/*
 * Copyright 2000-2015 JetBrains s.r.o.
 *
 * 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.jetbrains.concurrency;

import com.intellij.util.Consumer;
import org.jetbrains.annotations.NotNull;
import org.jetbrains.annotations.Nullable;

public class CountDownConsumer<T> implements Consumer<T> {
  private volatile int countDown;
  private final AsyncPromise<T> promise;
  private final T totalResult;

  public CountDownConsumer(int countDown, @NotNull AsyncPromise<T> promise, @Nullable T totalResult) {
    this.countDown = countDown;
    this.promise = promise;
    this.totalResult = totalResult;
  }

  @Override
  public void consume(T t) {
    if (--countDown == 0) {
      promise.setResult(totalResult);
    }
  }
}