SMP protocol: optimize batching transactions, remove Builder (#961)

* remove Builder

* fewer chunks

* remove lazy bytestrings

* optimize

* pad

src/Simplex/FileTransfer/Client.hs

@@ -13,7 +13,7 @@ import Control.Monad
 import Control.Monad.Except
 import Crypto.Random (ChaChaDRG)
 import Data.Bifunctor (first)
-import qualified Data.ByteString.Builder as BB
+import Data.ByteString.Builder (Builder, byteString)
 import Data.ByteString.Char8 (ByteString)
 import qualified Data.ByteString.Char8 as B
 import Data.Int (Int64)
@@ -25,7 +25,6 @@ import qualified Network.HTTP2.Client as H
 import Simplex.FileTransfer.Description (mb)
 import Simplex.FileTransfer.Protocol
 import Simplex.FileTransfer.Transport
-import Simplex.Messaging.Builder (Builder, builder)
 import Simplex.Messaging.Client
   ( NetworkConfig (..),
     ProtocolClientError (..),
@@ -142,7 +141,7 @@ sendXFTPCommand c@XFTPClient {http2Client = HTTP2Client {sessionId}} pKey fId cm
       xftpEncodeTransmission sessionId (Just pKey) ("", fId, FileCmd (sFileParty @p) cmd)
   sendXFTPTransmission c t chunkSpec_
 
-sendXFTPTransmission :: XFTPClient -> Builder -> Maybe XFTPChunkSpec -> ExceptT XFTPClientError IO (FileResponse, HTTP2Body)
+sendXFTPTransmission :: XFTPClient -> ByteString -> Maybe XFTPChunkSpec -> ExceptT XFTPClientError IO (FileResponse, HTTP2Body)
 sendXFTPTransmission XFTPClient {config, http2Client = http2@HTTP2Client {sessionId}} t chunkSpec_ = do
   let req = H.requestStreaming N.methodPost "/" [] streamBody
       reqTimeout = (\XFTPChunkSpec {chunkSize} -> chunkTimeout config chunkSize) <$> chunkSpec_
@@ -156,9 +155,9 @@ sendXFTPTransmission XFTPClient {config, http2Client = http2@HTTP2Client {sessio
       _ -> pure (r, body)
     Left e -> throwError $ PCEResponseError e
   where
-    streamBody :: (BB.Builder -> IO ()) -> IO () -> IO ()
+    streamBody :: (Builder -> IO ()) -> IO () -> IO ()
     streamBody send done = do
-      send $ builder t
+      send $ byteString t
       forM_ chunkSpec_ $ \XFTPChunkSpec {filePath, chunkOffset, chunkSize} ->
         withFile filePath ReadMode $ \h -> do
           hSeek h AbsoluteSeek $ fromIntegral chunkOffset

src/Simplex/FileTransfer/Protocol.hs

@@ -24,7 +24,6 @@ import Data.List.NonEmpty (NonEmpty (..))
 import Data.Maybe (isNothing)
 import Data.Type.Equality
 import Data.Word (Word32)
-import Simplex.Messaging.Builder (Builder)
 import qualified Simplex.Messaging.Crypto as C
 import Simplex.Messaging.Encoding
 import Simplex.Messaging.Encoding.String
@@ -49,8 +48,7 @@ import Simplex.Messaging.Protocol
     encodeTransmission,
     messageTagP,
     tDecodeParseValidate,
-    tEncode,
-    tEncodeBatch,
+    tEncodeBatch1,
     tParse,
   )
 import Simplex.Messaging.Transport (SessionId, TransportError (..))
@@ -395,7 +393,7 @@ checkParty' c = case testEquality (sFileParty @p) (sFileParty @p') of
   Just Refl -> Just c
   _ -> Nothing
 
-xftpEncodeTransmission :: ProtocolEncoding e c => SessionId -> Maybe C.APrivateSignKey -> Transmission c -> Either TransportError Builder
+xftpEncodeTransmission :: ProtocolEncoding e c => SessionId -> Maybe C.APrivateSignKey -> Transmission c -> Either TransportError ByteString
 xftpEncodeTransmission sessionId pKey (corrId, fId, msg) = do
   let t = encodeTransmission currentXFTPVersion sessionId (corrId, fId, msg)
   xftpEncodeBatch1 $ signTransmission t
@@ -404,10 +402,8 @@ xftpEncodeTransmission sessionId pKey (corrId, fId, msg) = do
     signTransmission t = ((`C.sign` t) <$> pKey, t)
 
 -- this function uses batch syntax but puts only one transmission in the batch
-xftpEncodeBatch1 :: (Maybe C.ASignature, ByteString) -> Either TransportError Builder
-xftpEncodeBatch1 (sig, t) =
-  let t' = tEncodeBatch 1 . encodeLarge $ tEncode (sig, t)
-   in first (const TELargeMsg) $ C.pad' t' xftpBlockSize
+xftpEncodeBatch1 :: SentRawTransmission -> Either TransportError ByteString
+xftpEncodeBatch1 t = first (const TELargeMsg) $ C.pad (tEncodeBatch1 t) xftpBlockSize
 
 xftpDecodeTransmission :: ProtocolEncoding e c => SessionId -> ByteString -> Either XFTPErrorType (SignedTransmission e c)
 xftpDecodeTransmission sessionId t = do

src/Simplex/FileTransfer/Server.hs

@@ -18,6 +18,7 @@ import Control.Monad.Except
 import Control.Monad.Reader
 import Data.Bifunctor (first)
 import qualified Data.ByteString.Base64.URL as B64
+import Data.ByteString.Builder (byteString)
 import Data.ByteString.Char8 (ByteString)
 import qualified Data.ByteString.Char8 as B
 import Data.Functor (($>))
@@ -43,7 +44,6 @@ import Simplex.FileTransfer.Server.Stats
 import Simplex.FileTransfer.Server.Store
 import Simplex.FileTransfer.Server.StoreLog
 import Simplex.FileTransfer.Transport
-import Simplex.Messaging.Builder (builder)
 import qualified Simplex.Messaging.Crypto as C
 import qualified Simplex.Messaging.Crypto.Lazy as LC
 import Simplex.Messaging.Encoding.String
@@ -242,7 +242,7 @@ processRequest HTTP2Request {sessionId, reqBody = body@HTTP2Body {bodyHead}, sen
               send "padding error" -- TODO respond with BLOCK error?
               done
             Right t -> do
-              send $ builder t
+              send $ byteString t
               -- timeout sending file in the same way as receiving
               forM_ serverFile_ $ \ServerFile {filePath, fileSize, sbState} -> do
                 withFile filePath ReadMode $ \h -> sendEncFile h send sbState (fromIntegral fileSize)