S3: support chunking

The assistant defaults to 1MiB chunk size for new S3 special remotes.
Which will work around a couple of bugs:
  http://git-annex.branchable.com/bugs/S3_memory_leaks/
  http://git-annex.branchable.com/bugs/S3_upload_not_using_multipart/

Assistant/WebApp/Configurators/AWS.hs

@@ -129,6 +129,7 @@ postAddS3R = awsConfigurator $ do
 				, ("type", "S3")
 				, ("datacenter", T.unpack $ datacenter input)
 				, ("storageclass", show $ storageClass input)
+				, ("chunk", "1MiB")
 				]
 		_ -> $(widgetFile "configurators/adds3")
 #else

Remote/S3.hs

@@ -25,12 +25,10 @@ import qualified Git
 import Config
 import Config.Cost
 import Remote.Helper.Special
-import Remote.Helper.Encryptable
+import Remote.Helper.ChunkedEncryptable
 import qualified Remote.Helper.AWS as AWS
-import Crypto
 import Creds
 import Utility.Metered
-import Annex.Content
 import Annex.UUID
 import Logs.Web
 
@@ -47,17 +45,17 @@ remote = RemoteType {
 gen :: Git.Repo -> UUID -> RemoteConfig -> RemoteGitConfig -> Annex (Maybe Remote)
 gen r u c gc = new <$> remoteCost gc expensiveRemoteCost
   where
-	new cst = Just $ encryptableRemote c
-		(storeEncrypted this)
-		(retrieveEncrypted this)
+	new cst = Just $ chunkedEncryptableRemote c
+		(prepareStore this)
+		(prepareRetrieve this)
 		this
 	  where
 		this = Remote {
 			uuid = u,
 			cost = cst,
 			name = Git.repoDescribe r,
-			storeKey = store this,
-			retrieveKeyFile = retrieve this,
+			storeKey = storeKeyDummy,
+			retrieveKeyFile = retreiveKeyFileDummy,
 			retrieveKeyFileCheap = retrieveCheap this,
 			removeKey = remove this c,
 			hasKey = checkPresent this,
@@ -123,67 +121,39 @@ s3Setup' u c = if isIA c then archiveorg else defaulthost
 		writeUUIDFile archiveconfig u
 		use archiveconfig
 
-store :: Remote -> Key -> AssociatedFile -> MeterUpdate -> Annex Bool
-store r k _f p = s3Action r False $ \(conn, bucket) -> 
-	sendAnnex k (void $ remove' r k) $ \src -> do
-		ok <- s3Bool =<< storeHelper (conn, bucket) r k p src
+prepareStore :: Remote -> Preparer Storer
+prepareStore r = resourcePrepare (const $ s3Action r False) $ \(conn, bucket) -> 
+	fileStorer $ \k src p -> do
+		ok <- s3Bool =<< liftIO (store (conn, bucket) r k p src)
 
 		-- Store public URL to item in Internet Archive.
-		when (ok && isIA (config r)) $
+		when (ok && isIA (config r) && not (isChunkKey k)) $
 			setUrlPresent k (iaKeyUrl r k)
 
 		return ok
 
-storeEncrypted :: Remote -> (Cipher, Key) -> Key -> MeterUpdate -> Annex Bool
-storeEncrypted r (cipher, enck) k p = s3Action r False $ \(conn, bucket) -> 
-	-- To get file size of the encrypted content, have to use a temp file.
-	-- (An alternative would be chunking to to a constant size.)
-	withTmp enck $ \tmp -> sendAnnex k (void $ remove' r enck) $ \src -> do
-		liftIO $ encrypt (getGpgEncParams r) cipher (feedFile src) $
-			readBytes $ L.writeFile tmp
-		s3Bool =<< storeHelper (conn, bucket) r enck p tmp
+store :: (AWSConnection, Bucket) -> Remote -> Key -> MeterUpdate -> FilePath -> IO (AWSResult ())
+store (conn, bucket) r k p file = do
+	size <- (fromIntegral . fileSize <$> getFileStatus file) :: IO Integer
+	withMeteredFile file p $ \content -> do
+		-- size is provided to S3 so the whole content
+		-- does not need to be buffered to calculate it
+		let object = S3Object
+			bucket (bucketFile r k) ""
+			(("Content-Length", show size) : getXheaders (config r))
+			content
+		sendObject conn $
+			setStorageClass (getStorageClass $ config r) object
 
-storeHelper :: (AWSConnection, Bucket) -> Remote -> Key -> MeterUpdate -> FilePath -> Annex (AWSResult ())
-storeHelper (conn, bucket) r k p file = do
-	size <- maybe getsize (return . fromIntegral) $ keySize k
-	meteredBytes (Just p) size $ \meterupdate ->
-		liftIO $ withMeteredFile file meterupdate $ \content -> do
-			-- size is provided to S3 so the whole content
-			-- does not need to be buffered to calculate it
-			let object = S3Object
-				bucket (bucketFile r k) ""
-				(("Content-Length", show size) : getXheaders (config r))
-				content
-			sendObject conn $
-				setStorageClass (getStorageClass $ config r) object
-  where
-	getsize = liftIO $ fromIntegral . fileSize <$> getFileStatus file
-
-retrieve :: Remote -> Key -> AssociatedFile -> FilePath -> MeterUpdate -> Annex Bool
-retrieve r k _f d p = s3Action r False $ \(conn, bucket) ->
-	metered (Just p) k $ \meterupdate -> do
-		res <- liftIO $ getObject conn $ bucketKey r bucket k
-		case res of
-			Right o -> do
-				liftIO $ meteredWriteFile meterupdate d $
-					obj_data o
-				return True
-			Left e -> s3Warning e
+prepareRetrieve :: Remote -> Preparer Retriever
+prepareRetrieve r = resourcePrepare (const $ s3Action r False) $ \(conn, bucket) ->
+	byteRetriever $ \k ->
+		liftIO (getObject conn $ bucketKey r bucket k)
+			>>= either s3Error (return . obj_data)
 
 retrieveCheap :: Remote -> Key -> FilePath -> Annex Bool
 retrieveCheap _ _ _ = return False
 
-retrieveEncrypted :: Remote -> (Cipher, Key) -> Key -> FilePath -> MeterUpdate -> Annex Bool
-retrieveEncrypted r (cipher, enck) k d p = s3Action r False $ \(conn, bucket) ->
-	metered (Just p) k $ \meterupdate -> do
-		res <- liftIO $ getObject conn $ bucketKey r bucket enck
-		case res of
-			Right o -> liftIO $ decrypt cipher (\h -> meteredWrite meterupdate h $ obj_data o) $ 
-				readBytes $ \content -> do
-					L.writeFile d content
-					return True
-			Left e -> s3Warning e
-
 {- Internet Archive doesn't easily allow removing content.
  - While it may remove the file, there are generally other files
  - derived from it that it does not remove. -}

Types/Key.hs

@@ -15,6 +15,7 @@ module Types.Key (
 	file2key,
 	nonChunkKey,
 	chunkKeyOffset,
+	isChunkKey,
 
 	prop_idempotent_key_encode,
 	prop_idempotent_key_decode
@@ -62,6 +63,9 @@ chunkKeyOffset k = (*)
 	<$> keyChunkSize k
 	<*> (pred <$> keyChunkNum k)
 
+isChunkKey :: Key -> Bool
+isChunkKey k = isJust (keyChunkSize k) && isJust (keyChunkNum k)
+
 fieldSep :: Char
 fieldSep = '-'
 

debian/changelog

@@ -1,7 +1,7 @@
 git-annex (5.20140718) UNRELEASED; urgency=medium
 
   * New chunk= option to chunk files stored in special remotes.
-    Currently supported by: directory, and all external special remotes.
+    Currently supported by: directory, S3, and all external special remotes.
   * Partially transferred files are automatically resumed when using
     chunked remotes!
   * The old chunksize= option is deprecated. Do not use for new remotes.

doc/special_remotes/S3.mdwn

@@ -18,6 +18,9 @@ the S3 remote.
 * `encryption` - One of "none", "hybrid", "shared", or "pubkey".
   See [[encryption]].
 
+* `chunk` - Enables [[chunking]] when storing large files.
+  `chunk=1MiB` is a good starting point for chunking.
+
 * `keyid` - Specifies the gpg key to use for [[encryption]].
 
 * `embedcreds` - Optional. Set to "yes" embed the login credentials inside

doc/tips/using_Amazon_S3.mdwn

@@ -14,7 +14,7 @@ like "2512E3C7"
 
 Next, create the S3 remote, and describe it. 
 
-	# git annex initremote cloud type=S3 keyid=2512E3C7
+	# git annex initremote cloud type=S3 chunk=1MiB keyid=2512E3C7
 	initremote cloud (encryption setup with gpg key C910D9222512E3C7) (checking bucket) (creating bucket in US) (gpg) ok
 	# git annex describe cloud "at Amazon's US datacenter"
 	describe cloud ok