mirror of
https://github.com/ClickHouse/ClickHouse.git
synced 2024-12-16 03:12:43 +00:00
330212e0f4
The original motivation for this commit was that shared_ptr_helper used std::shared_ptr<>() which does two heap allocations instead of make_shared<>() which does a single allocation. Turned out that 1. the affected code (--> Storages/) is not on a hot path (rendering the performance argument moot ...) 2. yet copying Storage objects is potentially dangerous and was previously allowed. Hence, this change - removes shared_ptr_helper and as a result all inherited create() methods, - instead, Storage objects are now created using make_shared<>() by the caller (for that to work, many constructors had to be made public), and - all Storage classes were marked as noncopyable using boost::noncopyable. In sum, we are (likely) not making things faster but the code becomes cleaner and harder to misuse.
68 lines
2.1 KiB
C++
68 lines
2.1 KiB
C++
#include <TableFunctions/TableFunctionDictionary.h>
|
|
|
|
#include <Parsers/ASTLiteral.h>
|
|
|
|
#include <Interpreters/Context.h>
|
|
#include <Interpreters/ExternalDictionariesLoader.h>
|
|
#include <Interpreters/evaluateConstantExpression.h>
|
|
|
|
#include <Storages/StorageDictionary.h>
|
|
|
|
#include <TableFunctions/TableFunctionFactory.h>
|
|
|
|
namespace DB
|
|
{
|
|
|
|
namespace ErrorCodes
|
|
{
|
|
extern const int LOGICAL_ERROR;
|
|
extern const int NUMBER_OF_ARGUMENTS_DOESNT_MATCH;
|
|
}
|
|
|
|
void TableFunctionDictionary::parseArguments(const ASTPtr & ast_function, ContextPtr context)
|
|
{
|
|
// Parse args
|
|
ASTs & args_func = ast_function->children;
|
|
|
|
if (args_func.size() != 1)
|
|
throw Exception(ErrorCodes::LOGICAL_ERROR, "Table function ({}) must have arguments.", quoteString(getName()));
|
|
|
|
ASTs & args = args_func.at(0)->children;
|
|
|
|
if (args.size() != 1)
|
|
throw Exception(ErrorCodes::NUMBER_OF_ARGUMENTS_DOESNT_MATCH, "Table function ({}) requires 1 arguments", quoteString(getName()));
|
|
|
|
for (auto & arg : args)
|
|
arg = evaluateConstantExpressionOrIdentifierAsLiteral(arg, context);
|
|
|
|
dictionary_name = args[0]->as<ASTLiteral &>().value.safeGet<String>();
|
|
}
|
|
|
|
ColumnsDescription TableFunctionDictionary::getActualTableStructure(ContextPtr context) const
|
|
{
|
|
const ExternalDictionariesLoader & external_loader = context->getExternalDictionariesLoader();
|
|
auto dictionary_structure = external_loader.getDictionaryStructure(dictionary_name, context);
|
|
auto result = ColumnsDescription(StorageDictionary::getNamesAndTypes(dictionary_structure));
|
|
|
|
return result;
|
|
}
|
|
|
|
StoragePtr TableFunctionDictionary::executeImpl(
|
|
const ASTPtr &, ContextPtr context, const std::string & table_name, ColumnsDescription) const
|
|
{
|
|
StorageID dict_id(getDatabaseName(), table_name);
|
|
auto dictionary_table_structure = getActualTableStructure(context);
|
|
|
|
auto result = std::make_shared<StorageDictionary>(
|
|
dict_id, dictionary_name, std::move(dictionary_table_structure), String{}, StorageDictionary::Location::Custom, context);
|
|
|
|
return result;
|
|
}
|
|
|
|
void registerTableFunctionDictionary(TableFunctionFactory & factory)
|
|
{
|
|
factory.registerFunction<TableFunctionDictionary>();
|
|
}
|
|
|
|
}
|