at.ac.univie.isc.asio.brood.Catalog.java Source code

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Here is the source code for at.ac.univie.isc.asio.brood.Catalog.java

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/*
 * #%L
 * asio server
 * %%
 * Copyright (C) 2013 - 2015 Research Group Scientific Computing, University of Vienna
 * %%
 * 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.
 * #L%
 */
package at.ac.univie.isc.asio.brood;

import at.ac.univie.isc.asio.Container;
import at.ac.univie.isc.asio.Id;
import at.ac.univie.isc.asio.Scope;
import at.ac.univie.isc.asio.insight.Emitter;
import com.google.common.annotations.VisibleForTesting;
import com.google.common.base.Optional;
import org.slf4j.Logger;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;

import java.util.HashMap;
import java.util.HashSet;
import java.util.Iterator;
import java.util.Map;
import java.util.Set;

import static java.util.Objects.requireNonNull;
import static org.slf4j.LoggerFactory.getLogger;

/**
 * Central registry to look up and manage deployed {@link Container}.
 * Adding or removing a container will trigger {@code Deployed} and {@code Dropped} events
 * respectively.
 */
@Component
/* final */ class Catalog {
    private static final Logger log = getLogger(Catalog.class);

    private final Map<Id, Container> catalog;
    private final Emitter events;

    @Autowired
    public Catalog(final Emitter events) {
        catalog = new HashMap<>();
        this.events = events;
    }

    // === public api ================================================================================

    /**
     * Add the given container to this catalog, replacing any schema with the same name.
     *
     * @param container schema that will be deployed
     * @return the replaced schema if one existed
     */
    public Optional<Container> deploy(final Container container) {
        log.debug(Scope.SYSTEM.marker(), "deploy {} as <{}>", container, container.name());
        requireNonNull(container);
        final Optional<Container> former = Optional.fromNullable(catalog.put(container.name(), container));
        if (former.isPresent()) {
            events.emit(dropEvent(former.get()));
        }
        events.emit(deployEvent(container));
        return former;
    }

    /**
     * Remove the schema with the given name from this catalog if one is present.
     *
     * @param id name of the schema that will be dropped
     * @return the removed schema if one existed
     */
    public Optional<Container> drop(final Id id) {
        log.debug(Scope.SYSTEM.marker(), "drop <{}>", id);
        final Optional<Container> removed = Optional.fromNullable(catalog.remove(id));
        if (removed.isPresent()) {
            events.emit(dropEvent(removed.get()));
        }
        return removed;
    }

    /**
     * {@link #drop(Id) Drop} all present containers.
     *
     * @return all container that were present when closing
     */
    Set<Container> clear() {
        log.info(Scope.SYSTEM.marker(), "clear - dropping all of {}", catalog.keySet());
        final Set<Container> dropped = new HashSet<>();
        final Iterator<Container> present = catalog.values().iterator();
        while (present.hasNext()) {
            final Container next = present.next();
            events.emit(dropEvent(next));
            dropped.add(next);
            present.remove();
        }
        return dropped;
    }

    // === helper ====================================================================================

    private ContainerEvent.Deployed deployEvent(final Container schema) {
        return new ContainerEvent.Deployed(schema);
    }

    private ContainerEvent.Dropped dropEvent(final Container schema) {
        return new ContainerEvent.Dropped(schema);
    }

    @VisibleForTesting
    Map<Id, Container> internal() {
        return catalog;
    }
}