The removal order of a binary heap is based on either the natural sort order of its elements or a specified Comparator . The remove() method always returns the first element as determined by the sort order. (The ascendingOrder flag in the constructors can be used to reverse the sort order, in which case remove() will always remove the last element.) The removal order is not the same as the order of iteration; elements are returned by the iterator in no particular order.

The add(Object) and remove() operations perform in logarithmic time. The get() operation performs in constant time. All other operations perform in linear time or worse.

Note that this implementation is not synchronized. Use synchronizedBuffer(Buffer) or decorate(Buffer) to provide synchronized access to a PriorityBuffer:

 Buffer heap = SynchronizedBuffer.decorate(new PriorityBuffer());
 

This class is Serializable from Commons Collections 3.2.