Safe Haskell	None
Language	Haskell2010

Ouroboros.Consensus.Util.Versioned

Synopsis

data Versioned a = Versioned {
- versionNumber :: !VersionNumber
- versioned :: !a
}
data VersionNumber
data VersionError
data VersionDecoder a where
- Incompatible :: String -> VersionDecoder a
- Decode :: (forall s. Decoder s a) -> VersionDecoder a
- Migrate :: VersionDecoder from -> (from -> Either String to) -> VersionDecoder to
encodeVersioned :: (a -> Encoding) -> Versioned a -> Encoding
encodeVersion :: VersionNumber -> Encoding -> Encoding
decodeVersioned :: [(VersionNumber, VersionDecoder a)] -> forall s. Decoder s (Versioned a)
decodeVersion :: [(VersionNumber, VersionDecoder a)] -> forall s. Decoder s a

Documentation

data Versioned a Source #

Constructors

Versioned
Fields versionNumber :: !VersionNumber versioned :: !a

Instances

Instances details

Eq a => Eq (Versioned a) Source #
Instance details Defined in Ouroboros.Consensus.Util.Versioned Methods (==) :: Versioned a -> Versioned a -> Bool # (/=) :: Versioned a -> Versioned a -> Bool #
Show a => Show (Versioned a) Source #
Instance details Defined in Ouroboros.Consensus.Util.Versioned Methods showsPrec :: Int -> Versioned a -> ShowS # show :: Versioned a -> String # showList :: [Versioned a] -> ShowS #

data VersionNumber Source #

Instances

Instances details

Eq VersionNumber Source #
Instance details Defined in Ouroboros.Consensus.Util.Versioned Methods (==) :: VersionNumber -> VersionNumber -> Bool # (/=) :: VersionNumber -> VersionNumber -> Bool #
Num VersionNumber Source #
Instance details Defined in Ouroboros.Consensus.Util.Versioned Methods (+) :: VersionNumber -> VersionNumber -> VersionNumber # (-) :: VersionNumber -> VersionNumber -> VersionNumber # (*) :: VersionNumber -> VersionNumber -> VersionNumber # negate :: VersionNumber -> VersionNumber # abs :: VersionNumber -> VersionNumber # signum :: VersionNumber -> VersionNumber # fromInteger :: Integer -> VersionNumber #
Ord VersionNumber Source #
Instance details Defined in Ouroboros.Consensus.Util.Versioned Methods compare :: VersionNumber -> VersionNumber -> Ordering # (<) :: VersionNumber -> VersionNumber -> Bool # (<=) :: VersionNumber -> VersionNumber -> Bool # (>) :: VersionNumber -> VersionNumber -> Bool # (>=) :: VersionNumber -> VersionNumber -> Bool # max :: VersionNumber -> VersionNumber -> VersionNumber # min :: VersionNumber -> VersionNumber -> VersionNumber #
Show VersionNumber Source #
Instance details Defined in Ouroboros.Consensus.Util.Versioned Methods showsPrec :: Int -> VersionNumber -> ShowS # show :: VersionNumber -> String # showList :: [VersionNumber] -> ShowS #
Serialise VersionNumber Source #
Instance details Defined in Ouroboros.Consensus.Util.Versioned Methods encode :: VersionNumber -> Encoding Source # decode :: Decoder s VersionNumber Source # encodeList :: [VersionNumber] -> Encoding Source # decodeList :: Decoder s [VersionNumber] Source #

data VersionError Source #

Constructors

IncompatibleVersion VersionNumber String

We cannot deserialise the version of the data with the given VersionNumber because its data format is incompatible.

For example, the given format lacks data that was added in later version that cannot be reconstructed from scratch.

UnknownVersion VersionNumber

The given VersionNumber is unknown and thus not supported.

MigrationFailed VersionNumber String

A migration from the given VersionNumber failed. See Migrate.

Instances

Instances details

Show VersionError Source #
Instance details Defined in Ouroboros.Consensus.Util.Versioned Methods showsPrec :: Int -> VersionError -> ShowS # show :: VersionError -> String # showList :: [VersionError] -> ShowS #
Exception VersionError Source #
Instance details Defined in Ouroboros.Consensus.Util.Versioned Methods toException :: VersionError -> SomeException # fromException :: SomeException -> Maybe VersionError # displayException :: VersionError -> String #

data VersionDecoder a where Source #

How to decode a version of a format.

Constructors

Incompatible :: String -> VersionDecoder a	This version is incompatible, fail with `IncompatibleVersion` and the given message.
Decode :: (forall s. Decoder s a) -> VersionDecoder a	Decode the version using the given `Decoder`.
Migrate :: VersionDecoder from -> (from -> Either String to) -> VersionDecoder to	Decode an other format (`from`) and migrate from that. When migration fails, the version decoder will fail with `MigrationFailed`.

encodeVersioned :: (a -> Encoding) -> Versioned a -> Encoding Source #

encodeVersion :: VersionNumber -> Encoding -> Encoding Source #

Given a VersionNumber and the encoding of an a, encode the corresponding Versioned a. Use decodeVersion to decode it.

decodeVersioned :: [(VersionNumber, VersionDecoder a)] -> forall s. Decoder s (Versioned a) Source #

decodeVersion :: [(VersionNumber, VersionDecoder a)] -> forall s. Decoder s a Source #

Decode a versioned a (encoded using encodeVersion or encodeVersioned).

The corresponding VersionDecoder for the deserialised VersionNumber is looked up in the given list. The first match is used (using the semantics of lookup). When no match is found, a decoder that fails with UnknownVersion is returned.