Network.Riak.Resolvable

Storage and retrieval of data with automatic conflict resolution.

Documentation

class Show a => Resolvable a where

A type that can automatically resolve a vector clock conflict between two or more versions of a value.

Instances must be symmetric in their behaviour, such that the following law is obeyed:

resolve a b == resolve b a

Otherwise, there are no restrictions on the behaviour of resolve. The result may be a, b, a value derived from a and b, or something else.

If several conflicting siblings are found, resolve will be applied over all of them using a fold, to yield a single "winner".

Minimal complete definition

resolve

Methods

resolve :: a -> a -> a

Resolve a conflict between two values.

Instances

Resolvable a => Resolvable (Maybe a)

Methods

resolve :: Maybe a -> Maybe a -> Maybe a

(Show a, Monoid a) => Resolvable (ResolvableMonoid a)

Methods

resolve :: ResolvableMonoid a -> ResolvableMonoid a -> ResolvableMonoid a

newtype ResolvableMonoid a

A newtype wrapper that uses the mappend method of a type's Monoid instance to perform vector clock conflict resolution.

Constructors

RM

Fields

• unRM :: a

Instances

Eq a => Eq (ResolvableMonoid a)

Methods

(==) :: ResolvableMonoid a -> ResolvableMonoid a -> Bool

(/=) :: ResolvableMonoid a -> ResolvableMonoid a -> Bool

Data a => Data (ResolvableMonoid a)

Methods

gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> ResolvableMonoid a -> c (ResolvableMonoid a)

gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c (ResolvableMonoid a)

toConstr :: ResolvableMonoid a -> Constr

dataTypeOf :: ResolvableMonoid a -> DataType

dataCast1 :: Typeable (* -> *) t => (forall d. Data d => c (t d)) -> Maybe (c (ResolvableMonoid a))

dataCast2 :: Typeable (* -> * -> *) t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c (ResolvableMonoid a))

gmapT :: (forall b. Data b => b -> b) -> ResolvableMonoid a -> ResolvableMonoid a

gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> ResolvableMonoid a -> r

gmapQr :: (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> ResolvableMonoid a -> r

gmapQ :: (forall d. Data d => d -> u) -> ResolvableMonoid a -> [u]

gmapQi :: Int -> (forall d. Data d => d -> u) -> ResolvableMonoid a -> u

gmapM :: Monad m => (forall d. Data d => d -> m d) -> ResolvableMonoid a -> m (ResolvableMonoid a)

gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> ResolvableMonoid a -> m (ResolvableMonoid a)

gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> ResolvableMonoid a -> m (ResolvableMonoid a)

Ord a => Ord (ResolvableMonoid a)

Methods

compare :: ResolvableMonoid a -> ResolvableMonoid a -> Ordering

(<) :: ResolvableMonoid a -> ResolvableMonoid a -> Bool

(<=) :: ResolvableMonoid a -> ResolvableMonoid a -> Bool

(>) :: ResolvableMonoid a -> ResolvableMonoid a -> Bool

(>=) :: ResolvableMonoid a -> ResolvableMonoid a -> Bool

max :: ResolvableMonoid a -> ResolvableMonoid a -> ResolvableMonoid a

min :: ResolvableMonoid a -> ResolvableMonoid a -> ResolvableMonoid a

Read a => Read (ResolvableMonoid a)

Methods

readsPrec :: Int -> ReadS (ResolvableMonoid a)

readList :: ReadS [ResolvableMonoid a]

readPrec :: ReadPrec (ResolvableMonoid a)

readListPrec :: ReadPrec [ResolvableMonoid a]

Show a => Show (ResolvableMonoid a)

Methods

showsPrec :: Int -> ResolvableMonoid a -> ShowS

show :: ResolvableMonoid a -> String

showList :: [ResolvableMonoid a] -> ShowS

Semigroup a => Semigroup (ResolvableMonoid a)

Methods

(<>) :: ResolvableMonoid a -> ResolvableMonoid a -> ResolvableMonoid a

sconcat :: NonEmpty (ResolvableMonoid a) -> ResolvableMonoid a

stimes :: Integral b => b -> ResolvableMonoid a -> ResolvableMonoid a

Monoid a => Monoid (ResolvableMonoid a)

Methods

mempty :: ResolvableMonoid a

mappend :: ResolvableMonoid a -> ResolvableMonoid a -> ResolvableMonoid a

mconcat :: [ResolvableMonoid a] -> ResolvableMonoid a

ToJSON a => ToJSON (ResolvableMonoid a)

Methods

toJSON :: ResolvableMonoid a -> Value

toEncoding :: ResolvableMonoid a -> Encoding

toJSONList :: [ResolvableMonoid a] -> Value

toEncodingList :: [ResolvableMonoid a] -> Encoding

FromJSON a => FromJSON (ResolvableMonoid a)

Methods

parseJSON :: Value -> Parser (ResolvableMonoid a)

parseJSONList :: Value -> Parser [ResolvableMonoid a]

(Show a, Monoid a) => Resolvable (ResolvableMonoid a)

Methods

resolve :: ResolvableMonoid a -> ResolvableMonoid a -> ResolvableMonoid a

IsContent a => IsContent (ResolvableMonoid a)

Methods

parseContent :: Content -> Parser (ResolvableMonoid a)

toContent :: ResolvableMonoid a -> Content

data ResolutionFailure

Automated conflict resolution failed.

Constructors

RetriesExceeded

Too many attempts were made to resolve a conflict, with each attempt resulting in another conflict.

The number of retries that the library will attempt is high (64). This makes it extremely unlikely that this exception will be thrown during normal application operation. Instead, this exception is most likely to be thrown as a result of a bug in your application code, for example if your resolve function is misbehaving.

Instances

Eq ResolutionFailure

Methods

(==) :: ResolutionFailure -> ResolutionFailure -> Bool

(/=) :: ResolutionFailure -> ResolutionFailure -> Bool

Show ResolutionFailure

Methods

showsPrec :: Int -> ResolutionFailure -> ShowS

show :: ResolutionFailure -> String

showList :: [ResolutionFailure] -> ShowS

Exception ResolutionFailure

Methods

toException :: ResolutionFailure -> SomeException

fromException :: SomeException -> Maybe ResolutionFailure

displayException :: ResolutionFailure -> String