git-annex/Remote/Web.hs

134 lines
3.3 KiB
Haskell

{- Web remotes.
-
- Copyright 2011 Joey Hess <joey@kitenet.net>
-
- Licensed under the GNU GPL version 3 or higher.
-}
module Remote.Web (
remote,
setUrl,
download
) where
import Control.Monad.State (liftIO)
import Control.Exception
import System.FilePath
import Network.Browser
import Network.HTTP
import Network.URI
import Types
import Types.Remote
import qualified Git
import qualified Annex
import Messages
import Utility
import UUID
import Config
import PresenceLog
import LocationLog
import Locations
type URLString = String
remote :: RemoteType Annex
remote = RemoteType {
typename = "web",
enumerate = list,
generate = gen,
setup = error "not supported"
}
-- There is only one web remote, and it always exists.
-- (If the web should cease to exist, remove this module and redistribute
-- a new release to the survivors by carrier pigeon.)
list :: Annex [Git.Repo]
list = return [Git.repoRemoteNameSet Git.repoFromUnknown "remote.web.dummy"]
-- Dummy uuid for the whole web. Do not alter.
webUUID :: UUID
webUUID = "00000000-0000-0000-0000-000000000001"
gen :: Git.Repo -> UUID -> Maybe RemoteConfig -> Annex (Remote Annex)
gen r _ _ =
return $ Remote {
uuid = webUUID,
cost = expensiveRemoteCost,
name = Git.repoDescribe r,
storeKey = uploadKey,
retrieveKeyFile = downloadKey,
removeKey = dropKey,
hasKey = checkKey,
hasKeyCheap = False,
config = Nothing
}
{- The urls for a key are stored in remote/web/hash/key.log
- in the git-annex branch. -}
urlLog :: Key -> FilePath
urlLog key = "remote/web" </> hashDirLower key </> show key ++ ".log"
getUrls :: Key -> Annex [URLString]
getUrls key = currentLog (urlLog key)
{- Records a change in an url for a key. -}
setUrl :: Key -> URLString -> LogStatus -> Annex ()
setUrl key url status = do
g <- Annex.gitRepo
addLog (urlLog key) =<< logNow status url
-- update location log to indicate that the web has the key, or not
us <- getUrls key
logChange g key webUUID (if null us then InfoMissing else InfoPresent)
downloadKey :: Key -> FilePath -> Annex Bool
downloadKey key file = do
us <- getUrls key
download us file
uploadKey :: Key -> Annex Bool
uploadKey _ = do
warning "upload to web not supported"
return False
dropKey :: Key -> Annex Bool
dropKey _ = do
warning "removal from web not supported"
return False
checkKey :: Key -> Annex (Either IOException Bool)
checkKey key = do
us <- getUrls key
if null us
then return $ Right False
else return . Right =<< checkKey' us
checkKey' :: [URLString] -> Annex Bool
checkKey' [] = return False
checkKey' (u:us) = do
showNote ("checking " ++ u)
e <- liftIO $ urlexists u
if e then return e else checkKey' us
urlexists :: URLString -> IO Bool
urlexists url = do
case parseURI url of
Nothing -> return False
Just u -> do
(_, r) <- Network.Browser.browse $ do
setErrHandler ignore
setOutHandler ignore
setAllowRedirects True
request (mkRequest HEAD u :: Request_String)
case rspCode r of
(2,_,_) -> return True
_ -> return False
where
ignore = const $ return ()
download :: [URLString] -> FilePath -> Annex Bool
download [] _ = return False
download (url:us) file = do
showProgress -- make way for curl progress bar
ok <- liftIO $ boolSystem "curl" [Params "-L -C - -# -o", File file, File url]
if ok then return ok else download us file