components/camel-salesforce/camel-salesforce-component/src/main/java/org/apache/camel/component/salesforce/internal/streaming/CometDReplayExtension.java

/**
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF 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.apache.camel.component.salesforce.internal.streaming;

import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentMap;
import java.util.concurrent.atomic.AtomicBoolean;

import org.cometd.bayeux.Channel;
import org.cometd.bayeux.Message;
import org.cometd.bayeux.client.ClientSession;
import org.cometd.bayeux.client.ClientSession.Extension.Adapter;

/**
 * CometDReplayExtension, typical usages are the following:
 * {@code client.addExtension(new CometDReplayExtension<>(replayMap));}
 *
 * @author yzhao
 * @since 198 (Winter '16)
 */
public class CometDReplayExtension<V> extends Adapter {
    private static final String EXTENSION_NAME = "replay";
    private final ConcurrentMap<String, V> dataMap = new ConcurrentHashMap<>();
    private final AtomicBoolean supported = new AtomicBoolean();

    public CometDReplayExtension(Map<String, V> dataMap) {
        this.dataMap.putAll(dataMap);
    }

    @Override
    @SuppressWarnings("unchecked")
    public boolean rcv(ClientSession session, Message.Mutable message) {
        Object data = message.get(EXTENSION_NAME);
        if (this.supported.get() && data != null) {
            try {
                dataMap.put(message.getChannel(), (V) data);
            } catch (ClassCastException e) {
                return false;
            }
        }
        return true;
    }

    @Override
    public boolean rcvMeta(ClientSession session, Message.Mutable message) {
        switch (message.getChannel()) {
        case Channel.META_HANDSHAKE:
            Map<String, Object> ext = message.getExt(false);
            this.supported.set(ext != null && Boolean.TRUE.equals(ext.get(EXTENSION_NAME)));
            break;
        default:
            break;
        }
        return true;
    }

    @Override
    public boolean sendMeta(ClientSession session, Message.Mutable message) {
        switch (message.getChannel()) {
        case Channel.META_HANDSHAKE:
            message.getExt(true).put(EXTENSION_NAME, Boolean.TRUE);
            break;
        case Channel.META_SUBSCRIBE:
            if (supported.get()) {
                message.getExt(true).put(EXTENSION_NAME, dataMap);
            }
            break;
        default:
            break;
        }
        return true;
    }
}