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 1.15 2001/06/22 12:36:34 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
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
95 #include "cbits/HsStd.h"
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 CLong
213 usec <- (#peek struct timeval,tv_usec) p_timeval :: IO CLong
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
370 toCalendarTime = clockToCalendarTime localtime False
372 toUTCTime :: ClockTime -> CalendarTime
373 toUTCTime = unsafePerformIO . clockToCalendarTime gmtime True
375 -- ToDo: should be made thread safe, because localtime uses static storage,
376 -- or use the localtime_r version.
377 clockToCalendarTime :: (Ptr CTime -> IO (Ptr CTm)) -> Bool -> ClockTime
379 clockToCalendarTime fun is_utc (TOD secs psec) = do
380 withObject (fromIntegral secs :: CTime) $ \ p_timer -> do
381 p_tm <- fun p_timer -- can't fail, according to POSIX
382 sec <- (#peek struct tm,tm_sec ) p_tm :: IO CInt
383 min <- (#peek struct tm,tm_min ) p_tm :: IO CInt
384 hour <- (#peek struct tm,tm_hour ) p_tm :: IO CInt
385 mday <- (#peek struct tm,tm_mday ) p_tm :: IO CInt
386 mon <- (#peek struct tm,tm_mon ) p_tm :: IO CInt
387 year <- (#peek struct tm,tm_year ) p_tm :: IO CInt
388 wday <- (#peek struct tm,tm_wday ) p_tm :: IO CInt
389 yday <- (#peek struct tm,tm_yday ) p_tm :: IO CInt
390 isdst <- (#peek struct tm,tm_isdst) p_tm :: IO CInt
394 tzname <- peekCString zone
396 let month | mon >= 0 && mon <= 11 = toEnum (fromIntegral mon)
397 | otherwise = error ("toCalendarTime: illegal month value: " ++ show mon)
400 (1900 + fromIntegral year)
407 (toEnum (fromIntegral wday))
409 (if is_utc then "UTC" else tzname)
410 (if is_utc then 0 else fromIntegral tz)
411 (if is_utc then False else isdst /= 0))
414 toClockTime :: CalendarTime -> ClockTime
415 toClockTime (CalendarTime year mon mday hour min sec psec
416 _wday _yday _tzname tz isdst) =
418 -- `isDst' causes the date to be wrong by one hour...
419 -- FIXME: check, whether this works on other arch's than Linux, too...
421 -- so we set it to (-1) (means `unknown') and let `mktime' determine
423 let isDst = -1 :: CInt in -- if isdst then (1::Int) else 0
425 if psec < 0 || psec > 999999999999 then
426 error "Time.toClockTime: picoseconds out of range"
427 else if tz < -43200 || tz > 43200 then
428 error "Time.toClockTime: timezone offset out of range"
431 allocaBytes (#const sizeof(struct tm)) $ \ p_tm -> do
432 (#poke struct tm,tm_sec ) p_tm (fromIntegral sec :: CInt)
433 (#poke struct tm,tm_min ) p_tm (fromIntegral min :: CInt)
434 (#poke struct tm,tm_hour ) p_tm (fromIntegral hour :: CInt)
435 (#poke struct tm,tm_mday ) p_tm (fromIntegral mday :: CInt)
436 (#poke struct tm,tm_mon ) p_tm (fromIntegral (fromEnum mon) :: CInt)
437 (#poke struct tm,tm_year ) p_tm (fromIntegral year - 1900 :: CInt)
438 (#poke struct tm,tm_isdst) p_tm isDst
439 t <- throwIf (== -1) (\_ -> "Time.toClockTime: invalid input")
442 -- mktime expects its argument to be in the local timezone, but
443 -- toUTCTime makes UTC-encoded CalendarTime's ...
445 -- Since there is no any_tz_struct_tm-to-time_t conversion
446 -- function, we have to fake one... :-) If not in all, it works in
447 -- most cases (before, it was the other way round...)
449 -- Luckily, mktime tells us, what it *thinks* the timezone is, so,
450 -- to compensate, we add the timezone difference to mktime's
453 gmtoff <- gmtoff p_tm
454 let res = fromIntegral t - tz + fromIntegral gmtoff
455 return (TOD (fromIntegral res) 0)
457 -- -----------------------------------------------------------------------------
458 -- Converting time values to strings.
460 calendarTimeToString :: CalendarTime -> String
461 calendarTimeToString = formatCalendarTime defaultTimeLocale "%c"
463 formatCalendarTime :: TimeLocale -> String -> CalendarTime -> String
464 formatCalendarTime l fmt (CalendarTime year mon day hour min sec _
465 wday yday tzname _ _) =
467 where doFmt ('%':'-':cs) = doFmt ('%':cs) -- padding not implemented
468 doFmt ('%':'_':cs) = doFmt ('%':cs) -- padding not implemented
469 doFmt ('%':c:cs) = decode c ++ doFmt cs
470 doFmt (c:cs) = c : doFmt cs
473 decode 'A' = fst (wDays l !! fromEnum wday) -- day of the week, full name
474 decode 'a' = snd (wDays l !! fromEnum wday) -- day of the week, abbrev.
475 decode 'B' = fst (months l !! fromEnum mon) -- month, full name
476 decode 'b' = snd (months l !! fromEnum mon) -- month, abbrev
477 decode 'h' = snd (months l !! fromEnum mon) -- ditto
478 decode 'C' = show2 (year `quot` 100) -- century
479 decode 'c' = doFmt (dateTimeFmt l) -- locale's data and time format.
480 decode 'D' = doFmt "%m/%d/%y"
481 decode 'd' = show2 day -- day of the month
482 decode 'e' = show2' day -- ditto, padded
483 decode 'H' = show2 hour -- hours, 24-hour clock, padded
484 decode 'I' = show2 (to12 hour) -- hours, 12-hour clock
485 decode 'j' = show3 yday -- day of the year
486 decode 'k' = show2' hour -- hours, 24-hour clock, no padding
487 decode 'l' = show2' (to12 hour) -- hours, 12-hour clock, no padding
488 decode 'M' = show2 min -- minutes
489 decode 'm' = show2 (fromEnum mon+1) -- numeric month
491 decode 'p' = (if hour < 12 then fst else snd) (amPm l) -- am or pm
492 decode 'R' = doFmt "%H:%M"
493 decode 'r' = doFmt (time12Fmt l)
494 decode 'T' = doFmt "%H:%M:%S"
496 decode 'S' = show2 sec -- seconds
497 decode 's' = show2 sec -- number of secs since Epoch. (ToDo.)
498 decode 'U' = show2 ((yday + 7 - fromEnum wday) `div` 7) -- week number, starting on Sunday.
499 decode 'u' = show (let n = fromEnum wday in -- numeric day of the week (1=Monday, 7=Sunday)
500 if n == 0 then 7 else n)
501 decode 'V' = -- week number (as per ISO-8601.)
502 let (week, days) = -- [yep, I've always wanted to be able to display that too.]
503 (yday + 7 - if fromEnum wday > 0 then
504 fromEnum wday - 1 else 6) `divMod` 7
505 in show2 (if days >= 4 then
507 else if week == 0 then 53 else week)
509 decode 'W' = -- week number, weeks starting on monday
510 show2 ((yday + 7 - if fromEnum wday > 0 then
511 fromEnum wday - 1 else 6) `div` 7)
512 decode 'w' = show (fromEnum wday) -- numeric day of the week, weeks starting on Sunday.
513 decode 'X' = doFmt (timeFmt l) -- locale's preferred way of printing time.
514 decode 'x' = doFmt (dateFmt l) -- locale's preferred way of printing dates.
515 decode 'Y' = show year -- year, including century.
516 decode 'y' = show2 (year `rem` 100) -- year, within century.
517 decode 'Z' = tzname -- timezone name
522 show2, show2', show3 :: Int -> String
523 show2 x = [intToDigit (x `quot` 10), intToDigit (x `rem` 10)]
525 show2' x = if x < 10 then [ ' ', intToDigit x] else show2 x
527 show3 x = intToDigit (x `quot` 100) : show2 (x `rem` 100)
530 to12 h = let h' = h `mod` 12 in if h' == 0 then 12 else h'
532 -- Useful extensions for formatting TimeDiffs.
534 timeDiffToString :: TimeDiff -> String
535 timeDiffToString = formatTimeDiff defaultTimeLocale "%c"
537 formatTimeDiff :: TimeLocale -> String -> TimeDiff -> String
538 formatTimeDiff l fmt td@(TimeDiff year month day hour min sec _)
542 doFmt ('%':'-':cs) = doFmt ('%':cs) -- padding not implemented
543 doFmt ('%':'_':cs) = doFmt ('%':cs) -- padding not implemented
544 doFmt ('%':c:cs) = decode c ++ doFmt cs
545 doFmt (c:cs) = c : doFmt cs
549 'B' -> fst (months l !! fromEnum month)
550 'b' -> snd (months l !! fromEnum month)
551 'h' -> snd (months l !! fromEnum month)
552 'c' -> defaultTimeDiffFmt td
553 'C' -> show2 (year `quot` 100)
554 'D' -> doFmt "%m/%d/%y"
558 'I' -> show2 (to12 hour)
560 'l' -> show2' (to12 hour)
562 'm' -> show2 (fromEnum month + 1)
564 'p' -> (if hour < 12 then fst else snd) (amPm l)
566 'r' -> doFmt (time12Fmt l)
567 'T' -> doFmt "%H:%M:%S"
570 's' -> show2 sec -- Implementation-dependent, sez the lib doc..
571 'X' -> doFmt (timeFmt l)
572 'x' -> doFmt (dateFmt l)
574 'y' -> show2 (year `rem` 100)
578 defaultTimeDiffFmt (TimeDiff year month day hour min sec _) =
579 foldr (\ (v,s) rest ->
581 then show v ++ ' ':(addS v s)
582 ++ if null rest then "" else ", "
586 (zip [year, month, day, hour, min, sec] (intervals l))
588 addS v s = if abs v == 1 then fst s else snd s
591 -- -----------------------------------------------------------------------------
592 -- Foreign time interface (POSIX)
594 type CTm = () -- struct tm
596 foreign import unsafe localtime :: Ptr CTime -> IO (Ptr CTm)
597 foreign import unsafe gmtime :: Ptr CTime -> IO (Ptr CTm)
598 foreign import unsafe mktime :: Ptr CTm -> IO CTime
599 foreign import unsafe time :: Ptr CTime -> IO CTime
601 #if HAVE_GETTIMEOFDAY
603 foreign import unsafe gettimeofday :: Ptr CTimeVal -> Ptr () -> IO CInt
608 #ifndef mingw32_TARGET_OS
609 foreign import unsafe ftime :: Ptr CTimeB -> IO CInt
611 foreign import unsafe ftime :: Ptr CTimeB -> IO ()