NioHttpClient.java

package com.hubspot.slack.client.http;

import com.google.common.util.concurrent.ListenableFuture;
import com.hubspot.horizon.AsyncHttpClient;
import com.hubspot.horizon.AsyncHttpClient.Callback;
import com.hubspot.horizon.HttpRequest;
import com.hubspot.horizon.HttpRequest.Options;
import com.hubspot.horizon.HttpResponse;
import com.hubspot.horizon.internal.AbstractHttpResponse;
import com.hubspot.slack.client.concurrency.MoreExecutors;
import java.io.Closeable;
import java.io.IOException;
import java.util.concurrent.CompletableFuture;
import java.util.concurrent.ExecutorService;
import java.util.function.Function;

public class NioHttpClient implements Closeable {

  private static final ExecutorService CALLBACK_EXECUTOR = MoreExecutors
    .threadPoolDaemonExecutorBuilder("NioHttpClient-Callback")
    .setFollowThreadLocals(false)
    .setUnbounded(true)
    .build();

  private final AsyncHttpClient delegate;

  public interface Factory {
    NioHttpClient wrap(AsyncHttpClient delegate);
  }

  public NioHttpClient(AsyncHttpClient delegate) {
    this.delegate = delegate;
  }

  /**
   * @deprecated Use {@link #executeCompletableFuture(HttpRequest)}
   */
  @Deprecated
  public ListenableFuture<HttpResponse> execute(HttpRequest httpRequest) {
    return delegate.execute(httpRequest);
  }

  /**
   * @deprecated Use {@link #executeCompletableFuture(HttpRequest)}
   */
  @Deprecated
  public ListenableFuture<HttpResponse> execute(
    HttpRequest httpRequest,
    Options options
  ) {
    return delegate.execute(httpRequest, options);
  }

  /**
   * @deprecated Use {@link #executeCompletableFuture(HttpRequest)}
   */
  @Deprecated
  public void execute(HttpRequest httpRequest, Callback callback) {
    delegate.execute(httpRequest, callback);
  }

  /**
   * @deprecated Use {@link #executeCompletableFuture(HttpRequest)}
   */
  @Deprecated
  public void execute(HttpRequest httpRequest, Options options, Callback callback) {
    delegate.execute(httpRequest, options, callback);
  }

  public CompletableFuture<HttpResponse> executeCompletableFuture(HttpRequest request) {
    CompletableFuture<HttpResponse> responseFuture = new CompletableFuture<>();
    execute(
      request,
      new Callback() {
        @Override
        public void completed(HttpResponse response) {
          if (response instanceof AbstractHttpResponse) {
            HttpResponse cached = CachingHttpResponse.from(
              (AbstractHttpResponse) response
            );
            responseFuture.complete(cached);
          } else {
            responseFuture.complete(response);
          }
        }

        @Override
        public void failed(Exception ex) {
          responseFuture.completeExceptionally(ex);
        }
      }
    );

    return responseFuture.thenApplyAsync(Function.identity(), CALLBACK_EXECUTOR);
  }

  @Override
  public void close() throws IOException {
    delegate.close();
  }
}