Subversion Repositories splitter

/*
 * Copyright (c) 2016, Gerd Petermann
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 3 as
 * published by the Free Software Foundation.
 *
 * 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
 * General Public License for more details.
 */

package uk.me.parabola.splitter;

import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.BlockingQueue;

import uk.me.parabola.splitter.OSMMessage.Type;

/**
 * Simple helper to allow all existing processors to use the producer/consumer
 * pattern. For each call of a supplier (one of the OSM parsers) it either
 * passes the call to the original processor or adds messages to the queue..
 *
 * @author Gerd Petermann
 *
 */
public class QueueProcessor extends AbstractMapProcessor {
        private final BlockingQueue<OSMMessage> queue;
        private final MapProcessor realProcessor;

        public QueueProcessor(BlockingQueue<OSMMessage> queue, MapProcessor realProcessor) {
                this.queue = queue;
                this.realProcessor = realProcessor;
        }

        @Override
        public boolean skipTags() {
                return realProcessor.skipTags();
        }

        @Override
        public boolean skipNodes() {
                return realProcessor.skipNodes();
        }

        @Override
        public boolean skipWays() {
                return realProcessor.skipWays();
        }

        @Override
        public boolean skipRels() {
                return realProcessor.skipRels();
        }

        @Override
        public void boundTag(Area bounds) {
                addToQueue(bounds);
        }

        @Override
        public void processNode(Node n) {
                addToQueue(n);
        }

        @Override
        public void processWay(Way w) {
                addToQueue(w);
        }

        @Override
        public void processRelation(Relation r) {
                addToQueue(r);
        }

        @Override
        public void startFile() {
                try {
                        flush();
                        queue.put(new OSMMessage(Type.START_FILE));
                } catch (InterruptedException e) {
                        throw new RuntimeException(e);
                }
        }
       
        @Override      
        public boolean endMap() {
                try {
                        flush();
                        queue.put(new OSMMessage(Type.END_MAP));
                } catch (InterruptedException e) {
                        throw new RuntimeException(e);
                }
                return true;
        }

        public int getPhase() {
                throw new UnsupportedOperationException("call getPhase() of real processor");
        }

        /** number of OSM elements to collect before adding them to the queue */
        private static final int NUM_STAGING = 1000;
        private List<Element> staging = new ArrayList<>(NUM_STAGING);

        private void addToQueue(Element el) {
                try {
                        staging.add(el);
                        if (staging.size() >= NUM_STAGING)
                                flush();
                } catch (InterruptedException e) {
                        throw new RuntimeException(e);
                }
        }

        private void addToQueue(Area bounds) {
                try {
                        flush();
                        queue.put(new OSMMessage(bounds));
                } catch (InterruptedException e) {
                        throw new RuntimeException(e);
                }
        }

        private void flush() throws InterruptedException {
                if (staging == null || staging.isEmpty())
                        return;
                queue.put(new OSMMessage(staging));
                staging = new ArrayList<>(NUM_STAGING);
        }
}