split out Types.Import and some changes to the types in it

Database/ContentIdentifier.hs

@@ -29,7 +29,7 @@ import qualified Database.Queue as H
 import Database.Init
 import Annex.Locations
 import Annex.Common hiding (delete)
-import Types.Remote (ContentIdentifier(..))
+import Types.Import
 
 import Database.Persist.Sql hiding (Key)
 import Database.Persist.TH

Database/Types.hs

@@ -23,7 +23,7 @@ import Key
 import Utility.InodeCache
 import Git.Types (Ref(..))
 import Types.UUID
-import Types.Remote (ContentIdentifier(..))
+import Types.Import
 
 -- A serialized Key
 newtype SKey = SKey String

Remote/Helper/ExportImport.hs

@@ -52,7 +52,7 @@ instance HasImportUnsupported (RemoteConfig -> RemoteGitConfig -> Annex Bool) wh
 
 instance HasImportUnsupported (ImportActions Annex) where
 	importUnsupported = ImportActions
-		{ listContents = return Nothing
+		{ listImportableContents = return Nothing
 		, retrieveExportWithContentIdentifier = \_ _ _ _ -> return Nothing
 		, storeExportWithContentIdentifier = \_ _ _ _ _ -> return Nothing
 		}

Types/Import.hs

@@ -0,0 +1,43 @@
+{- git-annex import types
+ -
+ - Copyright 2019 Joey Hess <id@joeyh.name>
+ -
+ - Licensed under the GNU GPL version 3 or higher.
+ -}
+
+module Types.Import where
+
+import qualified Data.ByteString as S
+import Data.Char
+
+import Types.Export
+import Utility.QuickCheck
+import Utility.FileSystemEncoding
+
+{- Location of content on a remote that can be imported. 
+ - This is just an alias to ExportLocation, because both are referring to a
+ - location on the remote. -}
+type ImportLocation = ExportLocation
+
+{- An identifier for content stored on a remote that has been imported into
+ - the repository. It should be reasonably short since it is stored in the
+ - git-annex branch. -}
+newtype ContentIdentifier = ContentIdentifier S.ByteString
+	deriving (Eq, Ord, Show)
+
+instance Arbitrary ContentIdentifier where
+	-- Avoid non-ascii ContentIdentifiers because fully arbitrary
+	-- strings may not be encoded using the filesystem
+	-- encoding, which is normally applied to all input.
+	arbitrary = ContentIdentifier . encodeBS
+		<$> arbitrary `suchThat` all isAscii
+
+{- List of files that can be imported from a remote. -}
+data ImportableContents = ImportableContents
+	{ importableContents :: [(ImportLocation, ContentIdentifier)]
+	, importableHistory :: [ImportableContents]
+	-- ^ Used by remotes that support importing historical versions of
+	-- files that are stored in them. This is equivilant to a git
+	-- commit history.
+	}
+	deriving (Show)

Types/Remote.hs

@@ -21,14 +21,11 @@ module Types.Remote
 	, RetrievalSecurityPolicy(..)
 	, isExportSupported
 	, ExportActions(..)
-	, ContentIdentifier(..)
-	, ContentHistory(..)
 	, ImportActions(..)
 	)
 	where
 
 import qualified Data.Map as M
-import qualified Data.ByteString as S
 import Data.Ord
 
 import qualified Git
@@ -40,12 +37,12 @@ import Types.Creds
 import Types.UrlContents
 import Types.NumCopies
 import Types.Export
+import Types.Import
 import Config.Cost
 import Utility.Metered
 import Git.Types (RemoteName)
 import Utility.SafeCommand
 import Utility.Url
-import Utility.QuickCheck
 
 type RemoteConfigKey = String
 
@@ -244,28 +241,13 @@ data ExportActions a = ExportActions
 	, renameExport :: Key -> ExportLocation -> ExportLocation -> a Bool
 	}
 
-{- An identifier for content stored on a remote. It should be reasonably
- - short since it is stored in the git-annex branch. -}
-newtype ContentIdentifier = ContentIdentifier S.ByteString
-	deriving (Eq, Ord, Show, Arbitrary)
-
-{- Some remotes may support importing a history of versions of content that
- - is stored in them. This is equivilant to a git commit history. -}
-data ContentHistory t
-	= ContentHistoryNode t
-	| ContentHistory
-		{ contentHistoryCurrent :: t
-		, contentHistoryPrev :: [ContentHistory t]
-		}
-	deriving (Show)
-
 data ImportActions a = ImportActions
 	-- Finds the current set of files that are stored in the remote,
 	-- along with their content identifiers.
 	--
 	-- May also find old versions of files that are still stored in the
-	-- remote, and return a ContentHistory with multiple nodes.
-	{ listContents :: a (Maybe (ContentHistory [(ExportLocation, ContentIdentifier)]))
+	-- remote.
+	{ listImportableContents :: a (Maybe ImportableContents)
 	-- Retrieves a file from the remote. Ensures that the file
 	-- it retrieves has the requested ContentIdentifier.
 	--

git-annex.cabal

@@ -976,6 +976,7 @@ Executable git-annex
     Types.FileMatcher
     Types.GitConfig
     Types.Group
+    Types.Import
     Types.Key
     Types.KeySource
     Types.LockCache