ClickHouse/src/Functions/filesystem.cpp
Li Yin 4088c0a7f3 Automated function registration
Automated register all functions with below naming convention by
iterating through the symbols:
void DB::registerXXX(DB::FunctionFactory &)
2022-07-29 15:39:50 +08:00

77 lines
2.2 KiB
C++

#include <Functions/IFunction.h>
#include <Functions/FunctionFactory.h>
#include <DataTypes/DataTypesNumber.h>
#include <Interpreters/Context.h>
#include <filesystem>
#include <Poco/Util/AbstractConfiguration.h>
namespace DB
{
namespace
{
struct FilesystemAvailable
{
static constexpr auto name = "filesystemAvailable";
static std::uintmax_t get(const std::filesystem::space_info & spaceinfo) { return spaceinfo.available; }
};
struct FilesystemFree
{
static constexpr auto name = "filesystemFree";
static std::uintmax_t get(const std::filesystem::space_info & spaceinfo) { return spaceinfo.free; }
};
struct FilesystemCapacity
{
static constexpr auto name = "filesystemCapacity";
static std::uintmax_t get(const std::filesystem::space_info & spaceinfo) { return spaceinfo.capacity; }
};
template <typename Impl>
class FilesystemImpl : public IFunction
{
public:
static constexpr auto name = Impl::name;
static FunctionPtr create(ContextPtr context)
{
return std::make_shared<FilesystemImpl<Impl>>(std::filesystem::space(context->getPath()));
}
bool isSuitableForShortCircuitArgumentsExecution(const DataTypesWithConstInfo & /*arguments*/) const override
{
return false;
}
explicit FilesystemImpl(std::filesystem::space_info spaceinfo_) : spaceinfo(spaceinfo_) { }
String getName() const override { return name; }
size_t getNumberOfArguments() const override { return 0; }
bool isDeterministic() const override { return false; }
DataTypePtr getReturnTypeImpl(const DataTypes & /*arguments*/) const override
{
return std::make_shared<DataTypeUInt64>();
}
ColumnPtr executeImpl(const ColumnsWithTypeAndName &, const DataTypePtr &, size_t input_rows_count) const override
{
return DataTypeUInt64().createColumnConst(input_rows_count, static_cast<UInt64>(Impl::get(spaceinfo)));
}
private:
std::filesystem::space_info spaceinfo;
};
}
REGISTER_FUNCTION(Filesystem)
{
factory.registerFunction<FilesystemImpl<FilesystemAvailable>>();
factory.registerFunction<FilesystemImpl<FilesystemCapacity>>();
factory.registerFunction<FilesystemImpl<FilesystemFree>>();
}
}