Is there a reason you're using an ArrayList rather than a LinkedList for the DefaultQueue? ArrayLists are great for indexing, but suck for variable-sized lists w/ lots off adds & removes. LinkedLists, on the other hand, excel at variable-sized lists with lots of adds/removes, but suck at indexing. Are you using indexing?
Also, for the FixedSizedQueue, you might want to consider a circular buffer, which is already part of the Excalibur Collection classes. Chad ----- Original Message ----- From: "Berin Loritsch" <[EMAIL PROTECTED]> To: <avalon-dev@jakarta.apache.org> Sent: Wednesday, December 19, 2001 12:04 PM Subject: [Report] Efficiencies of FixedSize and Default Queues > My initial testing (consisting of running the TestCases several times) > reveals the cost of an enqueue/dequeue operation. This consists of > both single element vs. multiple element enqueue/dequeue operations. > All calls are paired. > > The average cost of using the Default Queue is 1.156 usecs per > enqueue/dequeue operation. This is pretty decent considering that the > Queue is ThreadSafe (i.e. locking is performed). It uses an ArrayList > to perform it's duties. > > The average cost of using the Fixed Size Queue is 884.0 nsecs per > enqueue/dequeue operation. This is a little over half the cost of > the DefaultQueue, and it is also ThreadSafe. It directly manipulates > an array to perform it's duties. > > The array manipulation works like this: > > | 1 | 2 | 3 | 4 | 5 | > * * > S E > > S = Start > E = End > > The current figure shows a queue with 1 element enqueued. When S=E, > there are no elements enqueued. The next figure shows what happens > when the element is dequeued: > > | 1 | 2 | 3 | 4 | 5 | > ** > SE > > The Start pointer moves forward when there are elements to dequeue, > and the End pointer moves forward when a new element is enqueued. It > is also important to note that the entry where start is is nulled after > it is retrieved. > > The algorithm wraps the pointers back to 0 when they reach the maximum. > > This moving pointer system works quite well, and never requires useless > creation of objects or new queue sizes during the life of the Queue. > > -- > > "They that give up essential liberty to obtain a little temporary safety > deserve neither liberty nor safety." > - Benjamin Franklin > > > -- > To unsubscribe, e-mail: <mailto:[EMAIL PROTECTED]> > For additional commands, e-mail: <mailto:[EMAIL PROTECTED]> > > -- To unsubscribe, e-mail: <mailto:[EMAIL PROTECTED]> For additional commands, e-mail: <mailto:[EMAIL PROTECTED]>
