README

Generic interfaces package

Interfaces Defined

• EntryInterface - a key value pair
• HashSetInterface - a set interface using EntryInterface elements
• QueueInterface - a queue interface using EntryInterface elements
• RedrivableQueueInterface - a redrivable queue interface (see below)
• SetQueue - a Queue that dedupes entries based on a Set
• PubSubQueueInterface - a pub/sub topic provider based on a redrivable SetQueue

Definitions

RedrivableQueueInterface

A redrivable queue operates just like a normal queue (enqueue(), dequeue()) but adds two new interface methods:

• redrive() - replays all un-commit()ed dequeue()ed entries. All dequeue()ed entries are automatically appended to the redrive queue.
• commit() - marks an entry as non-redrivable (removes from the redrive queue)

So in operation, your workflow would be something like this:

$entry = $redrivableQ->dequeue();
$requiresRedrive = false;
try {
  $processStatus = processEntry($entry);
  if (SUCCESS == $processStatus) {
    $redrivableQ->commit($entry);
  }
} catch (\ProcessingException $e) {
    $requiresRedrive = true;
}