add a few tweaks to make it easy to use the Internet Archive's variant of S3

In particular, munge key filenames to comply with the IA's filename limits,
disable encryption, support their nonstandard way of creating buckets, and
allow x-amz-* headers to be specified in initremote to set item metadata.

Still TODO: initremote does not handle multiword metadata headers right.

Remote/S3real.hs

@@ -15,6 +15,9 @@ import Network.AWS.AWSResult
 import qualified Data.ByteString.Lazy.Char8 as L
 import qualified Data.Map as M
 import Data.Maybe
+import Data.List
+import Data.Char
+import Data.String.Utils
 import Control.Monad (when)
 import Control.Monad.State (liftIO)
 import System.Environment
@@ -68,24 +71,53 @@ gen' r u c cst = do
 		}
 
 s3Setup :: UUID -> RemoteConfig -> Annex RemoteConfig
-s3Setup u c = do
-	-- verify configuration is sane
-	c' <- encryptionSetup c
-	let fullconfig = M.union c' defaults
-
-	genBucket fullconfig
-	gitConfigSpecialRemote u fullconfig "s3" "true"
-	s3SetCreds fullconfig
+s3Setup u c = handlehost $ M.lookup "host" c
 	where
 		remotename = fromJust (M.lookup "name" c)
-		bucket = remotename ++ "-" ++ u
+		defbucket = remotename ++ "-" ++ u
 		defaults = M.fromList
 			[ ("datacenter", "US")
 			, ("storageclass", "STANDARD")
 			, ("host", defaultAmazonS3Host)
 			, ("port", show defaultAmazonS3Port)
-			, ("bucket", bucket)
+			, ("bucket", defbucket)
 			]
+		
+		handlehost Nothing = defaulthost
+		handlehost (Just h)
+			| ".archive.org" `isSuffixOf` (map toLower h) = archiveorg
+			| otherwise = defaulthost
+
+		use fullconfig = do
+			genBucket fullconfig
+			gitConfigSpecialRemote u fullconfig "s3" "true"
+			s3SetCreds fullconfig	
+
+		defaulthost = do
+			c' <- encryptionSetup c
+			use $ M.union c' defaults
+
+		archiveorg = do
+			showNote $ "Internet Archive mode"
+			maybe (error "specify bucket=") (const $ return ()) $
+				M.lookup "bucket" archiveconfig
+			use archiveconfig
+			where
+				archiveconfig =
+					-- hS3 does not pass through
+					-- x-archive-* headers
+					M.mapKeys (replace "x-archive-" "x-amz-") $
+					-- encryption does not make sense here
+					M.insert "encryption" "none" $
+					M.union c $
+					-- special constraints on key names
+					M.insert "mungekeys" "ia" $
+					-- buckets created only as files
+					-- are uploaded
+					M.insert "x-amz-auto-make-bucket" "1" $
+					-- no default bucket name; should
+					-- be human-readable
+					M.delete "bucket" defaults
 
 store :: Remote Annex -> Key -> Annex Bool
 store r k = s3Action r False $ \(conn, bucket) -> do
@@ -111,8 +143,8 @@ storeHelper (conn, bucket) r k file = do
 	-- buffered to calculate it
 	size <- maybe getsize (return . fromIntegral) $ keySize k
 	let object = setStorageClass storageclass $ 
-		S3Object bucket (show k) ""
-			[("Content-Length",(show size)), ("x-amz-auto-make-bucket","1")] content
+		S3Object bucket (bucketFile r k) ""
+			(("Content-Length", show size) : xheaders) content
 	sendObject conn object
 	where
 		storageclass =
@@ -122,10 +154,13 @@ storeHelper (conn, bucket) r k file = do
 		getsize = do
 			s <- liftIO $ getFileStatus file
 			return $ fileSize s
+		
+		xheaders = filter isxheader $ M.assocs $ fromJust $ config r
+		isxheader (h, _) = "x-amz-" `isPrefixOf` h
 
 retrieve :: Remote Annex -> Key -> FilePath -> Annex Bool
 retrieve r k f = s3Action r False $ \(conn, bucket) -> do
-	res <- liftIO $ getObject conn $ bucketKey bucket k
+	res <- liftIO $ getObject conn $ bucketKey r bucket k
 	case res of
 		Right o -> do
 			liftIO $ L.writeFile f $ obj_data o
@@ -134,7 +169,7 @@ retrieve r k f = s3Action r False $ \(conn, bucket) -> do
 
 retrieveEncrypted :: Remote Annex -> (Cipher, Key) -> FilePath -> Annex Bool
 retrieveEncrypted r (cipher, enck) f = s3Action r False $ \(conn, bucket) -> do
-	res <- liftIO $ getObject conn $ bucketKey bucket enck
+	res <- liftIO $ getObject conn $ bucketKey r bucket enck
 	case res of
 		Right o -> liftIO $ 
 			withDecryptedContent cipher (return $ obj_data o) $ \content -> do
@@ -144,13 +179,13 @@ retrieveEncrypted r (cipher, enck) f = s3Action r False $ \(conn, bucket) -> do
 
 remove :: Remote Annex -> Key -> Annex Bool
 remove r k = s3Action r False $ \(conn, bucket) -> do
-	res <- liftIO $ deleteObject conn $ bucketKey bucket k
+	res <- liftIO $ deleteObject conn $ bucketKey r bucket k
 	s3Bool res
 
 checkPresent :: Remote Annex -> Key -> Annex (Either IOException Bool)
 checkPresent r k = s3Action r noconn $ \(conn, bucket) -> do
 	showNote ("checking " ++ name r ++ "...")
-	res <- liftIO $ getObjectInfo conn $ bucketKey bucket k
+	res <- liftIO $ getObjectInfo conn $ bucketKey r bucket k
 	case res of
 		Right _ -> return $ Right True
 		Left (AWSError _ _) -> return $ Right False
@@ -182,8 +217,27 @@ s3Action r noconn action = do
 		(Just b, Just c) -> action (c, b)
 		_ -> return noconn
 
-bucketKey :: String -> Key -> S3Object
-bucketKey bucket k = S3Object bucket (show k) "" [] L.empty
+bucketFile :: Remote Annex -> Key -> FilePath
+bucketFile r k = (munge $ show k)
+	where
+		munge s = case M.lookup "mungekeys" $ fromJust $ config r of
+			Just "ia" -> iaMunge s
+			_ -> s
+
+bucketKey :: Remote Annex -> String -> Key -> S3Object
+bucketKey r bucket k = S3Object bucket (bucketFile r k) "" [] L.empty
+
+{- Internet Archive limits filenames to a subset of ascii,
+ - with no whitespace. Other characters are xml entity
+ - encoded. -}
+iaMunge :: String -> String
+iaMunge = concat . (map munge)
+	where
+		munge c
+			| isAsciiUpper c || isAsciiLower c || isNumber c = [c]
+			| c `elem` "_-.\"" = [c]
+			| isSpace c = []
+			| otherwise = "&" ++ show (ord c) ++ ";"
 
 genBucket :: RemoteConfig -> Annex ()
 genBucket c = do