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".

Methods

resolve :: a -> a -> a

Resolve a conflict between two values.

Instances

Resolvable a => Resolvable (Maybe a)

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

Data a => Data (ResolvableMonoid a)

Ord a => Ord (ResolvableMonoid a)

Read a => Read (ResolvableMonoid a)

Show a => Show (ResolvableMonoid a)

Monoid a => Monoid (ResolvableMonoid a)

ToJSON a => ToJSON (ResolvableMonoid a)

FromJSON a => FromJSON (ResolvableMonoid a)

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

IsContent a => IsContent (ResolvableMonoid a)

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

Show ResolutionFailure

Exception ResolutionFailure