package mirage-ptime

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Libraries and module types for portable clocks

Install

dune-project

Dependency

github.com Readme Changelog ISC License Edit opam file Versions (2)

Authors

Maintainers

H

hannes@mehnert.org

Sources

mirage-ptime-5.1.0.tbz

sha256=e9b3db31365e1a895130c3789e6adcf996771ea8e7016b63e15ecbe1f38a29f6

sha512=276a61bfcf7a025a3a6269b52f85ed158f9600385e1c2c2cf21d74985924bb013e703b804e7b15b7249708ef0cdee3c7c0da3cdf20b858a2b1d0da65829ed113

doc/mirage-ptime.unix/Mirage_ptime/index.html

Module `Mirage_ptime`Source

include module type of struct include Ptime_clock end

POSIX clock

Sourceval now : unit -> Ptime.t

now () is the current POSIX time, by definition always on the UTC timeline.

Raises Sys_error, see error handling.

Sourceval period : unit -> Ptime.span option

period () is a positive POSIX time span representing the clock's period (if available).

System time zone offset

Sourceval current_tz_offset_s : unit -> Ptime.tz_offset_s option

current_tz_offset_s () is the system's current local time zone offset to UTC in seconds, if known. This is the duration local time - UTC time in seconds.

POSIX clock raw interface

Sourceval now_d_ps : unit -> int * int64

now_d_ps () is (d, ps) representing POSIX time occuring at d * 86'400e12 + ps POSIX picoseconds from the epoch 1970-01-01 00:00:00 UTC. ps is in the range [0;86_399_999_999_999_999L].

Raises Sys_error, see error handling

Sourceval period_d_ps : unit -> (int * int64) option

period_d_ps () is if available Some (d, ps) representing the clock's picosecond period d * 86'400e12 + ps. ps is in the range [0;86_399_999_999_999_999L].

Error handling

The functions now and now_d_ps raise Sys_error whenever they can't determine the current time or that it doesn't fit in Ptime's well-defined range. This exception should only be catched at the toplevel of your program to log it and abort the program. It indicates a serious error condition in the system.

All the other functions, whose functionality is less essential, simply silently return None if they can't determine the information either because it is unavailable or because an error occured.

Platform support

Platforms with a POSIX clock (includes Linux) use clock_gettime with CLOCK_REALTIME.
On Darwin gettimeofday is used.
On Windows GetSystemTime and GetTimeZoneInformation are used.
On JavaScript Date.now () and Date.prototype.getTimezoneOffset are used.