ClickHouse/src/Functions/formatReadable.h
2021-08-09 18:01:08 +03:00

110 lines
3.4 KiB
C++

#pragma once
#include <Functions/IFunction.h>
#include <Functions/FunctionHelpers.h>
#include <Columns/ColumnString.h>
#include <Columns/ColumnVector.h>
#include <DataTypes/DataTypeString.h>
#include <IO/WriteBufferFromVector.h>
#include <IO/WriteHelpers.h>
namespace DB
{
namespace ErrorCodes
{
extern const int ILLEGAL_TYPE_OF_ARGUMENT;
extern const int ILLEGAL_COLUMN;
}
/** formatReadableSize - prints the transferred size in bytes in form `123.45 GiB`.
* formatReadableQuantity - prints the quantity in form of 123 million.
*/
template <typename Impl>
class FunctionFormatReadable : public IFunction
{
public:
static constexpr auto name = Impl::name;
static FunctionPtr create(ContextPtr) { return std::make_shared<FunctionFormatReadable<Impl>>(); }
String getName() const override
{
return name;
}
bool isSuitableForShortCircuitArgumentsExecution(const DataTypesWithConstInfo & /*arguments*/) const override
{
return true;
}
size_t getNumberOfArguments() const override { return 1; }
DataTypePtr getReturnTypeImpl(const DataTypes & arguments) const override
{
const IDataType & type = *arguments[0];
if (!isNativeNumber(type))
throw Exception("Cannot format " + type.getName() + " because it's not a native numeric type", ErrorCodes::ILLEGAL_TYPE_OF_ARGUMENT);
return std::make_shared<DataTypeString>();
}
bool useDefaultImplementationForConstants() const override { return true; }
ColumnPtr executeImpl(const ColumnsWithTypeAndName & arguments, const DataTypePtr &, size_t /*input_rows_count*/) const override
{
ColumnPtr res;
if (!((res = executeType<UInt8>(arguments))
|| (res = executeType<UInt16>(arguments))
|| (res = executeType<UInt32>(arguments))
|| (res = executeType<UInt64>(arguments))
|| (res = executeType<Int8>(arguments))
|| (res = executeType<Int16>(arguments))
|| (res = executeType<Int32>(arguments))
|| (res = executeType<Int64>(arguments))
|| (res = executeType<Float32>(arguments))
|| (res = executeType<Float64>(arguments))))
throw Exception("Illegal column " + arguments[0].column->getName()
+ " of argument of function " + getName(),
ErrorCodes::ILLEGAL_COLUMN);
return res;
}
private:
template <typename T>
ColumnPtr executeType(const ColumnsWithTypeAndName & arguments) const
{
if (const ColumnVector<T> * col_from = checkAndGetColumn<ColumnVector<T>>(arguments[0].column.get()))
{
auto col_to = ColumnString::create();
const typename ColumnVector<T>::Container & vec_from = col_from->getData();
ColumnString::Chars & data_to = col_to->getChars();
ColumnString::Offsets & offsets_to = col_to->getOffsets();
size_t size = vec_from.size();
data_to.resize(size * 2);
offsets_to.resize(size);
WriteBufferFromVector<ColumnString::Chars> buf_to(data_to);
for (size_t i = 0; i < size; ++i)
{
Impl::format(static_cast<double>(vec_from[i]), buf_to);
writeChar(0, buf_to);
offsets_to[i] = buf_to.count();
}
buf_to.finalize();
return col_to;
}
return nullptr;
}
};
}