Detailed Description

High-precision timestamp for use with PTP / IEEE1588.

The "Time" object can be used to represent a time-difference or an absolute time in the TAI epoch, matching the finest resolution supported by IEEE1588-2019.

The internal representation is based on increments of 1/65536 nanoseconds, which is referred to as a "subnanosecond" or "subns".

Definition at line 41 of file ptp_time.h.

#include <ptp_time.h>

Public Member Functions
constexpr	Time ()
	Default constructor.

constexpr	Time (s64 subnanoseconds)
	Single argument constructor is scaled in subnanoseconds. More...

constexpr	Time (const Time &other)
	Copy constructor.

	Time (u64 seconds, u32 nanoseconds, u16 subnanoseconds=0)
	Multi-argument constructor accepts seconds, nanoseconds, and subnanosecods. More...

s64	field_secs () const
	Read the "seconds" field without intermediate rounding.

u32	field_nsec () const
	Read the "nanoseconds" field, rounding down. More...

u64	field_subns () const
	Read the raw "subnanoseconds" field. More...

s64	round_secs () const
	Return "seconds" field after rounding to the nearest nanosecond. More...

u32	round_nsec () const
	Return "nanoseconds" field after rounding to the nearest nanosecond.

bool	read_from (satcat5::io::Readable *src)
	Read the standard 10-byte timestamp from a PTP message (e.g., originTimestamp: u48 seconds + u32 nanoseconds) Note: Add correctionField separately to maintain full precision.

void	write_to (satcat5::io::Writeable *dst) const
	Read or write the 10-byte timestamp from a PTP message. More...

void	log_to (satcat5::log::LogBuffer &wr) const
	User-readable format for logging. More...

u64	correction () const
	Get the correctionField value in subnanoseconds. More...

s64	to_datetime () const
	Convert to SatCat5 date/time. More...


s64	delta_subns () const
	Convert time-differences to the designated unit. More...

s64	delta_nsec () const
	Convert time-differences to the designated unit. More...

s64	delta_usec () const
	Convert time-differences to the designated unit. More...

s64	delta_msec () const
	Convert time-differences to the designated unit. More...


satcat5::ptp::Time	abs () const
	Standard arithmetic operations.

void	operator+= (const satcat5::ptp::Time &other)
	Standard arithmetic operations.

void	operator-= (const satcat5::ptp::Time &other)
	Standard arithmetic operations.

satcat5::ptp::Time	operator= (const satcat5::ptp::Time &other)
	Standard arithmetic operations.

satcat5::ptp::Time	operator+ (const satcat5::ptp::Time &other) const
	Standard arithmetic operations.

satcat5::ptp::Time	operator- (const satcat5::ptp::Time &other) const
	Standard arithmetic operations.

satcat5::ptp::Time	operator- () const
	Standard arithmetic operations.


void	operator*= (unsigned scale)
	Scalar multiply and divide are used for weighted averaging. More...

void	operator/= (unsigned scale)
	Scalar multiply and divide are used for weighted averaging. More...

satcat5::ptp::Time	operator* (unsigned scale) const
	Scalar multiply and divide are used for weighted averaging. More...

satcat5::ptp::Time	operator/ (unsigned scale) const
	Scalar multiply and divide are used for weighted averaging. More...


bool	operator== (const satcat5::ptp::Time &other) const
	Standard comparison operators.

bool	operator< (const satcat5::ptp::Time &other) const
	Standard comparison operators.

bool	operator> (const satcat5::ptp::Time &other) const
	Standard comparison operators.

bool	operator!= (const satcat5::ptp::Time &other) const
	Standard comparison operators.

bool	operator<= (const satcat5::ptp::Time &other) const
	Standard comparison operators.

bool	operator>= (const satcat5::ptp::Time &other) const
	Standard comparison operators.

Protected Member Functions
void	normalize ()

Protected Attributes
s64	m_secs

s64	m_subns

Constructor & Destructor Documentation

◆ Time() [1/2]

constexpr satcat5::ptp::Time::Time ( s64 subnanoseconds )

inlineexplicitconstexpr

Single argument constructor is scaled in subnanoseconds.

This matches the format used for the PTP "correction" field.

Definition at line 49 of file ptp_time.h.

◆ Time() [2/2]

Time::Time	(	u64	seconds,
		u32	nanoseconds,
		u16	subnanoseconds = `0`
	)

Multi-argument constructor accepts seconds, nanoseconds, and subnanosecods.

This matches the format used for the PTP "timestamp" field.

Definition at line 21 of file ptp_time.cc.

Member Function Documentation

◆ correction()

u64 satcat5::ptp::Time::correction ( ) const

inline

Get the correctionField value in subnanoseconds.

For use with field_sec, field_nsec, or write_to methods.

Returns: Residual offset in subnanoseconds.

Definition at line 108 of file ptp_time.h.

◆ delta_msec()

s64 Time::delta_msec ( ) const

Convert time-differences to the designated unit.

The representable range is always at least +/- 24 hours. Times beyond the safe range will return INT64_MIN or INT64_MAX.

Definition at line 61 of file ptp_time.cc.

◆ delta_nsec()

s64 Time::delta_nsec ( ) const

Convert time-differences to the designated unit.

The representable range is always at least +/- 24 hours. Times beyond the safe range will return INT64_MIN or INT64_MAX.

Definition at line 57 of file ptp_time.cc.

◆ delta_subns()

s64 Time::delta_subns ( ) const

Convert time-differences to the designated unit.

The representable range is always at least +/- 24 hours. Times beyond the safe range will return INT64_MIN or INT64_MAX.

Definition at line 55 of file ptp_time.cc.

◆ delta_usec()

s64 Time::delta_usec ( ) const

Convert time-differences to the designated unit.

The representable range is always at least +/- 24 hours. Times beyond the safe range will return INT64_MIN or INT64_MAX.

Definition at line 59 of file ptp_time.cc.

◆ field_nsec()

u32 satcat5::ptp::Time::field_nsec ( ) const

inline

Read the "nanoseconds" field, rounding down.

Use this method in combination with

See also: correction.

Definition at line 66 of file ptp_time.h.

◆ field_subns()

u64 satcat5::ptp::Time::field_subns ( ) const

inline

Read the raw "subnanoseconds" field.

This is equal to 65536 * field_nsec() + correction()

Definition at line 70 of file ptp_time.h.

◆ log_to()

void Time::log_to ( satcat5::log::LogBuffer & wr ) const

User-readable format for logging.

See also: satcat5::log::Log

Definition at line 83 of file ptp_time.cc.

◆ operator*()

Time Time::operator* ( unsigned scale ) const

Scalar multiply and divide are used for weighted averaging.

Do not use scaling factors larger than ~10000 or it may overflow.

Definition at line 195 of file ptp_time.cc.

◆ operator*=()

void Time::operator*= ( unsigned scale )

Scalar multiply and divide are used for weighted averaging.

Do not use scaling factors larger than ~10000 or it may overflow.

Definition at line 157 of file ptp_time.cc.

◆ operator/()

Time Time::operator/ ( unsigned scale ) const

Scalar multiply and divide are used for weighted averaging.

Do not use scaling factors larger than ~10000 or it may overflow.

Definition at line 201 of file ptp_time.cc.

◆ operator/=()

void Time::operator/= ( unsigned scale )

Scalar multiply and divide are used for weighted averaging.

Do not use scaling factors larger than ~10000 or it may overflow.

Definition at line 164 of file ptp_time.cc.

◆ round_secs()

s64 satcat5::ptp::Time::round_secs ( ) const

inline

Return "seconds" field after rounding to the nearest nanosecond.

If you use round_nsec, then you should also use round_sec.

Definition at line 75 of file ptp_time.h.

◆ to_datetime()

s64 Time::to_datetime ( ) const

Convert to SatCat5 date/time.

See also: datetime.h

Definition at line 96 of file ptp_time.cc.

◆ write_to()

void Time::write_to ( satcat5::io::Writeable * dst ) const

Read or write the 10-byte timestamp from a PTP message.

(e.g., originTimestamp: u48 seconds + u32 nanoseconds) Note: User must write correction to the PTP correctionField to maintain full end-to-end precision.

Definition at line 77 of file ptp_time.cc.

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

Detailed Description

Public Member Functions

Protected Member Functions

Protected Attributes

Constructor & Destructor Documentation

◆ Time() [1/2]

◆ Time() [2/2]

Member Function Documentation

◆ correction()

◆ delta_msec()

◆ delta_nsec()

◆ delta_subns()

◆ delta_usec()

◆ field_nsec()

◆ field_subns()

◆ log_to()

◆ operator*()

◆ operator*=()

◆ operator/()

◆ operator/=()

◆ round_secs()

◆ to_datetime()

◆ write_to()