2 * Copyright (C) 2004-2009 Internet Systems Consortium, Inc. ("ISC")
3 * Copyright (C) 1998-2001 Internet Software Consortium.
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18 /* $Id: time.h,v 1.38.56.2 2009/01/05 23:47:23 tbox Exp $ */
26 #include <isc/types.h>
34 * The contents of this structure are private, and MUST NOT be accessed
35 * directly by callers.
37 * The contents are exposed only to allow callers to avoid dynamic allocation.
41 unsigned int nanoseconds;
44 extern isc_interval_t *isc_interval_zero;
49 isc_interval_set(isc_interval_t *i,
50 unsigned int seconds, unsigned int nanoseconds);
52 * Set 'i' to a value representing an interval of 'seconds' seconds and
53 * 'nanoseconds' nanoseconds, suitable for use in isc_time_add() and
54 * isc_time_subtract().
58 *\li 't' is a valid pointer.
59 *\li nanoseconds < 1000000000.
63 isc_interval_iszero(const isc_interval_t *i);
65 * Returns ISC_TRUE iff. 'i' is the zero interval.
69 *\li 'i' is a valid pointer.
77 * The contents of this structure are private, and MUST NOT be accessed
78 * directly by callers.
80 * The contents are exposed only to allow callers to avoid dynamic allocation.
85 unsigned int nanoseconds;
88 extern isc_time_t *isc_time_epoch;
91 isc_time_set(isc_time_t *t, unsigned int seconds, unsigned int nanoseconds);
93 * Set 't' to a value which represents the given number of seconds and
94 * nanoseconds since 00:00:00 January 1, 1970, UTC.
97 *\li The Unix version of this call is equivalent to:
99 * isc_time_settoepoch(t);
100 * isc_interval_set(i, seconds, nanoseconds);
101 * isc_time_add(t, i, t);
105 *\li 't' is a valid pointer.
106 *\li nanoseconds < 1000000000.
110 isc_time_settoepoch(isc_time_t *t);
112 * Set 't' to the time of the epoch.
115 *\li The date of the epoch is platform-dependent.
119 *\li 't' is a valid pointer.
123 isc_time_isepoch(const isc_time_t *t);
125 * Returns ISC_TRUE iff. 't' is the epoch ("time zero").
129 *\li 't' is a valid pointer.
133 isc_time_now(isc_time_t *t);
135 * Set 't' to the current absolute time.
139 *\li 't' is a valid pointer.
144 *\li Unexpected error
145 * Getting the time from the system failed.
147 * The time from the system is too large to be represented
148 * in the current definition of isc_time_t.
152 isc_time_nowplusinterval(isc_time_t *t, const isc_interval_t *i);
154 * Set *t to the current absolute time + i.
157 *\li This call is equivalent to:
161 * isc_time_add(t, i, t);
166 *\li 't' and 'i' are valid pointers.
171 *\li Unexpected error
172 * Getting the time from the system failed.
174 * The interval added to the time from the system is too large to
175 * be represented in the current definition of isc_time_t.
179 isc_time_compare(const isc_time_t *t1, const isc_time_t *t2);
181 * Compare the times referenced by 't1' and 't2'
185 *\li 't1' and 't2' are valid pointers.
189 *\li -1 t1 < t2 (comparing times, not pointers)
195 isc_time_add(const isc_time_t *t, const isc_interval_t *i, isc_time_t *result);
197 * Add 'i' to 't', storing the result in 'result'.
201 *\li 't', 'i', and 'result' are valid pointers.
206 * The interval added to the time is too large to
207 * be represented in the current definition of isc_time_t.
211 isc_time_subtract(const isc_time_t *t, const isc_interval_t *i,
214 * Subtract 'i' from 't', storing the result in 'result'.
218 *\li 't', 'i', and 'result' are valid pointers.
223 * The interval is larger than the time since the epoch.
227 isc_time_microdiff(const isc_time_t *t1, const isc_time_t *t2);
229 * Find the difference in microseconds between time t1 and time t2.
230 * t2 is the subtrahend of t1; ie, difference = t1 - t2.
234 *\li 't1' and 't2' are valid pointers.
237 *\li The difference of t1 - t2, or 0 if t1 <= t2.
241 isc_time_seconds(const isc_time_t *t);
243 * Return the number of seconds since the epoch stored in a time structure.
247 *\li 't' is a valid pointer.
251 isc_time_secondsastimet(const isc_time_t *t, time_t *secondsp);
253 * Ensure the number of seconds in an isc_time_t is representable by a time_t.
256 *\li The number of seconds stored in an isc_time_t might be larger
257 * than the number of seconds a time_t is able to handle. Since
258 * time_t is mostly opaque according to the ANSI/ISO standard
259 * (essentially, all you can be sure of is that it is an arithmetic type,
260 * not even necessarily integral), it can be tricky to ensure that
261 * the isc_time_t is in the range a time_t can handle. Use this
262 * function in place of isc_time_seconds() any time you need to set a
263 * time_t from an isc_time_t.
266 *\li 't' is a valid pointer.
274 isc_time_nanoseconds(const isc_time_t *t);
276 * Return the number of nanoseconds stored in a time structure.
279 *\li This is the number of nanoseconds in excess of the number
280 * of seconds since the epoch; it will always be less than one
284 *\li 't' is a valid pointer.
287 *\li The returned value is less than 1*10^9.
291 isc_time_formattimestamp(const isc_time_t *t, char *buf, unsigned int len);
293 * Format the time 't' into the buffer 'buf' of length 'len',
294 * using a format like "30-Aug-2000 04:06:47.997" and the local time zone.
295 * If the text does not fit in the buffer, the result is indeterminate,
296 * but is always guaranteed to be null terminated.
300 *\li 'buf' points to an array of at least len chars
305 isc_time_formathttptimestamp(const isc_time_t *t, char *buf, unsigned int len);
307 * Format the time 't' into the buffer 'buf' of length 'len',
308 * using a format like "Mon, 30 Aug 2000 04:06:47 GMT"
309 * If the text does not fit in the buffer, the result is indeterminate,
310 * but is always guaranteed to be null terminated.
314 *\li 'buf' points to an array of at least len chars
319 isc_time_formatISO8601(const isc_time_t *t, char *buf, unsigned int len);
321 * Format the time 't' into the buffer 'buf' of length 'len',
322 * using the ISO8601 format: "yyyy-mm-ddThh:mm:ssZ"
323 * If the text does not fit in the buffer, the result is indeterminate,
324 * but is always guaranteed to be null terminated.
328 *\li 'buf' points to an array of at least len chars
334 #endif /* ISC_TIME_H */