org.springframework.cloud.stream.binder.pubsub.BatchingPubSubMessageHandler.java Source code

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Here is the source code for org.springframework.cloud.stream.binder.pubsub.BatchingPubSubMessageHandler.java

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/*
 *  Copyright 2016 original author or authors.
 *
 *  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.springframework.cloud.stream.binder.pubsub;

import java.time.Duration;
import java.util.List;

import com.fasterxml.jackson.databind.ObjectMapper;
import com.google.cloud.ByteArray;
import com.google.cloud.pubsub.TopicInfo;
import reactor.core.Cancellation;
import reactor.core.publisher.WorkQueueProcessor;
import reactor.core.scheduler.Schedulers;

import org.springframework.cloud.stream.binder.BinderHeaders;
import org.springframework.cloud.stream.binder.ExtendedProducerProperties;
import org.springframework.cloud.stream.binder.pubsub.support.GroupedMessage;
import org.springframework.cloud.stream.binder.pubsub.support.PubSubBinder;
import org.springframework.cloud.stream.binder.pubsub.support.PubSubMessage;
import org.springframework.messaging.Message;

/**
 * @author Vinicius Carvalho
 */
public class BatchingPubSubMessageHandler extends PubSubMessageHandler {

    private WorkQueueProcessor<PubSubMessage> processor;
    private Integer concurrency;
    private Cancellation processorCancellation;

    public BatchingPubSubMessageHandler(PubSubResourceManager resourceManager,
            ExtendedProducerProperties<PubSubProducerProperties> producerProperties, List<TopicInfo> topics) {
        super(resourceManager, producerProperties, topics);
        this.processor = WorkQueueProcessor.share(true);
    }

    @Override
    protected void handleMessageInternal(Message<?> message) throws Exception {
        PubSubMessage pubSubMessage = convert(message);
        processor.onNext(pubSubMessage);
    }

    @Override
    public void start() {
        if (this.concurrency == null) {
            // We are assuming Brian Goetz (http://www.ibm.com/developerworks/java/library/j-jtp0730/index.html) cores * 1 + (1 + wait/service) and that http wait is taking 2x more than service
            this.concurrency = Runtime.getRuntime().availableProcessors() * 3;
        }
        this.processorCancellation = processor.groupBy(PubSubMessage::getTopic)
                .flatMap(group -> group.map(pubSubMessage -> {
                    return pubSubMessage.getMessage();
                }).buffer(producerProperties.getExtension().getBatchSize(),
                        Duration.ofMillis(producerProperties.getExtension().getWindowSize())).map(messages -> {
                            return new GroupedMessage(group.key(), messages);
                        }))
                .parallel(concurrency).runOn(Schedulers.elastic()).doOnNext(groupedMessage -> {
                    logger.info("Dispatching messages");
                    resourceManager.publishMessages(groupedMessage);
                }).sequential().publishOn(Schedulers.elastic()).subscribe();
        running = true;
    }

    public Integer getConcurrency() {
        return concurrency;
    }

    public void setConcurrency(Integer concurrency) {
        if (concurrency != null && concurrency > 0) {
            this.concurrency = Math.min(8 * Runtime.getRuntime().availableProcessors(), concurrency);
        }
    }

    @Override
    public void stop() {
        processorCancellation.dispose();
        running = false;
    }

    @Override
    public boolean isRunning() {
        return running;
    }
}