ClickHouse/dbms/include/DB/Functions/FunctionsConversion.h
2015-05-04 20:52:19 +03:00

634 lines
27 KiB
C++
Raw Blame History

This file contains ambiguous Unicode characters

This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

#pragma once
#include <DB/IO/WriteBufferFromVector.h>
#include <DB/IO/ReadBufferFromString.h>
#include <DB/DataTypes/DataTypesNumberFixed.h>
#include <DB/DataTypes/DataTypeString.h>
#include <DB/DataTypes/DataTypeFixedString.h>
#include <DB/DataTypes/DataTypeDate.h>
#include <DB/DataTypes/DataTypeDateTime.h>
#include <DB/Columns/ColumnString.h>
#include <DB/Columns/ColumnFixedString.h>
#include <DB/Columns/ColumnConst.h>
#include <DB/Functions/IFunction.h>
#include <statdaemons/ext/range.hpp>
namespace DB
{
/** Функции преобразования типов.
* toType - преобразование "естественным образом";
*/
/** Преобразование чисел друг в друга, дат/дат-с-временем в числа и наоборот: делается обычным присваиванием.
* (дата внутри хранится как количество дней с какого-то, дата-с-временем - как unix timestamp)
*/
template <typename FromDataType, typename ToDataType, typename Name>
struct ConvertImpl
{
typedef typename FromDataType::FieldType FromFieldType;
typedef typename ToDataType::FieldType ToFieldType;
static void execute(Block & block, const ColumnNumbers & arguments, size_t result)
{
if (const ColumnVector<FromFieldType> * col_from = typeid_cast<const ColumnVector<FromFieldType> *>(&*block.getByPosition(arguments[0]).column))
{
ColumnVector<ToFieldType> * col_to = new ColumnVector<ToFieldType>;
block.getByPosition(result).column = col_to;
const typename ColumnVector<FromFieldType>::Container_t & vec_from = col_from->getData();
typename ColumnVector<ToFieldType>::Container_t & vec_to = col_to->getData();
size_t size = vec_from.size();
vec_to.resize(size);
for (size_t i = 0; i < size; ++i)
vec_to[i] = vec_from[i];
}
else if (const ColumnConst<FromFieldType> * col_from = typeid_cast<const ColumnConst<FromFieldType> *>(&*block.getByPosition(arguments[0]).column))
{
block.getByPosition(result).column = new ColumnConst<ToFieldType>(col_from->size(), col_from->getData());
}
else
throw Exception("Illegal column " + block.getByPosition(arguments[0]).column->getName()
+ " of first argument of function " + Name::name,
ErrorCodes::ILLEGAL_COLUMN);
}
};
/** Преобразование даты в дату-с-временем: добавление нулевого времени.
*/
template <typename Name>
struct ConvertImpl<DataTypeDate, DataTypeDateTime, Name>
{
typedef DataTypeDate::FieldType FromFieldType;
typedef DataTypeDateTime::FieldType ToFieldType;
static void execute(Block & block, const ColumnNumbers & arguments, size_t result)
{
typedef DataTypeDate::FieldType FromFieldType;
DateLUT & date_lut = DateLUT::instance();
if (const ColumnVector<FromFieldType> * col_from = typeid_cast<const ColumnVector<FromFieldType> *>(&*block.getByPosition(arguments[0]).column))
{
ColumnVector<ToFieldType> * col_to = new ColumnVector<ToFieldType>;
block.getByPosition(result).column = col_to;
const typename ColumnVector<FromFieldType>::Container_t & vec_from = col_from->getData();
typename ColumnVector<ToFieldType>::Container_t & vec_to = col_to->getData();
size_t size = vec_from.size();
vec_to.resize(size);
for (size_t i = 0; i < size; ++i)
{
vec_to[i] = date_lut.fromDayNum(DayNum_t(vec_from[i]));
}
}
else if (const ColumnConst<FromFieldType> * col_from = typeid_cast<const ColumnConst<FromFieldType> *>(&*block.getByPosition(arguments[0]).column))
{
block.getByPosition(result).column = new ColumnConst<ToFieldType>(col_from->size(), date_lut.fromDayNum(DayNum_t(col_from->getData())));
}
else
throw Exception("Illegal column " + block.getByPosition(arguments[0]).column->getName()
+ " of first argument of function " + Name::name,
ErrorCodes::ILLEGAL_COLUMN);
}
};
/** Преобразование даты-с-временем в дату: отбрасывание времени.
*/
template <typename Name>
struct ConvertImpl<DataTypeDateTime, DataTypeDate, Name>
{
typedef DataTypeDateTime::FieldType FromFieldType;
typedef DataTypeDate::FieldType ToFieldType;
static void execute(Block & block, const ColumnNumbers & arguments, size_t result)
{
DateLUT & date_lut = DateLUT::instance();
if (const ColumnVector<FromFieldType> * col_from = typeid_cast<const ColumnVector<FromFieldType> *>(&*block.getByPosition(arguments[0]).column))
{
ColumnVector<ToFieldType> * col_to = new ColumnVector<ToFieldType>;
block.getByPosition(result).column = col_to;
const typename ColumnVector<FromFieldType>::Container_t & vec_from = col_from->getData();
typename ColumnVector<ToFieldType>::Container_t & vec_to = col_to->getData();
size_t size = vec_from.size();
vec_to.resize(size);
for (size_t i = 0; i < size; ++i)
vec_to[i] = date_lut.toDayNum(vec_from[i]);
}
else if (const ColumnConst<FromFieldType> * col_from = typeid_cast<const ColumnConst<FromFieldType> *>(&*block.getByPosition(arguments[0]).column))
{
block.getByPosition(result).column = new ColumnConst<ToFieldType>(col_from->size(), date_lut.toDayNum(col_from->getData()));
}
else
throw Exception("Illegal column " + block.getByPosition(arguments[0]).column->getName()
+ " of first argument of function " + Name::name,
ErrorCodes::ILLEGAL_COLUMN);
}
};
/** Отдельный случай для преобразования (U)Int32 или (U)Int64 в Date.
* Если число меньше 65536, то оно понимается, как DayNum, а если больше - как unix timestamp.
* Немного нелогично, что мы, по сути, помещаем две разные функции в одну.
* Но зато это позволяет поддержать распространённый случай,
* когда пользователь пишет toDate(UInt32), ожидая, что это - перевод unix timestamp в дату
* (иначе такое использование было бы распространённой ошибкой).
*/
template <typename FromDataType, typename Name>
struct ConvertImpl32Or64ToDate
{
typedef typename FromDataType::FieldType FromFieldType;
typedef DataTypeDate::FieldType ToFieldType;
template <typename To, typename From>
static To convert(const From & from, const DateLUT & date_lut)
{
return from < 0xFFFF
? from
: date_lut.toDayNum(from);
}
static void execute(Block & block, const ColumnNumbers & arguments, size_t result)
{
DateLUT & date_lut = DateLUT::instance();
if (const ColumnVector<FromFieldType> * col_from
= typeid_cast<const ColumnVector<FromFieldType> *>(&*block.getByPosition(arguments[0]).column))
{
ColumnVector<ToFieldType> * col_to = new ColumnVector<ToFieldType>;
block.getByPosition(result).column = col_to;
const typename ColumnVector<FromFieldType>::Container_t & vec_from = col_from->getData();
typename ColumnVector<ToFieldType>::Container_t & vec_to = col_to->getData();
size_t size = vec_from.size();
vec_to.resize(size);
for (size_t i = 0; i < size; ++i)
vec_to[i] = convert<ToFieldType>(vec_from[i], date_lut);
}
else if (const ColumnConst<FromFieldType> * col_from
= typeid_cast<const ColumnConst<FromFieldType> *>(&*block.getByPosition(arguments[0]).column))
{
block.getByPosition(result).column = new ColumnConst<ToFieldType>(col_from->size(),
convert<ToFieldType>(col_from->getData(), date_lut));
}
else
throw Exception("Illegal column " + block.getByPosition(arguments[0]).column->getName()
+ " of first argument of function " + Name::name,
ErrorCodes::ILLEGAL_COLUMN);
}
};
template <typename Name> struct ConvertImpl<DataTypeUInt32, DataTypeDate, Name> : ConvertImpl32Or64ToDate<DataTypeUInt32, Name> {};
template <typename Name> struct ConvertImpl<DataTypeUInt64, DataTypeDate, Name> : ConvertImpl32Or64ToDate<DataTypeUInt64, Name> {};
template <typename Name> struct ConvertImpl<DataTypeInt32, DataTypeDate, Name> : ConvertImpl32Or64ToDate<DataTypeInt32, Name> {};
template <typename Name> struct ConvertImpl<DataTypeInt64, DataTypeDate, Name> : ConvertImpl32Or64ToDate<DataTypeInt64, Name> {};
/** Преобразование чисел, дат, дат-с-временем в строки: через форматирование.
*/
template <typename DataType> void formatImpl(typename DataType::FieldType x, WriteBuffer & wb) { writeText(x, wb); }
template <> inline void formatImpl<DataTypeDate>(DataTypeDate::FieldType x, WriteBuffer & wb) { writeDateText(DayNum_t(x), wb); }
template <> inline void formatImpl<DataTypeDateTime>(DataTypeDateTime::FieldType x, WriteBuffer & wb) { writeDateTimeText(x, wb); }
template <typename FromDataType, typename Name>
struct ConvertImpl<FromDataType, DataTypeString, Name>
{
typedef typename FromDataType::FieldType FromFieldType;
static void execute(Block & block, const ColumnNumbers & arguments, size_t result)
{
if (const ColumnVector<FromFieldType> * col_from = typeid_cast<const ColumnVector<FromFieldType> *>(&*block.getByPosition(arguments[0]).column))
{
ColumnString * col_to = new ColumnString;
block.getByPosition(result).column = col_to;
const typename ColumnVector<FromFieldType>::Container_t & vec_from = col_from->getData();
ColumnString::Chars_t & data_to = col_to->getChars();
ColumnString::Offsets_t & offsets_to = col_to->getOffsets();
size_t size = vec_from.size();
data_to.resize(size * 2);
offsets_to.resize(size);
WriteBufferFromVector<ColumnString::Chars_t> write_buffer(data_to);
for (size_t i = 0; i < size; ++i)
{
formatImpl<FromDataType>(vec_from[i], write_buffer);
writeChar(0, write_buffer);
offsets_to[i] = write_buffer.count();
}
data_to.resize(write_buffer.count());
}
else if (const ColumnConst<FromFieldType> * col_from = typeid_cast<const ColumnConst<FromFieldType> *>(&*block.getByPosition(arguments[0]).column))
{
std::vector<char> buf;
WriteBufferFromVector<std::vector<char> > write_buffer(buf);
formatImpl<FromDataType>(col_from->getData(), write_buffer);
block.getByPosition(result).column = new ColumnConstString(col_from->size(), std::string(&buf[0], write_buffer.count()));
}
else
throw Exception("Illegal column " + block.getByPosition(arguments[0]).column->getName()
+ " of first argument of function " + Name::name,
ErrorCodes::ILLEGAL_COLUMN);
}
};
/** Преобразование строк в числа, даты, даты-с-временем: через парсинг.
*/
template <typename DataType> void parseImpl(typename DataType::FieldType & x, ReadBuffer & rb) { readText(x,rb); }
template <> inline void parseImpl<DataTypeDate>(DataTypeDate::FieldType & x, ReadBuffer & rb)
{
DayNum_t tmp(0);
readDateText(tmp, rb);
x = tmp;
}
template <> inline void parseImpl<DataTypeDateTime>(DataTypeDateTime::FieldType & x, ReadBuffer & rb)
{
time_t tmp = 0;
readDateTimeText(tmp, rb);
x = tmp;
}
template <typename ToDataType, typename Name>
struct ConvertImpl<DataTypeString, ToDataType, Name>
{
typedef typename ToDataType::FieldType ToFieldType;
static void execute(Block & block, const ColumnNumbers & arguments, size_t result)
{
if (const ColumnString * col_from = typeid_cast<const ColumnString *>(&*block.getByPosition(arguments[0]).column))
{
ColumnVector<ToFieldType> * col_to = new ColumnVector<ToFieldType>;
block.getByPosition(result).column = col_to;
const ColumnString::Chars_t & data_from = col_from->getChars();
typename ColumnVector<ToFieldType>::Container_t & vec_to = col_to->getData();
size_t size = col_from->size();
vec_to.resize(size);
ReadBuffer read_buffer(const_cast<char *>(reinterpret_cast<const char *>(&data_from[0])), data_from.size(), 0);
char zero = 0;
for (size_t i = 0; i < size; ++i)
{
parseImpl<ToDataType>(vec_to[i], read_buffer);
readChar(zero, read_buffer);
if (zero != 0)
throw Exception("Cannot parse from string.", ErrorCodes::CANNOT_PARSE_NUMBER);
}
}
else if (const ColumnConstString * col_from = typeid_cast<const ColumnConstString *>(&*block.getByPosition(arguments[0]).column))
{
const String & s = col_from->getData();
ReadBufferFromString read_buffer(s);
ToFieldType x = 0;
parseImpl<ToDataType>(x, read_buffer);
block.getByPosition(result).column = new ColumnConst<ToFieldType>(col_from->size(), x);
}
else
throw Exception("Illegal column " + block.getByPosition(arguments[0]).column->getName()
+ " of first argument of function " + Name::name,
ErrorCodes::ILLEGAL_COLUMN);
}
};
/** Если типы совпадают - просто скопируем ссылку на столбец.
*/
template <typename Name>
struct ConvertImpl<DataTypeString, DataTypeString, Name>
{
static void execute(Block & block, const ColumnNumbers & arguments, size_t result)
{
block.getByPosition(result).column = block.getByPosition(arguments[0]).column;
}
};
/** Преобразование из FixedString.
*/
template <typename ToDataType, typename Name>
struct ConvertImpl<DataTypeFixedString, ToDataType, Name>
{
typedef typename ToDataType::FieldType ToFieldType;
static void execute(Block & block, const ColumnNumbers & arguments, size_t result)
{
if (const ColumnFixedString * col_from = typeid_cast<const ColumnFixedString *>(&*block.getByPosition(arguments[0]).column))
{
ColumnVector<ToFieldType> * col_to = new ColumnVector<ToFieldType>;
block.getByPosition(result).column = col_to;
const ColumnFixedString::Chars_t & data_from = col_from->getChars();
size_t n = col_from->getN();
typename ColumnVector<ToFieldType>::Container_t & vec_to = col_to->getData();
size_t size = col_from->size();
vec_to.resize(size);
for (size_t i = 0; i < size; ++i)
{
char * begin = const_cast<char *>(reinterpret_cast<const char *>(&data_from[i * n]));
char * end = begin + n;
ReadBuffer read_buffer(begin, n, 0);
parseImpl<ToDataType>(vec_to[i], read_buffer);
if (!read_buffer.eof())
{
while (read_buffer.position() < end && *read_buffer.position() == 0)
++read_buffer.position();
if (read_buffer.position() < end)
throw Exception("Cannot parse from fixed string.", ErrorCodes::CANNOT_PARSE_NUMBER);
}
}
}
else if (typeid_cast<const ColumnConstString *>(&*block.getByPosition(arguments[0]).column))
{
ConvertImpl<DataTypeString, ToDataType, Name>::execute(block, arguments, result);
}
else
throw Exception("Illegal column " + block.getByPosition(arguments[0]).column->getName()
+ " of first argument of function " + Name::name,
ErrorCodes::ILLEGAL_COLUMN);
}
};
/** Преобразование из FixedString в String.
* При этом, вырезаются последовательности нулевых байт с конца строк.
*/
template <typename Name>
struct ConvertImpl<DataTypeFixedString, DataTypeString, Name>
{
static void execute(Block & block, const ColumnNumbers & arguments, size_t result)
{
if (const ColumnFixedString * col_from = typeid_cast<const ColumnFixedString *>(&*block.getByPosition(arguments[0]).column))
{
ColumnString * col_to = new ColumnString;
block.getByPosition(result).column = col_to;
const ColumnFixedString::Chars_t & data_from = col_from->getChars();
ColumnString::Chars_t & data_to = col_to->getChars();
ColumnString::Offsets_t & offsets_to = col_to->getOffsets();
size_t size = col_from->size();
size_t n = col_from->getN();
data_to.resize(size * (n + 1)); /// + 1 - нулевой байт
offsets_to.resize(size);
size_t offset_from = 0;
size_t offset_to = 0;
for (size_t i = 0; i < size; ++i)
{
size_t bytes_to_copy = n;
while (bytes_to_copy > 0 && data_from[offset_from + bytes_to_copy - 1] == 0)
--bytes_to_copy;
memcpy(&data_to[offset_to], &data_from[offset_from], bytes_to_copy);
offset_from += n;
offset_to += bytes_to_copy;
data_to[offset_to] = 0;
++offset_to;
offsets_to[i] = offset_to;
}
data_to.resize(offset_to);
}
else if (const ColumnConstString * col_from = typeid_cast<const ColumnConstString *>(&*block.getByPosition(arguments[0]).column))
{
const String & s = col_from->getData();
size_t bytes_to_copy = s.size();
while (bytes_to_copy > 0 && s[bytes_to_copy - 1] == 0)
--bytes_to_copy;
block.getByPosition(result).column = new ColumnConstString(col_from->size(), s.substr(0, bytes_to_copy));
}
else
throw Exception("Illegal column " + block.getByPosition(arguments[0]).column->getName()
+ " of first argument of function " + Name::name,
ErrorCodes::ILLEGAL_COLUMN);
}
};
template <typename ToDataType, typename Name>
class FunctionConvert : public IFunction
{
public:
static constexpr auto name = Name::name;
static IFunction * create(const Context & context) { return new FunctionConvert; }
/// Получить имя функции.
String getName() const
{
return name;
}
/// Получить тип результата по типам аргументов. Если функция неприменима для данных аргументов - кинуть исключение.
DataTypePtr getReturnType(const DataTypes & arguments) const
{
if (arguments.size() != 1)
throw Exception("Number of arguments for function " + getName() + " doesn't match: passed "
+ toString(arguments.size()) + ", should be 1.",
ErrorCodes::NUMBER_OF_ARGUMENTS_DOESNT_MATCH);
return new ToDataType;
}
/// Выполнить функцию над блоком.
void execute(Block & block, const ColumnNumbers & arguments, size_t result)
{
IDataType * from_type = &*block.getByPosition(arguments[0]).type;
if (typeid_cast<const DataTypeUInt8 * >(from_type)) ConvertImpl<DataTypeUInt8, ToDataType, Name>::execute(block, arguments, result);
else if (typeid_cast<const DataTypeUInt16 * >(from_type)) ConvertImpl<DataTypeUInt16, ToDataType, Name>::execute(block, arguments, result);
else if (typeid_cast<const DataTypeUInt32 * >(from_type)) ConvertImpl<DataTypeUInt32, ToDataType, Name>::execute(block, arguments, result);
else if (typeid_cast<const DataTypeUInt64 * >(from_type)) ConvertImpl<DataTypeUInt64, ToDataType, Name>::execute(block, arguments, result);
else if (typeid_cast<const DataTypeInt8 * >(from_type)) ConvertImpl<DataTypeInt8, ToDataType, Name>::execute(block, arguments, result);
else if (typeid_cast<const DataTypeInt16 * >(from_type)) ConvertImpl<DataTypeInt16, ToDataType, Name>::execute(block, arguments, result);
else if (typeid_cast<const DataTypeInt32 * >(from_type)) ConvertImpl<DataTypeInt32, ToDataType, Name>::execute(block, arguments, result);
else if (typeid_cast<const DataTypeInt64 * >(from_type)) ConvertImpl<DataTypeInt64, ToDataType, Name>::execute(block, arguments, result);
else if (typeid_cast<const DataTypeFloat32 * >(from_type)) ConvertImpl<DataTypeFloat32, ToDataType, Name>::execute(block, arguments, result);
else if (typeid_cast<const DataTypeFloat64 * >(from_type)) ConvertImpl<DataTypeFloat64, ToDataType, Name>::execute(block, arguments, result);
else if (typeid_cast<const DataTypeDate * >(from_type)) ConvertImpl<DataTypeDate, ToDataType, Name>::execute(block, arguments, result);
else if (typeid_cast<const DataTypeDateTime * >(from_type)) ConvertImpl<DataTypeDateTime, ToDataType, Name>::execute(block, arguments, result);
else if (typeid_cast<const DataTypeString * >(from_type)) ConvertImpl<DataTypeString, ToDataType, Name>::execute(block, arguments, result);
else if (typeid_cast<const DataTypeFixedString *>(from_type)) ConvertImpl<DataTypeFixedString, ToDataType, Name>::execute(block, arguments, result);
else
throw Exception("Illegal type " + block.getByPosition(arguments[0]).type->getName() + " of argument of function " + getName(),
ErrorCodes::ILLEGAL_TYPE_OF_ARGUMENT);
}
};
/** Преобразование в строку фиксированной длины реализовано только из строк.
*/
class FunctionToFixedString : public IFunction
{
public:
static constexpr auto name = "toFixedString";
static IFunction * create(const Context & context) { return new FunctionToFixedString; };
/// Получить имя функции.
String getName() const
{
return name;
}
/** Получить тип результата по типам аргументов и значениям константных аргументов.
* Если функция неприменима для данных аргументов - кинуть исключение.
* Для неконстантных столбцов arguments[i].column = nullptr.
*/
void getReturnTypeAndPrerequisites(const ColumnsWithNameAndType & arguments,
DataTypePtr & out_return_type,
std::vector<ExpressionAction> & out_prerequisites)
{
if (arguments.size() != 2)
throw Exception("Number of arguments for function " + getName() + " doesn't match: passed "
+ toString(arguments.size()) + ", should be 2.",
ErrorCodes::NUMBER_OF_ARGUMENTS_DOESNT_MATCH);
if (!arguments[1].column)
throw Exception("Second argument for function " + getName() + " must be constant", ErrorCodes::ILLEGAL_COLUMN);
if (!typeid_cast<const DataTypeString *>(arguments[0].type.get()) &&
!typeid_cast<const DataTypeFixedString *>(arguments[0].type.get()))
throw Exception(getName() + " is only implemented for types String and FixedString", ErrorCodes::NOT_IMPLEMENTED);
const size_t n = getSize(arguments[1]);
out_return_type = new DataTypeFixedString(n);
}
/// Выполнить функцию над блоком.
void execute(Block & block, const ColumnNumbers & arguments, size_t result)
{
ColumnPtr column = block.getByPosition(arguments[0]).column;
size_t n = getSize(block.getByPosition(arguments[1]));
if (const ColumnConstString * column_const = typeid_cast<const ColumnConstString *>(&*column))
{
if (column_const->getData().size() > n)
throw Exception("String too long for type FixedString(" + toString(n) + ")",
ErrorCodes::TOO_LARGE_STRING_SIZE);
auto resized_string = column_const->getData();
resized_string.resize(n);
block.getByPosition(result).column = new ColumnConst<String>(column_const->size(), std::move(resized_string), new DataTypeFixedString(n));
}
else if (const ColumnString * column_string = typeid_cast<const ColumnString *>(&*column))
{
ColumnFixedString * column_fixed = new ColumnFixedString(n);
ColumnPtr result_ptr = column_fixed;
ColumnFixedString::Chars_t & out_chars = column_fixed->getChars();
const ColumnString::Chars_t & in_chars = column_string->getChars();
const ColumnString::Offsets_t & in_offsets = column_string->getOffsets();
out_chars.resize_fill(in_offsets.size() * n);
for (size_t i = 0; i < in_offsets.size(); ++i)
{
size_t off = i ? in_offsets[i - 1] : 0;
size_t len = in_offsets[i] - off - 1;
if (len > n)
throw Exception("String too long for type FixedString(" + toString(n) + ")",
ErrorCodes::TOO_LARGE_STRING_SIZE);
memcpy(&out_chars[i * n], &in_chars[off], len);
}
block.getByPosition(result).column = result_ptr;
}
else if (const auto column_fixed_string = typeid_cast<const ColumnFixedString *>(column.get()))
{
const auto src_n = column_fixed_string->getN();
if (src_n > n)
throw Exception{
"String too long for type FixedString(" + toString(n) + ")",
ErrorCodes::TOO_LARGE_STRING_SIZE
};
const auto column_fixed = new ColumnFixedString{n};
block.getByPosition(result).column = column_fixed;
auto & out_chars = column_fixed->getChars();
const auto & in_chars = column_fixed_string->getChars();
const auto size = column_fixed_string->size();
out_chars.resize_fill(size * n);
for (const auto i : ext::range(0, size))
memcpy(&out_chars[i * n], &in_chars[i * src_n], src_n);
}
else
throw Exception("Unexpected column: " + column->getName(), ErrorCodes::ILLEGAL_COLUMN);
}
private:
template <typename T>
bool getSizeTyped(const ColumnWithNameAndType & column, size_t & out_size)
{
if (!typeid_cast<const typename DataTypeFromFieldType<T>::Type *>(&*column.type))
return false;
const ColumnConst<T> * column_const = typeid_cast<const ColumnConst<T> *>(&*column.column);
if (!column_const)
throw Exception("Unexpected type of column for FixedString length: " + column.column->getName(), ErrorCodes::ILLEGAL_COLUMN);
T s = column_const->getData();
if (s <= 0)
throw Exception("FixedString length must be positive (unlike " + toString(s) + ")", ErrorCodes::ILLEGAL_COLUMN);
out_size = static_cast<size_t>(s);
return true;
}
size_t getSize(const ColumnWithNameAndType & column)
{
size_t res;
if (getSizeTyped<UInt8>(column, res) ||
getSizeTyped<UInt16>(column, res) ||
getSizeTyped<UInt32>(column, res) ||
getSizeTyped<UInt64>(column, res) ||
getSizeTyped< Int8 >(column, res) ||
getSizeTyped< Int16>(column, res) ||
getSizeTyped< Int32>(column, res) ||
getSizeTyped< Int64>(column, res))
return res;
throw Exception("Length of FixedString must be integer; got " + column.type->getName(), ErrorCodes::ILLEGAL_TYPE_OF_ARGUMENT);
}
};
struct NameToUInt8 { static constexpr auto name = "toUInt8"; };
struct NameToUInt16 { static constexpr auto name = "toUInt16"; };
struct NameToUInt32 { static constexpr auto name = "toUInt32"; };
struct NameToUInt64 { static constexpr auto name = "toUInt64"; };
struct NameToInt8 { static constexpr auto name = "toInt8"; };
struct NameToInt16 { static constexpr auto name = "toInt16"; };
struct NameToInt32 { static constexpr auto name = "toInt32"; };
struct NameToInt64 { static constexpr auto name = "toInt64"; };
struct NameToFloat32 { static constexpr auto name = "toFloat32"; };
struct NameToFloat64 { static constexpr auto name = "toFloat64"; };
struct NameToDate { static constexpr auto name = "toDate"; };
struct NameToDateTime { static constexpr auto name = "toDateTime"; };
struct NameToString { static constexpr auto name = "toString"; };
typedef FunctionConvert<DataTypeUInt8, NameToUInt8> FunctionToUInt8;
typedef FunctionConvert<DataTypeUInt16, NameToUInt16> FunctionToUInt16;
typedef FunctionConvert<DataTypeUInt32, NameToUInt32> FunctionToUInt32;
typedef FunctionConvert<DataTypeUInt64, NameToUInt64> FunctionToUInt64;
typedef FunctionConvert<DataTypeInt8, NameToInt8> FunctionToInt8;
typedef FunctionConvert<DataTypeInt16, NameToInt16> FunctionToInt16;
typedef FunctionConvert<DataTypeInt32, NameToInt32> FunctionToInt32;
typedef FunctionConvert<DataTypeInt64, NameToInt64> FunctionToInt64;
typedef FunctionConvert<DataTypeFloat32, NameToFloat32> FunctionToFloat32;
typedef FunctionConvert<DataTypeFloat64, NameToFloat64> FunctionToFloat64;
typedef FunctionConvert<DataTypeDate, NameToDate> FunctionToDate;
typedef FunctionConvert<DataTypeDateTime, NameToDateTime> FunctionToDateTime;
typedef FunctionConvert<DataTypeString, NameToString> FunctionToString;
}