WIP try sending using RequestBodyStreamChunked

May not work; if it does this is gonna be the simplest way to get good
memory size and progress reporting.

Remote/S3.hs

@@ -27,7 +27,6 @@ import Control.Monad.Trans.Resource
 import Control.Monad.Catch
 import Data.Conduit
 #if MIN_VERSION_aws(0,10,6)
-import qualified Aws.S3.Commands.Multipart as Multipart
 import qualified Data.Conduit.List as CL
 import qualified Data.Conduit.Binary as CB
 import Network.HTTP.Conduit (withManager)
@@ -160,10 +159,10 @@ prepareS3 r info = resourcePrepare $ const $
 store :: Remote -> S3Handle -> Storer
 store r h = fileStorer $ \k f p -> do
 	case partSize (hinfo h) of
-		Just sz -> do
+		Just partsz | partsz > 0 -> do
 			fsz <- fromIntegral . fileSize <$> liftIO (getFileStatus f)
-			if fsz > sz
-				then multipartupload sz k f p
+			if fsz > partsz
+				then multipartupload fsz partsz k f p
 				else singlepartupload k f p
 		Nothing -> singlepartupload k f p	
 	-- Store public URL to item in Internet Archive.
@@ -174,7 +173,7 @@ store r h = fileStorer $ \k f p -> do
 	singlepartupload k f p = do
 		rbody <- liftIO $ httpBodyStorer f p
 		void $ sendS3Handle h $ putObject h (bucketObject (hinfo h) k) rbody
-	multipartupload sz k f p = do
+	multipartupload fsz partsz k f p = do
 #if MIN_VERSION_aws(0,10,6)
 		let info = hinfo h
 		let object = bucketObject info k
@@ -187,19 +186,30 @@ store r h = fileStorer $ \k f p -> do
 				}
 		uploadid <- S3.imurUploadId <$> sendS3Handle h req
 
-		-- TODO: progress display
-		-- TODO: avoid needing tons of memory
-		--       https://github.com/aristidb/aws/issues/142
-		etags <- liftIO $ withManager $ \mgr -> 
-			CB.sourceFile f
-			$= Multipart.chunkedConduit sz
-			$= Multipart.putConduit (hawscfg h) (hs3cfg h) mgr (bucket info) object uploadid
-			$$ CL.consume
+		-- Send parts of the file, taking care to stream each part
+		-- w/o buffering in memory, since the parts can be large.
+		etags <- bracketIO (openBinaryFile f ReadMode) hClose $ \h -> do
+			let sendparts etags partnum = do
+				b <- liftIO $ hGetUntilMetered h (< partsz) p
+				if L.null b
+					then return (reverse etags)
+					else do
+						mvar <- newMVar $ L.toChunks b
+						let streamer sink = do
+							let getnextchunk = modifyMVar mvar $ pure . pop
+							sink getnextchunk
+						let body = RequestBodyStreamChunked streamer
+						S3.UploadPartResponse _ etag <- sendS3Handle h $
+							 S3.uploadPart (bucket info) object partnum uploadid body
+						sendparts (etag:etags) (partnum + 1)
+			sendparts [] 0 1
 
 		void $ sendS3Handle h $ S3.postCompleteMultipartUpload
 			(bucket info) object uploadid (zip [1..] etags)
+	pop [] = ([], S.empty)
+	pop (c:cs) = (cs, c)
 #else
-		warning $ "Cannot do multipart upload (partsize " ++ show sz ++ "); built with too old a version of the aws library."
+		warning $ "Cannot do multipart upload (partsize " ++ show partsz ++ " vs filesize " ++ show fsz ++ "); built with too old a version of the aws library."
 		singlepartupload k f p
 #endif