waitedForBatch

The purpose of this suspending function is to allow a batching entity to wait for a batch to be formed. If a batch can be formed using the candidate entity, then the batch is formed and the function returns false. If the batch cannot be formed, the candidate entity waits in the batch queue and suspends. If the batch can be formed, the batch is attached to the batching entity using the supplied batch name. The batching entity will hold the batched entities in a list associated with the supplied batch name via a map. The entities entering the batch queue wait until the number of entities satisfying the supplied predicate is equal to the supplied batch size. The returned Boolean value associated with the function indicates if the entity is part of the batch and if so, it must exit from the process. The entity that caused the batch to form, will cause the function to return false, when it returns from its suspension. All entities that enter this suspending function will suspend. The resumption of the suspension is predicated on the formation of the batch.

Notice that the associated BatchingQueue must hold entities that are the same type (subclass) of BatchingEntity. Only entities of the same type can be batched together via this functionality.

WARNING The proper use of this method must have the following form:

// within a process()

if (waitedForBatch(candidate, batchingQ, batchName, batchSize, predicate, suspensionName)) {
    return@process
}
// the continuing entity is the one that caused the batch to be formed

That is, you must wrap the usage of this suspending function within an if-statement construct.

Note the use of the explicitly labeled return to exit from the process. This is essential. The entities that waited for the batch because the if statement was true, will be resumed when the batch is formed and must be allowed to return from the process and not continue with the current process.

Parameters