AsyncUtils.java

package io.cattle.platform.async.utils;

import io.cattle.platform.util.exception.ExceptionUtils;
import io.cattle.platform.util.exception.UnreachableException;

import java.util.List;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.Future;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.TimeoutException;

import com.google.common.util.concurrent.Futures;
import com.google.common.util.concurrent.ListenableFuture;
import com.google.common.util.concurrent.SettableFuture;

public class AsyncUtils {

    public static <T> T get(Future<T> future, long timeout, TimeUnit unit) {
        try {
            return future.get(timeout, unit);
        } catch (InterruptedException e) {
            throw new IllegalStateException(e);
        } catch (ExecutionException e) {
            Throwable t = e.getCause();
            ExceptionUtils.rethrowExpectedRuntime(t);
            throw new UnreachableException();
        } catch (TimeoutException e) {
            throw new io.cattle.platform.async.utils.TimeoutException(e);
        }
    }

    public static <T> T get(Future<T> future) {
        try {
            return future.get();
        } catch (InterruptedException e) {
            throw new IllegalStateException(e);
        } catch (ExecutionException e) {
            Throwable t = e.getCause();
            if (t instanceof TimeoutException) {
                throw new io.cattle.platform.async.utils.TimeoutException(t);
            }
            ExceptionUtils.rethrowExpectedRuntime(t);
            throw new UnreachableException();
        }
    }

    public static ListenableFuture<?> done() {
        return done(true);
    }

    public static <T> ListenableFuture<T> done(T obj) {
        SettableFuture<T> future = SettableFuture.create();
        future.set(obj);

        return future;
    }

    public static <T> ListenableFuture<T> error(Throwable t) {
        SettableFuture<T> future = SettableFuture.create();
        future.setException(t);

        return future;
    }

    public static void waitAll(List<ListenableFuture<?>> futures) {
        AsyncUtils.get(Futures.allAsList(futures));
    }

    public static void waitAll(ListenableFuture<?>... futures) {
        AsyncUtils.get(Futures.allAsList(futures));
    }
}