ClickHouse/src/Functions/FunctionsMultiStringPosition.h
Robert Schulze 6df3c9d799
Merge pull request #39300 from ClickHouse/stringref-to-stringview
First try at reducing the use of StringRef
2022-07-18 19:20:16 +02:00

105 lines
4.5 KiB
C++

#pragma once
#include <Columns/ColumnArray.h>
#include <Columns/ColumnConst.h>
#include <Columns/ColumnString.h>
#include <Columns/ColumnFixedString.h>
#include <Columns/ColumnVector.h>
#include <DataTypes/DataTypeArray.h>
#include <DataTypes/DataTypeString.h>
#include <DataTypes/DataTypesNumber.h>
#include <Functions/FunctionHelpers.h>
#include <Functions/IFunction.h>
#include <IO/WriteHelpers.h>
#include <Interpreters/Context.h>
namespace DB
{
/**
* multiSearchAllPositions(haystack, [pattern_1, pattern_2, ..., pattern_n]) -- find first occurrences (positions) of all the const patterns inside haystack
* multiSearchAllPositionsUTF8(haystack, [pattern_1, pattern_2, ..., pattern_n])
* multiSearchAllPositionsCaseInsensitive(haystack, [pattern_1, pattern_2, ..., pattern_n])
* multiSearchAllPositionsCaseInsensitiveUTF8(haystack, [pattern_1, pattern_2, ..., pattern_n])
*/
namespace ErrorCodes
{
extern const int ILLEGAL_COLUMN;
extern const int ILLEGAL_TYPE_OF_ARGUMENT;
}
template <typename Impl>
class FunctionsMultiStringPosition : public IFunction
{
public:
static constexpr auto name = Impl::name;
static FunctionPtr create(ContextPtr) { return std::make_shared<FunctionsMultiStringPosition>(); }
String getName() const override { return name; }
size_t getNumberOfArguments() const override { return 2; }
bool useDefaultImplementationForConstants() const override { return true; }
bool isSuitableForShortCircuitArgumentsExecution(const DataTypesWithConstInfo & /*arguments*/) const override { return true; }
DataTypePtr getReturnTypeImpl(const DataTypes & arguments) const override
{
if (!isString(arguments[0]))
throw Exception(
ErrorCodes::ILLEGAL_TYPE_OF_ARGUMENT,
"Illegal type {} of argument of function {}", arguments[0]->getName(), getName());
const DataTypeArray * array_type = checkAndGetDataType<DataTypeArray>(arguments[1].get());
if (!array_type || !checkAndGetDataType<DataTypeString>(array_type->getNestedType().get()))
throw Exception(
ErrorCodes::ILLEGAL_TYPE_OF_ARGUMENT,
"Illegal type {} of argument of function {}", arguments[1]->getName(), getName());
return std::make_shared<DataTypeArray>(std::make_shared<DataTypeUInt64>());
}
ColumnPtr executeImpl(const ColumnsWithTypeAndName & arguments, const DataTypePtr &, size_t /*input_rows_count*/) const override
{
const ColumnPtr & haystack_ptr = arguments[0].column;
const ColumnPtr & needles_ptr = arguments[1].column;
const ColumnString * col_haystack_vector = checkAndGetColumn<ColumnString>(&*haystack_ptr);
const ColumnConst * col_haystack_const = checkAndGetColumnConst<ColumnString>(&*haystack_ptr);
assert(static_cast<bool>(col_haystack_vector) ^ static_cast<bool>(col_haystack_const));
const ColumnArray * col_needles_vector = checkAndGetColumn<ColumnArray>(needles_ptr.get());
const ColumnConst * col_needles_const = checkAndGetColumnConst<ColumnArray>(needles_ptr.get());
assert(static_cast<bool>(col_needles_vector) ^ static_cast<bool>(col_needles_const));
if (col_haystack_const && col_needles_vector)
throw Exception(ErrorCodes::ILLEGAL_COLUMN, "Function '{}' doesn't support search with non-constant needles in constant haystack", name);
using ResultType = typename Impl::ResultType;
auto col_res = ColumnVector<ResultType>::create();
auto col_offsets = ColumnArray::ColumnOffsets::create();
auto & vec_res = col_res->getData();
auto & offsets_res = col_offsets->getData();
/// the implementations are responsible for resizing the output column
if (col_needles_const)
Impl::vectorConstant(
col_haystack_vector->getChars(), col_haystack_vector->getOffsets(),
col_needles_const->getValue<Array>(),
vec_res, offsets_res);
else
Impl::vectorVector(
col_haystack_vector->getChars(), col_haystack_vector->getOffsets(),
col_needles_vector->getData(), col_needles_vector->getOffsets(),
vec_res, offsets_res);
// the combination of const haystack + const needle is not implemented because
// useDefaultImplementationForConstants() == true makes upper layers convert both to
// non-const columns
return ColumnArray::create(std::move(col_res), std::move(col_offsets));
}
};
}