com.ushahidi.swiftriver.core.dropqueue.MetadataResponseHandler.java Source code

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Here is the source code for com.ushahidi.swiftriver.core.dropqueue.MetadataResponseHandler.java

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/**
 *  This program is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU Affero General Public License as
 *  published by the Free Software Foundation, either version 3 of the
 *  License, or (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU Affero General Public License for more details.
 *
 *  You should have received a copy of the GNU Affero General Public License
 *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
package com.ushahidi.swiftriver.core.dropqueue;

import java.util.Map;
import java.util.concurrent.BlockingQueue;

import org.codehaus.jackson.map.ObjectMapper;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.amqp.core.Message;
import org.springframework.amqp.rabbit.core.ChannelAwareMessageListener;
import org.springframework.util.ErrorHandler;

import com.rabbitmq.client.Channel;
import com.ushahidi.swiftriver.core.dropqueue.model.RawDrop;

/**
 * Handler for incoming drops from metadata extractors.
 * 
 * Update the in memory drops map with the response from the metadata
 * extractors.
 * 
 * Puts drops that have completed metadata extraction onto a publish queue for
 * posting to the SwiftRiver REST API.
 * 
 */
public class MetadataResponseHandler implements ChannelAwareMessageListener, ErrorHandler {

    final Logger logger = LoggerFactory.getLogger(MetadataResponseHandler.class);

    private ObjectMapper objectMapper;

    private Map<String, RawDrop> dropsMap;

    private BlockingQueue<RawDrop> publishQueue;

    private BlockingQueue<String> dropFilterQueue;

    private Map<String, DeliveryFrame> deliveryFramesMap;

    public void setObjectMapper(ObjectMapper objectMapper) {
        this.objectMapper = objectMapper;
    }

    public void setDropsMap(Map<String, RawDrop> dropsMap) {
        this.dropsMap = dropsMap;
    }

    public void setPublishQueue(BlockingQueue<RawDrop> publishQueue) {
        this.publishQueue = publishQueue;
    }

    public void setDropFilterQueue(BlockingQueue<String> dropFilterQueue) {
        this.dropFilterQueue = dropFilterQueue;
    }

    public void setDeliveryFramesMap(Map<String, DeliveryFrame> deliveryFramesMap) {
        this.deliveryFramesMap = deliveryFramesMap;
    }

    /**
     * Receive drop that has completed metadata extraction.
     * 
     * Updates the locally cached drop with received metadata. 
     * Drops that have completed both media and sematic extraction
     * get added to the publishQueue for posting to the API.
     * 
     * @param message
     * @param channel
     * @throws Exception
     */
    public void onMessage(Message message, Channel channel) throws Exception {
        String correlationId = new String(message.getMessageProperties().getCorrelationId());
        RawDrop updatedDrop = objectMapper.readValue(new String(message.getBody()), RawDrop.class);

        logger.info("Metadata Response received from '{}' with correlation_id '{}'", updatedDrop.getSource(),
                correlationId);

        synchronized (dropsMap) {
            RawDrop cachedDrop = dropsMap.get(correlationId);

            // Verify that the drop exists in the in-memory cache
            if (cachedDrop == null) {
                logger.error("Drop with correlation id '{}' not found in cache", correlationId);

                // Acknowledge receipt
                channel.basicAck(message.getMessageProperties().getDeliveryTag(), false);
                return;
            }

            if (updatedDrop.getSource().equals("mediaextractor")) {
                cachedDrop.setMediaComplete(true);
                cachedDrop.setMedia(updatedDrop.getMedia());
                cachedDrop.setLinks(updatedDrop.getLinks());
            } else if (updatedDrop.getSource().equals("semantics")) {
                cachedDrop.setSemanticsComplete(true);
                cachedDrop.setTags(updatedDrop.getTags());
                cachedDrop.setPlaces(updatedDrop.getPlaces());
            } else if (updatedDrop.getSource().equals("rules")) {
                cachedDrop.setBucketIds(updatedDrop.getBucketIds());
                cachedDrop.setRiverIds(updatedDrop.getRiverIds());
                cachedDrop.setMarkAsRead(updatedDrop.getMarkAsRead());
                cachedDrop.setRulesComplete(true);
            }

            // When semantics and metadata extraction are complete,
            // submit for rules processing
            if (cachedDrop.isSemanticsComplete() && cachedDrop.isMediaComplete()) {
                logger.info("Sending drop with correlation id '{}' for rules processing", correlationId);
                dropFilterQueue.put(correlationId);
            }

            if (cachedDrop.isSemanticsComplete() && cachedDrop.isMediaComplete() && cachedDrop.isRulesComplete()) {

                // Queue the drop for posting via the API
                if (cachedDrop.getRiverIds() != null && !cachedDrop.getRiverIds().isEmpty()) {
                    publishQueue.put(cachedDrop);
                } else {
                    logger.info("No destination rivers for drop with correlation id '{}'", correlationId);
                }

                dropsMap.remove(correlationId);

                // Confirm the drop has completed processing
                DeliveryFrame deliveryFrame = deliveryFramesMap.remove(correlationId);
                Channel confirmChannel = deliveryFrame.getChannel();
                confirmChannel.basicAck(deliveryFrame.getDeliveryTag(), false);

                // Log
                logger.info("Drop with correlation id '{}' has completed metadata extraction", correlationId);
            }
        }
    }

    public void handleError(Throwable t) {
        logger.error("Metadata response error", t);
    }

}