ClickHouse/src/Functions/array/arrayConcat.cpp
2021-10-02 10:13:14 +03:00

107 lines
3.6 KiB
C++

#include <Functions/IFunction.h>
#include <Functions/FunctionFactory.h>
#include <Functions/GatherUtils/GatherUtils.h>
#include <DataTypes/DataTypeArray.h>
#include <DataTypes/getLeastSupertype.h>
#include <Interpreters/castColumn.h>
#include <Columns/ColumnArray.h>
#include <Columns/ColumnConst.h>
#include <Common/typeid_cast.h>
#include <base/range.h>
namespace DB
{
namespace ErrorCodes
{
extern const int LOGICAL_ERROR;
extern const int NUMBER_OF_ARGUMENTS_DOESNT_MATCH;
extern const int ILLEGAL_TYPE_OF_ARGUMENT;
}
/// arrayConcat(arr1, ...) - concatenate arrays.
class FunctionArrayConcat : public IFunction
{
public:
static constexpr auto name = "arrayConcat";
static FunctionPtr create(ContextPtr) { return std::make_shared<FunctionArrayConcat>(); }
String getName() const override { return name; }
bool isVariadic() const override { return true; }
size_t getNumberOfArguments() const override { return 0; }
bool isSuitableForShortCircuitArgumentsExecution(const DataTypesWithConstInfo & /*arguments*/) const override { return true; }
DataTypePtr getReturnTypeImpl(const DataTypes & arguments) const override
{
if (arguments.empty())
throw Exception{"Function " + getName() + " requires at least one argument.", ErrorCodes::NUMBER_OF_ARGUMENTS_DOESNT_MATCH};
for (auto i : collections::range(0, arguments.size()))
{
const auto * array_type = typeid_cast<const DataTypeArray *>(arguments[i].get());
if (!array_type)
throw Exception("Argument " + std::to_string(i) + " for function " + getName() + " must be an array but it has type "
+ arguments[i]->getName() + ".", ErrorCodes::ILLEGAL_TYPE_OF_ARGUMENT);
}
return getLeastSupertype(arguments);
}
ColumnPtr executeImpl(const ColumnsWithTypeAndName & arguments, const DataTypePtr & result_type, size_t input_rows_count) const override
{
if (result_type->onlyNull())
return result_type->createColumnConstWithDefaultValue(input_rows_count);
size_t rows = input_rows_count;
size_t num_args = arguments.size();
Columns preprocessed_columns(num_args);
for (size_t i = 0; i < num_args; ++i)
{
const ColumnWithTypeAndName & arg = arguments[i];
ColumnPtr preprocessed_column = arg.column;
if (!arg.type->equals(*result_type))
preprocessed_column = castColumn(arg, result_type);
preprocessed_columns[i] = std::move(preprocessed_column);
}
std::vector<std::unique_ptr<GatherUtils::IArraySource>> sources;
for (auto & argument_column : preprocessed_columns)
{
bool is_const = false;
if (const auto * argument_column_const = typeid_cast<const ColumnConst *>(argument_column.get()))
{
is_const = true;
argument_column = argument_column_const->getDataColumnPtr();
}
if (const auto * argument_column_array = typeid_cast<const ColumnArray *>(argument_column.get()))
sources.emplace_back(GatherUtils::createArraySource(*argument_column_array, is_const, rows));
else
throw Exception{"Arguments for function " + getName() + " must be arrays.", ErrorCodes::LOGICAL_ERROR};
}
auto sink = GatherUtils::concat(sources);
return sink;
}
bool useDefaultImplementationForConstants() const override { return true; }
};
void registerFunctionArrayConcat(FunctionFactory & factory)
{
factory.registerFunction<FunctionArrayConcat>();
}
}