Deferred object loading

1 files changed, 14 insertions, 0 deletions

diff --git a/src/Erebos/Network.hs b/src/Erebos/Network.hs
index b5cfa6b..3a6f259 100644
--- a/src/Erebos/Network.hs
+++ b/src/Erebos/Network.hs
@@ -26,6 +26,7 @@ module Erebos.Network (
     sendToPeerWith,
     runPeerService,
     modifyServiceGlobalState,
+    requestDataFromPeer, DataRequestResult(..),
 
     discoveryPort,
 ) where
@@ -1063,6 +1064,19 @@ modifyServiceGlobalState server proxy f = do
             throwErebosError $ UnhandledService svc
 
 
+data DataRequestResult
+    = DataRequestFulfilled Ref
+    | DataRequestRejected
+    | DataRequestInvalid
+
+requestDataFromPeer :: MonadIO m => Peer -> RefDigest -> (DataRequestResult -> ExceptT ErebosError IO ()) -> m ()
+requestDataFromPeer peer@Peer {..} dgst callback = do
+    liftIO $ atomically $ do
+        wref <- WaitingRef peerStorage_ (partialRefFromDigest peerInStorage dgst) (callback . DataRequestFulfilled) <$> newTVar (Left [])
+        putTMVar peerWaitingRefs . (wref :) =<< takeTMVar peerWaitingRefs
+        writeTQueue (serverDataResponse peerServer_) ( peer, Nothing )
+
+
 foreign import ccall unsafe "Network/ifaddrs.h erebos_join_multicast" cJoinMulticast :: CInt -> Ptr CSize -> IO (Ptr Word32)
 foreign import ccall unsafe "Network/ifaddrs.h erebos_local_addresses" cLocalAddresses :: Ptr CSize -> IO (Ptr InetAddress)
 foreign import ccall unsafe "Network/ifaddrs.h erebos_broadcast_addresses" cBroadcastAddresses :: IO (Ptr Word32)