Define msHeaderLength

Define msHeaderLength and use it instead of 8 as hardcoded headerlength.

network-mux/src/Network/Mux/Bearer/NamedPipe.hs

@@ -44,7 +44,7 @@ namedPipeAsBearer sduSize tracer h =
     readNamedPipe :: Mx.TimeoutFn IO -> IO (Mx.SDU, Time)
     readNamedPipe _ = do
       traceWith tracer Mx.TraceRecvHeaderStart
-      hbuf <- recvLen' True 8 []
+      hbuf <- recvLen' True Mx.msHeaderLength []
       case Mx.decodeSDU hbuf of
         Left e -> throwIO e
         Right header@Mx.SDU { Mx.msHeader } -> do

network-mux/src/Network/Mux/Bearer/Pipe.hs

@@ -86,7 +86,7 @@ pipeAsBearer sduSize tracer channel =
       readPipe :: Mx.TimeoutFn IO -> IO (Mx.SDU, Time)
       readPipe _ = do
           traceWith tracer Mx.TraceRecvHeaderStart
-          hbuf <- recvLen' 8 []
+          hbuf <- recvLen' (fromIntegral Mx.msHeaderLength) []
           case Mx.decodeSDU hbuf of
               Left e -> throwIO e
               Right header@Mx.SDU { Mx.msHeader } -> do

network-mux/src/Network/Mux/Bearer/Socket.hs

@@ -66,14 +66,12 @@ socketAsBearer sduSize batchSize readBuffer_m sduTimeout tracer sd =
         Mx.name      = "socket-bearer"
       }
     where
-      hdrLenght = 8
-
       readSocket :: Mx.TimeoutFn IO -> IO (Mx.SDU, Time)
       readSocket timeout = do
           traceWith tracer Mx.TraceRecvHeaderStart
 
           -- Wait for the first part of the header without any timeout
-          h0 <- recvAtMost True hdrLenght
+          h0 <- recvAtMost True Mx.msHeaderLength
 
           -- Optionally wait at most sduTimeout seconds for the complete SDU.
           r_m <- timeout sduTimeout $ recvRem h0
@@ -85,7 +83,7 @@ socketAsBearer sduSize batchSize readBuffer_m sduTimeout tracer sd =
 
       recvRem :: BL.ByteString -> IO (Mx.SDU, Time)
       recvRem !h0 = do
-          hbuf <- recvLen' (hdrLenght - BL.length h0) [h0]
+          hbuf <- recvLen' (Mx.msHeaderLength - BL.length h0) [h0]
           case Mx.decodeSDU hbuf of
                Left  e ->  throwIO e
                Right header@Mx.SDU { Mx.msHeader } -> do

network-mux/src/Network/Mux/Egress.hs

@@ -16,6 +16,7 @@ module Network.Mux.Egress
 
 import Control.Monad
 import Data.ByteString.Lazy qualified as BL
+import Data.Int
 
 import Control.Concurrent.Class.MonadSTM.Strict
 import Control.Monad.Class.MonadAsync
@@ -154,8 +155,8 @@ muxer egressQueue Bearer { writeMany, sduSize, batchSize } =
     maxSDUsPerBatch :: Int
     maxSDUsPerBatch = 100
 
-    sduLength :: SDU -> Int
-    sduLength sdu = 8 + fromIntegral (msLength sdu)
+    sduLength :: SDU -> Int64
+    sduLength sdu = msHeaderLength + fromIntegral (msLength sdu)
 
     -- Build a batch of SDUs to submit in one go to the bearer.
     -- The egress queue is still processed one SDU at the time
@@ -164,7 +165,7 @@ muxer egressQueue Bearer { writeMany, sduSize, batchSize } =
     -- (e.g the SO_SNDBUF for Socket) or number of SDUs.
     --
     buildBatch sdus _ | length sdus >= maxSDUsPerBatch   = return $ reverse sdus
-    buildBatch sdus sdusLength | sdusLength >= batchSize = return $ reverse sdus
+    buildBatch sdus sdusLength | sdusLength >= fromIntegral batchSize = return $ reverse sdus
     buildBatch sdus !sdusLength = do
       demand_m <- atomically $ tryReadTBQueue egressQueue
       case demand_m of

network-mux/src/Network/Mux/Types.hs

@@ -36,6 +36,7 @@ module Network.Mux.Types
   , msNum
   , msDir
   , msLength
+  , msHeaderLength
   , RemoteClockModel (..)
   , remoteClockPrecision
   , RuntimeError (..)
@@ -47,6 +48,7 @@ import Prelude hiding (read)
 import Control.Exception (Exception, SomeException)
 import Data.ByteString.Lazy qualified as BL
 import Data.Functor (void)
+import Data.Int
 import Data.Ix (Ix (..))
 import Data.Word
 import Foreign.Ptr (Ptr)
@@ -223,6 +225,9 @@ msDir = mhDir . msHeader
 msLength :: SDU -> Word16
 msLength = mhLength . msHeader
 
+-- | Size of a MuxHeader in Bytes
+msHeaderLength :: Int64
+msHeaderLength = 8
 
 -- | Low level access to underlying socket or pipe.  There are three smart
 -- constructors:

network-mux/test/Test/Mux.hs

@@ -274,12 +274,12 @@ instance Arbitrary ArbitrarySDU where
         invalidLenght = do
             ts  <- arbitrary
             mid <- arbitrary
-            realLen <- choose (0, 8) -- Size of mux header is 8
-            len <- if realLen == 8 then return 0
-                                   else arbitrary
+            realLen <- choose (0, Mx.msHeaderLength)
+            len <- if realLen == Mx.msHeaderLength then return 0
+                                                   else arbitrary
             p <- arbitrary
 
-            return $ ArbitraryInvalidSDU (InvalidSDU (Mx.RemoteClockModel ts) mid len realLen p)
+            return $ ArbitraryInvalidSDU (InvalidSDU (Mx.RemoteClockModel ts) mid len (fromIntegral realLen) p)
                                          (Mx.SDUDecodeError "")
 
 instance Arbitrary Mx.BearerState where