1 -- -----------------------------------------------------------------------------
2 -- $Id: Time.hsc,v 1.2 2001/01/12 16:40:07 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 defined(_WIN32) && !defined(cygwin32_TARGET_OS)
233 -- ftime() as implemented by cygwin (in B20.1) is
234 -- not right, so stay away & use time() there instead.
237 allocaBytes (#const sizeof(struct timeb)) $ \ p_timeb -> do
239 sec <- (#peek struct timeb,time) p_timeb :: IO CTime
240 msec <- (#peek struct timeb,millitime) p_timeb :: IO CUShort
241 return (TOD (fromIntegral sec) (fromIntegral msec * 1000{-ToDo: correct???-}))
243 #elif defined(HAVE_GETTIMEOFDAY)
245 allocaBytes (#const sizeof(struct timeval)) $ \ p_timeval -> do
246 throwErrnoIfMinus1_ "getClockTime" $ gettimeofday p_timeval nullPtr
247 sec <- (#peek struct timeval,tv_sec) p_timeval :: IO CLong
248 usec <- (#peek struct timeval,tv_usec) p_timeval :: IO CLong
249 return (TOD (fromIntegral sec) ((fromIntegral usec) * 1000))
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 -- toCalendarTime t converts t to a local time, modified by
331 -- the current timezone and daylight savings time settings. toUTCTime
332 -- t converts t into UTC time. toClockTime l converts l into the
333 -- corresponding internal ClockTime. The wday, yday, tzname, and isdst fields
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 */
379 toCalendarTime :: ClockTime -> IO CalendarTime
380 toCalendarTime = clockToCalendarTime localtime False
382 toUTCTime :: ClockTime -> CalendarTime
383 toUTCTime = unsafePerformIO . clockToCalendarTime gmtime True
385 -- ToDo: should be made thread safe, because localtime uses static storage,
386 -- or use the localtime_r version.
387 clockToCalendarTime :: (Ptr CTime -> IO (Ptr CTm)) -> Bool -> ClockTime
389 clockToCalendarTime 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 sec <- (#peek struct tm,tm_sec ) p_tm :: IO CInt
393 min <- (#peek struct tm,tm_min ) p_tm :: IO CInt
394 hour <- (#peek struct tm,tm_hour ) p_tm :: IO CInt
395 mday <- (#peek struct tm,tm_mday ) p_tm :: IO CInt
396 mon <- (#peek struct tm,tm_mon ) p_tm :: IO CInt
397 year <- (#peek struct tm,tm_year ) p_tm :: IO CInt
398 wday <- (#peek struct tm,tm_wday ) p_tm :: IO CInt
399 yday <- (#peek struct tm,tm_yday ) p_tm :: IO CInt
400 isdst <- (#peek struct tm,tm_isdst) p_tm :: IO CInt
404 tzname <- peekCString zone
406 let month | mon >= 0 && mon <= 11 = toEnum (fromIntegral mon)
407 | otherwise = error ("toCalendarTime: illegal month value: " ++ show mon)
410 (1900 + fromIntegral year)
417 (toEnum (fromIntegral wday))
419 (if is_utc then "UTC" else tzname)
420 (if is_utc then 0 else fromIntegral tz)
421 (if is_utc then False else isdst /= 0))
424 toClockTime :: CalendarTime -> ClockTime
425 toClockTime (CalendarTime year mon mday hour min sec psec
426 _wday _yday _tzname tz isdst) =
428 -- `isDst' causes the date to be wrong by one hour...
429 -- FIXME: check, whether this works on other arch's than Linux, too...
431 -- so we set it to (-1) (means `unknown') and let `mktime' determine
433 let isDst = -1 :: CInt in -- if isdst then (1::Int) else 0
435 if psec < 0 || psec > 999999999999 then
436 error "Time.toClockTime: picoseconds out of range"
437 else if tz < -43200 || tz > 43200 then
438 error "Time.toClockTime: timezone offset out of range"
441 allocaBytes (#const sizeof(struct tm)) $ \ p_tm -> do
442 (#poke struct tm,tm_sec ) p_tm (fromIntegral sec :: CInt)
443 (#poke struct tm,tm_min ) p_tm (fromIntegral min :: CInt)
444 (#poke struct tm,tm_hour ) p_tm (fromIntegral hour :: CInt)
445 (#poke struct tm,tm_mday ) p_tm (fromIntegral mday :: CInt)
446 (#poke struct tm,tm_mon ) p_tm (fromIntegral (fromEnum mon) :: CInt)
447 (#poke struct tm,tm_year ) p_tm (fromIntegral year - 1900 :: CInt)
448 (#poke struct tm,tm_isdst) p_tm isDst
449 t <- throwIf (== -1) (\_ -> "Time.toClockTime: invalid input")
452 -- mktime expects its argument to be in the local timezone, but
453 -- toUTCTime makes UTC-encoded CalendarTime's ...
455 -- Since there is no any_tz_struct_tm-to-time_t conversion
456 -- function, we have to fake one... :-) If not in all, it works in
457 -- most cases (before, it was the other way round...)
459 -- Luckily, mktime tells us, what it *thinks* the timezone is, so,
460 -- to compensate, we add the timezone difference to mktime's
463 gmtoff <- gmtoff p_tm
464 let res = fromIntegral t + tz + fromIntegral gmtoff
465 return (TOD (fromIntegral res) 0)
467 -- -----------------------------------------------------------------------------
468 -- Converting time values to strings.
470 calendarTimeToString :: CalendarTime -> String
471 calendarTimeToString = formatCalendarTime defaultTimeLocale "%c"
473 formatCalendarTime :: TimeLocale -> String -> CalendarTime -> String
474 formatCalendarTime l fmt (CalendarTime year mon day hour min sec _
475 wday yday tzname _ _) =
477 where doFmt ('%':'-':cs) = doFmt ('%':cs) -- padding not implemented
478 doFmt ('%':'_':cs) = doFmt ('%':cs) -- padding not implemented
479 doFmt ('%':c:cs) = decode c ++ doFmt cs
480 doFmt (c:cs) = c : doFmt cs
483 decode 'A' = fst (wDays l !! fromEnum wday) -- day of the week, full name
484 decode 'a' = snd (wDays l !! fromEnum wday) -- day of the week, abbrev.
485 decode 'B' = fst (months l !! fromEnum mon) -- month, full name
486 decode 'b' = snd (months l !! fromEnum mon) -- month, abbrev
487 decode 'h' = snd (months l !! fromEnum mon) -- ditto
488 decode 'C' = show2 (year `quot` 100) -- century
489 decode 'c' = doFmt (dateTimeFmt l) -- locale's data and time format.
490 decode 'D' = doFmt "%m/%d/%y"
491 decode 'd' = show2 day -- day of the month
492 decode 'e' = show2' day -- ditto, padded
493 decode 'H' = show2 hour -- hours, 24-hour clock, padded
494 decode 'I' = show2 (to12 hour) -- hours, 12-hour clock
495 decode 'j' = show3 yday -- day of the year
496 decode 'k' = show2' hour -- hours, 24-hour clock, no padding
497 decode 'l' = show2' (to12 hour) -- hours, 12-hour clock, no padding
498 decode 'M' = show2 min -- minutes
499 decode 'm' = show2 (fromEnum mon+1) -- numeric month
501 decode 'p' = (if hour < 12 then fst else snd) (amPm l) -- am or pm
502 decode 'R' = doFmt "%H:%M"
503 decode 'r' = doFmt (time12Fmt l)
504 decode 'T' = doFmt "%H:%M:%S"
506 decode 'S' = show2 sec -- seconds
507 decode 's' = show2 sec -- number of secs since Epoch. (ToDo.)
508 decode 'U' = show2 ((yday + 7 - fromEnum wday) `div` 7) -- week number, starting on Sunday.
509 decode 'u' = show (let n = fromEnum wday in -- numeric day of the week (1=Monday, 7=Sunday)
510 if n == 0 then 7 else n)
511 decode 'V' = -- week number (as per ISO-8601.)
512 let (week, days) = -- [yep, I've always wanted to be able to display that too.]
513 (yday + 7 - if fromEnum wday > 0 then
514 fromEnum wday - 1 else 6) `divMod` 7
515 in show2 (if days >= 4 then
517 else if week == 0 then 53 else week)
519 decode 'W' = -- week number, weeks starting on monday
520 show2 ((yday + 7 - if fromEnum wday > 0 then
521 fromEnum wday - 1 else 6) `div` 7)
522 decode 'w' = show (fromEnum wday) -- numeric day of the week, weeks starting on Sunday.
523 decode 'X' = doFmt (timeFmt l) -- locale's preferred way of printing time.
524 decode 'x' = doFmt (dateFmt l) -- locale's preferred way of printing dates.
525 decode 'Y' = show year -- year, including century.
526 decode 'y' = show2 (year `rem` 100) -- year, within century.
527 decode 'Z' = tzname -- timezone name
532 show2, show2', show3 :: Int -> String
533 show2 x = [intToDigit (x `quot` 10), intToDigit (x `rem` 10)]
535 show2' x = if x < 10 then [ ' ', intToDigit x] else show2 x
537 show3 x = intToDigit (x `quot` 100) : show2 (x `rem` 100)
540 to12 h = let h' = h `mod` 12 in if h' == 0 then 12 else h'
542 -- Useful extensions for formatting TimeDiffs.
544 timeDiffToString :: TimeDiff -> String
545 timeDiffToString = formatTimeDiff defaultTimeLocale "%c"
547 formatTimeDiff :: TimeLocale -> String -> TimeDiff -> String
548 formatTimeDiff l fmt td@(TimeDiff year month day hour min sec _)
552 doFmt ('%':'-':cs) = doFmt ('%':cs) -- padding not implemented
553 doFmt ('%':'_':cs) = doFmt ('%':cs) -- padding not implemented
554 doFmt ('%':c:cs) = decode c ++ doFmt cs
555 doFmt (c:cs) = c : doFmt cs
559 'B' -> fst (months l !! fromEnum month)
560 'b' -> snd (months l !! fromEnum month)
561 'h' -> snd (months l !! fromEnum month)
562 'c' -> defaultTimeDiffFmt td
563 'C' -> show2 (year `quot` 100)
564 'D' -> doFmt "%m/%d/%y"
568 'I' -> show2 (to12 hour)
570 'l' -> show2' (to12 hour)
572 'm' -> show2 (fromEnum month + 1)
574 'p' -> (if hour < 12 then fst else snd) (amPm l)
576 'r' -> doFmt (time12Fmt l)
577 'T' -> doFmt "%H:%M:%S"
580 's' -> show2 sec -- Implementation-dependent, sez the lib doc..
581 'X' -> doFmt (timeFmt l)
582 'x' -> doFmt (dateFmt l)
584 'y' -> show2 (year `rem` 100)
588 defaultTimeDiffFmt (TimeDiff year month day hour min sec _) =
589 foldr (\ (v,s) rest ->
591 then show v ++ ' ':(addS v s)
592 ++ if null rest then "" else ", "
596 (zip [year, month, day, hour, min, sec] (intervals l))
598 addS v s = if abs v == 1 then fst s else snd s
601 -- -----------------------------------------------------------------------------
602 -- Foreign time interface (POSIX)
604 type CTm = () -- struct tm
606 foreign import unsafe localtime :: Ptr CTime -> IO (Ptr CTm)
607 foreign import unsafe gmtime :: Ptr CTime -> IO (Ptr CTm)
608 foreign import unsafe strftime :: Ptr CChar -> CSize -> Addr## -> Ptr CTm -> IO CSize
609 foreign import unsafe mktime :: Ptr CTm -> IO CTime
610 foreign import unsafe time :: Ptr CTime -> IO CTime
612 #ifdef HAVE_GETTIMEOFDAY
614 foreign import unsafe gettimeofday :: Ptr CTimeVal -> Ptr () -> IO CInt
617 #if defined(_WIN32) && !defined(cygwin32_TARGET_OS)
619 foreign import unsafe ftime :: Ptr CTimeB -> IO CInt