Safe Haskell	Safe-Inferred
Language	GHC2021

Wire.UserStore.Unique

Contents

Re-exports

Description

Temporary exclusive claims on Textual values which may be subject to contention, i.e. where strong guarantees on uniqueness are desired.

Synopsis

withClaim :: Id a -> Text -> Timeout -> Client b -> Client (Maybe b)
deleteClaim :: Id a -> Text -> Timeout -> Client ()
lookupClaims :: MonadClient m => Text -> m [Id a]
data Timeout
data TimeoutUnit
- = NanoSecond
- | MicroSecond
- | MilliSecond
- | Second
- | Minute
- | Hour
- | Day
- | Week
(#) :: Word64 -> TimeoutUnit -> Timeout

Documentation

withClaim Source #

Arguments

:: Id a	The `Id` associated with the claim.
-> Text	The value on which to acquire the claim.
-> Timeout	The minimum timeout (i.e. duration) of the claim.
-> Client b	The computation to run with a successful claim.
-> Client (Maybe b)	'Just b' if the claim was successful and the `IO` computation completed within the given timeout.

Obtain a (temporary) exclusive claim on a Text value for some Identifier. The claim expires after the provided timeout, whether it was successful or not. Contention can thus render the value unavailable until the timeout expires if no contender succeeds. The given IO computation is only run when the claim was successful and is responsible for turning the temporary claim into permanent ownership, if desired.

deleteClaim Source #

Arguments

:: Id a	The `Id` associated with the claim.
-> Text	The value on which to acquire the claim.
-> Timeout	The minimum timeout (i.e. duration) of the rest of the claim. (Each claim can have more than one claimer (even though this is a feature we never use), so removing a claim is an update operation on the database. Therefore, we reset the TTL the same way we reset it in `withClaim`.)
-> Client ()

lookupClaims :: MonadClient m => Text -> m [Id a] Source #

Lookup the current claims on a value.

Re-exports

data Timeout Source #

Timeout in nanoseconds. The Printable instance renders timeouts as series of AmountUnit tokens, e.g.

     toString (1 # Day + 1500 # MilliSecond) = "1d1s500ms"

The full list of timeout unit abbreviations:

NanoSecond - ns
MicroSecond - us
MilliSecond - ms
Second - s
Minute - m
Hour - h
Day - d
Week - w

The Textual instance accepts this syntax and allows decimal fractions to be used as amounts:

    fmap toString (fromStringAs aTimeout "1m1.5s0.2us") = Just "1m1s500ms200ns"

Instances

Instances details

Bounded Timeout
Instance details Defined in Data.Timeout Methods minBound :: Timeout # maxBound :: Timeout #
Enum Timeout
Instance details Defined in Data.Timeout Methods succ :: Timeout -> Timeout # pred :: Timeout -> Timeout # toEnum :: Int -> Timeout # fromEnum :: Timeout -> Int # enumFrom :: Timeout -> [Timeout] # enumFromThen :: Timeout -> Timeout -> [Timeout] # enumFromTo :: Timeout -> Timeout -> [Timeout] # enumFromThenTo :: Timeout -> Timeout -> Timeout -> [Timeout] #
Ix Timeout
Instance details Defined in Data.Timeout Methods range :: (Timeout, Timeout) -> [Timeout] # index :: (Timeout, Timeout) -> Timeout -> Int # unsafeIndex :: (Timeout, Timeout) -> Timeout -> Int # inRange :: (Timeout, Timeout) -> Timeout -> Bool # rangeSize :: (Timeout, Timeout) -> Int # unsafeRangeSize :: (Timeout, Timeout) -> Int #
Num Timeout
Instance details Defined in Data.Timeout Methods (+) :: Timeout -> Timeout -> Timeout # (-) :: Timeout -> Timeout -> Timeout # (*) :: Timeout -> Timeout -> Timeout # negate :: Timeout -> Timeout # abs :: Timeout -> Timeout # signum :: Timeout -> Timeout # fromInteger :: Integer -> Timeout #
Read Timeout
Instance details Defined in Data.Timeout Methods readsPrec :: Int -> ReadS Timeout # readList :: ReadS [Timeout] # readPrec :: ReadPrec Timeout # readListPrec :: ReadPrec [Timeout] #
Integral Timeout
Instance details Defined in Data.Timeout Methods quot :: Timeout -> Timeout -> Timeout # rem :: Timeout -> Timeout -> Timeout # div :: Timeout -> Timeout -> Timeout # mod :: Timeout -> Timeout -> Timeout # quotRem :: Timeout -> Timeout -> (Timeout, Timeout) # divMod :: Timeout -> Timeout -> (Timeout, Timeout) # toInteger :: Timeout -> Integer #
Real Timeout
Instance details Defined in Data.Timeout Methods toRational :: Timeout -> Rational #
Show Timeout
Instance details Defined in Data.Timeout Methods showsPrec :: Int -> Timeout -> ShowS # show :: Timeout -> String # showList :: [Timeout] -> ShowS #
Printable Timeout
Instance details Defined in Data.Timeout Methods print :: Printer p => Timeout -> p Source #
Textual Timeout
Instance details Defined in Data.Timeout Methods textual :: (Monad μ, CharParsing μ) => μ Timeout Source #
Eq Timeout
Instance details Defined in Data.Timeout Methods (==) :: Timeout -> Timeout -> Bool # (/=) :: Timeout -> Timeout -> Bool #
Ord Timeout
Instance details Defined in Data.Timeout Methods compare :: Timeout -> Timeout -> Ordering # (<) :: Timeout -> Timeout -> Bool # (<=) :: Timeout -> Timeout -> Bool # (>) :: Timeout -> Timeout -> Bool # (>=) :: Timeout -> Timeout -> Bool # max :: Timeout -> Timeout -> Timeout # min :: Timeout -> Timeout -> Timeout #

data TimeoutUnit Source #

Timeout unit.

Constructors

NanoSecond
MicroSecond
MilliSecond
Second
Minute
Hour
Day
Week

Instances

Instances details

Bounded TimeoutUnit
Instance details Defined in Data.Timeout Methods minBound :: TimeoutUnit # maxBound :: TimeoutUnit #
Enum TimeoutUnit
Instance details Defined in Data.Timeout Methods succ :: TimeoutUnit -> TimeoutUnit # pred :: TimeoutUnit -> TimeoutUnit # toEnum :: Int -> TimeoutUnit # fromEnum :: TimeoutUnit -> Int # enumFrom :: TimeoutUnit -> [TimeoutUnit] # enumFromThen :: TimeoutUnit -> TimeoutUnit -> [TimeoutUnit] # enumFromTo :: TimeoutUnit -> TimeoutUnit -> [TimeoutUnit] # enumFromThenTo :: TimeoutUnit -> TimeoutUnit -> TimeoutUnit -> [TimeoutUnit] #
Ix TimeoutUnit
Instance details Defined in Data.Timeout Methods range :: (TimeoutUnit, TimeoutUnit) -> [TimeoutUnit] # index :: (TimeoutUnit, TimeoutUnit) -> TimeoutUnit -> Int # unsafeIndex :: (TimeoutUnit, TimeoutUnit) -> TimeoutUnit -> Int # inRange :: (TimeoutUnit, TimeoutUnit) -> TimeoutUnit -> Bool # rangeSize :: (TimeoutUnit, TimeoutUnit) -> Int # unsafeRangeSize :: (TimeoutUnit, TimeoutUnit) -> Int #
Read TimeoutUnit
Instance details Defined in Data.Timeout Methods readsPrec :: Int -> ReadS TimeoutUnit # readList :: ReadS [TimeoutUnit] # readPrec :: ReadPrec TimeoutUnit # readListPrec :: ReadPrec [TimeoutUnit] #
Show TimeoutUnit
Instance details Defined in Data.Timeout Methods showsPrec :: Int -> TimeoutUnit -> ShowS # show :: TimeoutUnit -> String # showList :: [TimeoutUnit] -> ShowS #
Printable TimeoutUnit
Instance details Defined in Data.Timeout Methods print :: Printer p => TimeoutUnit -> p Source #
Textual TimeoutUnit
Instance details Defined in Data.Timeout Methods textual :: (Monad μ, CharParsing μ) => μ TimeoutUnit Source #
Eq TimeoutUnit
Instance details Defined in Data.Timeout Methods (==) :: TimeoutUnit -> TimeoutUnit -> Bool # (/=) :: TimeoutUnit -> TimeoutUnit -> Bool #
Ord TimeoutUnit
Instance details Defined in Data.Timeout Methods compare :: TimeoutUnit -> TimeoutUnit -> Ordering # (<) :: TimeoutUnit -> TimeoutUnit -> Bool # (<=) :: TimeoutUnit -> TimeoutUnit -> Bool # (>) :: TimeoutUnit -> TimeoutUnit -> Bool # (>=) :: TimeoutUnit -> TimeoutUnit -> Bool # max :: TimeoutUnit -> TimeoutUnit -> TimeoutUnit # min :: TimeoutUnit -> TimeoutUnit -> TimeoutUnit #

(#) :: Word64 -> TimeoutUnit -> Timeout infix 9 Source #

Convert the given number of timeout units to Timeout.