/*
* Copyright (C) 1998-2001, 2004-2009, 2012, 2014-2016 Internet Systems Consortium, Inc. ("ISC")
*
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/.
*/
/* $Id: time.h,v 1.40 2009/01/05 23:47:54 tbox Exp $ */
#ifndef ISC_TIME_H
/*! \file */
/***
*** Intervals
***/
/*!
* \brief
* The contents of this structure are private, and MUST NOT be accessed
* directly by callers.
*
* The contents are exposed only to allow callers to avoid dynamic allocation.
*/
struct isc_interval {
unsigned int seconds;
unsigned int nanoseconds;
};
extern const isc_interval_t * const isc_interval_zero;
/*
* ISC_FORMATHTTPTIMESTAMP_SIZE needs to be 30 in C locale and potentially
* more for other locales to handle longer national abbreviations when
* expanding strftime's %a and %b.
*/
void
unsigned int seconds, unsigned int nanoseconds);
/*%<
* Set 'i' to a value representing an interval of 'seconds' seconds and
* 'nanoseconds' nanoseconds, suitable for use in isc_time_add() and
* isc_time_subtract().
*
* Requires:
*
*\li 't' is a valid pointer.
*\li nanoseconds < 1000000000.
*/
isc_interval_iszero(const isc_interval_t *i);
/*%<
* Returns ISC_TRUE iff. 'i' is the zero interval.
*
* Requires:
*
*\li 'i' is a valid pointer.
*/
/***
*** Absolute Times
***/
/*%
* The contents of this structure are private, and MUST NOT be accessed
* directly by callers.
*
* The contents are exposed only to allow callers to avoid dynamic allocation.
*/
struct isc_time {
unsigned int seconds;
unsigned int nanoseconds;
};
extern const isc_time_t * const isc_time_epoch;
void
/*%<
* Set 't' to a value which represents the given number of seconds and
* nanoseconds since 00:00:00 January 1, 1970, UTC.
*
* Notes:
*\li The Unix version of this call is equivalent to:
*\code
* isc_time_settoepoch(t);
* isc_interval_set(i, seconds, nanoseconds);
* isc_time_add(t, i, t);
*\endcode
*
* Requires:
*\li 't' is a valid pointer.
*\li nanoseconds < 1000000000.
*/
void
/*%<
* Set 't' to the time of the epoch.
*
* Notes:
*\li The date of the epoch is platform-dependent.
*
* Requires:
*
*\li 't' is a valid pointer.
*/
isc_time_isepoch(const isc_time_t *t);
/*%<
* Returns ISC_TRUE iff. 't' is the epoch ("time zero").
*
* Requires:
*
*\li 't' is a valid pointer.
*/
isc_time_now(isc_time_t *t);
/*%<
* Set 't' to the current absolute time.
*
* Requires:
*
*\li 't' is a valid pointer.
*
* Returns:
*
*\li Success
*\li Unexpected error
* Getting the time from the system failed.
*\li Out of range
* The time from the system is too large to be represented
* in the current definition of isc_time_t.
*/
/*%<
* Set *t to the current absolute time + i.
*
* Note:
*\li This call is equivalent to:
*
*\code
* isc_time_now(t);
* isc_time_add(t, i, t);
*\endcode
*
* Requires:
*
*\li 't' and 'i' are valid pointers.
*
* Returns:
*
*\li Success
*\li Unexpected error
* Getting the time from the system failed.
*\li Out of range
* The interval added to the time from the system is too large to
* be represented in the current definition of isc_time_t.
*/
int
/*%<
* Compare the times referenced by 't1' and 't2'
*
* Requires:
*
*\li 't1' and 't2' are valid pointers.
*
* Returns:
*
*\li -1 t1 < t2 (comparing times, not pointers)
*\li 0 t1 = t2
*\li 1 t1 > t2
*/
/*%<
* Add 'i' to 't', storing the result in 'result'.
*
* Requires:
*
*\li 't', 'i', and 'result' are valid pointers.
*
* Returns:
*\li Success
*\li Out of range
* The interval added to the time is too large to
* be represented in the current definition of isc_time_t.
*/
isc_time_t *result);
/*%<
* Subtract 'i' from 't', storing the result in 'result'.
*
* Requires:
*
*\li 't', 'i', and 'result' are valid pointers.
*
* Returns:
*\li Success
*\li Out of range
* The interval is larger than the time since the epoch.
*/
/*%<
* Find the difference in microseconds between time t1 and time t2.
* t2 is the subtrahend of t1; ie, difference = t1 - t2.
*
* Requires:
*
*\li 't1' and 't2' are valid pointers.
*
* Returns:
*\li The difference of t1 - t2, or 0 if t1 <= t2.
*/
isc_time_seconds(const isc_time_t *t);
/*%<
* Return the number of seconds since the epoch stored in a time structure.
*
* Requires:
*
*\li 't' is a valid pointer.
*/
/*%<
* Ensure the number of seconds in an isc_time_t is representable by a time_t.
*
* Notes:
*\li The number of seconds stored in an isc_time_t might be larger
* than the number of seconds a time_t is able to handle. Since
* (essentially, all you can be sure of is that it is an arithmetic type,
* not even necessarily integral), it can be tricky to ensure that
* the isc_time_t is in the range a time_t can handle. Use this
* function in place of isc_time_seconds() any time you need to set a
* time_t from an isc_time_t.
*
* Requires:
*\li 't' is a valid pointer.
*
* Returns:
*\li Success
*\li Out of range
*/
isc_time_nanoseconds(const isc_time_t *t);
/*%<
* Return the number of nanoseconds stored in a time structure.
*
* Notes:
*\li This is the number of nanoseconds in excess of the number
* of seconds since the epoch; it will always be less than one
* full second.
*
* Requires:
*\li 't' is a valid pointer.
*
* Ensures:
*\li The returned value is less than 1*10^9.
*/
void
/*%<
* Format the time 't' into the buffer 'buf' of length 'len',
* using a format like "30-Aug-2000 04:06:47.997" and the local time zone.
* If the text does not fit in the buffer, the result is indeterminate,
* but is always guaranteed to be null terminated.
*
* Requires:
*\li 'len' > 0
*\li 'buf' points to an array of at least len chars
*
*/
void
/*%<
* Format the time 't' into the buffer 'buf' of length 'len',
* using a format like "Mon, 30 Aug 2000 04:06:47 GMT"
* If the text does not fit in the buffer, the result is indeterminate,
* but is always guaranteed to be null terminated.
*
* Requires:
*\li 'len' > 0
*\li 'buf' points to an array of at least len chars
*
*/
/*%<
* Parse the time in 'input' into the isc_time_t pointed to by 't',
* expecting a format like "Mon, 30 Aug 2000 04:06:47 GMT"
*
* Requires:
*\li 'buf' and 't' are not NULL.
*/
void
/*%<
* Format the time 't' into the buffer 'buf' of length 'len',
* using the ISO8601 format: "yyyy-mm-ddThh:mm:ssZ"
* If the text does not fit in the buffer, the result is indeterminate,
* but is always guaranteed to be null terminated.
*
* Requires:
*\li 'len' > 0
*\li 'buf' points to an array of at least len chars
*
*/
void
/*%<
* Format the time 't' into the buffer 'buf' of length 'len',
* using the ISO8601 format: "yyyy-mm-ddThh:mm:ss.sssZ"
* If the text does not fit in the buffer, the result is indeterminate,
* but is always guaranteed to be null terminated.
*
* Requires:
*\li 'len' > 0
*\li 'buf' points to an array of at least len chars
*
*/
#endif /* ISC_TIME_H */