-- ----------------------------------------------------------------------------- -- $Id: Time.hsc,v 1.5 2001/01/14 15:36:04 simonmar Exp $ -- -- (c) The University of Glasgow, 1995-2001 -- {- Haskell 98 Time of Day Library ------------------------------ The Time library provides standard functionality for clock times, including timezone information (i.e, the functionality of "time.h", adapted to the Haskell environment), It follows RFC 1129 in its use of Coordinated Universal Time (UTC). 2000/06/17 : RESTRICTIONS: * min./max. time diff currently is restricted to [minBound::Int, maxBound::Int] * surely other restrictions wrt. min/max bounds NOTES: * printing times `showTime' (used in `instance Show ClockTime') always prints time converted to the local timezone (even if it is taken from `(toClockTime . toUTCTime)'), whereas `calendarTimeToString' honors the tzone & tz fields and prints UTC or whatever timezone is stored inside CalendarTime. Maybe `showTime' should be changed to use UTC, since it would better correspond to the actual representation of `ClockTime' (can be done by replacing localtime(3) by gmtime(3)). BUGS: * add proper handling of microsecs, currently, they're mostly ignored * `formatFOO' case of `%s' is currently broken... TODO: * check for unusual date cases, like 1970/1/1 00:00h, and conversions between different timezone's etc. * check, what needs to be in the IO monad, the current situation seems to be a bit inconsistent to me * check whether `isDst = -1' works as expected on other arch's (Solaris anyone?) * add functions to parse strings to `CalendarTime' (some day...) * implement padding capabilities ("%_", "%-") in `formatFOO' * add rfc822 timezone (+0200 is CEST) representation ("%z") in `formatFOO' -} module Time ( Month(..) , Day(..) , ClockTime(..) -- non-standard, lib. report gives this as abstract , getClockTime , TimeDiff(..) , noTimeDiff -- non-standard (but useful when constructing TimeDiff vals.) , diffClockTimes , addToClockTime , normalizeTimeDiff -- non-standard , timeDiffToString -- non-standard , formatTimeDiff -- non-standard , CalendarTime(..) , toCalendarTime , toUTCTime , toClockTime , calendarTimeToString , formatCalendarTime ) where #include "config.h" #if defined(HAVE_GETTIMEOFDAY) # ifdef HAVE_SYS_TIME_H # include # endif #elif defined(HAVE_GETCLOCK) # ifdef HAVE_SYS_TIMERS_H # define POSIX_4D9 1 # include # endif #elif defined(HAVE_TIME_H) # include #endif #ifdef HAVE_WINDOWS_H #include #include #include #endif import Ix import Locale import PrelMarshalAlloc import PrelMarshalUtils import PrelMarshalError import PrelStorable import PrelCString import PrelCTypesISO import PrelCTypes import PrelCError import PrelInt import PrelPtr import PrelIOBase import PrelShow import PrelNum import PrelBase -- One way to partition and give name to chunks of a year and a week: data Month = January | February | March | April | May | June | July | August | September | October | November | December deriving (Eq, Ord, Enum, Bounded, Ix, Read, Show) data Day = Sunday | Monday | Tuesday | Wednesday | Thursday | Friday | Saturday deriving (Eq, Ord, Enum, Bounded, Ix, Read, Show) -- @ClockTime@ is an abstract type, used for the internal clock time. -- Clock times may be compared, converted to strings, or converted to an -- external calendar time @CalendarTime@. data ClockTime = TOD Integer -- Seconds since 00:00:00 on 1 Jan 1970 Integer -- Picoseconds with the specified second deriving (Eq, Ord) -- When a @ClockTime@ is shown, it is converted to a string of the form -- @"Mon Nov 28 21:45:41 GMT 1994"@. -- For now, we are restricted to roughly: -- Fri Dec 13 20:45:52 1901 through Tue Jan 19 03:14:07 2038, because -- we use the C library routines based on 32 bit integers. instance Show ClockTime where showsPrec _ (TOD secs _nsec) = showString $ unsafePerformIO $ do withObject (fromIntegral secs :: CTime) $ \ p_timer -> do p_tm <- localtime p_timer -- can't fail, according to POSIX allocaBytes 64 $ \ p_buf -> do -- big enough for error message r <- strftime p_buf 50 "%a %b %d %H:%M:%S %Z %Y"## p_tm if r == 0 then return "ClockTime.show{Time}: internal error" else peekCString p_buf showList = showList__ (showsPrec 0) {- @CalendarTime@ is a user-readable and manipulable representation of the internal $ClockTime$ type. The numeric fields have the following ranges. \begin{verbatim} Value Range Comments ----- ----- -------- year -maxInt .. maxInt [Pre-Gregorian dates are inaccurate] mon 0 .. 11 [Jan = 0, Dec = 11] day 1 .. 31 hour 0 .. 23 min 0 .. 59 sec 0 .. 61 [Allows for two leap seconds] picosec 0 .. (10^12)-1 [This could be over-precise?] wday 0 .. 6 [Sunday = 0, Saturday = 6] yday 0 .. 365 [364 in non-Leap years] tz -43200 .. 43200 [Variation from UTC in seconds] \end{verbatim} The {\em tzname} field is the name of the time zone. The {\em isdst} field indicates whether Daylight Savings Time would be in effect. -} data CalendarTime = CalendarTime { ctYear :: Int, ctMonth :: Month, ctDay :: Int, ctHour :: Int, ctMin :: Int, ctSec :: Int, ctPicosec :: Integer, ctWDay :: Day, ctYDay :: Int, ctTZName :: String, ctTZ :: Int, ctIsDST :: Bool } deriving (Eq,Ord,Read,Show) -- The @TimeDiff@ type records the difference between two clock times in -- a user-readable way. data TimeDiff = TimeDiff { tdYear :: Int, tdMonth :: Int, tdDay :: Int, tdHour :: Int, tdMin :: Int, tdSec :: Int, tdPicosec :: Integer -- not standard } deriving (Eq,Ord,Read,Show) noTimeDiff :: TimeDiff noTimeDiff = TimeDiff 0 0 0 0 0 0 0 -- ----------------------------------------------------------------------------- -- getClockTime returns the current time in its internal representation. #if HAVE_GETTIMEOFDAY getClockTime = do allocaBytes (#const sizeof(struct timeval)) $ \ p_timeval -> do throwErrnoIfMinus1_ "getClockTime" $ gettimeofday p_timeval nullPtr sec <- (#peek struct timeval,tv_sec) p_timeval :: IO CLong usec <- (#peek struct timeval,tv_usec) p_timeval :: IO CLong return (TOD (fromIntegral sec) ((fromIntegral usec) * 1000)) #elif HAVE_FTIME && !defined(cygwin32_TARGET_OS) -- -- ftime() as implemented by cygwin (in B20.1) is -- not right, so stay away & use time() there instead. -- getClockTime = do allocaBytes (#const sizeof(struct timeb)) $ \ p_timeb -> do ftime p_timeb sec <- (#peek struct timeb,time) p_timeb :: IO CTime msec <- (#peek struct timeb,millitime) p_timeb :: IO CUShort return (TOD (fromIntegral sec) (fromIntegral msec * 1000{-ToDo: correct???-})) #else /* use POSIX time() */ getClockTime = do secs <- time nullPtr -- can't fail, according to POSIX return (TOD (fromIntegral secs) 0) #endif -- ----------------------------------------------------------------------------- -- addToClockTime d t adds a time difference d and a -- clock time t to yield a new clock time. The difference d -- may be either positive or negative. diffClockTimes t1 t2 returns -- the difference between two clock times t1 and t2 as a TimeDiff. addToClockTime :: TimeDiff -> ClockTime -> ClockTime addToClockTime (TimeDiff year mon day hour min sec psec) (TOD c_sec c_psec) = let sec_diff = fromInt sec + 60 * fromInt min + 3600 * fromInt hour + 24 * 3600 * fromInt day cal = toUTCTime (TOD (c_sec + sec_diff) (c_psec + psec)) -- FIXME! ^^^^ new_mon = fromEnum (ctMonth cal) + r_mon (month', yr_diff) | new_mon < 0 = (toEnum (12 + new_mon), (-1)) | new_mon > 11 = (toEnum (new_mon `mod` 12), 1) | otherwise = (toEnum new_mon, 0) (r_yr, r_mon) = mon `quotRem` 12 year' = ctYear cal + year + r_yr + yr_diff in toClockTime cal{ctMonth=month', ctYear=year'} diffClockTimes :: ClockTime -> ClockTime -> TimeDiff -- diffClockTimes is meant to be the dual to `addToClockTime'. -- If you want to have the TimeDiff properly splitted, use -- `normalizeTimeDiff' on this function's result -- -- CAVEAT: see comment of normalizeTimeDiff diffClockTimes (TOD sa pa) (TOD sb pb) = noTimeDiff{ tdSec = fromIntegral (sa - sb) -- FIXME: can handle just 68 years... , tdPicosec = pa - pb } normalizeTimeDiff :: TimeDiff -> TimeDiff -- FIXME: handle psecs properly -- FIXME: ?should be called by formatTimeDiff automagically? -- -- when applied to something coming out of `diffClockTimes', you loose -- the duality to `addToClockTime', since a year does not always have -- 365 days, etc. -- -- apply this function as late as possible to prevent those "rounding" -- errors normalizeTimeDiff td = let rest0 = tdSec td + 60 * (tdMin td + 60 * (tdHour td + 24 * (tdDay td + 30 * (tdMonth td + 365 * tdYear td)))) (diffYears, rest1) = rest0 `quotRem` (365 * 24 * 3600) (diffMonths, rest2) = rest1 `quotRem` (30 * 24 * 3600) (diffDays, rest3) = rest2 `quotRem` (24 * 3600) (diffHours, rest4) = rest3 `quotRem` 3600 (diffMins, diffSecs) = rest4 `quotRem` 60 in td{ tdYear = diffYears , tdMonth = diffMonths , tdDay = diffDays , tdHour = diffHours , tdMin = diffMins , tdSec = diffSecs } -- ----------------------------------------------------------------------------- -- How do we deal with timezones on this architecture? -- The POSIX way to do it is through the global variable tzname[]. -- But that's crap, so we do it The BSD Way if we can: namely use the -- tm_zone and tm_gmtoff fields of struct tm, if they're available. #if HAVE_TM_ZONE zone x = (#peek struct tm,tm_zone) x :: IO (Ptr CChar) gmtoff x = (#peek struct tm,tm_gmtoff) x :: IO CLong #else /* ! HAVE_TM_ZONE */ # if HAVE_TZNAME || _WIN32 # if cygwin32_TARGET_OS # define tzname _tzname # endif # ifndef mingw32_TARGET_OS foreign label tzname :: Ptr (Ptr CChar) # endif zone x = do dst <- (#peek struct tm,tm_isdst) x if dst then peekArray tzname 1 else peekArray tzname 0 # else /* ! HAVE_TZNAME */ -- We're in trouble. If you should end up here, please report this as a bug. # error Dont know how to get at timezone name on your OS. # endif /* ! HAVE_TZNAME */ -- Get the offset in secs from UTC, if (struct tm) doesn't supply it. */ #if defined(mingw32_TARGET_OS) || defined(cygwin32_TARGET_OS) #define timezone _timezone #endif # if HAVE_ALTZONE foreign label altzone :: Ptr CTime foreign label timezone :: Ptr CTime gmtoff x = do dst <- (#peek struct tm,tm_isdst) x tz <- if dst then peek altzone else peek timezone return (fromIntegral tz) # define GMTOFF(x) (((struct tm *)x)->tm_isdst ? altzone : timezone ) # else /* ! HAVE_ALTZONE */ -- Assume that DST offset is 1 hour ... gmtoff x = do dst <- (#peek struct tm,tm_isdst) x tz <- peek timezone if dst then return (fromIngtegral tz - 3600) else return tz # endif /* ! HAVE_ALTZONE */ #endif /* ! HAVE_TM_ZONE */ -- ----------------------------------------------------------------------------- -- toCalendarTime t converts t to a local time, modified by -- the current timezone and daylight savings time settings. toUTCTime -- t converts t into UTC time. toClockTime l converts l into the -- corresponding internal ClockTime. The wday, yday, tzname, and isdst fields -- are ignored. toCalendarTime :: ClockTime -> IO CalendarTime toCalendarTime = clockToCalendarTime localtime False toUTCTime :: ClockTime -> CalendarTime toUTCTime = unsafePerformIO . clockToCalendarTime gmtime True -- ToDo: should be made thread safe, because localtime uses static storage, -- or use the localtime_r version. clockToCalendarTime :: (Ptr CTime -> IO (Ptr CTm)) -> Bool -> ClockTime -> IO CalendarTime clockToCalendarTime fun is_utc (TOD secs psec) = do withObject (fromIntegral secs :: CTime) $ \ p_timer -> do p_tm <- fun p_timer -- can't fail, according to POSIX sec <- (#peek struct tm,tm_sec ) p_tm :: IO CInt min <- (#peek struct tm,tm_min ) p_tm :: IO CInt hour <- (#peek struct tm,tm_hour ) p_tm :: IO CInt mday <- (#peek struct tm,tm_mday ) p_tm :: IO CInt mon <- (#peek struct tm,tm_mon ) p_tm :: IO CInt year <- (#peek struct tm,tm_year ) p_tm :: IO CInt wday <- (#peek struct tm,tm_wday ) p_tm :: IO CInt yday <- (#peek struct tm,tm_yday ) p_tm :: IO CInt isdst <- (#peek struct tm,tm_isdst) p_tm :: IO CInt zone <- zone p_tm tz <- gmtoff p_tm tzname <- peekCString zone let month | mon >= 0 && mon <= 11 = toEnum (fromIntegral mon) | otherwise = error ("toCalendarTime: illegal month value: " ++ show mon) return (CalendarTime (1900 + fromIntegral year) month (fromIntegral mday) (fromIntegral hour) (fromIntegral min) (fromIntegral sec) psec (toEnum (fromIntegral wday)) (fromIntegral yday) (if is_utc then "UTC" else tzname) (if is_utc then 0 else fromIntegral tz) (if is_utc then False else isdst /= 0)) toClockTime :: CalendarTime -> ClockTime toClockTime (CalendarTime year mon mday hour min sec psec _wday _yday _tzname tz isdst) = -- `isDst' causes the date to be wrong by one hour... -- FIXME: check, whether this works on other arch's than Linux, too... -- -- so we set it to (-1) (means `unknown') and let `mktime' determine -- the real value... let isDst = -1 :: CInt in -- if isdst then (1::Int) else 0 if psec < 0 || psec > 999999999999 then error "Time.toClockTime: picoseconds out of range" else if tz < -43200 || tz > 43200 then error "Time.toClockTime: timezone offset out of range" else unsafePerformIO $ do allocaBytes (#const sizeof(struct tm)) $ \ p_tm -> do (#poke struct tm,tm_sec ) p_tm (fromIntegral sec :: CInt) (#poke struct tm,tm_min ) p_tm (fromIntegral min :: CInt) (#poke struct tm,tm_hour ) p_tm (fromIntegral hour :: CInt) (#poke struct tm,tm_mday ) p_tm (fromIntegral mday :: CInt) (#poke struct tm,tm_mon ) p_tm (fromIntegral (fromEnum mon) :: CInt) (#poke struct tm,tm_year ) p_tm (fromIntegral year - 1900 :: CInt) (#poke struct tm,tm_isdst) p_tm isDst t <- throwIf (== -1) (\_ -> "Time.toClockTime: invalid input") (mktime p_tm) -- -- mktime expects its argument to be in the local timezone, but -- toUTCTime makes UTC-encoded CalendarTime's ... -- -- Since there is no any_tz_struct_tm-to-time_t conversion -- function, we have to fake one... :-) If not in all, it works in -- most cases (before, it was the other way round...) -- -- Luckily, mktime tells us, what it *thinks* the timezone is, so, -- to compensate, we add the timezone difference to mktime's -- result. -- gmtoff <- gmtoff p_tm let res = fromIntegral t + tz - fromIntegral gmtoff return (TOD (fromIntegral res) 0) -- ----------------------------------------------------------------------------- -- Converting time values to strings. calendarTimeToString :: CalendarTime -> String calendarTimeToString = formatCalendarTime defaultTimeLocale "%c" formatCalendarTime :: TimeLocale -> String -> CalendarTime -> String formatCalendarTime l fmt (CalendarTime year mon day hour min sec _ wday yday tzname _ _) = doFmt fmt where doFmt ('%':'-':cs) = doFmt ('%':cs) -- padding not implemented doFmt ('%':'_':cs) = doFmt ('%':cs) -- padding not implemented doFmt ('%':c:cs) = decode c ++ doFmt cs doFmt (c:cs) = c : doFmt cs doFmt "" = "" decode 'A' = fst (wDays l !! fromEnum wday) -- day of the week, full name decode 'a' = snd (wDays l !! fromEnum wday) -- day of the week, abbrev. decode 'B' = fst (months l !! fromEnum mon) -- month, full name decode 'b' = snd (months l !! fromEnum mon) -- month, abbrev decode 'h' = snd (months l !! fromEnum mon) -- ditto decode 'C' = show2 (year `quot` 100) -- century decode 'c' = doFmt (dateTimeFmt l) -- locale's data and time format. decode 'D' = doFmt "%m/%d/%y" decode 'd' = show2 day -- day of the month decode 'e' = show2' day -- ditto, padded decode 'H' = show2 hour -- hours, 24-hour clock, padded decode 'I' = show2 (to12 hour) -- hours, 12-hour clock decode 'j' = show3 yday -- day of the year decode 'k' = show2' hour -- hours, 24-hour clock, no padding decode 'l' = show2' (to12 hour) -- hours, 12-hour clock, no padding decode 'M' = show2 min -- minutes decode 'm' = show2 (fromEnum mon+1) -- numeric month decode 'n' = "\n" decode 'p' = (if hour < 12 then fst else snd) (amPm l) -- am or pm decode 'R' = doFmt "%H:%M" decode 'r' = doFmt (time12Fmt l) decode 'T' = doFmt "%H:%M:%S" decode 't' = "\t" decode 'S' = show2 sec -- seconds decode 's' = show2 sec -- number of secs since Epoch. (ToDo.) decode 'U' = show2 ((yday + 7 - fromEnum wday) `div` 7) -- week number, starting on Sunday. decode 'u' = show (let n = fromEnum wday in -- numeric day of the week (1=Monday, 7=Sunday) if n == 0 then 7 else n) decode 'V' = -- week number (as per ISO-8601.) let (week, days) = -- [yep, I've always wanted to be able to display that too.] (yday + 7 - if fromEnum wday > 0 then fromEnum wday - 1 else 6) `divMod` 7 in show2 (if days >= 4 then week+1 else if week == 0 then 53 else week) decode 'W' = -- week number, weeks starting on monday show2 ((yday + 7 - if fromEnum wday > 0 then fromEnum wday - 1 else 6) `div` 7) decode 'w' = show (fromEnum wday) -- numeric day of the week, weeks starting on Sunday. decode 'X' = doFmt (timeFmt l) -- locale's preferred way of printing time. decode 'x' = doFmt (dateFmt l) -- locale's preferred way of printing dates. decode 'Y' = show year -- year, including century. decode 'y' = show2 (year `rem` 100) -- year, within century. decode 'Z' = tzname -- timezone name decode '%' = "%" decode c = [c] show2, show2', show3 :: Int -> String show2 x = [intToDigit (x `quot` 10), intToDigit (x `rem` 10)] show2' x = if x < 10 then [ ' ', intToDigit x] else show2 x show3 x = intToDigit (x `quot` 100) : show2 (x `rem` 100) to12 :: Int -> Int to12 h = let h' = h `mod` 12 in if h' == 0 then 12 else h' -- Useful extensions for formatting TimeDiffs. timeDiffToString :: TimeDiff -> String timeDiffToString = formatTimeDiff defaultTimeLocale "%c" formatTimeDiff :: TimeLocale -> String -> TimeDiff -> String formatTimeDiff l fmt td@(TimeDiff year month day hour min sec _) = doFmt fmt where doFmt "" = "" doFmt ('%':'-':cs) = doFmt ('%':cs) -- padding not implemented doFmt ('%':'_':cs) = doFmt ('%':cs) -- padding not implemented doFmt ('%':c:cs) = decode c ++ doFmt cs doFmt (c:cs) = c : doFmt cs decode spec = case spec of 'B' -> fst (months l !! fromEnum month) 'b' -> snd (months l !! fromEnum month) 'h' -> snd (months l !! fromEnum month) 'c' -> defaultTimeDiffFmt td 'C' -> show2 (year `quot` 100) 'D' -> doFmt "%m/%d/%y" 'd' -> show2 day 'e' -> show2' day 'H' -> show2 hour 'I' -> show2 (to12 hour) 'k' -> show2' hour 'l' -> show2' (to12 hour) 'M' -> show2 min 'm' -> show2 (fromEnum month + 1) 'n' -> "\n" 'p' -> (if hour < 12 then fst else snd) (amPm l) 'R' -> doFmt "%H:%M" 'r' -> doFmt (time12Fmt l) 'T' -> doFmt "%H:%M:%S" 't' -> "\t" 'S' -> show2 sec 's' -> show2 sec -- Implementation-dependent, sez the lib doc.. 'X' -> doFmt (timeFmt l) 'x' -> doFmt (dateFmt l) 'Y' -> show year 'y' -> show2 (year `rem` 100) '%' -> "%" c -> [c] defaultTimeDiffFmt (TimeDiff year month day hour min sec _) = foldr (\ (v,s) rest -> (if v /= 0 then show v ++ ' ':(addS v s) ++ if null rest then "" else ", " else "") ++ rest ) "" (zip [year, month, day, hour, min, sec] (intervals l)) addS v s = if abs v == 1 then fst s else snd s -- ----------------------------------------------------------------------------- -- Foreign time interface (POSIX) type CTm = () -- struct tm foreign import unsafe localtime :: Ptr CTime -> IO (Ptr CTm) foreign import unsafe gmtime :: Ptr CTime -> IO (Ptr CTm) foreign import unsafe strftime :: Ptr CChar -> CSize -> Addr## -> Ptr CTm -> IO CSize foreign import unsafe mktime :: Ptr CTm -> IO CTime foreign import unsafe time :: Ptr CTime -> IO CTime #if HAVE_GETTIMEOFDAY type CTimeVal = () foreign import unsafe gettimeofday :: Ptr CTimeVal -> Ptr () -> IO CInt #endif #if HAVE_FTIME type CTimeB = () foreign import unsafe ftime :: Ptr CTimeB -> IO CInt #endif