FieldSortedHitQueue rise in memory

[Brian Doyle]

We've implemented a custom sort class and use it to sort by distance.   We
have implemented the equals and hashcode in the sort comparator.   After
running for a few hours we're reaching peak memory usage and eventually the
server runs out of memory.   We did some profiling and noticed that a large
chunk of memory is being used in the
lucence.search.FieldSortedHitQueueclass.   Has anyone seen this
behavior before or know how we can stop this
class from growing in size?