com.eincs.decanter.container.simple.route.SimpleRouter.java Source code

Introduction

Here is the source code for com.eincs.decanter.container.simple.route.SimpleRouter.java

Source

/*
 * Copyright 2012 The Decanter Project
 *
 * The Decanter Project licenses this file to you 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 com.eincs.decanter.container.simple.route;

import java.util.List;
import java.util.Map.Entry;
import java.util.concurrent.ExecutionException;

import com.eincs.decanter.message.DecanterRequest;
import com.google.common.cache.CacheBuilder;
import com.google.common.cache.CacheLoader;
import com.google.common.cache.LoadingCache;
import com.google.common.collect.ArrayListMultimap;
import com.google.common.collect.Lists;
import com.google.common.collect.Multimap;

/**
 * @author Jung-Haeng Lee
 */
public class SimpleRouter implements Router {

    private final LoadingCache<SimpleRouteServiceId, RouteResult> resultCache;
    private Multimap<SimpleRouteServiceId, SimpleRouteService> services;

    public SimpleRouter() {
        resultCache = CacheBuilder.newBuilder().build(new SimpleRouterCacheLoader());
        services = ArrayListMultimap.create();
    }

    @Override
    public RouteResult route(DecanterRequest request) throws RouteException {
        SimpleRouteServiceId serviceId = SimpleRouteServiceId.create(request);
        try {
            if (services.containsKey(serviceId)) {
                return resultCache.get(serviceId);
            } else {
                // return empty result directly when there is no possibility of
                // cache hit (no negative caching)
                return SimpleRouteResult.EMPTY_RESULT;
            }
        } catch (ExecutionException e) {
            throw new RouteException(e);
        }
    }

    @Override
    public void add(Object serviceObj) throws RouteReflectException {
        Multimap<SimpleRouteServiceId, SimpleRouteService> newServices = SimpleRouteService
                .createServices(serviceObj);
        services.putAll(newServices);
        resultCache.invalidateAll();
    }

    @Override
    public void remove(Object serviceObj) throws RouteReflectException {
        Multimap<SimpleRouteServiceId, SimpleRouteService> newServices = SimpleRouteService
                .createServices(serviceObj);
        for (Entry<SimpleRouteServiceId, SimpleRouteService> entry : newServices.entries()) {
            services.remove(entry.getKey(), entry.getValue());
        }
        resultCache.invalidateAll();
    }

    @Override
    public void clear() {
        services.clear();
    }

    /**
     * @author Jung-Haeng Lee
     */
    private class SimpleRouterCacheLoader extends CacheLoader<SimpleRouteServiceId, RouteResult> {

        @Override
        public RouteResult load(SimpleRouteServiceId key) throws Exception {
            List<RouteService> resultServices = Lists.newArrayList();
            resultServices.addAll(services.get(key));
            SimpleRouteResult result = new SimpleRouteResult(resultServices);
            return result;
        }

    }

}