iceberg::Decimal Class Reference

Represents 128-bit fixed-point decimal numbers. The max decimal precision that can be safely represented is 38 significant digits. More...

#include <decimal.h>

Inheritance diagram for iceberg::Decimal:

Public Member Functions
constexpr	Decimal () noexcept=default
	Default constructor initializes to zero.
constexpr	Decimal (int128_t value) noexcept
	Create a Decimal from a 128-bit integer.
template<typename T > requires (std::is_integral_v<T> && (sizeof(T) <= sizeof(uint64_t)))
constexpr	Decimal (T value) noexcept
	Create a Decimal from any integer not wider than 64 bits.
	Decimal (std::string_view str)
	Parse a Decimal from a string representation.
constexpr	Decimal (int64_t high, uint64_t low) noexcept
	Create a Decimal from two 64-bit integers.
Decimal &	Negate ()
	Negate the current Decimal value (in place)
Decimal &	Abs ()
	Absolute value of the current Decimal value (in place)
Decimal &	operator+= (const Decimal &other)
	Add a number to this one. The result is truncated to 128 bits.
Decimal &	operator-= (const Decimal &other)
	Subtract a number from this one. The result is truncated to 128 bits.
Decimal &	operator*= (const Decimal &other)
	Multiply this number by another. The result is truncated to 128 bits.
Result< std::pair< Decimal, Decimal > >	Divide (const Decimal &divisor) const
	Divide this number by another.
Decimal &	operator/= (const Decimal &other)
	In place division.
Decimal &	operator|= (const Decimal &other)
	Bitwise OR operation.
Decimal &	operator&= (const Decimal &other)
	Bitwise AND operation.
Decimal &	operator<<= (uint32_t shift)
	Shift left by the given number of bits (in place).
Decimal	operator<< (uint32_t shift) const
	Shift left by the given number of bits.
Decimal &	operator>>= (uint32_t shift)
	Shift right by the given number of bits (in place).
Decimal	operator>> (uint32_t shift) const
	Shift right by the given number of bits.
constexpr int128_t	value () const
	Get the underlying 128-bit integer representation of the number.
constexpr int64_t	high () const
	Get the high bits of the two's complement representation of the number.
constexpr uint64_t	low () const
	Get the low bits of the two's complement representation of the number.
Result< std::string >	ToString (int32_t scale) const
	Convert the Decimal value to a base 10 decimal string with the given scale.
std::string	ToIntegerString () const
	Convert the Decimal value to an integer string.
std::string	ToString () const override
	Returns an integer string representation of the decimal value.
std::vector< uint8_t >	ToBigEndian () const
	Convert Decimal's unscaled value to two’s-complement big-endian binary, using the minimum number of bytes for the value.
Result< Decimal >	Rescale (int32_t orig_scale, int32_t new_scale) const
	Convert Decimal from one scale to another.
bool	FitsInPrecision (int32_t precision) const
	Whether this number fits in the given precision.
std::strong_ordering	operator<=> (const Decimal &other) const
	Spaceship operator for three-way comparison.
const uint8_t *	native_endian_bytes () const
std::array< uint8_t, kByteWidth >	ToBytes () const
	Returns the raw bytes of the value in native-endian byte order.
int64_t	Sign () const
	Returns 1 if positive or zero, -1 if strictly negative.
bool	IsNegative () const
	Check if the Decimal value is negative.
	operator bool () const

Static Public Member Functions
static Decimal	Abs (const Decimal &value)
	Absolute value of the current Decimal value.
static Result< Decimal >	FromString (std::string_view str, int32_t *precision=nullptr, int32_t *scale=nullptr)
	Convert the decimal string to a Decimal value, optionally including precision and scale if they are provided not null.
static Result< Decimal >	FromBigEndian (const uint8_t *data, int32_t length)
	Convert from a big-endian byte representation. The length must be between 1 and 16.
static std::partial_ordering	Compare (const Decimal &lhs, const Decimal &rhs, int32_t lhs_scale, int32_t rhs_scale)
	Compare two Decimals with different scales.

Static Public Attributes
static constexpr int32_t	kBitWidth = 128
static constexpr int32_t	kByteWidth = kBitWidth / 8
static constexpr int32_t	kMaxPrecision = 38
static constexpr int32_t	kMaxScale = 38

Friends
bool	operator== (const Decimal &lhs, const Decimal &rhs)
bool	operator!= (const Decimal &lhs, const Decimal &rhs)
ICEBERG_EXPORT friend Decimal	operator- (const Decimal &operand)
ICEBERG_EXPORT friend Decimal	operator~ (const Decimal &operand)
ICEBERG_EXPORT friend Decimal	operator+ (const Decimal &lhs, const Decimal &rhs)
ICEBERG_EXPORT friend Decimal	operator- (const Decimal &lhs, const Decimal &rhs)
ICEBERG_EXPORT friend Decimal	operator* (const Decimal &lhs, const Decimal &rhs)
ICEBERG_EXPORT friend Decimal	operator/ (const Decimal &lhs, const Decimal &rhs)
ICEBERG_EXPORT friend Decimal	operator% (const Decimal &lhs, const Decimal &rhs)

Detailed Description

Represents 128-bit fixed-point decimal numbers. The max decimal precision that can be safely represented is 38 significant digits.

Constructor & Destructor Documentation

Decimal()

iceberg::Decimal::Decimal ( std::string_view  str )

explicit

Parse a Decimal from a string representation.

Exceptions

This	constructor throws an exception if parsing fails. Use Decimal::FromString() if you want to handle errors more gracefully.

Member Function Documentation

Divide()

Result< std::pair< Decimal, Decimal > > iceberg::Decimal::Divide

(

const Decimal &

divisor

)

const

Divide this number by another.

The operation does not modify the current Decimal value. The answer rounds towards zero. Signs work like: 21 / 5 -> 4, 1 -21 / 5 -> -4, -1 21 / -5 -> -4, 1 -21 / -5 -> 4, -1

Parameters

[in]

divisor

the number to divide by

Returns

the pair of the quotient and the remainder

FitsInPrecision()

bool iceberg::Decimal::FitsInPrecision

(

int32_t

precision

)

const

Whether this number fits in the given precision.

Returns true if the number of significant digits is less or equal to precision.

FromBigEndian()

Result< Decimal > iceberg::Decimal::FromBigEndian ( const uint8_t *  data, int32_t  length  )

static

Convert from a big-endian byte representation. The length must be between 1 and 16.

Returns

error status if the length is an invalid value

FromString()

Result< Decimal > iceberg::Decimal::FromString ( std::string_view  str, int32_t *  precision = nullptr, int32_t *  scale = nullptr  )

static

Convert the decimal string to a Decimal value, optionally including precision and scale if they are provided not null.

Parameters

	str	The string representation of the Decimal value.
[out]	precision	Optional pointer to store the precision of the parsed value.
[out]	scale	Optional pointer to store the scale of the parsed value.

Returns

The Decimal value.

ToBigEndian()

std::vector< uint8_t > iceberg::Decimal::ToBigEndian

(

)

const

Convert Decimal's unscaled value to two’s-complement big-endian binary, using the minimum number of bytes for the value.

Returns

A vector containing the big-endian bytes.

ToString() [1/2]

std::string iceberg::Decimal::ToString ( ) const

inlineoverridevirtual

Returns an integer string representation of the decimal value.

Implements iceberg::util::Formattable.

ToString() [2/2]

Result< std::string > iceberg::Decimal::ToString

(

int32_t

scale

)

const

Convert the Decimal value to a base 10 decimal string with the given scale.

Parameters

scale

The scale to use for the string representation.

Returns

The string representation of the Decimal value.

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The documentation for this class was generated from the following files:

• iceberg/util/decimal.h
• iceberg/util/decimal.cc