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 1.19 2001/07/24 05:53:27 ken 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
73 -- instance Show (non-standard)
78 , noTimeDiff -- non-standard (but useful when constructing TimeDiff vals.)
82 , normalizeTimeDiff -- non-standard
83 , timeDiffToString -- non-standard
84 , formatTimeDiff -- non-standard
90 , calendarTimeToString
100 import PrelMarshalAlloc
101 import PrelMarshalUtils
102 import PrelMarshalError
115 -- One way to partition and give name to chunks of a year and a week:
118 = January | February | March | April
119 | May | June | July | August
120 | September | October | November | December
121 deriving (Eq, Ord, Enum, Bounded, Ix, Read, Show)
124 = Sunday | Monday | Tuesday | Wednesday
125 | Thursday | Friday | Saturday
126 deriving (Eq, Ord, Enum, Bounded, Ix, Read, Show)
128 -- @ClockTime@ is an abstract type, used for the internal clock time.
129 -- Clock times may be compared, converted to strings, or converted to an
130 -- external calendar time @CalendarTime@.
132 data ClockTime = TOD Integer -- Seconds since 00:00:00 on 1 Jan 1970
133 Integer -- Picoseconds with the specified second
136 -- When a ClockTime is shown, it is converted to a CalendarTime in the current
137 -- timezone and then printed. FIXME: This is arguably wrong, since we can't
138 -- get the current timezone without being in the IO monad.
140 instance Show ClockTime where
141 showsPrec _ t = showString (calendarTimeToString
142 (unsafePerformIO (toCalendarTime t)))
143 showList = showList__ (showsPrec 0)
146 @CalendarTime@ is a user-readable and manipulable
147 representation of the internal $ClockTime$ type. The
148 numeric fields have the following ranges.
154 year -maxInt .. maxInt [Pre-Gregorian dates are inaccurate]
155 mon 0 .. 11 [Jan = 0, Dec = 11]
159 sec 0 .. 61 [Allows for two leap seconds]
160 picosec 0 .. (10^12)-1 [This could be over-precise?]
161 wday 0 .. 6 [Sunday = 0, Saturday = 6]
162 yday 0 .. 365 [364 in non-Leap years]
163 tz -43200 .. 43200 [Variation from UTC in seconds]
166 The {\em tzname} field is the name of the time zone. The {\em isdst}
167 field indicates whether Daylight Savings Time would be in effect.
178 ctPicosec :: Integer,
185 deriving (Eq,Ord,Read,Show)
187 -- The @TimeDiff@ type records the difference between two clock times in
188 -- a user-readable way.
198 tdPicosec :: Integer -- not standard
200 deriving (Eq,Ord,Read,Show)
202 noTimeDiff :: TimeDiff
203 noTimeDiff = TimeDiff 0 0 0 0 0 0 0
205 -- -----------------------------------------------------------------------------
206 -- getClockTime returns the current time in its internal representation.
208 #if HAVE_GETTIMEOFDAY
210 allocaBytes (#const sizeof(struct timeval)) $ \ p_timeval -> do
211 throwErrnoIfMinus1_ "getClockTime" $ gettimeofday p_timeval nullPtr
212 sec <- (#peek struct timeval,tv_sec) p_timeval :: IO Int32
213 usec <- (#peek struct timeval,tv_usec) p_timeval :: IO Int32
214 return (TOD (fromIntegral sec) ((fromIntegral usec) * 1000))
218 allocaBytes (#const sizeof(struct timeb)) $ \ p_timeb -> do
220 sec <- (#peek struct timeb,time) p_timeb :: IO CTime
221 msec <- (#peek struct timeb,millitm) p_timeb :: IO CUShort
222 return (TOD (fromIntegral sec) (fromIntegral msec * 1000{-ToDo: correct???-}))
224 #else /* use POSIX time() */
226 secs <- time nullPtr -- can't fail, according to POSIX
227 return (TOD (fromIntegral secs) 0)
231 -- -----------------------------------------------------------------------------
232 -- addToClockTime d t adds a time difference d and a
233 -- clock time t to yield a new clock time. The difference d
234 -- may be either positive or negative. diffClockTimes t1 t2 returns
235 -- the difference between two clock times t1 and t2 as a TimeDiff.
237 addToClockTime :: TimeDiff -> ClockTime -> ClockTime
238 addToClockTime (TimeDiff year mon day hour min sec psec)
241 sec_diff = toInteger sec +
243 3600 * toInteger hour +
244 24 * 3600 * toInteger day
245 cal = toUTCTime (TOD (c_sec + sec_diff) (c_psec + psec))
247 new_mon = fromEnum (ctMonth cal) + r_mon
249 | new_mon < 0 = (toEnum (12 + new_mon), (-1))
250 | new_mon > 11 = (toEnum (new_mon `mod` 12), 1)
251 | otherwise = (toEnum new_mon, 0)
253 (r_yr, r_mon) = mon `quotRem` 12
255 year' = ctYear cal + year + r_yr + yr_diff
257 toClockTime cal{ctMonth=month', ctYear=year'}
259 diffClockTimes :: ClockTime -> ClockTime -> TimeDiff
260 -- diffClockTimes is meant to be the dual to `addToClockTime'.
261 -- If you want to have the TimeDiff properly splitted, use
262 -- `normalizeTimeDiff' on this function's result
264 -- CAVEAT: see comment of normalizeTimeDiff
265 diffClockTimes (TOD sa pa) (TOD sb pb) =
266 noTimeDiff{ tdSec = fromIntegral (sa - sb)
267 -- FIXME: can handle just 68 years...
268 , tdPicosec = pa - pb
272 normalizeTimeDiff :: TimeDiff -> TimeDiff
273 -- FIXME: handle psecs properly
274 -- FIXME: ?should be called by formatTimeDiff automagically?
276 -- when applied to something coming out of `diffClockTimes', you loose
277 -- the duality to `addToClockTime', since a year does not always have
280 -- apply this function as late as possible to prevent those "rounding"
282 normalizeTimeDiff td =
289 + 365 * tdYear td))))
291 (diffYears, rest1) = rest0 `quotRem` (365 * 24 * 3600)
292 (diffMonths, rest2) = rest1 `quotRem` (30 * 24 * 3600)
293 (diffDays, rest3) = rest2 `quotRem` (24 * 3600)
294 (diffHours, rest4) = rest3 `quotRem` 3600
295 (diffMins, diffSecs) = rest4 `quotRem` 60
297 td{ tdYear = diffYears
298 , tdMonth = diffMonths
305 -- -----------------------------------------------------------------------------
306 -- How do we deal with timezones on this architecture?
308 -- The POSIX way to do it is through the global variable tzname[].
309 -- But that's crap, so we do it The BSD Way if we can: namely use the
310 -- tm_zone and tm_gmtoff fields of struct tm, if they're available.
312 zone :: Ptr CTm -> IO (Ptr CChar)
313 gmtoff :: Ptr CTm -> IO CLong
315 zone x = (#peek struct tm,tm_zone) x
316 gmtoff x = (#peek struct tm,tm_gmtoff) x
318 #else /* ! HAVE_TM_ZONE */
319 # if HAVE_TZNAME || defined(_WIN32)
320 # if cygwin32_TARGET_OS
321 # define tzname _tzname
323 # ifndef mingw32_TARGET_OS
324 foreign label tzname :: Ptr (Ptr CChar)
326 foreign import "ghcTimezone" unsafe timezone :: Ptr CLong
327 foreign import "ghcTzname" unsafe tzname :: Ptr (Ptr CChar)
328 # def inline long *ghcTimezone(void) { return &_timezone; }
329 # def inline char **ghcTzname(void) { return _tzname; }
332 dst <- (#peek struct tm,tm_isdst) x
333 if dst then peekElemOff tzname 1 else peekElemOff tzname 0
334 # else /* ! HAVE_TZNAME */
335 -- We're in trouble. If you should end up here, please report this as a bug.
336 # error "Don't know how to get at timezone name on your OS."
337 # endif /* ! HAVE_TZNAME */
339 -- Get the offset in secs from UTC, if (struct tm) doesn't supply it. */
340 #if defined(mingw32_TARGET_OS) || defined(cygwin32_TARGET_OS)
341 #define timezone _timezone
345 foreign label altzone :: Ptr CTime
346 foreign label timezone :: Ptr CTime
348 dst <- (#peek struct tm,tm_isdst) x
349 tz <- if dst then peek altzone else peek timezone
350 return (fromIntegral tz)
351 # define GMTOFF(x) (((struct tm *)x)->tm_isdst ? altzone : timezone )
352 # else /* ! HAVE_ALTZONE */
353 -- Assume that DST offset is 1 hour ...
355 dst <- (#peek struct tm,tm_isdst) x
357 if dst then return (fromIntegral tz - 3600) else return tz
358 # endif /* ! HAVE_ALTZONE */
359 #endif /* ! HAVE_TM_ZONE */
361 -- -----------------------------------------------------------------------------
362 -- toCalendarTime t converts t to a local time, modified by
363 -- the current timezone and daylight savings time settings. toUTCTime
364 -- t converts t into UTC time. toClockTime l converts l into the
365 -- corresponding internal ClockTime. The wday, yday, tzname, and isdst fields
369 toCalendarTime :: ClockTime -> IO CalendarTime
371 toCalendarTime = clockToCalendarTime_reentrant (throwAwayReturnPointer localtime_r) False
373 toCalendarTime = clockToCalendarTime_static localtime False
376 toUTCTime :: ClockTime -> CalendarTime
378 toUTCTime = unsafePerformIO . clockToCalendarTime_reentrant (throwAwayReturnPointer gmtime_r) True
380 toUTCTime = unsafePerformIO . clockToCalendarTime_static gmtime True
383 throwAwayReturnPointer :: (Ptr CTime -> Ptr CTm -> IO (Ptr CTm))
384 -> (Ptr CTime -> Ptr CTm -> IO ( ))
385 throwAwayReturnPointer fun x y = fun x y >> return ()
387 clockToCalendarTime_static :: (Ptr CTime -> IO (Ptr CTm)) -> Bool -> ClockTime
389 clockToCalendarTime_static fun is_utc (TOD secs psec) = do
390 withObject (fromIntegral secs :: CTime) $ \ p_timer -> do
391 p_tm <- fun p_timer -- can't fail, according to POSIX
392 clockToCalendarTime_aux is_utc p_tm psec
394 clockToCalendarTime_reentrant :: (Ptr CTime -> Ptr CTm -> IO ()) -> Bool -> ClockTime
396 clockToCalendarTime_reentrant fun is_utc (TOD secs psec) = do
397 withObject (fromIntegral secs :: CTime) $ \ p_timer -> do
398 allocaBytes (#const sizeof(struct tm)) $ \ p_tm -> do
400 clockToCalendarTime_aux is_utc p_tm psec
402 clockToCalendarTime_aux :: Bool -> Ptr CTm -> Integer -> IO CalendarTime
403 clockToCalendarTime_aux is_utc p_tm psec = do
404 sec <- (#peek struct tm,tm_sec ) p_tm :: IO CInt
405 min <- (#peek struct tm,tm_min ) p_tm :: IO CInt
406 hour <- (#peek struct tm,tm_hour ) p_tm :: IO CInt
407 mday <- (#peek struct tm,tm_mday ) p_tm :: IO CInt
408 mon <- (#peek struct tm,tm_mon ) p_tm :: IO CInt
409 year <- (#peek struct tm,tm_year ) p_tm :: IO CInt
410 wday <- (#peek struct tm,tm_wday ) p_tm :: IO CInt
411 yday <- (#peek struct tm,tm_yday ) p_tm :: IO CInt
412 isdst <- (#peek struct tm,tm_isdst) p_tm :: IO CInt
416 tzname <- peekCString zone
418 let month | mon >= 0 && mon <= 11 = toEnum (fromIntegral mon)
419 | otherwise = error ("toCalendarTime: illegal month value: " ++ show mon)
422 (1900 + fromIntegral year)
429 (toEnum (fromIntegral wday))
431 (if is_utc then "UTC" else tzname)
432 (if is_utc then 0 else fromIntegral tz)
433 (if is_utc then False else isdst /= 0))
436 toClockTime :: CalendarTime -> ClockTime
437 toClockTime (CalendarTime year mon mday hour min sec psec
438 _wday _yday _tzname tz isdst) =
440 -- `isDst' causes the date to be wrong by one hour...
441 -- FIXME: check, whether this works on other arch's than Linux, too...
443 -- so we set it to (-1) (means `unknown') and let `mktime' determine
445 let isDst = -1 :: CInt in -- if isdst then (1::Int) else 0
447 if psec < 0 || psec > 999999999999 then
448 error "Time.toClockTime: picoseconds out of range"
449 else if tz < -43200 || tz > 43200 then
450 error "Time.toClockTime: timezone offset out of range"
453 allocaBytes (#const sizeof(struct tm)) $ \ p_tm -> do
454 (#poke struct tm,tm_sec ) p_tm (fromIntegral sec :: CInt)
455 (#poke struct tm,tm_min ) p_tm (fromIntegral min :: CInt)
456 (#poke struct tm,tm_hour ) p_tm (fromIntegral hour :: CInt)
457 (#poke struct tm,tm_mday ) p_tm (fromIntegral mday :: CInt)
458 (#poke struct tm,tm_mon ) p_tm (fromIntegral (fromEnum mon) :: CInt)
459 (#poke struct tm,tm_year ) p_tm (fromIntegral year - 1900 :: CInt)
460 (#poke struct tm,tm_isdst) p_tm isDst
461 t <- throwIf (== -1) (\_ -> "Time.toClockTime: invalid input")
464 -- mktime expects its argument to be in the local timezone, but
465 -- toUTCTime makes UTC-encoded CalendarTime's ...
467 -- Since there is no any_tz_struct_tm-to-time_t conversion
468 -- function, we have to fake one... :-) If not in all, it works in
469 -- most cases (before, it was the other way round...)
471 -- Luckily, mktime tells us, what it *thinks* the timezone is, so,
472 -- to compensate, we add the timezone difference to mktime's
475 gmtoff <- gmtoff p_tm
476 let res = fromIntegral t - tz + fromIntegral gmtoff
477 return (TOD (fromIntegral res) 0)
479 -- -----------------------------------------------------------------------------
480 -- Converting time values to strings.
482 calendarTimeToString :: CalendarTime -> String
483 calendarTimeToString = formatCalendarTime defaultTimeLocale "%c"
485 formatCalendarTime :: TimeLocale -> String -> CalendarTime -> String
486 formatCalendarTime l fmt (CalendarTime year mon day hour min sec _
487 wday yday tzname _ _) =
489 where doFmt ('%':'-':cs) = doFmt ('%':cs) -- padding not implemented
490 doFmt ('%':'_':cs) = doFmt ('%':cs) -- padding not implemented
491 doFmt ('%':c:cs) = decode c ++ doFmt cs
492 doFmt (c:cs) = c : doFmt cs
495 decode 'A' = fst (wDays l !! fromEnum wday) -- day of the week, full name
496 decode 'a' = snd (wDays l !! fromEnum wday) -- day of the week, abbrev.
497 decode 'B' = fst (months l !! fromEnum mon) -- month, full name
498 decode 'b' = snd (months l !! fromEnum mon) -- month, abbrev
499 decode 'h' = snd (months l !! fromEnum mon) -- ditto
500 decode 'C' = show2 (year `quot` 100) -- century
501 decode 'c' = doFmt (dateTimeFmt l) -- locale's data and time format.
502 decode 'D' = doFmt "%m/%d/%y"
503 decode 'd' = show2 day -- day of the month
504 decode 'e' = show2' day -- ditto, padded
505 decode 'H' = show2 hour -- hours, 24-hour clock, padded
506 decode 'I' = show2 (to12 hour) -- hours, 12-hour clock
507 decode 'j' = show3 yday -- day of the year
508 decode 'k' = show2' hour -- hours, 24-hour clock, no padding
509 decode 'l' = show2' (to12 hour) -- hours, 12-hour clock, no padding
510 decode 'M' = show2 min -- minutes
511 decode 'm' = show2 (fromEnum mon+1) -- numeric month
513 decode 'p' = (if hour < 12 then fst else snd) (amPm l) -- am or pm
514 decode 'R' = doFmt "%H:%M"
515 decode 'r' = doFmt (time12Fmt l)
516 decode 'T' = doFmt "%H:%M:%S"
518 decode 'S' = show2 sec -- seconds
519 decode 's' = show2 sec -- number of secs since Epoch. (ToDo.)
520 decode 'U' = show2 ((yday + 7 - fromEnum wday) `div` 7) -- week number, starting on Sunday.
521 decode 'u' = show (let n = fromEnum wday in -- numeric day of the week (1=Monday, 7=Sunday)
522 if n == 0 then 7 else n)
523 decode 'V' = -- week number (as per ISO-8601.)
524 let (week, days) = -- [yep, I've always wanted to be able to display that too.]
525 (yday + 7 - if fromEnum wday > 0 then
526 fromEnum wday - 1 else 6) `divMod` 7
527 in show2 (if days >= 4 then
529 else if week == 0 then 53 else week)
531 decode 'W' = -- week number, weeks starting on monday
532 show2 ((yday + 7 - if fromEnum wday > 0 then
533 fromEnum wday - 1 else 6) `div` 7)
534 decode 'w' = show (fromEnum wday) -- numeric day of the week, weeks starting on Sunday.
535 decode 'X' = doFmt (timeFmt l) -- locale's preferred way of printing time.
536 decode 'x' = doFmt (dateFmt l) -- locale's preferred way of printing dates.
537 decode 'Y' = show year -- year, including century.
538 decode 'y' = show2 (year `rem` 100) -- year, within century.
539 decode 'Z' = tzname -- timezone name
544 show2, show2', show3 :: Int -> String
545 show2 x = [intToDigit (x `quot` 10), intToDigit (x `rem` 10)]
547 show2' x = if x < 10 then [ ' ', intToDigit x] else show2 x
549 show3 x = intToDigit (x `quot` 100) : show2 (x `rem` 100)
552 to12 h = let h' = h `mod` 12 in if h' == 0 then 12 else h'
554 -- Useful extensions for formatting TimeDiffs.
556 timeDiffToString :: TimeDiff -> String
557 timeDiffToString = formatTimeDiff defaultTimeLocale "%c"
559 formatTimeDiff :: TimeLocale -> String -> TimeDiff -> String
560 formatTimeDiff l fmt td@(TimeDiff year month day hour min sec _)
564 doFmt ('%':'-':cs) = doFmt ('%':cs) -- padding not implemented
565 doFmt ('%':'_':cs) = doFmt ('%':cs) -- padding not implemented
566 doFmt ('%':c:cs) = decode c ++ doFmt cs
567 doFmt (c:cs) = c : doFmt cs
571 'B' -> fst (months l !! fromEnum month)
572 'b' -> snd (months l !! fromEnum month)
573 'h' -> snd (months l !! fromEnum month)
574 'c' -> defaultTimeDiffFmt td
575 'C' -> show2 (year `quot` 100)
576 'D' -> doFmt "%m/%d/%y"
580 'I' -> show2 (to12 hour)
582 'l' -> show2' (to12 hour)
584 'm' -> show2 (fromEnum month + 1)
586 'p' -> (if hour < 12 then fst else snd) (amPm l)
588 'r' -> doFmt (time12Fmt l)
589 'T' -> doFmt "%H:%M:%S"
592 's' -> show2 sec -- Implementation-dependent, sez the lib doc..
593 'X' -> doFmt (timeFmt l)
594 'x' -> doFmt (dateFmt l)
596 'y' -> show2 (year `rem` 100)
600 defaultTimeDiffFmt (TimeDiff year month day hour min sec _) =
601 foldr (\ (v,s) rest ->
603 then show v ++ ' ':(addS v s)
604 ++ if null rest then "" else ", "
608 (zip [year, month, day, hour, min, sec] (intervals l))
610 addS v s = if abs v == 1 then fst s else snd s
613 -- -----------------------------------------------------------------------------
614 -- Foreign time interface (POSIX)
616 type CTm = () -- struct tm
619 foreign import unsafe localtime_r :: Ptr CTime -> Ptr CTm -> IO (Ptr CTm)
621 foreign import unsafe localtime :: Ptr CTime -> IO (Ptr CTm)
624 foreign import unsafe gmtime_r :: Ptr CTime -> Ptr CTm -> IO (Ptr CTm)
626 foreign import unsafe gmtime :: Ptr CTime -> IO (Ptr CTm)
628 foreign import unsafe mktime :: Ptr CTm -> IO CTime
629 foreign import unsafe time :: Ptr CTime -> IO CTime
631 #if HAVE_GETTIMEOFDAY
633 foreign import unsafe gettimeofday :: Ptr CTimeVal -> Ptr () -> IO CInt
638 #ifndef mingw32_TARGET_OS
639 foreign import unsafe ftime :: Ptr CTimeB -> IO CInt
641 foreign import unsafe ftime :: Ptr CTimeB -> IO ()