From 0194cb4b59438d8d46fc05a4b1abd85eeb69972f Mon Sep 17 00:00:00 2001
From: ti-srebot <66930949+ti-srebot@users.noreply.github.com>
Date: Thu, 1 Jul 2021 14:24:20 +0800
Subject: [PATCH] init nested value for nullable column for function
 `TiDBCast`, `TiDBTimestampDiff` and `TiDBDateDiff` (#2289) (#2291)

---
 dbms/src/Columns/ColumnDecimal.h             |  9 +++++++++
 dbms/src/Functions/FunctionsDateTime.h       |  8 ++++----
 dbms/src/Functions/FunctionsTiDBConversion.h | 12 ++++--------
 3 files changed, 17 insertions(+), 12 deletions(-)

diff --git a/dbms/src/Columns/ColumnDecimal.h b/dbms/src/Columns/ColumnDecimal.h
index d2484d7f910..c11a3a9e35b 100644
--- a/dbms/src/Columns/ColumnDecimal.h
+++ b/dbms/src/Columns/ColumnDecimal.h
@@ -28,6 +28,11 @@ class DecimalPaddedPODArray : public PaddedPODArray<T>
         scale(scale_)
     {}
 
+    DecimalPaddedPODArray(size_t size, const T & x, UInt32 scale_)
+        :   Base(size, x),
+            scale(scale_)
+    {}
+
     DecimalPaddedPODArray(const DecimalPaddedPODArray & other)
     :   Base(other.begin(), other.end()),
         scale(other.scale)
@@ -73,6 +78,10 @@ class ColumnDecimal final : public COWPtrHelper<ColumnVectorHelper, ColumnDecima
     :   data(n, scale_),
         scale(scale_)
     {}
+    ColumnDecimal(const size_t n, const T & x, UInt32 scale_)
+        :   data(n, x, scale_),
+            scale(scale_)
+    {}
 
     ColumnDecimal(const ColumnDecimal & src)
     :   data(src.data),
diff --git a/dbms/src/Functions/FunctionsDateTime.h b/dbms/src/Functions/FunctionsDateTime.h
index f51fbca7b99..2a86a209288 100644
--- a/dbms/src/Functions/FunctionsDateTime.h
+++ b/dbms/src/Functions/FunctionsDateTime.h
@@ -1359,8 +1359,8 @@ class FunctionTiDBTimestampDiff : public IFunction
         const IColumn & y = *y_p;
 
         size_t rows = block.rows();
-        auto res = ColumnInt64::create(rows);
-        auto result_null_map = ColumnUInt8::create(rows);
+        auto res = ColumnInt64::create(rows, 0);
+        auto result_null_map = ColumnUInt8::create(rows, 0);
         if (unit == "year")
             dispatchForColumns<MonthDiffCalculatorImpl, YearDiffResultCalculator>(x, y, res->getData(), result_null_map->getData());
         else if (unit == "quarter")
@@ -1720,8 +1720,8 @@ class FunctionTiDBDateDiff : public IFunction
         const IColumn & y = *y_p;
 
         size_t rows = block.rows();
-        auto res = ColumnInt64::create(rows);
-        auto result_null_map = ColumnUInt8::create(rows);
+        auto res = ColumnInt64::create(rows, 0);
+        auto result_null_map = ColumnUInt8::create(rows, 0);
 
         dispatch(x, y, res->getData(), result_null_map->getData());
 
diff --git a/dbms/src/Functions/FunctionsTiDBConversion.h b/dbms/src/Functions/FunctionsTiDBConversion.h
index 339ba5ee19c..60d1ba0e25d 100644
--- a/dbms/src/Functions/FunctionsTiDBConversion.h
+++ b/dbms/src/Functions/FunctionsTiDBConversion.h
@@ -441,9 +441,8 @@ struct TiDBConvertToInteger
     {
         size_t size = block.getByPosition(arguments[0]).column->size();
 
-        auto col_to = ColumnVector<ToFieldType>::create();
+        auto col_to = ColumnVector<ToFieldType>::create(size, 0);
         typename ColumnVector<ToFieldType>::Container & vec_to = col_to->getData();
-        vec_to.resize(size);
 
         ColumnUInt8::MutablePtr col_null_map_to;
         ColumnUInt8::Container * vec_null_map_to [[maybe_unused]] = nullptr;
@@ -684,9 +683,8 @@ struct TiDBConvertToFloat
         size_t size = block.getByPosition(arguments[0]).column->size();
 
         /// NOTICE: Since ToFieldType only can be Float32 or Float64, convert from_value to Float64 and then implicitly cast to ToFieldType is fine.
-        auto col_to = ColumnVector<ToFieldType>::create();
+        auto col_to = ColumnVector<ToFieldType>::create(size, 0);
         typename ColumnVector<ToFieldType>::Container & vec_to = col_to->getData();
-        vec_to.resize(size);
 
         ColumnUInt8::MutablePtr col_null_map_to;
         ColumnUInt8::Container * vec_null_map_to [[maybe_unused]] = nullptr;
@@ -1096,9 +1094,8 @@ struct TiDBConvertToDecimal
         bool, const tipb::FieldType &, const Context & context)
     {
         size_t size = block.getByPosition(arguments[0]).column->size();
-        auto col_to = ColumnDecimal<ToFieldType>::create(0, scale);
+        auto col_to = ColumnDecimal<ToFieldType>::create(size, static_cast<ToFieldType>(0), scale);
         typename ColumnDecimal<ToFieldType>::Container & vec_to = col_to->getData();
-        vec_to.resize(size);
 
         ColumnUInt8::MutablePtr col_null_map_to;
         ColumnUInt8::Container * vec_null_map_to [[maybe_unused]] = nullptr;
@@ -1193,9 +1190,8 @@ struct TiDBConvertToTime
         Block & block, const ColumnNumbers & arguments, size_t result, bool, const tipb::FieldType &, const Context & context)
     {
         size_t size = block.getByPosition(arguments[0]).column->size();
-        auto col_to = ColumnUInt64::create();
+        auto col_to = ColumnUInt64::create(size, 0);
         ColumnUInt64::Container & vec_to = col_to->getData();
-        vec_to.resize(size);
 
         ColumnUInt8::MutablePtr col_null_map_to;
         ColumnUInt8::Container * vec_null_map_to [[maybe_unused]] = nullptr;