content: /*
   * Copyright (C) 2012 Facebook, Inc.
   *
   * 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 io.airlift.drift.client;
  
  import com.google.common.collect.ImmutableList;
  import com.google.common.util.concurrent.Futures;
  import com.google.common.util.concurrent.ListenableFuture;
  import com.google.errorprone.annotations.concurrent.GuardedBy;
  import io.airlift.drift.transport.client.InvokeRequest;
  import io.airlift.drift.transport.client.MethodInvoker;
  import io.airlift.testing.TestingTicker;
  import io.airlift.units.Duration;
  
  import java.util.ArrayList;
  import java.util.List;
  import java.util.function.Function;
  import java.util.function.Supplier;
  
  import static java.util.Objects.requireNonNull;
  import static java.util.concurrent.TimeUnit.MILLISECONDS;
  
  public class MockMethodInvoker
          implements MethodInvoker, Supplier<InvokeRequest>
  {
      private final Function<InvokeRequest, ListenableFuture<Object>> resultsSupplier;
      private final TestingTicker ticker;
  
      @GuardedBy("this")
      private InvokeRequest request;
  
      @GuardedBy("this")
      private final List<Duration> delays = new ArrayList<>();
  
      public MockMethodInvoker(Supplier<ListenableFuture<Object>> resultsSupplier)
      {
          this(resultsSupplier, new TestingTicker());
      }
  
      public MockMethodInvoker(Function<InvokeRequest, ListenableFuture<Object>> resultsSupplier)
      {
          this(resultsSupplier, new TestingTicker());
      }
  
      public MockMethodInvoker(Supplier<ListenableFuture<Object>> resultsSupplier, TestingTicker ticker)
      {
          this(request -> resultsSupplier.get(), ticker);
      }
  
      private MockMethodInvoker(Function<InvokeRequest, ListenableFuture<Object>> resultsSupplier, TestingTicker ticker)
      {
          this.resultsSupplier = requireNonNull(resultsSupplier, "resultsSupplier is null");
          this.ticker = requireNonNull(ticker, "ticker is null");
      }
  
      @Override
      public synchronized InvokeRequest get()
      {
          return request;
      }
  
      public synchronized List<Duration> getDelays()
      {
          return ImmutableList.copyOf(delays);
      }
  
      @Override
      public synchronized ListenableFuture<Object> invoke(InvokeRequest request)
      {
          this.request = request;
          return resultsSupplier.apply(request);
      }
  
      @Override
      public synchronized ListenableFuture<?> delay(Duration duration)
      {
          delays.add(duration);
          ticker.increment(duration.toMillis(), MILLISECONDS);
          return Futures.immediateFuture(null);
      }
  }
  