On Jun 7, 2006, at 3:43 PM, Chris Hostetter wrote:
Getting the inverse of a DocSet is currently not a built in
operation, you
have to use the getBits() method and operate on it, something like
this
should work...
DocSet definedSet = search.getDocSet(parseQuery("field:[* TO *]"));
DocSet unDefinedSet = new BitDocSet(fieldDefinedSet.getBits().flip
(0,search.maxDoc()))
int count = unDefinedSet.intersectionCount(results.docSet)
...at least, i think it should work .. i've never really had to worry
about inverted sets.
Here's how I build "inverse" BitSets that represent documents that do
not have a value in a facet field:
BitSet catchall = new BitSet(reader.numDocs());
TermEnum termEnum = reader.terms(new Term(field, ""));
while (true) {
Term term = termEnum.term();
if (term == null || !term.field().equals(field)) break;
termDocs.seek(term);
BitSet bitSet = new BitSet(reader.numDocs());
while (termDocs.next()) {
bitSet.set(termDocs.doc());
}
catchall.or(bitSet);
// ... cache bitSet ...
if (! termEnum.next()) break;
}
// ... cache catchall ...
Solr's DocSets are a better way to go in the long run, I'm convinced
- I'm just now starting to leverage them in other ways. I do still
need to do these kinds of inverted sets somehow.
Erik
