time_source.cpp File Reference

Multi-source time fallback matrix - implementation. More...

#include "time_source.h"
#include "shared_primitives/http_date.h"

Go to the source code of this file.

Functions
bool	pc_time_source_add (const char *, uint8_t, TimeSourceFn)
	Register a time source.
uint32_t	pc_time_now (void)
	Current best time.
const char *	pc_time_source_active (void)
	Name of the source that satisfied the last pc_time_now(), or nullptr.
void	pc_time_source_reset (void)
	Clear all registered sources.
size_t	pc_time_http_date (char *out, size_t out_cap)
	The current best time (pc_time_now, any registered NTP / GPS / RTC / ... source) formatted as an RFC 7231 IMF-fixdate into out.

Detailed Description

Multi-source time fallback matrix - implementation.

A fixed BSS table of sources queried in ascending priority. See time_source.h.

Definition in file time_source.cpp.

Function Documentation

pc_time_source_add()

bool pc_time_source_add	(	const char *	name,
		uint8_t	priority,
		TimeSourceFn	fn
	)

Register a time source.

Parameters

name	stable label (referenced by pointer; must outlive the source - point it at a string literal / static, like the rest of the lib).
priority	lower value = higher priority (queried first).
fn	the source callback.

Returns

true if registered; false if fn is null or the table is full.

Definition at line 111 of file time_source.cpp.

pc_time_now()

uint32_t pc_time_now

(

void

)

Current best time.

Queries registered sources in ascending priority and returns the first nonzero epoch (stopping at the first valid source). Returns 0 if none have valid time.

Definition at line 115 of file time_source.cpp.

Referenced by pc_time_http_date().

pc_time_source_active()

const char * pc_time_source_active

(

void

)

Name of the source that satisfied the last pc_time_now(), or nullptr.

Definition at line 119 of file time_source.cpp.

pc_time_source_reset()

void pc_time_source_reset

(

void

)

Clear all registered sources.

Definition at line 123 of file time_source.cpp.

pc_time_http_date()

size_t pc_time_http_date	(	char *	out,
		size_t	out_cap
	)

The current best time (pc_time_now, any registered NTP / GPS / RTC / ... source) formatted as an RFC 7231 IMF-fixdate into out.

Returns

bytes written, or 0 with an empty out when no source currently has a valid time.

This is what lets the HTTP Date: header be fed by whatever time source is enabled, not just NTP: register RTC / GPS / NTP via pc_time_source_add() and the header follows the priority.

Definition at line 132 of file time_source.cpp.

References pc_http_date(), and pc_time_now().