65 lines
1.6 KiB
C
65 lines
1.6 KiB
C
|
/**
|
||
|
|
* @file lstab.h
|
||
|
|
* @note Copyright (C) 2012 Richard Cochran <richardcochran@gmail.com>
|
||
|
|
* @note SPDX-License-Identifier: GPL-2.0+
|
||
|
|
*/
|
||
|
|
#ifndef HAVE_LEAP_SECONDS_H
|
||
|
|
#define HAVE_LEAP_SECONDS_H
|
||
|
|
|
||
|
|
#include <stdint.h>
|
||
|
|
|
||
|
|
/** Opaque type */
|
||
|
|
struct lstab;
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Creates an instance of a leap second table.
|
||
|
|
* @param filename File from which to initialize the table. If NULL or empty,
|
||
|
|
* the hard coded default table will be used.
|
||
|
|
* @return A pointer to a leap second table on success, NULL otherwise.
|
||
|
|
*/
|
||
|
|
struct lstab *lstab_create(const char *filename);
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Destroys a leap second table instance.
|
||
|
|
* @param lstab A pointer obtained via lstab_create().
|
||
|
|
*/
|
||
|
|
void lstab_destroy(struct lstab *lstab);
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Enumerates the possible result code for the lstab_utc2tai() method.
|
||
|
|
*/
|
||
|
|
enum lstab_result {
|
||
|
|
/**
|
||
|
|
* The given UTC value was found in the table, and the
|
||
|
|
* corresponding TAI time is utctime + tai_offset.
|
||
|
|
*/
|
||
|
|
LSTAB_OK,
|
||
|
|
|
||
|
|
/**
|
||
|
|
* The given UTC value is out of the range of the table, and
|
||
|
|
* the tai_offset return value is not set.
|
||
|
|
*/
|
||
|
|
LSTAB_UNKNOWN,
|
||
|
|
|
||
|
|
/**
|
||
|
|
* The given UTC value is ambiguous. The corresponding TAI time is either
|
||
|
|
*
|
||
|
|
* utctime + tai_offset
|
||
|
|
* or
|
||
|
|
* utctime + tai_offset + 1.
|
||
|
|
*/
|
||
|
|
LSTAB_AMBIGUOUS,
|
||
|
|
};
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Returns the TAI - UTC offset for a given UTC time value.
|
||
|
|
* @param lstab A pointer obtained via lstab_create().
|
||
|
|
* @param utctime The UTC time value of interest.
|
||
|
|
* @param tai_offset Pointer to a buffer to hold the result.
|
||
|
|
* @return One of the lstab_result enumeration values.
|
||
|
|
*/
|
||
|
|
enum lstab_result lstab_utc2tai(struct lstab *lstab, uint64_t utctime,
|
||
|
|
int *tai_offset);
|
||
|
|
|
||
|
|
#endif
|