http://www.kotancode.com/2013/02/02/sending-and-receiving-google-protocol-buffers-via-akka-io-and-scala/
Used the code from
http://cognitiveentity.wordpress.com/2012/03/10/akka-system-io-client/ and
http://cognitiveentity.wordpress.com/2012/02/23/simpler-akka-io-example/ to send data serialized using ProtoBufs
These examples are all string based, primarily to make the code easy to test with curl.
The string representation of the length can be replaced with its 4 byte binary representation.
The payload is still a byte[], derived from a String for convenience
Client
case s: String => handle.foreach {
h =>
val bb = ByteBuffer.allocate(4)
bb.putInt(s.length)
bb.flip
h write ByteString(bb)
h write ByteString(s.getBytes("US-ASCII"))
}
Server
def readMessage: IO.Iteratee[String] =
for {
lengthBytes <- take(4)
len = lengthBytes.asByteBuffer.getInt()
bytes <- take(len)
} yield {
ascii(bytes)
}
}