Example usage for com.google.common.util.concurrent Futures transformAsync

Introduction

In this page you can find the example usage for com.google.common.util.concurrent Futures transformAsync.

Prototype

public static <I, O> ListenableFuture<O> transformAsync(ListenableFuture<I> input,
        AsyncFunction<? super I, ? extends O> function, Executor executor)

Source Link

Document

Returns a new ListenableFuture whose result is asynchronously derived from the result of the given Future .

Usage

From source file:com.facebook.buck.rules.CachingBuildRuleBuilder.java

private ListenableFuture<Optional<BuildResult>> transformBuildResultAsyncIfNotPresent(
        ListenableFuture<Optional<BuildResult>> future,
        Callable<ListenableFuture<Optional<BuildResult>>> function) {
    // Immediately (i.e. without posting a task), returns the current result if it's already present
    // or a cancelled result if we've already seen a failure.
    return Futures.transformAsync(future, (result) -> {
        if (result.isPresent()) {
            return Futures.immediateFuture(result);
        }//from   w w w. ja  va 2s . c om
        if (!buildRuleBuilderDelegate.shouldKeepGoing(buildContext)) {
            Preconditions.checkNotNull(buildRuleBuilderDelegate.getFirstFailure());
            return Futures.immediateFuture(
                    Optional.of(BuildResult.canceled(rule, buildRuleBuilderDelegate.getFirstFailure())));
        }
        return function.call();
    }, MoreExecutors.directExecutor());
}