prep for fixing find --branch --unlocked

Added LinkType to ProvidedInfo, and unified MatchingKey with
ProvidedInfo. They're both used in the same way, so there was no real
reason to keep separate.

Note that addLocked and addUnlocked still set matchNeedsFileName,
because to handle MatchingFile, they do need it. However, they
don't use it when MatchingInfo is provided. This should be ok,
the --branch case will be able skip checking matchNeedsFileName,
since it will provide a filename in any case.

Types/FileMatcher.hs

@@ -1,6 +1,6 @@
 {- git-annex file matcher types
  -
- - Copyright 2013-2020 Joey Hess <id@joeyh.name>
+ - Copyright 2013-2021 Joey Hess <id@joeyh.name>
  -
  - Licensed under the GNU AGPL version 3 or higher.
  -}
@@ -8,7 +8,8 @@
 module Types.FileMatcher where
 
 import Types.UUID (UUID)
-import Types.Key (Key, AssociatedFile)
+import Types.Key (Key)
+import Types.Link (LinkType)
 import Types.Mime
 import Utility.Matcher (Matcher, Token)
 import Utility.FileSize
@@ -21,10 +22,6 @@ import qualified Data.Set as S
 -- Information about a file and/or a key that can be matched on.
 data MatchInfo
 	= MatchingFile FileInfo
-	| MatchingKey Key AssociatedFile
-	-- ^ This is used when matching a file that may be in another
-	-- branch. The AssociatedFile is the filename, but it should not be
-	-- accessed from disk when matching.
 	| MatchingInfo ProvidedInfo
 	| MatchingUserInfo UserProvidedInfo
 
@@ -41,11 +38,13 @@ data FileInfo = FileInfo
 	}
 
 data ProvidedInfo = ProvidedInfo
-	{ providedFilePath :: RawFilePath
+	{ providedFilePath :: Maybe RawFilePath
+	-- ^ filepath to match on, should not be accessed from disk.
 	, providedKey :: Maybe Key
-	, providedFileSize :: FileSize
+	, providedFileSize :: Maybe FileSize
 	, providedMimeType :: Maybe MimeType
 	, providedMimeEncoding :: Maybe MimeEncoding
+	, providedLinkType :: Maybe LinkType
 	}
 
 -- This is used when testing a matcher, with values to match against

Types/Link.hs

@@ -0,0 +1,13 @@
+{- Types for links to content
+ -
+ - Copyright 2013-2021 Joey Hess <id@joeyh.name>
+ -
+ - Licensed under the GNU AGPL version 3 or higher.
+ -}
+
+module Types.Link where
+
+-- A locked link is stored in git as a symlink, while an unlocked link is
+-- stored as a pointer file.
+data LinkType = LockedLink | UnlockedLink
+	deriving (Show, Eq)