ClickHouse/src/Columns/FilterDescription.cpp
2020-05-14 11:30:18 +03:00

105 lines
3.3 KiB
C++

#include <Common/typeid_cast.h>
#include <Common/assert_cast.h>
#include <Columns/FilterDescription.h>
#include <Columns/ColumnsNumber.h>
#include <Columns/ColumnNullable.h>
#include <Columns/ColumnConst.h>
#include <Core/ColumnWithTypeAndName.h>
namespace DB
{
namespace ErrorCodes
{
extern const int ILLEGAL_TYPE_OF_COLUMN_FOR_FILTER;
}
ConstantFilterDescription::ConstantFilterDescription(const IColumn & column)
{
if (column.onlyNull())
{
always_false = true;
return;
}
if (isColumnConst(column))
{
const ColumnConst & column_const = assert_cast<const ColumnConst &>(column);
ColumnPtr column_nested = column_const.getDataColumnPtr()->convertToFullColumnIfLowCardinality();
if (!typeid_cast<const ColumnUInt8 *>(column_nested.get()))
{
const ColumnNullable * column_nested_nullable = checkAndGetColumn<ColumnNullable>(*column_nested);
if (!column_nested_nullable || !typeid_cast<const ColumnUInt8 *>(&column_nested_nullable->getNestedColumn()))
{
throw Exception("Illegal type " + column_nested->getName() + " of column for constant filter. Must be UInt8 or Nullable(UInt8).",
ErrorCodes::ILLEGAL_TYPE_OF_COLUMN_FOR_FILTER);
}
}
if (column_const.getValue<UInt64>())
always_true = true;
else
always_false = true;
return;
}
}
FilterDescription::FilterDescription(const IColumn & column_)
{
if (column_.lowCardinality())
data_holder = column_.convertToFullColumnIfLowCardinality();
const auto & column = data_holder ? *data_holder : column_;
if (const ColumnUInt8 * concrete_column = typeid_cast<const ColumnUInt8 *>(&column))
{
data = &concrete_column->getData();
return;
}
if (const auto * nullable_column = checkAndGetColumn<ColumnNullable>(column))
{
ColumnPtr nested_column = nullable_column->getNestedColumnPtr();
MutableColumnPtr mutable_holder = IColumn::mutate(std::move(nested_column));
ColumnUInt8 * concrete_column = typeid_cast<ColumnUInt8 *>(mutable_holder.get());
if (!concrete_column)
throw Exception("Illegal type " + column.getName() + " of column for filter. Must be UInt8 or Nullable(UInt8).",
ErrorCodes::ILLEGAL_TYPE_OF_COLUMN_FOR_FILTER);
const NullMap & null_map = nullable_column->getNullMapData();
IColumn::Filter & res = concrete_column->getData();
size_t size = res.size();
for (size_t i = 0; i < size; ++i)
res[i] = res[i] && !null_map[i];
data = &res;
data_holder = std::move(mutable_holder);
return;
}
throw Exception("Illegal type " + column.getName() + " of column for filter. Must be UInt8 or Nullable(UInt8) or Const variants of them.",
ErrorCodes::ILLEGAL_TYPE_OF_COLUMN_FOR_FILTER);
}
void checkColumnCanBeUsedAsFilter(const ColumnWithTypeAndName & column_elem)
{
ConstantFilterDescription const_filter;
if (column_elem.column)
const_filter = ConstantFilterDescription(*column_elem.column);
if (!const_filter.always_false && !const_filter.always_true)
{
auto column = column_elem.column ? column_elem.column : column_elem.type->createColumn();
FilterDescription filter(*column);
}
}
}