This Sort Comparator uses a mixed strategy to retrieve the term values. If we are retrieving less than 1% of the
documents in the index, we get each document value individually. Once passed the 1% threshold however we switch
to reading through the terms dictionary in lucene, and builds up a list of ordered terms. It then
sorts the documents according to the order that they appear in the terms list.
This latter approach, whilst very fast, does load the entire term dictionary into memory, and allocates a slot
for every document value, which is why we do not use it all the time.
We believe that most searches in very large JIRA installations
will return a very small portion of the document index, either because they are over only one of
many projects or they return only open issues, especially on dashboards and in GreenHopper and similar plugins as
well as in general navigator searches.
Returns an object which, when sorted according by the comparator returned from
getComparator() , will order the Term values in the correct order.
For example, if the
Terms contained integer values, this method would return
new Integer(termtext). Note that this
might not always be the most efficient implementation - for this particular example, a better implementation
might be to make a ScoreDocLookupComparator that uses an internal lookup table of int.
||The textual value of the term.