1 -- -----------------------------------------------------------------------------
2 -- $Id: Time.hsc,v 1.4 2001/01/12 17:04:00 simonmar Exp $
4 -- (c) The University of Glasgow, 1995-2001
8 Haskell 98 Time of Day Library
9 ------------------------------
11 The Time library provides standard functionality for clock times,
12 including timezone information (i.e, the functionality of "time.h",
13 adapted to the Haskell environment), It follows RFC 1129 in its use of
14 Coordinated Universal Time (UTC).
16 2000/06/17 <michael.weber@post.rwth-aachen.de>:
18 * min./max. time diff currently is restricted to
19 [minBound::Int, maxBound::Int]
21 * surely other restrictions wrt. min/max bounds
27 `showTime' (used in `instance Show ClockTime') always prints time
28 converted to the local timezone (even if it is taken from
29 `(toClockTime . toUTCTime)'), whereas `calendarTimeToString'
30 honors the tzone & tz fields and prints UTC or whatever timezone
31 is stored inside CalendarTime.
33 Maybe `showTime' should be changed to use UTC, since it would
34 better correspond to the actual representation of `ClockTime'
35 (can be done by replacing localtime(3) by gmtime(3)).
39 * add proper handling of microsecs, currently, they're mostly
42 * `formatFOO' case of `%s' is currently broken...
46 * check for unusual date cases, like 1970/1/1 00:00h, and conversions
47 between different timezone's etc.
49 * check, what needs to be in the IO monad, the current situation
50 seems to be a bit inconsistent to me
52 * check whether `isDst = -1' works as expected on other arch's
55 * add functions to parse strings to `CalendarTime' (some day...)
57 * implement padding capabilities ("%_", "%-") in `formatFOO'
59 * add rfc822 timezone (+0200 is CEST) representation ("%z") in `formatFOO'
67 , ClockTime(..) -- non-standard, lib. report gives this as abstract
71 , noTimeDiff -- non-standard (but useful when constructing TimeDiff vals.)
75 , normalizeTimeDiff -- non-standard
76 , timeDiffToString -- non-standard
77 , formatTimeDiff -- non-standard
83 , calendarTimeToString
90 #if defined(HAVE_GETTIMEOFDAY)
91 # ifdef HAVE_SYS_TIME_H
92 # include <sys/time.h>
94 #elif defined(HAVE_GETCLOCK)
95 # ifdef HAVE_SYS_TIMERS_H
97 # include <sys/timers.h>
99 #elif defined(HAVE_TIME_H)
103 #ifdef HAVE_WINDOWS_H
105 #include <sys/types.h>
106 #include <sys/timeb.h>
112 import PrelMarshalAlloc
113 import PrelMarshalUtils
114 import PrelMarshalError
127 -- One way to partition and give name to chunks of a year and a week:
130 = January | February | March | April
131 | May | June | July | August
132 | September | October | November | December
133 deriving (Eq, Ord, Enum, Bounded, Ix, Read, Show)
136 = Sunday | Monday | Tuesday | Wednesday
137 | Thursday | Friday | Saturday
138 deriving (Eq, Ord, Enum, Bounded, Ix, Read, Show)
140 -- @ClockTime@ is an abstract type, used for the internal clock time.
141 -- Clock times may be compared, converted to strings, or converted to an
142 -- external calendar time @CalendarTime@.
144 data ClockTime = TOD Integer -- Seconds since 00:00:00 on 1 Jan 1970
145 Integer -- Picoseconds with the specified second
148 -- When a @ClockTime@ is shown, it is converted to a string of the form
149 -- @"Mon Nov 28 21:45:41 GMT 1994"@.
151 -- For now, we are restricted to roughly:
152 -- Fri Dec 13 20:45:52 1901 through Tue Jan 19 03:14:07 2038, because
153 -- we use the C library routines based on 32 bit integers.
155 instance Show ClockTime where
156 showsPrec _ (TOD secs _nsec) =
157 showString $ unsafePerformIO $ do
158 withObject (fromIntegral secs :: CTime) $ \ p_timer -> do
159 p_tm <- localtime p_timer -- can't fail, according to POSIX
160 allocaBytes 64 $ \ p_buf -> do -- big enough for error message
161 r <- strftime p_buf 50 "%a %b %d %H:%M:%S %Z %Y"## p_tm
163 then return "ClockTime.show{Time}: internal error"
164 else peekCString p_buf
166 showList = showList__ (showsPrec 0)
169 @CalendarTime@ is a user-readable and manipulable
170 representation of the internal $ClockTime$ type. The
171 numeric fields have the following ranges.
177 year -maxInt .. maxInt [Pre-Gregorian dates are inaccurate]
178 mon 0 .. 11 [Jan = 0, Dec = 11]
182 sec 0 .. 61 [Allows for two leap seconds]
183 picosec 0 .. (10^12)-1 [This could be over-precise?]
184 wday 0 .. 6 [Sunday = 0, Saturday = 6]
185 yday 0 .. 365 [364 in non-Leap years]
186 tz -43200 .. 43200 [Variation from UTC in seconds]
189 The {\em tzname} field is the name of the time zone. The {\em isdst}
190 field indicates whether Daylight Savings Time would be in effect.
201 ctPicosec :: Integer,
208 deriving (Eq,Ord,Read,Show)
210 -- The @TimeDiff@ type records the difference between two clock times in
211 -- a user-readable way.
221 tdPicosec :: Integer -- not standard
223 deriving (Eq,Ord,Read,Show)
225 noTimeDiff :: TimeDiff
226 noTimeDiff = TimeDiff 0 0 0 0 0 0 0
228 -- -----------------------------------------------------------------------------
229 -- getClockTime returns the current time in its internal representation.
231 #if HAVE_GETTIMEOFDAY
233 allocaBytes (#const sizeof(struct timeval)) $ \ p_timeval -> do
234 throwErrnoIfMinus1_ "getClockTime" $ gettimeofday p_timeval nullPtr
235 sec <- (#peek struct timeval,tv_sec) p_timeval :: IO CLong
236 usec <- (#peek struct timeval,tv_usec) p_timeval :: IO CLong
237 return (TOD (fromIntegral sec) ((fromIntegral usec) * 1000))
239 #elif HAVE_FTIME && !defined(cygwin32_TARGET_OS)
241 -- ftime() as implemented by cygwin (in B20.1) is
242 -- not right, so stay away & use time() there instead.
245 allocaBytes (#const sizeof(struct timeb)) $ \ p_timeb -> do
247 sec <- (#peek struct timeb,time) p_timeb :: IO CTime
248 msec <- (#peek struct timeb,millitime) 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.
337 zone x = (#peek struct tm,tm_zone) x :: IO (Ptr CChar)
338 gmtoff x = (#peek struct tm,tm_gmtoff) x :: IO CLong
340 #else /* ! HAVE_TM_ZONE */
341 # if HAVE_TZNAME || _WIN32
342 # if cygwin32_TARGET_OS
343 # define tzname _tzname
345 # ifndef mingw32_TARGET_OS
346 foreign label tzname :: Ptr (Ptr CChar)
349 dst <- (#peek struct tm,tm_isdst) x
350 if dst then peekArray tzname 1 else peekArray tzname 0
351 # else /* ! HAVE_TZNAME */
352 -- We're in trouble. If you should end up here, please report this as a bug.
353 # error Dont know how to get at timezone name on your OS.
354 # endif /* ! HAVE_TZNAME */
356 -- Get the offset in secs from UTC, if (struct tm) doesn't supply it. */
357 #if defined(mingw32_TARGET_OS) || defined(cygwin32_TARGET_OS)
358 #define timezone _timezone
362 foreign label altzone :: Ptr CTime
363 foreign label timezone :: Ptr CTime
365 dst <- (#peek struct tm,tm_isdst) x
366 tz <- if dst then peek altzone else peek timezone
367 return (fromIntegral tz)
368 # define GMTOFF(x) (((struct tm *)x)->tm_isdst ? altzone : timezone )
369 # else /* ! HAVE_ALTZONE */
370 -- Assume that DST offset is 1 hour ...
372 dst <- (#peek struct tm,tm_isdst) x
374 if dst then return (fromIngtegral tz - 3600) else return tz
375 # endif /* ! HAVE_ALTZONE */
376 #endif /* ! HAVE_TM_ZONE */
378 -- -----------------------------------------------------------------------------
379 -- toCalendarTime t converts t to a local time, modified by
380 -- the current timezone and daylight savings time settings. toUTCTime
381 -- t converts t into UTC time. toClockTime l converts l into the
382 -- corresponding internal ClockTime. The wday, yday, tzname, and isdst fields
386 toCalendarTime :: ClockTime -> IO CalendarTime
387 toCalendarTime = clockToCalendarTime localtime False
389 toUTCTime :: ClockTime -> CalendarTime
390 toUTCTime = unsafePerformIO . clockToCalendarTime gmtime True
392 -- ToDo: should be made thread safe, because localtime uses static storage,
393 -- or use the localtime_r version.
394 clockToCalendarTime :: (Ptr CTime -> IO (Ptr CTm)) -> Bool -> ClockTime
396 clockToCalendarTime fun is_utc (TOD secs psec) = do
397 withObject (fromIntegral secs :: CTime) $ \ p_timer -> do
398 p_tm <- fun p_timer -- can't fail, according to POSIX
399 sec <- (#peek struct tm,tm_sec ) p_tm :: IO CInt
400 min <- (#peek struct tm,tm_min ) p_tm :: IO CInt
401 hour <- (#peek struct tm,tm_hour ) p_tm :: IO CInt
402 mday <- (#peek struct tm,tm_mday ) p_tm :: IO CInt
403 mon <- (#peek struct tm,tm_mon ) p_tm :: IO CInt
404 year <- (#peek struct tm,tm_year ) p_tm :: IO CInt
405 wday <- (#peek struct tm,tm_wday ) p_tm :: IO CInt
406 yday <- (#peek struct tm,tm_yday ) p_tm :: IO CInt
407 isdst <- (#peek struct tm,tm_isdst) p_tm :: IO CInt
411 tzname <- peekCString zone
413 let month | mon >= 0 && mon <= 11 = toEnum (fromIntegral mon)
414 | otherwise = error ("toCalendarTime: illegal month value: " ++ show mon)
417 (1900 + fromIntegral year)
424 (toEnum (fromIntegral wday))
426 (if is_utc then "UTC" else tzname)
427 (if is_utc then 0 else fromIntegral tz)
428 (if is_utc then False else isdst /= 0))
431 toClockTime :: CalendarTime -> ClockTime
432 toClockTime (CalendarTime year mon mday hour min sec psec
433 _wday _yday _tzname tz isdst) =
435 -- `isDst' causes the date to be wrong by one hour...
436 -- FIXME: check, whether this works on other arch's than Linux, too...
438 -- so we set it to (-1) (means `unknown') and let `mktime' determine
440 let isDst = -1 :: CInt in -- if isdst then (1::Int) else 0
442 if psec < 0 || psec > 999999999999 then
443 error "Time.toClockTime: picoseconds out of range"
444 else if tz < -43200 || tz > 43200 then
445 error "Time.toClockTime: timezone offset out of range"
448 allocaBytes (#const sizeof(struct tm)) $ \ p_tm -> do
449 (#poke struct tm,tm_sec ) p_tm (fromIntegral sec :: CInt)
450 (#poke struct tm,tm_min ) p_tm (fromIntegral min :: CInt)
451 (#poke struct tm,tm_hour ) p_tm (fromIntegral hour :: CInt)
452 (#poke struct tm,tm_mday ) p_tm (fromIntegral mday :: CInt)
453 (#poke struct tm,tm_mon ) p_tm (fromIntegral (fromEnum mon) :: CInt)
454 (#poke struct tm,tm_year ) p_tm (fromIntegral year - 1900 :: CInt)
455 (#poke struct tm,tm_isdst) p_tm isDst
456 t <- throwIf (== -1) (\_ -> "Time.toClockTime: invalid input")
459 -- mktime expects its argument to be in the local timezone, but
460 -- toUTCTime makes UTC-encoded CalendarTime's ...
462 -- Since there is no any_tz_struct_tm-to-time_t conversion
463 -- function, we have to fake one... :-) If not in all, it works in
464 -- most cases (before, it was the other way round...)
466 -- Luckily, mktime tells us, what it *thinks* the timezone is, so,
467 -- to compensate, we add the timezone difference to mktime's
470 gmtoff <- gmtoff p_tm
471 let res = fromIntegral t + tz + fromIntegral gmtoff
472 return (TOD (fromIntegral res) 0)
474 -- -----------------------------------------------------------------------------
475 -- Converting time values to strings.
477 calendarTimeToString :: CalendarTime -> String
478 calendarTimeToString = formatCalendarTime defaultTimeLocale "%c"
480 formatCalendarTime :: TimeLocale -> String -> CalendarTime -> String
481 formatCalendarTime l fmt (CalendarTime year mon day hour min sec _
482 wday yday tzname _ _) =
484 where doFmt ('%':'-':cs) = doFmt ('%':cs) -- padding not implemented
485 doFmt ('%':'_':cs) = doFmt ('%':cs) -- padding not implemented
486 doFmt ('%':c:cs) = decode c ++ doFmt cs
487 doFmt (c:cs) = c : doFmt cs
490 decode 'A' = fst (wDays l !! fromEnum wday) -- day of the week, full name
491 decode 'a' = snd (wDays l !! fromEnum wday) -- day of the week, abbrev.
492 decode 'B' = fst (months l !! fromEnum mon) -- month, full name
493 decode 'b' = snd (months l !! fromEnum mon) -- month, abbrev
494 decode 'h' = snd (months l !! fromEnum mon) -- ditto
495 decode 'C' = show2 (year `quot` 100) -- century
496 decode 'c' = doFmt (dateTimeFmt l) -- locale's data and time format.
497 decode 'D' = doFmt "%m/%d/%y"
498 decode 'd' = show2 day -- day of the month
499 decode 'e' = show2' day -- ditto, padded
500 decode 'H' = show2 hour -- hours, 24-hour clock, padded
501 decode 'I' = show2 (to12 hour) -- hours, 12-hour clock
502 decode 'j' = show3 yday -- day of the year
503 decode 'k' = show2' hour -- hours, 24-hour clock, no padding
504 decode 'l' = show2' (to12 hour) -- hours, 12-hour clock, no padding
505 decode 'M' = show2 min -- minutes
506 decode 'm' = show2 (fromEnum mon+1) -- numeric month
508 decode 'p' = (if hour < 12 then fst else snd) (amPm l) -- am or pm
509 decode 'R' = doFmt "%H:%M"
510 decode 'r' = doFmt (time12Fmt l)
511 decode 'T' = doFmt "%H:%M:%S"
513 decode 'S' = show2 sec -- seconds
514 decode 's' = show2 sec -- number of secs since Epoch. (ToDo.)
515 decode 'U' = show2 ((yday + 7 - fromEnum wday) `div` 7) -- week number, starting on Sunday.
516 decode 'u' = show (let n = fromEnum wday in -- numeric day of the week (1=Monday, 7=Sunday)
517 if n == 0 then 7 else n)
518 decode 'V' = -- week number (as per ISO-8601.)
519 let (week, days) = -- [yep, I've always wanted to be able to display that too.]
520 (yday + 7 - if fromEnum wday > 0 then
521 fromEnum wday - 1 else 6) `divMod` 7
522 in show2 (if days >= 4 then
524 else if week == 0 then 53 else week)
526 decode 'W' = -- week number, weeks starting on monday
527 show2 ((yday + 7 - if fromEnum wday > 0 then
528 fromEnum wday - 1 else 6) `div` 7)
529 decode 'w' = show (fromEnum wday) -- numeric day of the week, weeks starting on Sunday.
530 decode 'X' = doFmt (timeFmt l) -- locale's preferred way of printing time.
531 decode 'x' = doFmt (dateFmt l) -- locale's preferred way of printing dates.
532 decode 'Y' = show year -- year, including century.
533 decode 'y' = show2 (year `rem` 100) -- year, within century.
534 decode 'Z' = tzname -- timezone name
539 show2, show2', show3 :: Int -> String
540 show2 x = [intToDigit (x `quot` 10), intToDigit (x `rem` 10)]
542 show2' x = if x < 10 then [ ' ', intToDigit x] else show2 x
544 show3 x = intToDigit (x `quot` 100) : show2 (x `rem` 100)
547 to12 h = let h' = h `mod` 12 in if h' == 0 then 12 else h'
549 -- Useful extensions for formatting TimeDiffs.
551 timeDiffToString :: TimeDiff -> String
552 timeDiffToString = formatTimeDiff defaultTimeLocale "%c"
554 formatTimeDiff :: TimeLocale -> String -> TimeDiff -> String
555 formatTimeDiff l fmt td@(TimeDiff year month day hour min sec _)
559 doFmt ('%':'-':cs) = doFmt ('%':cs) -- padding not implemented
560 doFmt ('%':'_':cs) = doFmt ('%':cs) -- padding not implemented
561 doFmt ('%':c:cs) = decode c ++ doFmt cs
562 doFmt (c:cs) = c : doFmt cs
566 'B' -> fst (months l !! fromEnum month)
567 'b' -> snd (months l !! fromEnum month)
568 'h' -> snd (months l !! fromEnum month)
569 'c' -> defaultTimeDiffFmt td
570 'C' -> show2 (year `quot` 100)
571 'D' -> doFmt "%m/%d/%y"
575 'I' -> show2 (to12 hour)
577 'l' -> show2' (to12 hour)
579 'm' -> show2 (fromEnum month + 1)
581 'p' -> (if hour < 12 then fst else snd) (amPm l)
583 'r' -> doFmt (time12Fmt l)
584 'T' -> doFmt "%H:%M:%S"
587 's' -> show2 sec -- Implementation-dependent, sez the lib doc..
588 'X' -> doFmt (timeFmt l)
589 'x' -> doFmt (dateFmt l)
591 'y' -> show2 (year `rem` 100)
595 defaultTimeDiffFmt (TimeDiff year month day hour min sec _) =
596 foldr (\ (v,s) rest ->
598 then show v ++ ' ':(addS v s)
599 ++ if null rest then "" else ", "
603 (zip [year, month, day, hour, min, sec] (intervals l))
605 addS v s = if abs v == 1 then fst s else snd s
608 -- -----------------------------------------------------------------------------
609 -- Foreign time interface (POSIX)
611 type CTm = () -- struct tm
613 foreign import unsafe localtime :: Ptr CTime -> IO (Ptr CTm)
614 foreign import unsafe gmtime :: Ptr CTime -> IO (Ptr CTm)
615 foreign import unsafe strftime :: Ptr CChar -> CSize -> Addr## -> Ptr CTm -> IO CSize
616 foreign import unsafe mktime :: Ptr CTm -> IO CTime
617 foreign import unsafe time :: Ptr CTime -> IO CTime
619 #if HAVE_GETTIMEOFDAY
621 foreign import unsafe gettimeofday :: Ptr CTimeVal -> Ptr () -> IO CInt
626 foreign import unsafe ftime :: Ptr CTimeB -> IO CInt