From cbd2d8f8a2876f7b7c503fe27b1bf9f471012c6d Mon Sep 17 00:00:00 2001
From: Ganlin Zhao <ganlinzhao@hotmail.com>
Date: Fri, 15 Jul 2022 17:54:45 +0800
Subject: [PATCH] fix(query): add spread function scalar version

TD-17344
---
 include/libs/scalar/scalar.h        |  1 +
 source/libs/function/src/builtins.c |  1 +
 source/libs/scalar/src/sclfunc.c    | 42 +++++++++++++++++++++++++++++
 3 files changed, 44 insertions(+)

diff --git a/include/libs/scalar/scalar.h b/include/libs/scalar/scalar.h
index df3e27225f..e0beaff262 100644
--- a/include/libs/scalar/scalar.h
+++ b/include/libs/scalar/scalar.h
@@ -106,6 +106,7 @@ int32_t stddevScalarFunction(SScalarParam *pInput, int32_t inputNum, SScalarPara
 int32_t leastSQRScalarFunction(SScalarParam *pInput, int32_t inputNum, SScalarParam *pOutput);
 int32_t percentileScalarFunction(SScalarParam *pInput, int32_t inputNum, SScalarParam *pOutput);
 int32_t apercentileScalarFunction(SScalarParam *pInput, int32_t inputNum, SScalarParam *pOutput);
+int32_t spreadScalarFunction(SScalarParam *pInput, int32_t inputNum, SScalarParam *pOutput);
 
 #ifdef __cplusplus
 }
diff --git a/source/libs/function/src/builtins.c b/source/libs/function/src/builtins.c
index 74c0e54640..208022ad1a 100644
--- a/source/libs/function/src/builtins.c
+++ b/source/libs/function/src/builtins.c
@@ -2115,6 +2115,7 @@ const SBuiltinFuncDefinition funcMgtBuiltins[] = {
     .getEnvFunc   = getSpreadFuncEnv,
     .initFunc     = spreadFunctionSetup,
     .processFunc  = spreadFunction,
+    .sprocessFunc = spreadScalarFunction,
     .finalizeFunc = spreadFinalize,
     .invertFunc   = NULL,
     .combineFunc  = spreadCombine,
diff --git a/source/libs/scalar/src/sclfunc.c b/source/libs/scalar/src/sclfunc.c
index 8808d17454..9a8f570a52 100644
--- a/source/libs/scalar/src/sclfunc.c
+++ b/source/libs/scalar/src/sclfunc.c
@@ -2338,3 +2338,45 @@ int32_t percentileScalarFunction(SScalarParam *pInput, int32_t inputNum, SScalar
 int32_t apercentileScalarFunction(SScalarParam *pInput, int32_t inputNum, SScalarParam *pOutput) {
   return percentileScalarFunction(pInput, inputNum, pOutput);
 }
+
+int32_t spreadScalarFunction(SScalarParam *pInput, int32_t inputNum, SScalarParam *pOutput) {
+  SColumnInfoData *pInputData  = pInput->columnData;
+  SColumnInfoData *pOutputData = pOutput->columnData;
+
+  int32_t type = GET_PARAM_TYPE(pInput);
+
+  double min, max;
+  SET_DOUBLE_VAL(&min, DBL_MAX);
+  SET_DOUBLE_VAL(&max, -DBL_MAX);
+
+  bool hasNull = false;
+  for (int32_t i = 0; i < pInput->numOfRows; ++i) {
+    if (colDataIsNull_s(pInputData, i)) {
+      hasNull = true;
+      break;
+    }
+
+    char *in = pInputData->pData;
+
+    double val = 0;
+    GET_TYPED_DATA(val, double, type, in);
+
+    if (val < GET_DOUBLE_VAL(&min)) {
+      SET_DOUBLE_VAL(&min, val);
+    }
+
+    if (val > GET_DOUBLE_VAL(&max)) {
+      SET_DOUBLE_VAL(&max, val);
+    }
+  }
+
+  if (hasNull) {
+    colDataAppendNULL(pOutputData, 0);
+  } else {
+    double result = max - min;
+    colDataAppend(pOutputData, 0, (char *)&result, false);
+  }
+
+  pOutput->numOfRows = 1;
+  return TSDB_CODE_SUCCESS;
+}