/*
 * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
 * or more contributor license agreements. Licensed under the Elastic License
 * 2.0 and the Server Side Public License, v 1; you may not use this file except
 * in compliance with, at your election, the Elastic License 2.0 or the Server
 * Side Public License, v 1.
 *
 * ============================================================================
 *
 * Copyright 2012 The Netty Project
 *
 * The Netty 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 org.elasticsearch.transport.netty4;

import io.netty.channel.socket.nio.NioServerSocketChannel;
import io.netty.util.internal.SocketUtils;

import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;

import java.nio.channels.SocketChannel;
import java.util.List;

/**
 * This class is adapted from {@link NioServerSocketChannel} class in the Netty project. It overrides the
 * channel read messages behavior to ensure that a {@link CopyBytesSocketChannel} socket channel is created.
 */
public class CopyBytesServerSocketChannel extends NioServerSocketChannel {

    private static final Logger logger = LogManager.getLogger(CopyBytesServerSocketChannel.class);

    @Override
    protected int doReadMessages(List<Object> buf) throws Exception {
        SocketChannel ch = SocketUtils.accept(javaChannel());

        try {
            if (ch != null) {
                buf.add(new CopyBytesSocketChannel(this, ch));
                return 1;
            }
        } catch (Throwable t) {
            logger.warn("Failed to create a new channel from an accepted socket.", t);

            try {
                ch.close();
            } catch (Throwable t2) {
                logger.warn("Failed to close a socket.", t2);
            }
        }

        return 0;
    }
}
