1 {-# OPTIONS -optc-DNON_POSIX_SOURCE #-}
2 -- JRS 010117: we had to say NON_POSIX_SOURCE to get the resulting .hc
3 -- to compile on sparc-solaris. Blargh.
5 -- -----------------------------------------------------------------------------
6 -- $Id: Time.hsc,v 1.9 2001/01/30 10:59:04 simonmar Exp $
8 -- (c) The University of Glasgow, 1995-2001
12 Haskell 98 Time of Day Library
13 ------------------------------
15 The Time library provides standard functionality for clock times,
16 including timezone information (i.e, the functionality of "time.h",
17 adapted to the Haskell environment), It follows RFC 1129 in its use of
18 Coordinated Universal Time (UTC).
20 2000/06/17 <michael.weber@post.rwth-aachen.de>:
22 * min./max. time diff currently is restricted to
23 [minBound::Int, maxBound::Int]
25 * surely other restrictions wrt. min/max bounds
31 `showTime' (used in `instance Show ClockTime') always prints time
32 converted to the local timezone (even if it is taken from
33 `(toClockTime . toUTCTime)'), whereas `calendarTimeToString'
34 honors the tzone & tz fields and prints UTC or whatever timezone
35 is stored inside CalendarTime.
37 Maybe `showTime' should be changed to use UTC, since it would
38 better correspond to the actual representation of `ClockTime'
39 (can be done by replacing localtime(3) by gmtime(3)).
43 * add proper handling of microsecs, currently, they're mostly
46 * `formatFOO' case of `%s' is currently broken...
50 * check for unusual date cases, like 1970/1/1 00:00h, and conversions
51 between different timezone's etc.
53 * check, what needs to be in the IO monad, the current situation
54 seems to be a bit inconsistent to me
56 * check whether `isDst = -1' works as expected on other arch's
59 * add functions to parse strings to `CalendarTime' (some day...)
61 * implement padding capabilities ("%_", "%-") in `formatFOO'
63 * add rfc822 timezone (+0200 is CEST) representation ("%z") in `formatFOO'
71 , ClockTime(..) -- non-standard, lib. report gives this as abstract
75 , noTimeDiff -- non-standard (but useful when constructing TimeDiff vals.)
79 , normalizeTimeDiff -- non-standard
80 , timeDiffToString -- non-standard
81 , formatTimeDiff -- non-standard
87 , calendarTimeToString
94 #if defined(HAVE_GETTIMEOFDAY)
95 # ifdef HAVE_SYS_TIME_H
96 # include <sys/time.h>
98 #elif defined(HAVE_GETCLOCK)
99 # ifdef HAVE_SYS_TIMERS_H
101 # include <sys/timers.h>
103 #elif defined(HAVE_TIME_H)
107 #ifdef HAVE_SYS_TYPES_H
108 #include <sys/types.h>
111 #ifdef HAVE_SYS_TIMEB_H
112 #include <sys/timeb.h>
115 #ifdef HAVE_WINDOWS_H
122 import PrelMarshalAlloc
123 import PrelMarshalUtils
124 import PrelMarshalError
137 -- One way to partition and give name to chunks of a year and a week:
140 = January | February | March | April
141 | May | June | July | August
142 | September | October | November | December
143 deriving (Eq, Ord, Enum, Bounded, Ix, Read, Show)
146 = Sunday | Monday | Tuesday | Wednesday
147 | Thursday | Friday | Saturday
148 deriving (Eq, Ord, Enum, Bounded, Ix, Read, Show)
150 -- @ClockTime@ is an abstract type, used for the internal clock time.
151 -- Clock times may be compared, converted to strings, or converted to an
152 -- external calendar time @CalendarTime@.
154 data ClockTime = TOD Integer -- Seconds since 00:00:00 on 1 Jan 1970
155 Integer -- Picoseconds with the specified second
158 -- When a @ClockTime@ is shown, it is converted to a string of the form
159 -- @"Mon Nov 28 21:45:41 GMT 1994"@.
161 -- For now, we are restricted to roughly:
162 -- Fri Dec 13 20:45:52 1901 through Tue Jan 19 03:14:07 2038, because
163 -- we use the C library routines based on 32 bit integers.
165 instance Show ClockTime where
166 showsPrec _ (TOD secs _nsec) =
167 showString $ unsafePerformIO $ do
168 withObject (fromIntegral secs :: CTime) $ \ p_timer -> do
169 p_tm <- localtime p_timer -- can't fail, according to POSIX
170 allocaBytes 64 $ \ p_buf -> do -- big enough for error message
171 r <- strftime p_buf 50 "%a %b %d %H:%M:%S %Z %Y"## p_tm
173 then return "ClockTime.show{Time}: internal error"
174 else peekCString p_buf
176 showList = showList__ (showsPrec 0)
179 @CalendarTime@ is a user-readable and manipulable
180 representation of the internal $ClockTime$ type. The
181 numeric fields have the following ranges.
187 year -maxInt .. maxInt [Pre-Gregorian dates are inaccurate]
188 mon 0 .. 11 [Jan = 0, Dec = 11]
192 sec 0 .. 61 [Allows for two leap seconds]
193 picosec 0 .. (10^12)-1 [This could be over-precise?]
194 wday 0 .. 6 [Sunday = 0, Saturday = 6]
195 yday 0 .. 365 [364 in non-Leap years]
196 tz -43200 .. 43200 [Variation from UTC in seconds]
199 The {\em tzname} field is the name of the time zone. The {\em isdst}
200 field indicates whether Daylight Savings Time would be in effect.
211 ctPicosec :: Integer,
218 deriving (Eq,Ord,Read,Show)
220 -- The @TimeDiff@ type records the difference between two clock times in
221 -- a user-readable way.
231 tdPicosec :: Integer -- not standard
233 deriving (Eq,Ord,Read,Show)
235 noTimeDiff :: TimeDiff
236 noTimeDiff = TimeDiff 0 0 0 0 0 0 0
238 -- -----------------------------------------------------------------------------
239 -- getClockTime returns the current time in its internal representation.
241 #if HAVE_GETTIMEOFDAY
243 allocaBytes (#const sizeof(struct timeval)) $ \ p_timeval -> do
244 throwErrnoIfMinus1_ "getClockTime" $ gettimeofday p_timeval nullPtr
245 sec <- (#peek struct timeval,tv_sec) p_timeval :: IO CLong
246 usec <- (#peek struct timeval,tv_usec) p_timeval :: IO CLong
247 return (TOD (fromIntegral sec) ((fromIntegral usec) * 1000))
251 allocaBytes (#const sizeof(struct timeb)) $ \ p_timeb -> do
253 sec <- (#peek struct timeb,time) p_timeb :: IO CTime
254 msec <- (#peek struct timeb,millitm) p_timeb :: IO CUShort
255 return (TOD (fromIntegral sec) (fromIntegral msec * 1000{-ToDo: correct???-}))
257 #else /* use POSIX time() */
259 secs <- time nullPtr -- can't fail, according to POSIX
260 return (TOD (fromIntegral secs) 0)
264 -- -----------------------------------------------------------------------------
265 -- addToClockTime d t adds a time difference d and a
266 -- clock time t to yield a new clock time. The difference d
267 -- may be either positive or negative. diffClockTimes t1 t2 returns
268 -- the difference between two clock times t1 and t2 as a TimeDiff.
270 addToClockTime :: TimeDiff -> ClockTime -> ClockTime
271 addToClockTime (TimeDiff year mon day hour min sec psec)
274 sec_diff = fromInt sec + 60 * fromInt min + 3600 * fromInt hour + 24 * 3600 * fromInt day
275 cal = toUTCTime (TOD (c_sec + sec_diff) (c_psec + psec))
277 new_mon = fromEnum (ctMonth cal) + r_mon
279 | new_mon < 0 = (toEnum (12 + new_mon), (-1))
280 | new_mon > 11 = (toEnum (new_mon `mod` 12), 1)
281 | otherwise = (toEnum new_mon, 0)
283 (r_yr, r_mon) = mon `quotRem` 12
285 year' = ctYear cal + year + r_yr + yr_diff
287 toClockTime cal{ctMonth=month', ctYear=year'}
289 diffClockTimes :: ClockTime -> ClockTime -> TimeDiff
290 -- diffClockTimes is meant to be the dual to `addToClockTime'.
291 -- If you want to have the TimeDiff properly splitted, use
292 -- `normalizeTimeDiff' on this function's result
294 -- CAVEAT: see comment of normalizeTimeDiff
295 diffClockTimes (TOD sa pa) (TOD sb pb) =
296 noTimeDiff{ tdSec = fromIntegral (sa - sb)
297 -- FIXME: can handle just 68 years...
298 , tdPicosec = pa - pb
302 normalizeTimeDiff :: TimeDiff -> TimeDiff
303 -- FIXME: handle psecs properly
304 -- FIXME: ?should be called by formatTimeDiff automagically?
306 -- when applied to something coming out of `diffClockTimes', you loose
307 -- the duality to `addToClockTime', since a year does not always have
310 -- apply this function as late as possible to prevent those "rounding"
312 normalizeTimeDiff td =
319 + 365 * tdYear td))))
321 (diffYears, rest1) = rest0 `quotRem` (365 * 24 * 3600)
322 (diffMonths, rest2) = rest1 `quotRem` (30 * 24 * 3600)
323 (diffDays, rest3) = rest2 `quotRem` (24 * 3600)
324 (diffHours, rest4) = rest3 `quotRem` 3600
325 (diffMins, diffSecs) = rest4 `quotRem` 60
327 td{ tdYear = diffYears
328 , tdMonth = diffMonths
335 -- -----------------------------------------------------------------------------
336 -- How do we deal with timezones on this architecture?
338 -- The POSIX way to do it is through the global variable tzname[].
339 -- But that's crap, so we do it The BSD Way if we can: namely use the
340 -- tm_zone and tm_gmtoff fields of struct tm, if they're available.
342 zone :: Ptr CTm -> IO (Ptr CChar)
343 gmtoff :: Ptr CTm -> IO CLong
345 zone x = (#peek struct tm,tm_zone) x
346 gmtoff x = (#peek struct tm,tm_gmtoff) x
348 #else /* ! HAVE_TM_ZONE */
349 # if HAVE_TZNAME || _WIN32
350 # if cygwin32_TARGET_OS
351 # define tzname _tzname
353 # ifndef mingw32_TARGET_OS
354 foreign label tzname :: Ptr (Ptr CChar)
356 foreign import "ghcTimezone" unsafe timezone :: Ptr CLong
357 foreign import "ghcTzname" unsafe tzname :: Ptr (Ptr CChar)
358 # def inline long *ghcTimezone(void) { return &_timezone; }
359 # def inline char **ghcTzname(void) { return _tzname; }
362 dst <- (#peek struct tm,tm_isdst) x
363 if dst then peekElemOff tzname 1 else peekElemOff tzname 0
364 # else /* ! HAVE_TZNAME */
365 -- We're in trouble. If you should end up here, please report this as a bug.
366 # error "Don't know how to get at timezone name on your OS."
367 # endif /* ! HAVE_TZNAME */
369 -- Get the offset in secs from UTC, if (struct tm) doesn't supply it. */
370 #if defined(mingw32_TARGET_OS) || defined(cygwin32_TARGET_OS)
371 #define timezone _timezone
375 foreign label altzone :: Ptr CTime
376 foreign label timezone :: Ptr CTime
378 dst <- (#peek struct tm,tm_isdst) x
379 tz <- if dst then peek altzone else peek timezone
380 return (fromIntegral tz)
381 # define GMTOFF(x) (((struct tm *)x)->tm_isdst ? altzone : timezone )
382 # else /* ! HAVE_ALTZONE */
383 -- Assume that DST offset is 1 hour ...
385 dst <- (#peek struct tm,tm_isdst) x
387 if dst then return (fromIntegral tz - 3600) else return tz
388 # endif /* ! HAVE_ALTZONE */
389 #endif /* ! HAVE_TM_ZONE */
391 -- -----------------------------------------------------------------------------
392 -- toCalendarTime t converts t to a local time, modified by
393 -- the current timezone and daylight savings time settings. toUTCTime
394 -- t converts t into UTC time. toClockTime l converts l into the
395 -- corresponding internal ClockTime. The wday, yday, tzname, and isdst fields
399 toCalendarTime :: ClockTime -> IO CalendarTime
400 toCalendarTime = clockToCalendarTime localtime False
402 toUTCTime :: ClockTime -> CalendarTime
403 toUTCTime = unsafePerformIO . clockToCalendarTime gmtime True
405 -- ToDo: should be made thread safe, because localtime uses static storage,
406 -- or use the localtime_r version.
407 clockToCalendarTime :: (Ptr CTime -> IO (Ptr CTm)) -> Bool -> ClockTime
409 clockToCalendarTime fun is_utc (TOD secs psec) = do
410 withObject (fromIntegral secs :: CTime) $ \ p_timer -> do
411 p_tm <- fun p_timer -- can't fail, according to POSIX
412 sec <- (#peek struct tm,tm_sec ) p_tm :: IO CInt
413 min <- (#peek struct tm,tm_min ) p_tm :: IO CInt
414 hour <- (#peek struct tm,tm_hour ) p_tm :: IO CInt
415 mday <- (#peek struct tm,tm_mday ) p_tm :: IO CInt
416 mon <- (#peek struct tm,tm_mon ) p_tm :: IO CInt
417 year <- (#peek struct tm,tm_year ) p_tm :: IO CInt
418 wday <- (#peek struct tm,tm_wday ) p_tm :: IO CInt
419 yday <- (#peek struct tm,tm_yday ) p_tm :: IO CInt
420 isdst <- (#peek struct tm,tm_isdst) p_tm :: IO CInt
424 tzname <- peekCString zone
426 let month | mon >= 0 && mon <= 11 = toEnum (fromIntegral mon)
427 | otherwise = error ("toCalendarTime: illegal month value: " ++ show mon)
430 (1900 + fromIntegral year)
437 (toEnum (fromIntegral wday))
439 (if is_utc then "UTC" else tzname)
440 (if is_utc then 0 else fromIntegral tz)
441 (if is_utc then False else isdst /= 0))
444 toClockTime :: CalendarTime -> ClockTime
445 toClockTime (CalendarTime year mon mday hour min sec psec
446 _wday _yday _tzname tz isdst) =
448 -- `isDst' causes the date to be wrong by one hour...
449 -- FIXME: check, whether this works on other arch's than Linux, too...
451 -- so we set it to (-1) (means `unknown') and let `mktime' determine
453 let isDst = -1 :: CInt in -- if isdst then (1::Int) else 0
455 if psec < 0 || psec > 999999999999 then
456 error "Time.toClockTime: picoseconds out of range"
457 else if tz < -43200 || tz > 43200 then
458 error "Time.toClockTime: timezone offset out of range"
461 allocaBytes (#const sizeof(struct tm)) $ \ p_tm -> do
462 (#poke struct tm,tm_sec ) p_tm (fromIntegral sec :: CInt)
463 (#poke struct tm,tm_min ) p_tm (fromIntegral min :: CInt)
464 (#poke struct tm,tm_hour ) p_tm (fromIntegral hour :: CInt)
465 (#poke struct tm,tm_mday ) p_tm (fromIntegral mday :: CInt)
466 (#poke struct tm,tm_mon ) p_tm (fromIntegral (fromEnum mon) :: CInt)
467 (#poke struct tm,tm_year ) p_tm (fromIntegral year - 1900 :: CInt)
468 (#poke struct tm,tm_isdst) p_tm isDst
469 t <- throwIf (== -1) (\_ -> "Time.toClockTime: invalid input")
472 -- mktime expects its argument to be in the local timezone, but
473 -- toUTCTime makes UTC-encoded CalendarTime's ...
475 -- Since there is no any_tz_struct_tm-to-time_t conversion
476 -- function, we have to fake one... :-) If not in all, it works in
477 -- most cases (before, it was the other way round...)
479 -- Luckily, mktime tells us, what it *thinks* the timezone is, so,
480 -- to compensate, we add the timezone difference to mktime's
483 gmtoff <- gmtoff p_tm
484 let res = fromIntegral t + tz - fromIntegral gmtoff
485 return (TOD (fromIntegral res) 0)
487 -- -----------------------------------------------------------------------------
488 -- Converting time values to strings.
490 calendarTimeToString :: CalendarTime -> String
491 calendarTimeToString = formatCalendarTime defaultTimeLocale "%c"
493 formatCalendarTime :: TimeLocale -> String -> CalendarTime -> String
494 formatCalendarTime l fmt (CalendarTime year mon day hour min sec _
495 wday yday tzname _ _) =
497 where doFmt ('%':'-':cs) = doFmt ('%':cs) -- padding not implemented
498 doFmt ('%':'_':cs) = doFmt ('%':cs) -- padding not implemented
499 doFmt ('%':c:cs) = decode c ++ doFmt cs
500 doFmt (c:cs) = c : doFmt cs
503 decode 'A' = fst (wDays l !! fromEnum wday) -- day of the week, full name
504 decode 'a' = snd (wDays l !! fromEnum wday) -- day of the week, abbrev.
505 decode 'B' = fst (months l !! fromEnum mon) -- month, full name
506 decode 'b' = snd (months l !! fromEnum mon) -- month, abbrev
507 decode 'h' = snd (months l !! fromEnum mon) -- ditto
508 decode 'C' = show2 (year `quot` 100) -- century
509 decode 'c' = doFmt (dateTimeFmt l) -- locale's data and time format.
510 decode 'D' = doFmt "%m/%d/%y"
511 decode 'd' = show2 day -- day of the month
512 decode 'e' = show2' day -- ditto, padded
513 decode 'H' = show2 hour -- hours, 24-hour clock, padded
514 decode 'I' = show2 (to12 hour) -- hours, 12-hour clock
515 decode 'j' = show3 yday -- day of the year
516 decode 'k' = show2' hour -- hours, 24-hour clock, no padding
517 decode 'l' = show2' (to12 hour) -- hours, 12-hour clock, no padding
518 decode 'M' = show2 min -- minutes
519 decode 'm' = show2 (fromEnum mon+1) -- numeric month
521 decode 'p' = (if hour < 12 then fst else snd) (amPm l) -- am or pm
522 decode 'R' = doFmt "%H:%M"
523 decode 'r' = doFmt (time12Fmt l)
524 decode 'T' = doFmt "%H:%M:%S"
526 decode 'S' = show2 sec -- seconds
527 decode 's' = show2 sec -- number of secs since Epoch. (ToDo.)
528 decode 'U' = show2 ((yday + 7 - fromEnum wday) `div` 7) -- week number, starting on Sunday.
529 decode 'u' = show (let n = fromEnum wday in -- numeric day of the week (1=Monday, 7=Sunday)
530 if n == 0 then 7 else n)
531 decode 'V' = -- week number (as per ISO-8601.)
532 let (week, days) = -- [yep, I've always wanted to be able to display that too.]
533 (yday + 7 - if fromEnum wday > 0 then
534 fromEnum wday - 1 else 6) `divMod` 7
535 in show2 (if days >= 4 then
537 else if week == 0 then 53 else week)
539 decode 'W' = -- week number, weeks starting on monday
540 show2 ((yday + 7 - if fromEnum wday > 0 then
541 fromEnum wday - 1 else 6) `div` 7)
542 decode 'w' = show (fromEnum wday) -- numeric day of the week, weeks starting on Sunday.
543 decode 'X' = doFmt (timeFmt l) -- locale's preferred way of printing time.
544 decode 'x' = doFmt (dateFmt l) -- locale's preferred way of printing dates.
545 decode 'Y' = show year -- year, including century.
546 decode 'y' = show2 (year `rem` 100) -- year, within century.
547 decode 'Z' = tzname -- timezone name
552 show2, show2', show3 :: Int -> String
553 show2 x = [intToDigit (x `quot` 10), intToDigit (x `rem` 10)]
555 show2' x = if x < 10 then [ ' ', intToDigit x] else show2 x
557 show3 x = intToDigit (x `quot` 100) : show2 (x `rem` 100)
560 to12 h = let h' = h `mod` 12 in if h' == 0 then 12 else h'
562 -- Useful extensions for formatting TimeDiffs.
564 timeDiffToString :: TimeDiff -> String
565 timeDiffToString = formatTimeDiff defaultTimeLocale "%c"
567 formatTimeDiff :: TimeLocale -> String -> TimeDiff -> String
568 formatTimeDiff l fmt td@(TimeDiff year month day hour min sec _)
572 doFmt ('%':'-':cs) = doFmt ('%':cs) -- padding not implemented
573 doFmt ('%':'_':cs) = doFmt ('%':cs) -- padding not implemented
574 doFmt ('%':c:cs) = decode c ++ doFmt cs
575 doFmt (c:cs) = c : doFmt cs
579 'B' -> fst (months l !! fromEnum month)
580 'b' -> snd (months l !! fromEnum month)
581 'h' -> snd (months l !! fromEnum month)
582 'c' -> defaultTimeDiffFmt td
583 'C' -> show2 (year `quot` 100)
584 'D' -> doFmt "%m/%d/%y"
588 'I' -> show2 (to12 hour)
590 'l' -> show2' (to12 hour)
592 'm' -> show2 (fromEnum month + 1)
594 'p' -> (if hour < 12 then fst else snd) (amPm l)
596 'r' -> doFmt (time12Fmt l)
597 'T' -> doFmt "%H:%M:%S"
600 's' -> show2 sec -- Implementation-dependent, sez the lib doc..
601 'X' -> doFmt (timeFmt l)
602 'x' -> doFmt (dateFmt l)
604 'y' -> show2 (year `rem` 100)
608 defaultTimeDiffFmt (TimeDiff year month day hour min sec _) =
609 foldr (\ (v,s) rest ->
611 then show v ++ ' ':(addS v s)
612 ++ if null rest then "" else ", "
616 (zip [year, month, day, hour, min, sec] (intervals l))
618 addS v s = if abs v == 1 then fst s else snd s
621 -- -----------------------------------------------------------------------------
622 -- Foreign time interface (POSIX)
624 type CTm = () -- struct tm
626 foreign import unsafe localtime :: Ptr CTime -> IO (Ptr CTm)
627 foreign import unsafe gmtime :: Ptr CTime -> IO (Ptr CTm)
628 foreign import unsafe strftime :: Ptr CChar -> CSize -> Addr## -> Ptr CTm -> IO CSize
629 foreign import unsafe mktime :: Ptr CTm -> IO CTime
630 foreign import unsafe time :: Ptr CTime -> IO CTime
632 #if HAVE_GETTIMEOFDAY
634 foreign import unsafe gettimeofday :: Ptr CTimeVal -> Ptr () -> IO CInt
639 #ifndef mingw32_TARGET_OS
640 foreign import unsafe ftime :: Ptr CTimeB -> IO CInt
642 foreign import unsafe ftime :: Ptr CTimeB -> IO ()