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 1.7 2001/01/26 16:16:19 rrt 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_WINDOWS_H
109 #include <sys/types.h>
110 #include <sys/timeb.h>
116 import PrelMarshalAlloc
117 import PrelMarshalUtils
118 import PrelMarshalError
131 -- One way to partition and give name to chunks of a year and a week:
134 = January | February | March | April
135 | May | June | July | August
136 | September | October | November | December
137 deriving (Eq, Ord, Enum, Bounded, Ix, Read, Show)
140 = Sunday | Monday | Tuesday | Wednesday
141 | Thursday | Friday | Saturday
142 deriving (Eq, Ord, Enum, Bounded, Ix, Read, Show)
144 -- @ClockTime@ is an abstract type, used for the internal clock time.
145 -- Clock times may be compared, converted to strings, or converted to an
146 -- external calendar time @CalendarTime@.
148 data ClockTime = TOD Integer -- Seconds since 00:00:00 on 1 Jan 1970
149 Integer -- Picoseconds with the specified second
152 -- When a @ClockTime@ is shown, it is converted to a string of the form
153 -- @"Mon Nov 28 21:45:41 GMT 1994"@.
155 -- For now, we are restricted to roughly:
156 -- Fri Dec 13 20:45:52 1901 through Tue Jan 19 03:14:07 2038, because
157 -- we use the C library routines based on 32 bit integers.
159 instance Show ClockTime where
160 showsPrec _ (TOD secs _nsec) =
161 showString $ unsafePerformIO $ do
162 withObject (fromIntegral secs :: CTime) $ \ p_timer -> do
163 p_tm <- localtime p_timer -- can't fail, according to POSIX
164 allocaBytes 64 $ \ p_buf -> do -- big enough for error message
165 r <- strftime p_buf 50 "%a %b %d %H:%M:%S %Z %Y"## p_tm
167 then return "ClockTime.show{Time}: internal error"
168 else peekCString p_buf
170 showList = showList__ (showsPrec 0)
173 @CalendarTime@ is a user-readable and manipulable
174 representation of the internal $ClockTime$ type. The
175 numeric fields have the following ranges.
181 year -maxInt .. maxInt [Pre-Gregorian dates are inaccurate]
182 mon 0 .. 11 [Jan = 0, Dec = 11]
186 sec 0 .. 61 [Allows for two leap seconds]
187 picosec 0 .. (10^12)-1 [This could be over-precise?]
188 wday 0 .. 6 [Sunday = 0, Saturday = 6]
189 yday 0 .. 365 [364 in non-Leap years]
190 tz -43200 .. 43200 [Variation from UTC in seconds]
193 The {\em tzname} field is the name of the time zone. The {\em isdst}
194 field indicates whether Daylight Savings Time would be in effect.
205 ctPicosec :: Integer,
212 deriving (Eq,Ord,Read,Show)
214 -- The @TimeDiff@ type records the difference between two clock times in
215 -- a user-readable way.
225 tdPicosec :: Integer -- not standard
227 deriving (Eq,Ord,Read,Show)
229 noTimeDiff :: TimeDiff
230 noTimeDiff = TimeDiff 0 0 0 0 0 0 0
232 -- -----------------------------------------------------------------------------
233 -- getClockTime returns the current time in its internal representation.
235 #if HAVE_GETTIMEOFDAY
237 allocaBytes (#const sizeof(struct timeval)) $ \ p_timeval -> do
238 throwErrnoIfMinus1_ "getClockTime" $ gettimeofday p_timeval nullPtr
239 sec <- (#peek struct timeval,tv_sec) p_timeval :: IO CLong
240 usec <- (#peek struct timeval,tv_usec) p_timeval :: IO CLong
241 return (TOD (fromIntegral sec) ((fromIntegral usec) * 1000))
245 allocaBytes (#const sizeof(struct timeb)) $ \ p_timeb -> do
247 sec <- (#peek struct timeb,time) p_timeb :: IO CTime
248 msec <- (#peek struct timeb,millitm) p_timeb :: IO CUShort
249 return (TOD (fromIntegral sec) (fromIntegral msec * 1000{-ToDo: correct???-}))
251 #else /* use POSIX time() */
253 secs <- time nullPtr -- can't fail, according to POSIX
254 return (TOD (fromIntegral secs) 0)
258 -- -----------------------------------------------------------------------------
259 -- addToClockTime d t adds a time difference d and a
260 -- clock time t to yield a new clock time. The difference d
261 -- may be either positive or negative. diffClockTimes t1 t2 returns
262 -- the difference between two clock times t1 and t2 as a TimeDiff.
264 addToClockTime :: TimeDiff -> ClockTime -> ClockTime
265 addToClockTime (TimeDiff year mon day hour min sec psec)
268 sec_diff = fromInt sec + 60 * fromInt min + 3600 * fromInt hour + 24 * 3600 * fromInt day
269 cal = toUTCTime (TOD (c_sec + sec_diff) (c_psec + psec))
271 new_mon = fromEnum (ctMonth cal) + r_mon
273 | new_mon < 0 = (toEnum (12 + new_mon), (-1))
274 | new_mon > 11 = (toEnum (new_mon `mod` 12), 1)
275 | otherwise = (toEnum new_mon, 0)
277 (r_yr, r_mon) = mon `quotRem` 12
279 year' = ctYear cal + year + r_yr + yr_diff
281 toClockTime cal{ctMonth=month', ctYear=year'}
283 diffClockTimes :: ClockTime -> ClockTime -> TimeDiff
284 -- diffClockTimes is meant to be the dual to `addToClockTime'.
285 -- If you want to have the TimeDiff properly splitted, use
286 -- `normalizeTimeDiff' on this function's result
288 -- CAVEAT: see comment of normalizeTimeDiff
289 diffClockTimes (TOD sa pa) (TOD sb pb) =
290 noTimeDiff{ tdSec = fromIntegral (sa - sb)
291 -- FIXME: can handle just 68 years...
292 , tdPicosec = pa - pb
296 normalizeTimeDiff :: TimeDiff -> TimeDiff
297 -- FIXME: handle psecs properly
298 -- FIXME: ?should be called by formatTimeDiff automagically?
300 -- when applied to something coming out of `diffClockTimes', you loose
301 -- the duality to `addToClockTime', since a year does not always have
304 -- apply this function as late as possible to prevent those "rounding"
306 normalizeTimeDiff td =
313 + 365 * tdYear td))))
315 (diffYears, rest1) = rest0 `quotRem` (365 * 24 * 3600)
316 (diffMonths, rest2) = rest1 `quotRem` (30 * 24 * 3600)
317 (diffDays, rest3) = rest2 `quotRem` (24 * 3600)
318 (diffHours, rest4) = rest3 `quotRem` 3600
319 (diffMins, diffSecs) = rest4 `quotRem` 60
321 td{ tdYear = diffYears
322 , tdMonth = diffMonths
329 -- -----------------------------------------------------------------------------
330 -- How do we deal with timezones on this architecture?
332 -- The POSIX way to do it is through the global variable tzname[].
333 -- But that's crap, so we do it The BSD Way if we can: namely use the
334 -- tm_zone and tm_gmtoff fields of struct tm, if they're available.
336 zone :: Ptr CTm -> IO (Ptr CChar)
337 gmtoff :: Ptr CTm -> IO CLong
339 zone x = (#peek struct tm,tm_zone) x
340 gmtoff x = (#peek struct tm,tm_gmtoff) x
342 #else /* ! HAVE_TM_ZONE */
343 # if HAVE_TZNAME || _WIN32
344 # if cygwin32_TARGET_OS
345 # define tzname _tzname
347 # ifndef mingw32_TARGET_OS
348 foreign label tzname :: Ptr (Ptr CChar)
351 dst <- (#peek struct tm,tm_isdst) x
352 if dst then peekElemOff tzname 1 else peekElemOff tzname 0
353 # else /* ! HAVE_TZNAME */
354 -- We're in trouble. If you should end up here, please report this as a bug.
355 # error "Don't know how to get at timezone name on your OS."
356 # endif /* ! HAVE_TZNAME */
358 -- Get the offset in secs from UTC, if (struct tm) doesn't supply it. */
359 #if defined(mingw32_TARGET_OS) || defined(cygwin32_TARGET_OS)
360 #define timezone _timezone
364 foreign label altzone :: Ptr CTime
365 foreign label timezone :: Ptr CTime
367 dst <- (#peek struct tm,tm_isdst) x
368 tz <- if dst then peek altzone else peek timezone
369 return (fromIntegral tz)
370 # define GMTOFF(x) (((struct tm *)x)->tm_isdst ? altzone : timezone )
371 # else /* ! HAVE_ALTZONE */
372 -- Assume that DST offset is 1 hour ...
374 dst <- (#peek struct tm,tm_isdst) x
376 if dst then return (fromIntegral tz - 3600) else return tz
377 # endif /* ! HAVE_ALTZONE */
378 #endif /* ! HAVE_TM_ZONE */
380 -- -----------------------------------------------------------------------------
381 -- toCalendarTime t converts t to a local time, modified by
382 -- the current timezone and daylight savings time settings. toUTCTime
383 -- t converts t into UTC time. toClockTime l converts l into the
384 -- corresponding internal ClockTime. The wday, yday, tzname, and isdst fields
388 toCalendarTime :: ClockTime -> IO CalendarTime
389 toCalendarTime = clockToCalendarTime localtime False
391 toUTCTime :: ClockTime -> CalendarTime
392 toUTCTime = unsafePerformIO . clockToCalendarTime gmtime True
394 -- ToDo: should be made thread safe, because localtime uses static storage,
395 -- or use the localtime_r version.
396 clockToCalendarTime :: (Ptr CTime -> IO (Ptr CTm)) -> Bool -> ClockTime
398 clockToCalendarTime fun is_utc (TOD secs psec) = do
399 withObject (fromIntegral secs :: CTime) $ \ p_timer -> do
400 p_tm <- fun p_timer -- can't fail, according to POSIX
401 sec <- (#peek struct tm,tm_sec ) p_tm :: IO CInt
402 min <- (#peek struct tm,tm_min ) p_tm :: IO CInt
403 hour <- (#peek struct tm,tm_hour ) p_tm :: IO CInt
404 mday <- (#peek struct tm,tm_mday ) p_tm :: IO CInt
405 mon <- (#peek struct tm,tm_mon ) p_tm :: IO CInt
406 year <- (#peek struct tm,tm_year ) p_tm :: IO CInt
407 wday <- (#peek struct tm,tm_wday ) p_tm :: IO CInt
408 yday <- (#peek struct tm,tm_yday ) p_tm :: IO CInt
409 isdst <- (#peek struct tm,tm_isdst) p_tm :: IO CInt
413 tzname <- peekCString zone
415 let month | mon >= 0 && mon <= 11 = toEnum (fromIntegral mon)
416 | otherwise = error ("toCalendarTime: illegal month value: " ++ show mon)
419 (1900 + fromIntegral year)
426 (toEnum (fromIntegral wday))
428 (if is_utc then "UTC" else tzname)
429 (if is_utc then 0 else fromIntegral tz)
430 (if is_utc then False else isdst /= 0))
433 toClockTime :: CalendarTime -> ClockTime
434 toClockTime (CalendarTime year mon mday hour min sec psec
435 _wday _yday _tzname tz isdst) =
437 -- `isDst' causes the date to be wrong by one hour...
438 -- FIXME: check, whether this works on other arch's than Linux, too...
440 -- so we set it to (-1) (means `unknown') and let `mktime' determine
442 let isDst = -1 :: CInt in -- if isdst then (1::Int) else 0
444 if psec < 0 || psec > 999999999999 then
445 error "Time.toClockTime: picoseconds out of range"
446 else if tz < -43200 || tz > 43200 then
447 error "Time.toClockTime: timezone offset out of range"
450 allocaBytes (#const sizeof(struct tm)) $ \ p_tm -> do
451 (#poke struct tm,tm_sec ) p_tm (fromIntegral sec :: CInt)
452 (#poke struct tm,tm_min ) p_tm (fromIntegral min :: CInt)
453 (#poke struct tm,tm_hour ) p_tm (fromIntegral hour :: CInt)
454 (#poke struct tm,tm_mday ) p_tm (fromIntegral mday :: CInt)
455 (#poke struct tm,tm_mon ) p_tm (fromIntegral (fromEnum mon) :: CInt)
456 (#poke struct tm,tm_year ) p_tm (fromIntegral year - 1900 :: CInt)
457 (#poke struct tm,tm_isdst) p_tm isDst
458 t <- throwIf (== -1) (\_ -> "Time.toClockTime: invalid input")
461 -- mktime expects its argument to be in the local timezone, but
462 -- toUTCTime makes UTC-encoded CalendarTime's ...
464 -- Since there is no any_tz_struct_tm-to-time_t conversion
465 -- function, we have to fake one... :-) If not in all, it works in
466 -- most cases (before, it was the other way round...)
468 -- Luckily, mktime tells us, what it *thinks* the timezone is, so,
469 -- to compensate, we add the timezone difference to mktime's
472 gmtoff <- gmtoff p_tm
473 let res = fromIntegral t + tz - fromIntegral gmtoff
474 return (TOD (fromIntegral res) 0)
476 -- -----------------------------------------------------------------------------
477 -- Converting time values to strings.
479 calendarTimeToString :: CalendarTime -> String
480 calendarTimeToString = formatCalendarTime defaultTimeLocale "%c"
482 formatCalendarTime :: TimeLocale -> String -> CalendarTime -> String
483 formatCalendarTime l fmt (CalendarTime year mon day hour min sec _
484 wday yday tzname _ _) =
486 where doFmt ('%':'-':cs) = doFmt ('%':cs) -- padding not implemented
487 doFmt ('%':'_':cs) = doFmt ('%':cs) -- padding not implemented
488 doFmt ('%':c:cs) = decode c ++ doFmt cs
489 doFmt (c:cs) = c : doFmt cs
492 decode 'A' = fst (wDays l !! fromEnum wday) -- day of the week, full name
493 decode 'a' = snd (wDays l !! fromEnum wday) -- day of the week, abbrev.
494 decode 'B' = fst (months l !! fromEnum mon) -- month, full name
495 decode 'b' = snd (months l !! fromEnum mon) -- month, abbrev
496 decode 'h' = snd (months l !! fromEnum mon) -- ditto
497 decode 'C' = show2 (year `quot` 100) -- century
498 decode 'c' = doFmt (dateTimeFmt l) -- locale's data and time format.
499 decode 'D' = doFmt "%m/%d/%y"
500 decode 'd' = show2 day -- day of the month
501 decode 'e' = show2' day -- ditto, padded
502 decode 'H' = show2 hour -- hours, 24-hour clock, padded
503 decode 'I' = show2 (to12 hour) -- hours, 12-hour clock
504 decode 'j' = show3 yday -- day of the year
505 decode 'k' = show2' hour -- hours, 24-hour clock, no padding
506 decode 'l' = show2' (to12 hour) -- hours, 12-hour clock, no padding
507 decode 'M' = show2 min -- minutes
508 decode 'm' = show2 (fromEnum mon+1) -- numeric month
510 decode 'p' = (if hour < 12 then fst else snd) (amPm l) -- am or pm
511 decode 'R' = doFmt "%H:%M"
512 decode 'r' = doFmt (time12Fmt l)
513 decode 'T' = doFmt "%H:%M:%S"
515 decode 'S' = show2 sec -- seconds
516 decode 's' = show2 sec -- number of secs since Epoch. (ToDo.)
517 decode 'U' = show2 ((yday + 7 - fromEnum wday) `div` 7) -- week number, starting on Sunday.
518 decode 'u' = show (let n = fromEnum wday in -- numeric day of the week (1=Monday, 7=Sunday)
519 if n == 0 then 7 else n)
520 decode 'V' = -- week number (as per ISO-8601.)
521 let (week, days) = -- [yep, I've always wanted to be able to display that too.]
522 (yday + 7 - if fromEnum wday > 0 then
523 fromEnum wday - 1 else 6) `divMod` 7
524 in show2 (if days >= 4 then
526 else if week == 0 then 53 else week)
528 decode 'W' = -- week number, weeks starting on monday
529 show2 ((yday + 7 - if fromEnum wday > 0 then
530 fromEnum wday - 1 else 6) `div` 7)
531 decode 'w' = show (fromEnum wday) -- numeric day of the week, weeks starting on Sunday.
532 decode 'X' = doFmt (timeFmt l) -- locale's preferred way of printing time.
533 decode 'x' = doFmt (dateFmt l) -- locale's preferred way of printing dates.
534 decode 'Y' = show year -- year, including century.
535 decode 'y' = show2 (year `rem` 100) -- year, within century.
536 decode 'Z' = tzname -- timezone name
541 show2, show2', show3 :: Int -> String
542 show2 x = [intToDigit (x `quot` 10), intToDigit (x `rem` 10)]
544 show2' x = if x < 10 then [ ' ', intToDigit x] else show2 x
546 show3 x = intToDigit (x `quot` 100) : show2 (x `rem` 100)
549 to12 h = let h' = h `mod` 12 in if h' == 0 then 12 else h'
551 -- Useful extensions for formatting TimeDiffs.
553 timeDiffToString :: TimeDiff -> String
554 timeDiffToString = formatTimeDiff defaultTimeLocale "%c"
556 formatTimeDiff :: TimeLocale -> String -> TimeDiff -> String
557 formatTimeDiff l fmt td@(TimeDiff year month day hour min sec _)
561 doFmt ('%':'-':cs) = doFmt ('%':cs) -- padding not implemented
562 doFmt ('%':'_':cs) = doFmt ('%':cs) -- padding not implemented
563 doFmt ('%':c:cs) = decode c ++ doFmt cs
564 doFmt (c:cs) = c : doFmt cs
568 'B' -> fst (months l !! fromEnum month)
569 'b' -> snd (months l !! fromEnum month)
570 'h' -> snd (months l !! fromEnum month)
571 'c' -> defaultTimeDiffFmt td
572 'C' -> show2 (year `quot` 100)
573 'D' -> doFmt "%m/%d/%y"
577 'I' -> show2 (to12 hour)
579 'l' -> show2' (to12 hour)
581 'm' -> show2 (fromEnum month + 1)
583 'p' -> (if hour < 12 then fst else snd) (amPm l)
585 'r' -> doFmt (time12Fmt l)
586 'T' -> doFmt "%H:%M:%S"
589 's' -> show2 sec -- Implementation-dependent, sez the lib doc..
590 'X' -> doFmt (timeFmt l)
591 'x' -> doFmt (dateFmt l)
593 'y' -> show2 (year `rem` 100)
597 defaultTimeDiffFmt (TimeDiff year month day hour min sec _) =
598 foldr (\ (v,s) rest ->
600 then show v ++ ' ':(addS v s)
601 ++ if null rest then "" else ", "
605 (zip [year, month, day, hour, min, sec] (intervals l))
607 addS v s = if abs v == 1 then fst s else snd s
610 -- -----------------------------------------------------------------------------
611 -- Foreign time interface (POSIX)
613 type CTm = () -- struct tm
615 foreign import unsafe localtime :: Ptr CTime -> IO (Ptr CTm)
616 foreign import unsafe gmtime :: Ptr CTime -> IO (Ptr CTm)
617 foreign import unsafe strftime :: Ptr CChar -> CSize -> Addr## -> Ptr CTm -> IO CSize
618 foreign import unsafe mktime :: Ptr CTm -> IO CTime
619 foreign import unsafe time :: Ptr CTime -> IO CTime
621 #if HAVE_GETTIMEOFDAY
623 foreign import unsafe gettimeofday :: Ptr CTimeVal -> Ptr () -> IO CInt
628 foreign import unsafe ftime :: Ptr CTimeB -> IO CInt