ClickHouse/src/TableFunctions/TableFunctionZeros.cpp
Ivan 495c6e03aa
Replace all Context references with std::weak_ptr ()
* Replace all Context references with std::weak_ptr

* Fix shared context captured by value

* Fix build

* Fix Context with named sessions

* Fix copy context

* Fix gcc build

* Merge with master and fix build

* Fix gcc-9 build
2021-04-11 02:33:54 +03:00

62 lines
2.1 KiB
C++

#include <TableFunctions/ITableFunction.h>
#include <TableFunctions/TableFunctionZeros.h>
#include <TableFunctions/TableFunctionFactory.h>
#include <Parsers/ASTFunction.h>
#include <Parsers/ASTLiteral.h>
#include <Storages/System/StorageSystemZeros.h>
#include <DataTypes/DataTypesNumber.h>
#include <Interpreters/evaluateConstantExpression.h>
#include <Interpreters/Context.h>
#include "registerTableFunctions.h"
namespace DB
{
namespace ErrorCodes
{
extern const int NUMBER_OF_ARGUMENTS_DOESNT_MATCH;
}
template <bool multithreaded>
ColumnsDescription TableFunctionZeros<multithreaded>::getActualTableStructure(ContextPtr /*context*/) const
{
/// NOTE: https://bugs.llvm.org/show_bug.cgi?id=47418
return ColumnsDescription{{{"zero", std::make_shared<DataTypeUInt8>()}}};
}
template <bool multithreaded>
StoragePtr TableFunctionZeros<multithreaded>::executeImpl(const ASTPtr & ast_function, ContextPtr context, const std::string & table_name, ColumnsDescription /*cached_columns*/) const
{
if (const auto * function = ast_function->as<ASTFunction>())
{
auto arguments = function->arguments->children;
if (arguments.size() != 1)
throw Exception("Table function '" + getName() + "' requires 'length'.", ErrorCodes::NUMBER_OF_ARGUMENTS_DOESNT_MATCH);
UInt64 length = evaluateArgument(context, arguments[0]);
auto res = StorageSystemZeros::create(StorageID(getDatabaseName(), table_name), multithreaded, length);
res->startup();
return res;
}
throw Exception("Table function '" + getName() + "' requires 'limit'.", ErrorCodes::NUMBER_OF_ARGUMENTS_DOESNT_MATCH);
}
void registerTableFunctionZeros(TableFunctionFactory & factory)
{
factory.registerFunction<TableFunctionZeros<true>>();
factory.registerFunction<TableFunctionZeros<false>>();
}
template <bool multithreaded>
UInt64 TableFunctionZeros<multithreaded>::evaluateArgument(ContextPtr context, ASTPtr & argument) const
{
return evaluateConstantExpressionOrIdentifierAsLiteral(argument, context)->as<ASTLiteral &>().value.safeGet<UInt64>();
}
}