压缩消息

namespace g = ::google::cloud;
namespace pubsub = ::google::cloud::pubsub;
[](std::string project_id, std::string topic_id) {
  auto topic = pubsub::Topic(std::move(project_id), std::move(topic_id));
  auto publisher = pubsub::Publisher(pubsub::MakePublisherConnection(
      std::move(topic),
      g::Options{}
          // Compress any batch of messages over 10 bytes. By default, no
          // messages are compressed, set this to 0 to compress all batches,
          // regardless of their size.
          .set<pubsub::CompressionThresholdOption>(10)
          // Compress using the GZIP algorithm. By default, the library uses
          // GRPC_COMPRESS_DEFLATE.
          .set<pubsub::CompressionAlgorithmOption>(GRPC_COMPRESS_GZIP)));
  auto message_id = publisher.Publish(
      pubsub::MessageBuilder{}.SetData("Hello World!").Build());
  auto done = message_id.then([](g::future<g::StatusOr<std::string>> f) {
    auto id = f.get();
    if (!id) throw std::move(id).status();
    std::cout << "Hello World! published with id=" << *id << "\n";
  });
  // Block until the message is published
  done.get();
}

import com.google.api.core.ApiFuture;
import com.google.cloud.pubsub.v1.Publisher;
import com.google.protobuf.ByteString;
import com.google.pubsub.v1.PubsubMessage;
import com.google.pubsub.v1.TopicName;
import java.io.IOException;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.TimeUnit;

public class PublishWithGrpcCompressionExample {
  public static void main(String... args) throws Exception {
    // TODO(developer): Replace these variables before running the sample.
    String projectId = "your-project-id";
    // Choose an existing topic.
    String topicId = "your-topic-id";

    publishWithGrpcCompressionExample(projectId, topicId);
  }

  public static void publishWithGrpcCompressionExample(String projectId, String topicId)
      throws IOException, ExecutionException, InterruptedException {
    TopicName topicName = TopicName.of(projectId, topicId);

    // Create a publisher and set enable compression to true.
    Publisher publisher = null;
    try {
      // Enable compression and configure the compression threshold to 10 bytes (default to 240 B).
      // Publish requests of sizes > 10 B (excluding the request headers) will get compressed.
      // The number of messages in a publish request is determined by publisher batch settings.
      // Batching is turned off by default, i.e. each publish request contains only one message.
      publisher =
          Publisher.newBuilder(topicName)
              .setEnableCompression(true)
              .setCompressionBytesThreshold(10L)
              .build();

      byte[] bytes = new byte[1024];
      ByteString data = ByteString.copyFrom(bytes);
      PubsubMessage pubsubMessage = PubsubMessage.newBuilder().setData(data).build();

      // Once published, returns a server-assigned message id (unique within the topic).
      // You can look up the actual size of the outbound data using the Java Logging API.
      // Configure logging properties as shown in
      // https://github.com/googleapis/java-pubsub/tree/main/samples/snippets/src/main/resources/logging.properties
      // and look for "OUTBOUND DATA" with "length=" in the output log.
      ApiFuture<String> messageIdFuture = publisher.publish(pubsubMessage);
      String messageId = messageIdFuture.get();
      System.out.println("Published a compressed message of message ID: " + messageId);
    } finally {
      if (publisher != null) {
        // When finished with the publisher, shutdown to free up resources.
        publisher.shutdown();
        publisher.awaitTermination(1, TimeUnit.MINUTES);
      }
    }
  }
}