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Merge pull request #9342 from ClickHouse/improve-performance-reinterpret-as-fixed-string

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Improve performance of "reinterpretAsFixedString" function
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alexey-milovidov 2020-02-25 01:33:55 +03:00 committed by GitHub
commit f2cbfb0fc2
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1 changed files with 16 additions and 2 deletions
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18
dbms/src/Functions/FunctionsReinterpret.h
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@ -118,7 +118,7 @@ public:
throw Exception("Cannot reinterpret " + type.getName() + " as FixedString because it is not fixed size and contiguous in memory", ErrorCodes::ILLEGAL_TYPE_OF_ARGUMENT);
}
void executeToFixedString(const IColumn & src, ColumnFixedString & dst, size_t n)
void NO_INLINE executeToFixedString(const IColumn & src, ColumnFixedString & dst, size_t n)
{
size_t rows = src.size();
ColumnFixedString::Chars & data_to = dst.getChars();
@ -133,6 +133,15 @@ public:
}
}
void NO_INLINE executeContiguousToFixedString(const IColumn & src, ColumnFixedString & dst, size_t n)
{
size_t rows = src.size();
ColumnFixedString::Chars & data_to = dst.getChars();
data_to.resize(n * rows);
memcpy(data_to.data(), src.getRawData().data, data_to.size());
}
bool useDefaultImplementationForConstants() const override { return true; }
void executeImpl(Block & block, const ColumnNumbers & arguments, size_t result, size_t /*input_rows_count*/) override
@ -141,7 +150,12 @@ public:
MutableColumnPtr dst = block.getByPosition(result).type->createColumn();
if (ColumnFixedString * dst_concrete = typeid_cast<ColumnFixedString *>(dst.get()))
executeToFixedString(src, *dst_concrete, dst_concrete->getN());
{
if (src.isFixedAndContiguous() && src.sizeOfValueIfFixed() == dst_concrete->getN())
executeContiguousToFixedString(src, *dst_concrete, dst_concrete->getN());
else
executeToFixedString(src, *dst_concrete, dst_concrete->getN());
}
else
throw Exception("Illegal column " + src.getName() + " of argument of function " + getName(), ErrorCodes::ILLEGAL_COLUMN);