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optimize map function

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taiyang-li 2024-08-04 16:16:51 +08:00
parent a498259ec8
commit 00a9c30363
1 changed files with 42 additions and 2 deletions
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44
src/Functions/map.cpp
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@ -32,11 +32,18 @@ class FunctionMap : public IFunction
public:
static constexpr auto name = "map";
explicit FunctionMap(bool use_variant_as_common_type_) : use_variant_as_common_type(use_variant_as_common_type_) {}
explicit FunctionMap(ContextPtr context_)
: context(std::move(context_))
, use_variant_as_common_type(
context->getSettingsRef().allow_experimental_variant_type && context->getSettingsRef().use_variant_as_common_type)
, function_array(FunctionFactory::instance().get("array", context))
, function_map_from_arrays(FunctionFactory::instance().get("mapFromArrays", context))
{
}
static FunctionPtr create(ContextPtr context)
{
return std::make_shared<FunctionMap>(context->getSettingsRef().allow_experimental_variant_type && context->getSettingsRef().use_variant_as_common_type);
return std::make_shared<FunctionMap>(std::move(context));
}
String getName() const override
@ -97,7 +104,36 @@ public:
ColumnPtr executeImpl(const ColumnsWithTypeAndName & arguments, const DataTypePtr & result_type, size_t input_rows_count) const override
{
size_t num_elements = arguments.size();
if (num_elements == 0)
return result_type->createColumnConstWithDefaultValue(input_rows_count);
ColumnsWithTypeAndName key_args;
ColumnsWithTypeAndName value_args;
for (size_t i = 0; i < num_elements; i += 2)
{
key_args.emplace_back(arguments[i]);
value_args.emplace_back(arguments[i+1]);
}
const auto & result_type_map = static_cast<const DataTypeMap &>(*result_type);
const DataTypePtr & key_type = result_type_map.getKeyType();
const DataTypePtr & value_type = result_type_map.getValueType();
const DataTypePtr & key_array_type = std::make_shared<DataTypeArray>(key_type);
const DataTypePtr & value_array_type = std::make_shared<DataTypeArray>(value_type);
/// key_array = array(args[0], args[2]...)
ColumnPtr key_array = function_array->build(key_args)->execute(key_args, key_array_type, input_rows_count);
/// value_array = array(args[1], args[3]...)
ColumnPtr value_array = function_array->build(value_args)->execute(value_args, value_array_type, input_rows_count);
/// result = mapFromArrays(key_array, value_array)
ColumnsWithTypeAndName map_args{{key_array, key_array_type, ""}, {value_array, value_array_type, ""}};
return function_map_from_arrays->build(map_args)->execute(map_args, result_type, input_rows_count);
}
/*
ColumnPtr executeImpl(const ColumnsWithTypeAndName & arguments, const DataTypePtr & result_type, size_t input_rows_count) const override
{
size_t num_elements = arguments.size();
if (num_elements == 0)
return result_type->createColumnConstWithDefaultValue(input_rows_count);
@ -164,9 +200,13 @@ public:
return ColumnMap::create(nested_column);
}
*/
private:
ContextPtr context;
bool use_variant_as_common_type = false;
FunctionOverloadResolverPtr function_array;
FunctionOverloadResolverPtr function_map_from_arrays;
};
/// mapFromArrays(keys, values) is a function that allows you to make key-value pair from a pair of arrays