/*
 * Copyright (c) 2009, 2020 Oracle and/or its affiliates. All rights reserved.
 *
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Public License v. 2.0, which is available at
 * http://www.eclipse.org/legal/epl-2.0.
 *
 * This Source Code may also be made available under the following Secondary
 * Licenses when the conditions for such availability set forth in the
 * Eclipse Public License v. 2.0 are satisfied: GNU General Public License,
 * version 2 with the GNU Classpath Exception, which is available at
 * https://www.gnu.org/software/classpath/license.html.
 *
 * SPDX-License-Identifier: EPL-2.0 OR GPL-2.0 WITH Classpath-exception-2.0
 */

package org.glassfish.grizzly.strategies;

import java.io.IOException;
import java.util.concurrent.Executor;
import java.util.logging.Logger;

import org.glassfish.grizzly.Connection;
import org.glassfish.grizzly.Grizzly;
import org.glassfish.grizzly.IOEvent;
import org.glassfish.grizzly.IOEventLifeCycleListener;
import org.glassfish.grizzly.Processor;

IOStrategy, which executes Processors in worker thread. 
Author:
Alexey Stashok/**
 * {@link org.glassfish.grizzly.IOStrategy}, which executes {@link Processor}s in worker thread.
 *
 * @author Alexey Stashok
 */
public final class WorkerThreadIOStrategy extends AbstractIOStrategy {

    private static final WorkerThreadIOStrategy INSTANCE = new WorkerThreadIOStrategy();

    private static final Logger logger = Grizzly.logger(WorkerThreadIOStrategy.class);

    // ------------------------------------------------------------ Constructors

    private WorkerThreadIOStrategy() {
    }

    // ---------------------------------------------------------- Public Methods

    public static WorkerThreadIOStrategy getInstance() {
        return INSTANCE;
    }

    // ------------------------------------------------- Methods from IOStrategy

    @Override
    public boolean executeIoEvent(final Connection connection, final IOEvent ioEvent, final boolean isIoEventEnabled) throws IOException {

        final boolean isReadOrWriteEvent = isReadWrite(ioEvent);

        final IOEventLifeCycleListener listener;
        if (isReadOrWriteEvent) {
            if (isIoEventEnabled) {
                connection.disableIOEvent(ioEvent);
            }

            listener = ENABLE_INTEREST_LIFECYCLE_LISTENER;
        } else {
            listener = null;
        }

        final Executor threadPool = getThreadPoolFor(connection, ioEvent);
        if (threadPool != null) {
            threadPool.execute(new WorkerThreadRunnable(connection, ioEvent, listener));
        } else {
            run0(connection, ioEvent, listener);
        }

        return true;
    }

    // --------------------------------------------------------- Private Methods

    private static void run0(final Connection connection, final IOEvent ioEvent, final IOEventLifeCycleListener lifeCycleListener) {

        fireIOEvent(connection, ioEvent, lifeCycleListener, logger);

    }

    private static final class WorkerThreadRunnable implements Runnable {
        final Connection connection;
        final IOEvent ioEvent;
        final IOEventLifeCycleListener lifeCycleListener;

        private WorkerThreadRunnable(final Connection connection, final IOEvent ioEvent, final IOEventLifeCycleListener lifeCycleListener) {
            this.connection = connection;
            this.ioEvent = ioEvent;
            this.lifeCycleListener = lifeCycleListener;

        }

        @Override
        public void run() {
            run0(connection, ioEvent, lifeCycleListener);
        }
    }

}