DefaultServiceRegistry.java

/*
 * Copyright (c) 2016 Couchbase, 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 com.couchbase.client.core.node;

import com.couchbase.client.core.message.CouchbaseRequest;
import com.couchbase.client.core.message.analytics.AnalyticsRequest;
import com.couchbase.client.core.message.config.ConfigRequest;
import com.couchbase.client.core.message.dcp.DCPRequest;
import com.couchbase.client.core.message.kv.BinaryRequest;
import com.couchbase.client.core.message.query.QueryRequest;
import com.couchbase.client.core.message.search.SearchRequest;
import com.couchbase.client.core.message.view.ViewRequest;
import com.couchbase.client.core.service.BucketServiceMapping;
import com.couchbase.client.core.service.Service;
import com.couchbase.client.core.service.ServiceType;

import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;

/**
 * The default implementation of a {@link ServiceRegistry}.
 */
public class DefaultServiceRegistry implements ServiceRegistry {

    /**
     * Contains services which work across buckets.
     */
    private final Map<ServiceType, Service> globalServices;

    /**
     * Contains bucket-local services.
     */
    private final Map<String, Map<ServiceType, Service>> localServices;

    private volatile Service[] serviceCache;

    /**
     * Create a new {@link DefaultServiceRegistry} with custom containers.
     *
     * This constructor is intended to be used for unit tests only.
     *
     * @param globalServices the global service set.
     * @param localServices the bucket-local services.
     */
    DefaultServiceRegistry(final Map<ServiceType, Service> globalServices,
        final Map<String, Map<ServiceType, Service>> localServices) {
        this.globalServices = globalServices;
        this.localServices = localServices;
        this.serviceCache = new Service[] {};
    }

    /**
     * Create a new {@link DefaultServiceRegistry}.
     */
    public DefaultServiceRegistry() {
        this(new ConcurrentHashMap<ServiceType, Service>(), new ConcurrentHashMap<String, Map<ServiceType, Service>>());
    }

    @Override
    public Service addService(final Service service, final String bucket) {
        if (service.mapping() == BucketServiceMapping.ONE_BY_ONE) {
            if (!localServices.containsKey(bucket)) {
                localServices.put(bucket, new ConcurrentHashMap<ServiceType, Service>());
            }
            if (!localServices.get(bucket).containsKey(service.type())) {
                localServices.get(bucket).put(service.type(), service);
            }
        } else {
            if (!globalServices.containsKey(service.type())) {
                globalServices.put(service.type(), service);
            }
        }
        recalculateServiceCache();
        return service;
    }

    @Override
    public Service removeService(final Service service, final String bucket) {
        if (service.mapping() == BucketServiceMapping.ONE_BY_ONE) {
            if (localServices.containsKey(bucket) && localServices.get(bucket).containsKey(service.type())) {
                localServices.get(bucket).remove(service.type());
            }
            if (localServices.get(bucket).isEmpty()) {
                localServices.remove(bucket);
            }
        } else {
            if (globalServices.containsKey(service.type())) {
                globalServices.remove(service.type());
            }
        }
        recalculateServiceCache();
        return service;
    }

    @Override
    public Service locate(final CouchbaseRequest request) {
        ServiceType type = serviceTypeFor(request);
        if (type.mapping() == BucketServiceMapping.ONE_BY_ONE) {
            Map<ServiceType, Service> services = localServices.get(request.bucket());
            if (services == null) {
                return null;
            }
            return services.get(type);
        } else {
            return globalServices.get(type);
        }
    }

    @Override
    public Service[] services() {
        return serviceCache;
    }

    private void recalculateServiceCache() {
        List<Service> services = new ArrayList<Service>();
        for (Service service : globalServices.values()) {
            services.add(service);
        }
        for (Map<ServiceType, Service> bucket : localServices.values()) {
            for (Service service : bucket.values()) {
                services.add(service);
            }
        }
        serviceCache = services.toArray(new Service[services.size()]);
    }

    @Override
    public Service serviceBy(final ServiceType type, final String bucket) {
        if (type.mapping() == BucketServiceMapping.ONE_BY_ONE) {
            if (localServices.get(bucket) == null) {
                return null;
            }
            return localServices.get(bucket).get(type);
        } else {
            return globalServices.get(type);
        }
    }

    /**
     * Returns the mapping for a given {@link CouchbaseRequest}.
     *
     * @param request the request to check.
     * @return the mapping for the request.
     */
    private static ServiceType serviceTypeFor(final CouchbaseRequest request) {
        if (request instanceof BinaryRequest) {
            return ServiceType.BINARY;
        } else if (request instanceof ConfigRequest) {
            return ServiceType.CONFIG;
        } else if (request instanceof ViewRequest) {
            return ServiceType.VIEW;
        } else if (request instanceof QueryRequest) {
            return ServiceType.QUERY;
        } else if (request instanceof DCPRequest) {
            return ServiceType.DCP;
        } else if (request instanceof SearchRequest) {
            return ServiceType.SEARCH;
        } else if (request instanceof AnalyticsRequest) {
            return ServiceType.ANALYTICS;
        } else {
            throw new IllegalStateException("Unknown Request: " + request);
        }
    }

    @Override
    public String toString() {
        return "DefaultServiceRegistry{"
            + "globalServices=" + globalServices
            + ", localServices=" + localServices
            + ", serviceCache=" + serviceCache
            + '}';
    }
}