hop-2012/java/hop/NodeContainer.java

103 lines
2.8 KiB
Java

/*
* Copyright (c) 2011 Tony Garnock-Jones. All rights reserved.
*/
package hop;
import java.io.Flushable;
import java.io.IOException;
import java.lang.ref.WeakReference;
import java.util.*;
/**
*/
public class NodeContainer implements Flushable {
public String _name;
public Map<String, WeakReference<Node>> _directory;
public NodeContainer() {
this(UUID.randomUUID().toString());
}
public NodeContainer(String name) {
_name = name;
_directory = new Hashtable<String, WeakReference<Node>>();
}
public String getName() {
return _name;
}
public synchronized boolean bind(String name, Node n) {
WeakReference<Node> ref = _directory.get(name);
if (ref != null && ref.get() != null) {
return false;
}
ref = new WeakReference<Node>(n);
_directory.put(name, ref);
return true;
}
public synchronized boolean unbind(String name) {
if (!_directory.containsKey(name))
return false;
_directory.remove(name);
return true;
}
public void flush() throws IOException {
ArrayList<Flushable> fs = new ArrayList<Flushable>();
synchronized (this) {
for (Map.Entry<String, WeakReference<Node>> e : _directory.entrySet()) {
Node n = e.getValue().get();
if (n instanceof Flushable) {
fs.add((Flushable) n);
}
}
}
for (Flushable f : fs) {
f.flush();
}
}
public void flush(String name) throws IOException {
Flushable f;
synchronized (this) {
WeakReference<Node> ref = _directory.get(name);
if (ref == null) return;
Node n = ref.get();
if (n == null) return;
if (!(n instanceof Flushable)) return;
f = ((Flushable) n);
}
f.flush();
}
public synchronized void unbindReferencesTo(Node n) {
for (Map.Entry<String, WeakReference<Node>> e : _directory.entrySet()) {
if (e.getValue().get() == n) {
_directory.remove(e.getKey());
}
}
}
public synchronized Node lookup(String name) {
WeakReference<Node> r = _directory.get(name);
return (r == null) ? null : r.get();
}
public boolean post(String sink, Object name, Object message, Object token) {
return send(sink, SexpMessage.post(name, message, token));
}
public boolean send(String name, Object message) {
Node n = lookup(name);
if (n == null) {
System.err.println("Warning: sending to nonexistent node " + name + "; message " + message);
return false;
}
n.handle(message);
return true;
}
}