1 files changed, 221 insertions, 0 deletions
diff --git a/src/com/isode/stroke/disco/DiscoServiceWalker.java b/src/com/isode/stroke/disco/DiscoServiceWalker.java
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+++ b/src/com/isode/stroke/disco/DiscoServiceWalker.java
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+/*
+ * Copyright (c) 2010 Isode Limited.
+ * All rights reserved.
+ * See the COPYING file for more information.
+ */
+/*
+ * Copyright (c) 2015 Tarun Gupta.
+ * Licensed under the simplified BSD license.
+ * See Documentation/Licenses/BSD-simplified.txt for more information.
+ */
+
+package com.isode.stroke.disco;
+
+import com.isode.stroke.jid.JID;
+import com.isode.stroke.elements.DiscoInfo;
+import com.isode.stroke.elements.DiscoItems;
+import com.isode.stroke.elements.ErrorPayload;
+import com.isode.stroke.disco.GetDiscoInfoRequest;
+import com.isode.stroke.disco.GetDiscoItemsRequest;
+import com.isode.stroke.queries.IQRouter;
+import com.isode.stroke.signals.Signal;
+import com.isode.stroke.signals.Slot2;
+import com.isode.stroke.signals.Signal2;
+import com.isode.stroke.signals.SignalConnection;
+import com.isode.stroke.base.NotNull;
+import java.util.logging.Logger;
+import java.util.HashSet;
+import java.util.Set;
+import com.isode.stroke.base.NotNull;
+
+/**
+ * Recursively walk service discovery trees to find all services offered.
+ * This stops on any disco item that's not reporting itself as a server.
+ */
+public class DiscoServiceWalker {
+
+	private JID service_;
+	private IQRouter iqRouter_;
+	private long maxSteps_;
+	private boolean active_;
+	private Set<JID> servicesBeingSearched_ = new HashSet<JID>();
+	private Set<JID> searchedServices_ = new HashSet<JID>();
+	private Set<GetDiscoInfoRequest> pendingDiscoInfoRequests_ = new HashSet<GetDiscoInfoRequest>();
+	private Set<GetDiscoItemsRequest> pendingDiscoItemsRequests_ = new HashSet<GetDiscoItemsRequest>();
+	private Logger logger_ = Logger.getLogger(this.getClass().getName());
+	private SignalConnection onServiceFoundConnection;
+	private SignalConnection onWalkAbortedConnection;
+	private SignalConnection onWalkCompleteConnection;
+	private SignalConnection onResponseDiscoInfoConnection;
+	private SignalConnection onResponseDiscoItemsConnection;
+
+	/** Emitted for each service found. */
+	public final Signal2<JID, DiscoInfo> onServiceFound = new Signal2<JID, DiscoInfo>();
+
+	/** Emitted when walking is aborted. */
+	public final Signal onWalkAborted = new Signal();
+
+	/** Emitted when walking is complete.*/
+	public final Signal onWalkComplete = new Signal();
+
+	/**
+	* Parameterized Constructor.
+	* @param service, Not Null.
+	* @param iqRouter, Not Null.
+	*/
+	public DiscoServiceWalker(JID service, IQRouter iqRouter) {
+		this(service, iqRouter, 200);
+	}
+
+	/**
+	* Parameterized Constructor.
+	* @param service, Not Null.
+	* @param iqRouter, Not Null.
+	* @param maxSteps.
+	*/
+	public DiscoServiceWalker(JID service, IQRouter iqRouter, long maxSteps) {
+		NotNull.exceptIfNull(service, "service");
+		NotNull.exceptIfNull(iqRouter, "iqRouter");
+		this.service_ = service;
+		this.iqRouter_ = iqRouter;
+		this.maxSteps_ = maxSteps;
+		this.active_ = false;
+	}
+
+	/**
+	 * Start the walk.
+	 *
+	 * Call this exactly once.
+	 */
+	public void beginWalk() {
+		logger_.fine("Starting walk to " + service_ + "\n");
+		assert(!active_);
+		assert(servicesBeingSearched_.isEmpty());
+		active_ = true;
+		walkNode(service_);
+	}
+
+	/**
+	 * End the walk.
+	 */
+	public void endWalk() {
+		if (active_) {
+			logger_.fine("Ending walk to" + service_ + "\n");
+			for (GetDiscoInfoRequest request : pendingDiscoInfoRequests_) {
+				onResponseDiscoInfoConnection.disconnect();
+			}
+			for (GetDiscoItemsRequest request : pendingDiscoItemsRequests_) {
+				onResponseDiscoItemsConnection.disconnect();
+			}
+			active_ = false;
+			onWalkAborted.emit();
+		}		
+	}
+
+	public boolean isActive() {
+		return active_;
+	}
+
+	private void walkNode(JID jid) {
+		logger_.fine("Walking node" + jid + "\n");
+		servicesBeingSearched_.add(jid);
+		searchedServices_.add(jid);
+		final GetDiscoInfoRequest discoInfoRequest = GetDiscoInfoRequest.create(jid, iqRouter_);
+		onResponseDiscoInfoConnection = discoInfoRequest.onResponse.connect(new Slot2<DiscoInfo, ErrorPayload>() {
+
+			@Override
+			public void call(DiscoInfo info, ErrorPayload error) {
+				handleDiscoInfoResponse(info, error, discoInfoRequest);
+			}
+		});
+		pendingDiscoInfoRequests_.add(discoInfoRequest);
+		discoInfoRequest.send();
+	}
+
+	private void markNodeCompleted(JID jid) {
+		logger_.fine("Node completed " + jid + "\n");
+		servicesBeingSearched_.remove(jid);
+		/* All results are in */
+		if (servicesBeingSearched_.isEmpty()) {
+			active_ = false;
+			onWalkComplete.emit();
+		}
+		/* Check if we're on a rampage */
+		else if (searchedServices_.size() >= maxSteps_) {
+			active_ = false;
+			onWalkComplete.emit();
+		}
+	}
+
+	private void handleDiscoInfoResponse(DiscoInfo info, ErrorPayload error, GetDiscoInfoRequest request) {
+		/* If we got canceled, don't do anything */
+		if (!active_) {
+			return;
+		}
+
+		logger_.fine("Disco info response from " + request.getReceiver() + "\n");
+
+		pendingDiscoInfoRequests_.remove(request);
+		if (error != null) {
+			handleDiscoError(request.getReceiver(), error);
+			return;
+		}
+
+		boolean couldContainServices = false;
+		for (DiscoInfo.Identity identity : info.getIdentities()) {
+			if (identity.getCategory().equals("server")) {
+				couldContainServices = true;
+			}
+		}
+		boolean completed = false;
+		if (couldContainServices) {
+			final GetDiscoItemsRequest discoItemsRequest = GetDiscoItemsRequest.create(request.getReceiver(), iqRouter_);
+			onResponseDiscoItemsConnection = discoItemsRequest.onResponse.connect(new Slot2<DiscoItems, ErrorPayload>() {
+
+				@Override
+				public void call(DiscoItems item, ErrorPayload error) {
+					handleDiscoItemsResponse(item, error, discoItemsRequest);
+				}
+			});
+			pendingDiscoItemsRequests_.add(discoItemsRequest);
+			discoItemsRequest.send();
+		} else {
+			completed = true;
+		}
+		onServiceFound.emit(request.getReceiver(), info);
+		if (completed) {
+			markNodeCompleted(request.getReceiver());
+		}		
+	}
+
+	private void handleDiscoItemsResponse(DiscoItems items, ErrorPayload error, GetDiscoItemsRequest request) {
+		/* If we got canceled, don't do anything */
+		if (!active_) {
+			return;
+		}
+
+		logger_.fine("Received disco items from " + request.getReceiver() + "\n");
+		pendingDiscoItemsRequests_.remove(request);
+		if (error != null) {
+			handleDiscoError(request.getReceiver(), error);
+			return;
+		}
+		for (DiscoItems.Item item : items.getItems()) {
+			if (item.getNode().isEmpty()) {
+				/* Don't look at noded items. It's possible that this will exclude some services,
+				 * but I've never seen one in the wild, and it's an easy fix for not looping.
+				 */
+				if(!searchedServices_.contains(item.getJID())) {
+					logger_.fine("Received disco item " + item.getJID() + "\n");
+					walkNode(item.getJID());
+				}
+			}
+		}
+		markNodeCompleted(request.getReceiver());
+	}
+
+	private void handleDiscoError(JID jid, ErrorPayload error) {
+		logger_.fine("Disco error from " + jid + "\n");
+		markNodeCompleted(jid);
+	}
+}
+\ No newline at end of file