ClickHouse/dbms/src/Functions/FunctionHelpers.cpp
2019-10-31 19:14:06 +03:00

122 lines
4.0 KiB
C++

#include <Functions/FunctionHelpers.h>
#include <Functions/IFunction.h>
#include <Columns/ColumnTuple.h>
#include <Columns/ColumnString.h>
#include <Columns/ColumnFixedString.h>
#include <Columns/ColumnNullable.h>
#include <Columns/ColumnLowCardinality.h>
#include <Common/assert_cast.h>
#include <DataTypes/DataTypeNullable.h>
#include <DataTypes/DataTypeLowCardinality.h>
#include <IO/WriteHelpers.h>
namespace DB
{
namespace ErrorCodes
{
extern const int ILLEGAL_COLUMN;
extern const int NUMBER_OF_ARGUMENTS_DOESNT_MATCH;
}
const ColumnConst * checkAndGetColumnConstStringOrFixedString(const IColumn * column)
{
if (!isColumnConst(*column))
return {};
const ColumnConst * res = assert_cast<const ColumnConst *>(column);
if (checkColumn<ColumnString>(&res->getDataColumn())
|| checkColumn<ColumnFixedString>(&res->getDataColumn()))
return res;
return {};
}
Columns convertConstTupleToConstantElements(const ColumnConst & column)
{
const ColumnTuple & src_tuple = assert_cast<const ColumnTuple &>(column.getDataColumn());
const auto & src_tuple_columns = src_tuple.getColumns();
size_t tuple_size = src_tuple_columns.size();
size_t rows = column.size();
Columns res(tuple_size);
for (size_t i = 0; i < tuple_size; ++i)
res[i] = ColumnConst::create(src_tuple_columns[i], rows);
return res;
}
static Block createBlockWithNestedColumnsImpl(const Block & block, const std::unordered_set<size_t> & args)
{
Block res;
size_t columns = block.columns();
for (size_t i = 0; i < columns; ++i)
{
const auto & col = block.getByPosition(i);
if (args.count(i) && col.type->isNullable())
{
const DataTypePtr & nested_type = static_cast<const DataTypeNullable &>(*col.type).getNestedType();
if (!col.column)
{
res.insert({nullptr, nested_type, col.name});
}
else if (auto * nullable = checkAndGetColumn<ColumnNullable>(*col.column))
{
const auto & nested_col = nullable->getNestedColumnPtr();
res.insert({nested_col, nested_type, col.name});
}
else if (auto * const_column = checkAndGetColumn<ColumnConst>(*col.column))
{
const auto & nested_col = checkAndGetColumn<ColumnNullable>(const_column->getDataColumn())->getNestedColumnPtr();
res.insert({ ColumnConst::create(nested_col, col.column->size()), nested_type, col.name});
}
else
throw Exception("Illegal column for DataTypeNullable", ErrorCodes::ILLEGAL_COLUMN);
}
else
res.insert(col);
}
return res;
}
Block createBlockWithNestedColumns(const Block & block, const ColumnNumbers & args)
{
std::unordered_set<size_t> args_set(args.begin(), args.end());
return createBlockWithNestedColumnsImpl(block, args_set);
}
Block createBlockWithNestedColumns(const Block & block, const ColumnNumbers & args, size_t result)
{
std::unordered_set<size_t> args_set(args.begin(), args.end());
args_set.insert(result);
return createBlockWithNestedColumnsImpl(block, args_set);
}
void validateArgumentType(const IFunction & func, const DataTypes & arguments,
size_t argument_index, bool (* validator_func)(const IDataType &),
const char * expected_type_description)
{
if (arguments.size() <= argument_index)
throw Exception("Incorrect number of arguments of function " + func.getName(),
ErrorCodes::NUMBER_OF_ARGUMENTS_DOESNT_MATCH);
const auto & argument = arguments[argument_index];
if (validator_func(*argument) == false)
throw Exception("Illegal type " + argument->getName() +
" of " + std::to_string(argument_index) +
" argument of function " + func.getName() +
" expected " + expected_type_description,
ErrorCodes::ILLEGAL_TYPE_OF_ARGUMENT);
}
}