make writeHandler async

libp2p/stream/bufferstream.nim

@@ -35,14 +35,14 @@ import chronos
 import ../stream/lpstream
 
 type
-  WriteHandler* = proc (data: seq[byte]) {.gcsafe.} # TODO: figure out how to make this generic to avoid casts
+  WriteHandler* = proc (data: seq[byte]): Future[void] {.gcsafe.} # TODO: figure out how to make this generic to avoid casts
 
   BufferStream* = ref object of LPStream
     maxSize*: int
     readBuf: Deque[byte] # a deque is based on a ring buffer
     readReqs: Deque[Future[int]] # use dequeue to fire reads in order
     dataReadEvent: AsyncEvent
-    writeHandler: WriteHandler
+    writeHandler*: WriteHandler
 
 proc requestReadBytes(s: BufferStream): Future[int] = 
   ## create a future that will complete when more 
@@ -236,7 +236,7 @@ method write*(s: BufferStream,
   ## Return number of bytes actually consumed (discarded).
   var buf: seq[byte] = newSeq[byte](nbytes)
   copyMem(addr buf[0], pbytes, nbytes)
-  s.writeHandler(buf)
+  result = s.writeHandler(buf)
 
 method write*(s: BufferStream, 
               msg: string, 
@@ -251,7 +251,7 @@ method write*(s: BufferStream,
   ## stream.
   var buf = ""
   shallowCopy(buf, if msglen > 0: msg[0..<msglen] else: msg)
-  s.writeHandler(cast[seq[byte]](toSeq(buf.items)))
+  result = s.writeHandler(cast[seq[byte]](toSeq(buf.items)))
 
 method write*(s: BufferStream, 
               msg: seq[byte], 
@@ -267,7 +267,7 @@ method write*(s: BufferStream,
   ## stream.
   var buf: seq[byte]
   shallowCopy(buf, if msglen > 0: msg[0..<msglen] else: msg)
-  s.writeHandler(buf)
+  result = s.writeHandler(buf)
 
 method close*(s: BufferStream) {.async, gcsafe.} =
   ## close the stream and clear the buffer