/**
* Copyright (C) 2009-2014 Typesafe Inc. <http://www.typesafe.com>
*/
package docs.io.japi;
import java.net.InetSocketAddress;
import java.util.LinkedList;
import java.util.Queue;
import akka.actor.ActorRef;
import akka.actor.UntypedActor;
import akka.event.Logging;
import akka.event.LoggingAdapter;
import akka.io.Tcp.ConnectionClosed;
import akka.io.Tcp.Event;
import akka.io.Tcp.Received;
import akka.io.TcpMessage;
import akka.japi.Procedure;
import akka.util.ByteString;
//#simple-echo-handler
public class SimpleEchoHandler extends UntypedActor {
final LoggingAdapter log = Logging
.getLogger(getContext().system(), getSelf());
final ActorRef connection;
final InetSocketAddress remote;
public static final long maxStored = 100000000;
public static final long highWatermark = maxStored * 5 / 10;
public static final long lowWatermark = maxStored * 2 / 10;
public SimpleEchoHandler(ActorRef connection, InetSocketAddress remote) {
this.connection = connection;
this.remote = remote;
// sign death pact: this actor stops when the connection is closed
getContext().watch(connection);
}
@Override
public void onReceive(Object msg) throws Exception {
if (msg instanceof Received) {
final ByteString data = ((Received) msg).data();
buffer(data);
connection.tell(TcpMessage.write(data, ACK), getSelf());
// now switch behavior to “waiting for acknowledgement”
getContext().become(buffering, false);
} else if (msg instanceof ConnectionClosed) {
getContext().stop(getSelf());
}
}
private final Procedure<Object> buffering = new Procedure<Object>() {
@Override
public void apply(Object msg) throws Exception {
if (msg instanceof Received) {
buffer(((Received) msg).data());
} else if (msg == ACK) {
acknowledge();
} else if (msg instanceof ConnectionClosed) {
if (((ConnectionClosed) msg).isPeerClosed()) {
closing = true;
} else {
// could also be ErrorClosed, in which case we just give up
getContext().stop(getSelf());
}
}
}
};
//#storage-omitted
public void postStop() {
log.info("transferred {} bytes from/to [{}]", transferred, remote);
}
private long transferred;
private long stored = 0;
private Queue<ByteString> storage = new LinkedList<ByteString>();
private boolean suspended = false;
private boolean closing = false;
private final Event ACK = new Event() {};
//#simple-helpers
protected void buffer(ByteString data) {
storage.add(data);
stored += data.size();
if (stored > maxStored) {
log.warning("drop connection to [{}] (buffer overrun)", remote);
getContext().stop(getSelf());
} else if (stored > highWatermark) {
log.debug("suspending reading");
connection.tell(TcpMessage.suspendReading(), getSelf());
suspended = true;
}
}
protected void acknowledge() {
final ByteString acked = storage.remove();
stored -= acked.size();
transferred += acked.size();
if (suspended && stored < lowWatermark) {
log.debug("resuming reading");
connection.tell(TcpMessage.resumeReading(), getSelf());
suspended = false;
}
if (storage.isEmpty()) {
if (closing) {
getContext().stop(getSelf());
} else {
getContext().unbecome();
}
} else {
connection.tell(TcpMessage.write(storage.peek(), ACK), getSelf());
}
}
//#simple-helpers
//#storage-omitted
}
//#simple-echo-handler