13bbb61a51
Needed for resuming from chunks. Url keys are considered not stable. I considered treating url keys with a known size as stable, but just don't feel that is enough information.
34 lines
974 B
Haskell
34 lines
974 B
Haskell
{- git-annex key/value backend data type
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-
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- Most things should not need this, using Types instead
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-
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- Copyright 2010,2012 Joey Hess <joey@kitenet.net>
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-
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- Licensed under the GNU GPL version 3 or higher.
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-}
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module Types.Backend where
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import Types.Key
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import Types.KeySource
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data BackendA a = Backend
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{ name :: String
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, getKey :: KeySource -> a (Maybe Key)
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-- Checks the content of a key.
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, fsckKey :: Maybe (Key -> FilePath -> a Bool)
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-- Checks if a key can be upgraded to a better form.
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, canUpgradeKey :: Maybe (Key -> Bool)
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-- Checks if there is a fast way to migrate a key to a different
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-- backend (ie, without re-hashing).
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, fastMigrate :: Maybe (Key -> BackendA a -> Maybe Key)
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-- Checks if a key is known (or assumed) to always refer to the
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-- same data.
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, isStableKey :: Key -> Bool
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}
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instance Show (BackendA a) where
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show backend = "Backend { name =\"" ++ name backend ++ "\" }"
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instance Eq (BackendA a) where
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a == b = name a == name b
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