NoopChannelPool.java

/*
 *    Copyright (c) 2014-2024 AsyncHttpClient Project. All rights reserved.
 *
 *    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 org.asynchttpclient.channel;

import io.netty.channel.Channel;
import org.jspecify.annotations.Nullable;

import java.util.Collections;
import java.util.Map;
import java.util.function.Predicate;

/**
 * A {@link ChannelPool} implementation that doesn't pool anything.
 */
public enum NoopChannelPool implements ChannelPool {

    INSTANCE;

    /**
     * @return always false since this is a {@link NoopChannelPool}
     */
    @Override
    public boolean offer(Channel channel, Object partitionKey) {
        return false;
    }

    /**
     * @return always null since this is a {@link NoopChannelPool}
     */
    @Override
    public @Nullable Channel poll(Object partitionKey) {
        return null;
    }

    /**
     * @return always false since this is a {@link NoopChannelPool}
     */
    @Override
    public boolean removeAll(Channel channel) {
        return false;
    }

    /**
     * @return always true since this is a {@link NoopChannelPool}
     */
    @Override
    public boolean isOpen() {
        return true;
    }

    /**
     * Does nothing since this is a {@link NoopChannelPool}
     */
    @Override
    public void destroy() {
    }

    /**
     * Does nothing since this is a {@link NoopChannelPool}
     */
    @Override
    public void flushPartitions(Predicate<Object> predicate) {
    }

    /**
     * @return always {@link Collections#emptyMap()} since this is a {@link NoopChannelPool}
     */
    @Override
    public Map<String, Long> getIdleChannelCountPerHost() {
        return Collections.emptyMap();
    }
}