult = DATA_SET_FLAG;
+        memcpy(buf, data, pCtx->inputBytes);
+
+        *(TSKEY*)buf = ts;
+//        DO_UPDATE_TAG_COLUMNS(pCtx, ts);
+      }
+
+      numOfElems++;
+      break;
+    }
+  }
+
+  SET_VAL(pResInfo, numOfElems, 1);
+}