git-annex/Types/FileMatcher.hs
Joey Hess 8b74f01a26
split ProvidedInfo and UserProvidedInfo
The latter is for git-annex matchexpression and matching against it can
throw an exception. Splitting out the former reduces the potential for
mistakes and avoids needing to worry about matching against that
throwing an exception.

This is more groundwork for matching largefiles while importing,
without downloading content.

This commit was sponsored by Graham Spencer on Patreon.
2020-09-28 12:12:38 -04:00

88 lines
2.6 KiB
Haskell

{- git-annex file matcher types
-
- Copyright 2013-2020 Joey Hess <id@joeyh.name>
-
- Licensed under the GNU AGPL version 3 or higher.
-}
module Types.FileMatcher where
import Types.UUID (UUID)
import Types.Key (Key, AssociatedFile)
import Types.Mime
import Utility.Matcher (Matcher, Token)
import Utility.FileSize
import Utility.FileSystemEncoding
import Control.Monad.IO.Class
import qualified Data.Map as M
import qualified Data.Set as S
-- Information about a file or a key that can be matched on.
data MatchInfo
= MatchingFile FileInfo
| MatchingKey Key AssociatedFile
| MatchingInfo ProvidedInfo
| MatchingUserInfo UserProvidedInfo
data FileInfo = FileInfo
{ contentFile :: Maybe RawFilePath
-- ^ path to a file containing the content, for operations
-- that examine it
, matchFile :: RawFilePath
-- ^ filepath to match on; may be relative to top of repo or cwd
}
data ProvidedInfo = ProvidedInfo
{ providedFilePath :: RawFilePath
, providedKey :: Maybe Key
, providedFileSize :: FileSize
, providedMimeType :: Maybe MimeType
, providedMimeEncoding :: Maybe MimeEncoding
}
-- This is used when testing a matcher, with values to match against
-- provided by the user.
data UserProvidedInfo = UserProvidedInfo
{ userProvidedFilePath :: UserInfo FilePath
, userProvidedKey :: UserInfo Key
, userProvidedFileSize :: UserInfo FileSize
, userProvidedMimeType :: UserInfo MimeType
, userProvidedMimeEncoding :: UserInfo MimeEncoding
}
-- This may fail if the user did not provide the information.
type UserInfo a = Either (IO a) a
-- If the UserInfo is not available, accessing it may result in eg an
-- exception being thrown.
getUserInfo :: MonadIO m => UserInfo a -> m a
getUserInfo (Right i) = return i
getUserInfo (Left e) = liftIO e
type FileMatcherMap a = M.Map UUID (FileMatcher a)
type MkLimit a = String -> Either String (MatchFiles a)
type AssumeNotPresent = S.Set UUID
data MatchFiles a = MatchFiles
{ matchAction :: AssumeNotPresent -> MatchInfo -> a Bool
, matchNeedsFileName :: Bool
-- ^ does the matchAction need a filename in order to match?
, matchNeedsFileContent :: Bool
-- ^ does the matchAction need the file content to be present in
-- order to succeed?
, matchNeedsKey :: Bool
-- ^ does the matchAction look at information about the key?
, matchNeedsLocationLog :: Bool
-- ^ does the matchAction look at the location log?
}
type FileMatcher a = Matcher (MatchFiles a)
-- This is a matcher that can have tokens added to it while it's being
-- built, and once complete is compiled to an unchangable matcher.
data ExpandableMatcher a
= BuildingMatcher [Token (MatchFiles a)]
| CompleteMatcher (Matcher (MatchFiles a))