got rid of the .git-annex/key.backend files

Annex.hs

@@ -25,8 +25,8 @@ import LocationLog
 import Types
 
 {- Checks if a given key is currently present in the annexLocation -}
-inAnnex :: State -> Key -> IO Bool
-inAnnex state key = doesFileExist $ annexLocation state key
+inAnnex :: State -> Backend -> Key -> IO Bool
+inAnnex state backend key = doesFileExist $ annexLocation state backend key
 
 {- On startup, examine the git repo, prepare it, and record state for
  - later. -}
@@ -56,15 +56,14 @@ annexFile state file = do
 				Just (key, backend) -> setup key backend
 	where
 		setup key backend = do
-			let dest = annexLocation state key
+			let dest = annexLocation state backend key
 			createDirectoryIfMissing True (parentDir dest)
 			renameFile file dest
 			createSymbolicLink dest file
-			gitRun (repo state) ["add", file, bfile]
+			gitRun (repo state) ["add", file]
 			gitRun (repo state) ["commit", "-m", 
-				("git-annex annexed " ++ file), file, bfile]
+				("git-annex annexed " ++ file), file]
 			logStatus state key ValuePresent
-				where bfile = backendFile state backend file
 		checkLegal file = do
 			s <- getSymbolicLinkStatus file
 			if ((isSymbolicLink s) || (not $ isRegularFile s))
@@ -82,16 +81,15 @@ unannexFile state file = do
 			case (mkey) of
 				Nothing -> return ()
 				Just (key, backend) -> do
-					let src = annexLocation state key
+					let src = annexLocation state backend key
 					removeFile file
-					gitRun (repo state) ["rm", file, bfile]
+					gitRun (repo state) ["rm", file]
 					gitRun (repo state) ["commit", "-m",
 						("git-annex unannexed " ++ file),
-						file, bfile]
+						file]
 					renameFile src file
 					logStatus state key ValueMissing
 					return ()
-						where bfile = backendFile state backend file
 
 {- Transfers the file from a remote. -}
 annexGetFile :: State -> FilePath -> IO ()
@@ -100,12 +98,12 @@ annexGetFile state file = do
 	case (alreadyannexed) of
 		Nothing -> error $ "not annexed " ++ file
 		Just backend -> do
-			key <- lookupKey state backend file
-			inannex <- inAnnex state key
+			key <- fileKey file
+			inannex <- inAnnex state backend key
 			if (inannex)
 				then return ()
 				else do
-					let dest = annexLocation state key
+					let dest = annexLocation state backend key
 					createDirectoryIfMissing True (parentDir dest)
 					success <- retrieveFile state file dest
 					if (success)

Backend.hs

@@ -17,12 +17,14 @@ module Backend (
 	lookupBackend,
 	storeFile,
 	retrieveFile,
-	lookupKey,
+	fileKey,
 	dropFile
 ) where
 
 import System.Directory
+import System.FilePath
 import Data.String.Utils
+import System.Posix.Files
 import Locations
 import GitRepo
 import Utility
@@ -41,7 +43,6 @@ storeFile' (b:bs) state file = do
 			if (not stored)
 				then nextbackend
 				else do
-					recordKey state b file key
 					return $ Just (key, b)
 	where
 		nextbackend = storeFile' bs state file
@@ -53,9 +54,9 @@ retrieveFile state file dest = do
 	result <- lookupBackend state file
 	case (result) of
 		Nothing -> return False
-		Just b -> do
-			key <- lookupKey state b file
-			(retrieveKeyFile b) state key dest
+		Just backend -> do
+			key <- fileKey file
+			(retrieveKeyFile backend) state key dest
 
 {- Drops the key for a file from the backend that has it. -}
 dropFile :: State -> FilePath -> IO (Maybe (Key, Backend))
@@ -63,11 +64,10 @@ dropFile state file = do
 	result <- lookupBackend state file
 	case (result) of
 		Nothing -> return Nothing
-		Just b -> do
-			key <- lookupKey state b file
-			(removeKey b) state key
-			removeFile $ backendFile state b file
-			return $ Just (key, b)
+		Just backend -> do
+			key <- fileKey file
+			(removeKey backend) state key
+			return $ Just (key, backend)
 
 {- Looks up the backend used for an already annexed file. -}
 lookupBackend :: State -> FilePath -> IO (Maybe Backend)
@@ -83,22 +83,12 @@ lookupBackend' (b:bs) state file = do
 
 {- Checks if a file is available via a given backend. -}
 checkBackend :: Backend -> State -> FilePath -> IO (Bool)
-checkBackend backend state file = doesFileExist $ backendFile state backend file
+checkBackend backend state file = 
+	doesFileExist $ annexLocation state backend file
 
-{- Looks up the key a backend uses for an already annexed file. -}
-lookupKey :: State -> Backend -> FilePath -> IO Key
-lookupKey state backend file = do
-	k <- readFile (backendFile state backend file)
-	return $ chomp k
-	where
-		chomp s = if (endswith "\n" s)
-				then (reverse . (drop 1) . reverse) s
-				else s
-
-{- Records the key used for an annexed file. -}
-recordKey :: State -> Backend -> FilePath -> Key -> IO ()
-recordKey state backend file key = do
-	createDirectoryIfMissing True (parentDir record)
-	writeFile record $ key ++ "\n"
-	where
-		record = backendFile state backend file
+{- Looks up the key corresponding to an annexed file,
+ - by examining what the file symlinks to. -}
+fileKey :: FilePath -> IO Key
+fileKey file = do
+	l <- readSymbolicLink (file)
+	return $ takeFileName $ l

Locations.hs

@@ -5,8 +5,7 @@ module Locations (
 	gitStateDir,
 	stateLoc,
 	keyFile,
-	annexLocation,
-	backendFile
+	annexLocation
 ) where
 
 import Data.String.Utils
@@ -25,15 +24,10 @@ gitStateDir repo = (gitWorkTree repo) ++ "/" ++ stateLoc ++ "/"
 keyFile :: Key -> FilePath
 keyFile key = replace "/" "&s" $ replace "&" "&a" key
 
-{- An annexed file's content is stored somewhere under .git/annex/,
- - based on the key. -}
-annexLocation :: State -> Key -> FilePath
-annexLocation state key = gitDir (repo state) ++ "/annex/" ++ (keyFile key)
-
-{- The mapping from filename to its key is stored in the .git-annex directory,
- - in a file named `key/$filename.$backend` -}
-backendFile :: State -> Backend -> FilePath -> String
-backendFile state backend file =
-	gitStateDir (repo state) ++ "key/" ++
-		(gitRelative (repo state) file) ++ 
-		"." ++ (name backend)
+{- An annexed file's content is stored in 
+ - .git/annex/<backend>/<key> ; this allows deriving the key and backend
+ - by looking at the symlink to it. -}
+annexLocation :: State -> Backend -> Key -> FilePath
+annexLocation state backend key =
+	gitDir (repo state) ++ "/annex/" ++ (name backend) ++ 
+		"/" ++ (keyFile key)

TODO

@@ -1,6 +1,13 @@
 * bug when annexing files in a subdir of a git repo
 * how to handle git mv file?
 
+* if the annexed files were in .git/annex/<backend>/key, and 
+  files in the repo symlink to that, the .git-annex/key/<file>.<backend>
+  would be redundant, and not needed 
+
+     -- no separate merge problem with it
+     -- want to add an url? `ln -s .git/annex/<backend>/http:%%kitenet.net%foo myfile`
+
 * implement retrieval for backendfile
 
 * query remotes for their annex.uuid settings

git-annex.mdwn

@@ -91,11 +91,9 @@ used to store the file contents, and git-annex would then retrieve them
 as needed and put them in `.git/annex/`.
 
 When a file is annexed, a key is generated from its content and/or metadata.
-This key can later be used to retrieve the file's content (its value). This
-key generation must be stable for a given file content, name, and size.
-
-The mapping from filename to its key is stored in the .git-annex directory,
-in a file named `key/$filename.$backend`
+The file checked into git symlinks to the key. This key can later be used
+to retrieve the file's content (its value). This key generation must be
+stable for a given file content, name, and size.
 
 Multiple pluggable backends are supported, and more than one can be used
 to store different files' contents in a given repository.
@@ -183,8 +181,8 @@ not be dropped right away, depending on number of copies available.
 
 ### branching
 
-The use of `.git-annex` to store state means that if a repo has branches 
-and the user switched between them, git-annex will see different state in
-the different branches. Whether that is a bug or a feature may depend on
-point of view -- call it Too Be Determined. An alternative would be to
-store data directly in the git repo as `pristine-tar` does.
+The use of `.git-annex` to store logs means that if a repo has branches 
+and the user switched between them, git-annex will see different logs in
+the different branches, and so may miss info about what remotes have which
+files (though it can re-learn). An alternative would be to
+store the log data directly in the git repo as `pristine-tar` does.