| Safe Haskell | None |
|---|---|
| Language | Haskell2010 |
Data.Time.Clock.TAI.Support
- data TAISync
- type UpdatePolicy = IO (IORef LeapSecondList)
- initSync :: MonadIO m => UpdatePolicy -> m TAISync
- getTAI :: MonadIO m => TAISync -> m AbsoluteTime
- absGuessUtc :: MonadIO m => TAISync -> AbsoluteTime -> m UTCTime
- utcGuessAbs :: MonadIO m => TAISync -> UTCTime -> m AbsoluteTime
- currentLeapMap :: MonadIO m => TAISync -> m LeapSecondMap
- periodicBackgroundDownload :: LeapSources -> Int -> Int -> UpdatePolicy
Documentation
type UpdatePolicy = IO (IORef LeapSecondList) Source #
A function that enacts the periodic update of the LeapSecondList leap second data. Usually periodicBackgroundDownload will satisfy a user's needs, but some enviroments may want another policy.
initSync :: MonadIO m => UpdatePolicy -> m TAISync Source #
Given an UpdatePolicy, generate a TAISync to be used to interact with TAI though the other library functions.
absGuessUtc :: MonadIO m => TAISync -> AbsoluteTime -> m UTCTime Source #
Given our information about leap seconds, generate a UTC time from a TAI time as a total function. As the relation between TAI is only known for a specific time range, we give a best-guess outside said time range. Specificly we only know the offset after some point in the past, and up to about 6 months into the future. Outside this range we assume the last known mapping between UTC and TAI doesn't drift.
utcGuessAbs :: MonadIO m => TAISync -> UTCTime -> m AbsoluteTime Source #
Given our information about leap seconds, generate a TAI time rom a UTC time as a total function. As the relation between TAI is only known for a specific time range, we give a best-guess outside said time range. Specificly we only know the offset after some point in the past, and up to about 6 months into the future. Outside this range we assume the last known mapping between UTC and TAI doesn't drift.
currentLeapMap :: MonadIO m => TAISync -> m LeapSecondMap Source #
Gets the current leap second data in a time compatable form.
periodicBackgroundDownload :: LeapSources -> Int -> Int -> UpdatePolicy Source #
Update the leap second table by redownloading the tables periodicly in the background. This policy uses the TimeoutManager to check for a new table every dbetween days, trying again dretry if there is a failure. Recomended values are 30 and 1 for these. Given the validity period for leap second data, this should generally suffice. There can be problems with local files being near their expiration though.
This policy requires a threaded runtime.