ClickHouse/src/Functions/addressToSymbol.cpp
Nikolai Kochetov 21c1a2e44d Part 2.
2020-10-17 18:22:42 +03:00

102 lines
2.9 KiB
C++

#if defined(__ELF__) && !defined(__FreeBSD__)
#include <Common/SymbolIndex.h>
#include <Columns/ColumnString.h>
#include <Columns/ColumnsNumber.h>
#include <DataTypes/DataTypeString.h>
#include <Functions/IFunctionImpl.h>
#include <Functions/FunctionFactory.h>
#include <Access/AccessFlags.h>
#include <Interpreters/Context.h>
#include <IO/WriteHelpers.h>
namespace DB
{
namespace ErrorCodes
{
extern const int ILLEGAL_COLUMN;
extern const int ILLEGAL_TYPE_OF_ARGUMENT;
extern const int NUMBER_OF_ARGUMENTS_DOESNT_MATCH;
}
namespace
{
class FunctionAddressToSymbol : public IFunction
{
public:
static constexpr auto name = "addressToSymbol";
static FunctionPtr create(const Context & context)
{
context.checkAccess(AccessType::addressToSymbol);
return std::make_shared<FunctionAddressToSymbol>();
}
String getName() const override
{
return name;
}
size_t getNumberOfArguments() const override
{
return 1;
}
DataTypePtr getReturnTypeImpl(const ColumnsWithTypeAndName & arguments) const override
{
if (arguments.size() != 1)
throw Exception("Function " + getName() + " needs exactly one argument; passed "
+ toString(arguments.size()) + ".", ErrorCodes::NUMBER_OF_ARGUMENTS_DOESNT_MATCH);
const auto & type = arguments[0].type;
if (!WhichDataType(type.get()).isUInt64())
throw Exception("The only argument for function " + getName() + " must be UInt64. Found "
+ type->getName() + " instead.", ErrorCodes::ILLEGAL_TYPE_OF_ARGUMENT);
return std::make_shared<DataTypeString>();
}
bool useDefaultImplementationForConstants() const override
{
return true;
}
ColumnPtr executeImpl(ColumnsWithTypeAndName & arguments, const DataTypePtr &, size_t input_rows_count) const override
{
const SymbolIndex & symbol_index = SymbolIndex::instance();
const ColumnPtr & column = arguments[0].column;
const ColumnUInt64 * column_concrete = checkAndGetColumn<ColumnUInt64>(column.get());
if (!column_concrete)
throw Exception("Illegal column " + column->getName() + " of argument of function " + getName(), ErrorCodes::ILLEGAL_COLUMN);
const typename ColumnVector<UInt64>::Container & data = column_concrete->getData();
auto result_column = ColumnString::create();
for (size_t i = 0; i < input_rows_count; ++i)
{
if (const auto * symbol = symbol_index.findSymbol(reinterpret_cast<const void *>(data[i])))
result_column->insertDataWithTerminatingZero(symbol->name, strlen(symbol->name) + 1);
else
result_column->insertDefault();
}
return result_column;
}
};
}
void registerFunctionAddressToSymbol(FunctionFactory & factory)
{
factory.registerFunction<FunctionAddressToSymbol>();
}
}
#endif