/*
 * Copyright (C) 2016 Google 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 com.googlecode.android_scripting.future;

import java.util.concurrent.CountDownLatch;
import java.util.concurrent.Future;
import java.util.concurrent.TimeUnit;

/**
 * FutureResult represents an eventual execution result for asynchronous operations.
 *
 * @author Damon Kohler (damonkohler@gmail.com)
 */
public class FutureResult<T> implements Future<T> {

    private final CountDownLatch mLatch = new CountDownLatch(1);
    private volatile T mResult = null;

    public void set(T result) {
        mResult = result;
        mLatch.countDown();
    }

    @Override
    public boolean cancel(boolean mayInterruptIfRunning) {
        return false;
    }

    @Override
    public T get() throws InterruptedException {
        mLatch.await();
        return mResult;
    }

    @Override
    public T get(long timeout, TimeUnit unit) throws InterruptedException {
        mLatch.await(timeout, unit);
        return mResult;
    }

    @Override
    public boolean isCancelled() {
        return false;
    }

    @Override
    public boolean isDone() {
        return mResult != null;
    }

}