@SuppressWarnings("unchecked")
public static <T, V> Task<V> attributePostProcessedWhenReady(
final Entity source,
final AttributeSensor<T> sensor,
final Predicate<? super T> ready,
final Function<? super T, V> postProcess) {
Builder<T, T> builder1 = DependentConfiguration.builder().attributeWhenReady(source, sensor);
// messy generics here to support null postProcess; would be nice to disallow that here
Builder<T, V> builder;
if (postProcess != null) {
builder = builder1.postProcess(postProcess);
} else {
builder = (Builder<T, V>) builder1;
}
if (ready != null) builder.readiness(ready);
return builder.build();
}
public Task<V2> build() {
List<Task<V>> tasks = MutableList.of();
for (AttributeAndSensorCondition<?> source : multiSource) {
builder.source(source.source);
builder.sensor((AttributeSensor) source.sensor);
builder.readiness((Predicate) source.predicate);
tasks.add(builder.build());
}
final Task<List<V>> parallelTask =
Tasks.<List<V>>builder()
.parallel(true)
.addAll(tasks)
.displayName(name)
.description(
descriptionBase + (builder.timeout != null ? ", timeout " + builder.timeout : ""))
.build();
if (postProcessFromMultiple == null) {
// V2 should be the right type in normal operations
return (Task<V2>) parallelTask;
} else {
return Tasks.<V2>builder()
.displayName(name)
.description(descriptionBase)
.tag("attributeWhenReady")
.body(
new Callable<V2>() {
@Override
public V2 call() throws Exception {
List<V> prePostProgress = DynamicTasks.queue(parallelTask).get();
return DynamicTasks.queue(
Tasks.<V2>builder()
.displayName("post-processing")
.description("Applying " + postProcessFromMultiple)
.body(
Functionals.callable(postProcessFromMultiple, prePostProgress))
.build())
.get();
}
})
.build();
}
}
@Beta
protected MultiBuilder(
Iterable<? extends Entity> sources,
AttributeSensor<T> sensor,
Predicate<? super T> readiness) {
builder = new Builder<T, V>(null, sensor);
builder.readiness(readiness);
for (Entity s : checkNotNull(sources, "sources")) {
multiSource.add(new AttributeAndSensorCondition<T>(s, sensor, readiness));
}
this.name = "waiting on " + sensor.getName();
this.descriptionBase =
"waiting on "
+ sensor.getName()
+ " "
+ readiness
+ " from "
+ Iterables.size(sources)
+ " entit"
+ Strings.ies(sources);
}
/**
* returns an unsubmitted {@link Task} which blocks until the given sensor on the given source
* entity gives a value that satisfies ready, then returns that value; particular useful in Entity
* configuration where config will block until Tasks have a value
*/
public static <T> Task<T> attributeWhenReady(
final Entity source, final AttributeSensor<T> sensor, final Predicate<? super T> ready) {
Builder<T, T> builder = builder().attributeWhenReady(source, sensor);
if (ready != null) builder.readiness(ready);
return builder.build();
}