SystemStateResultFactory.java

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/*
 * Copyright (C) 2012 Google Inc.
 * 
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not
 * use this file except in compliance with the License. You may obtain a copy of
 * the License at
 * 
 * http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations under
 * the License.
 */

package org.ros.internal.node.response;

import com.google.common.collect.Maps;
import com.google.common.collect.Sets;

import org.ros.master.client.SystemState;
import org.ros.master.client.TopicSystemState;

import java.util.Arrays;
import java.util.HashSet;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Set;

public class SystemStateResultFactory implements ResultFactory<SystemState> {

        @Override
        public SystemState newFromValue(Object value) {
                Object[] vals = (Object[]) value;

                Map<String, Set<String>> publisherMap = getPublishers(vals[0]);
                Map<String, Set<String>> subscriberMap = getSubscribers(vals[1]);

                Map<String, TopicSystemState> topics = Maps.newHashMap();

                for (Entry<String, Set<String>> publisherData : publisherMap.entrySet()) {
                        String topicName = publisherData.getKey();

                        Set<String> subscriberNodes = subscriberMap.remove(topicName);

                        // Return empty lists if no subscribers
                        if (subscriberNodes == null) {
                                subscriberNodes = Sets.newHashSet();
                        }

                        topics.put(topicName,
                                        new TopicSystemState(topicName, publisherData.getValue(),
                                                        subscriberNodes));
                }

                for (Entry<String, Set<String>> subscriberData : subscriberMap
                                .entrySet()) {
                        // At this point there are no publishers with the same topic name
                        HashSet<String> noPublishers = Sets.newHashSet();
                        String topicName = subscriberData.getKey();
                        topics.put(topicName, new TopicSystemState(topicName,
                                        noPublishers, subscriberData.getValue()));
                }

                // TODO(keith): Get service state in here.

                return new SystemState(topics.values());
        }

        private Map<String, Set<String>> getPublishers(Object pubPairs) {
                Map<String, Set<String>> topicToPublishers = Maps.newHashMap();

                for (Object topicData : Arrays.asList((Object[]) pubPairs)) {
                        String topicName = (String) ((Object[]) topicData)[0];

                        Set<String> publishers =Sets.newHashSet();
                        Object[] publisherData = (Object[])((Object[]) topicData)[1];
                        for (Object publisher : publisherData) {
                                publishers.add(publisher.toString());
                        }

                        topicToPublishers.put(topicName, publishers);
                }

                return topicToPublishers;
        }

        private Map<String, Set<String>> getSubscribers(Object subPairs) {
                Map<String, Set<String>> topicToSubscribers = Maps.newHashMap();

                for (Object topicData : Arrays.asList((Object[]) subPairs)) {
                        String topicName = (String) ((Object[]) topicData)[0];

                        Set<String> subscribers =Sets.newHashSet();
                        Object[] subscriberData = (Object[])((Object[]) topicData)[1];
                        for (Object subscriber : subscriberData) {
                                subscribers.add(subscriber.toString());
                        }

                        topicToSubscribers.put(topicName, subscribers);
                }

                return topicToSubscribers;
        }
}