This commit is contained in:
Joey Hess 2010-10-10 15:04:18 -04:00
parent f4d2a05e86
commit cc23519235
6 changed files with 79 additions and 30 deletions

View file

@ -18,24 +18,60 @@
module Backend where
import GitRepo
import System.Directory
import GitRepo
import Utility
type Key = String
data Backend = Backend {
name :: String, -- name of this backend
keyvalue :: FilePath -> Maybe String, -- maps from key to value
retrievekey :: IO String -> IO (Bool) -- retrieves value given key
-- name of this backend
name :: String,
-- converts a filename to a key
getKey :: FilePath -> IO (Maybe Key),
-- stores a file's contents to a key
storeFileKey :: FilePath -> Key -> IO (Bool),
-- retrieves a key's contents to a file
retrieveKeyFile :: IO Key -> FilePath -> IO (Bool)
}
instance Show Backend where
show backend = "Backend { name =\"" ++ (name backend) ++ "\" }"
{- Name of state file that holds the key for an annexed file,
- using a given backend. -}
backendFile :: Backend -> GitRepo -> FilePath -> String
backendFile backend repo file = gitStateDir repo ++
(gitRelative repo file) ++ "." ++ (name backend)
{- Attempts to Stores a file in one of the backends. -}
storeFile :: [Backend] -> GitRepo -> FilePath -> IO (Bool)
storeFile [] _ _ = return False
storeFile (b:bs) repo file = do
try <- (getKey b) (gitRelative repo file)
case (try) of
Nothing -> storeFile bs repo file
Just key -> do
(storeFileKey b) file key
createDirectoryIfMissing True (parentDir backendfile)
writeFile backendfile key
return True
where backendfile = backendFile b repo file
{- Attempts to retrieve an file from one of the backends, saving it to
- a specified location. -}
retrieveFile :: [Backend] -> GitRepo -> FilePath -> FilePath -> IO (Bool)
retrieveFile backends repo file dest = do
result <- lookupBackend backends repo file
case (result) of
Nothing -> return False
Just b -> (retrieveKeyFile b) key dest
where
key = readFile (backendFile b repo file)
{- Looks up the backend used for an already annexed file. -}
lookupBackend :: [Backend] -> GitRepo -> FilePath -> IO (Maybe Backend)
lookupBackend [] repo file = return Nothing
lookupBackend [] _ _ = return Nothing
lookupBackend (b:bs) repo file = do
present <- checkBackend b repo file
if present
@ -47,12 +83,3 @@ lookupBackend (b:bs) repo file = do
{- Checks if a file is available via a given backend. -}
checkBackend :: Backend -> GitRepo -> FilePath -> IO (Bool)
checkBackend backend repo file = doesFileExist $ backendFile backend repo file
{- Attempts to retrieve an annexed file from one of the backends. -}
retrieveFile :: [Backend] -> GitRepo -> FilePath -> IO (Bool)
retrieveFile backends repo file = do
result <- lookupBackend backends repo file
case (result) of
Nothing -> return False
Just b -> (retrievekey b) key
where key = readFile (backendFile b repo file)

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@ -7,11 +7,18 @@ import Backend
backend = Backend {
name = "file",
keyvalue = keyValue,
retrievekey = copyFile
getKey = keyValue,
storeFileKey = moveToAnnex,
retrieveKeyFile = copyFromOtherRepo
}
-- direct mapping from filename to key
keyValue k = Just $ id k
keyValue :: FilePath -> IO (Maybe Key)
keyValue k = return $ Just $ id k
moveToAnnex :: FilePath -> Key -> IO (Bool)
moveToAnnex file key = return False
copyFromOtherRepo :: IO Key -> FilePath -> IO (Bool)
copyFromOtherRepo key file = return False
copyFile f = error "unimplemented"

View file

@ -7,11 +7,18 @@ import Backend
backend = Backend {
name = "url",
keyvalue = keyValue,
retrievekey = downloadUrl
getKey = keyValue,
storeFileKey = dummyStore,
retrieveKeyFile = downloadUrl
}
-- cannot generate url from filename
keyValue k = Nothing
keyValue :: FilePath -> IO (Maybe Key)
keyValue k = return Nothing
downloadUrl k = error "unimplemented"
-- cannot store to urls
dummyStore :: FilePath -> Key -> IO (Bool)
dummyStore file url = return False
downloadUrl :: IO Key -> FilePath -> IO (Bool)
downloadUrl url file = error "unimplemented"

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@ -57,15 +57,22 @@ gitPrep repo = do
attributes <- gitAttributes repo
exists <- doesFileExist attributes
if (not exists)
then writeFile attributes $ attrLine ++ "\n"
then do
writeFile attributes $ attrLine ++ "\n"
gitAdd repo attributes
else do
content <- readFile attributes
if (all (/= attrLine) (lines content))
then do
appendFile attributes $ attrLine ++ "\n"
-- TODO check attributes file into git?
gitAdd repo attributes
else return ()
{- Stages a changed file in git's index. -}
gitAdd repo file = do
-- TODO
return ()
{- Finds the top of the current git repository, which may be in a parent
- directory. -}
repoTop :: IO GitRepo

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@ -84,6 +84,7 @@ appendLog file line = do
createDirectoryIfMissing True (parentDir file)
withFileLocked file AppendMode $ \h ->
hPutStrLn h $ show line
-- TODO git add log
{- Writes a set of lines to a log file -}
writeLog :: FilePath -> [LogLine] -> IO ()
@ -99,17 +100,16 @@ logNow status repo = do
return $ LogLine now status repo
{- Returns the filename of the log file for a given annexed file. -}
logFile :: FilePath -> IO String
logFile annexedFile = do
repo <- repoTop
logFile :: GitRepo -> FilePath -> IO String
logFile repo annexedFile = do
return $ (gitStateDir repo) ++
(gitRelative repo annexedFile) ++ ".log"
{- Returns a list of repositories that, according to the log, have
- the content of a file -}
fileLocations :: FilePath -> IO [String]
fileLocations file = do
log <- logFile file
fileLocations :: GitRepo -> FilePath -> IO [String]
fileLocations thisrepo file = do
log <- logFile thisrepo file
lines <- readLog log
return $ map repo (filterPresent lines)

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@ -4,6 +4,7 @@
import LocationLog
import GitRepo
import Backend
import Annex
-- When adding a new backend, import it here and add it to the backends list.
import qualified BackendFile