// returns true if multigroup
private boolean openDocumentIndex(int docID) throws Exception {
// The data is only the data for this document id. Thus the base is set
// to zero.
_data = _env.getPositions(docID);
_base = 0;
_startingIndex = 0;
int kk = _data[_base] & 0xFF, k2;
switch (kk >> 6) // get type
{
case 0: // single group, no extents
k2 = _data[_base + 1];
_firstGenerator.init(_data, _base += 2, k2);
// decode concept table
_nConcepts = _firstGenerator.decodeConcepts(kk & 0x3F, 0, _concepts);
return false;
case 2: // multi group, no extents
_kTable.clear();
_offsets.clear();
_maxConcepts.clear();
ByteArrayDecompressor compr = new ByteArrayDecompressor(_data, _base + 1);
compr.decode(kk & 0x3F, _kTable);
compr.ascDecode(_kTable.popLast(), _offsets);
compr.ascDecode(_kTable.popLast(), _maxConcepts);
_base += 1 + compr.bytesRead();
_limit = _maxConcepts.cardinality();
return true;
case 1: // single group, extents
case 3: // multi group, extents
throw new Exception("extents not yet implemented\n");
}
return false;
}
private ConceptGroupGenerator makeGenerator(int group) throws Exception {
int shift, index;
if (group > 0) {
index = _base + _offsets.at(group - 1);
shift = _maxConcepts.at(group - 1);
} else {
index = _base;
shift = 0;
}
// initialize generator
ConceptGroupGenerator gen = new ConceptGroupGenerator(_data, index, _kTable.at(2 * group + 1));
// decode concept table
_nConcepts = gen.decodeConcepts(_kTable.at(2 * group), shift, _concepts);
if (group < _limit) _max = _concepts[_nConcepts] = _maxConcepts.at(group);
else _max = _concepts[_nConcepts - 1];
_genHeap.addGenerator(gen);
_startingIndex = 0; // in _concepts; lower search index
return gen;
}
private int nextDocument(RoleFiller[] start) throws Exception {
while (_nextDocGenHeap.isNonEmpty()) // still something to do
{
for (int i = 0; i < _nQueries; i++) if (_query[i] != null) _query[i].resetForNextDocument();
// gather all concepts this document has and store associated conceptData
int index = 0;
_document = _nextDocGenHeap.getDocument();
_docConcepts.clear();
_queryMasks.clear();
do {
_docConcepts.add(_nextDocGenHeap.getConcept());
_queryMasks.add(_nextDocGenHeap.getQueryMask());
(_conceptData[index++] = _nextDocGenHeap.getTerms()).runBy(_query);
_nextDocGenHeap.step();
} while (_nextDocGenHeap.atDocument(_document));
// if there is no saturation model, some query will always vote YES
// and so every document will be opened
// even if this case, however, savings can be achieved by not generating fillers
// for some queries (not scoring, etc)
// and, with more care, creation of some GroupGenerators can be avoided
// saturating queries with lots of good hits will lead to best results
int voteMask = 0;
for (int i = 0; i < _nQueries; i++)
if (_query[i] != null)
if (_query[i].vote()) {
start[i] = null; // normal reset
voteMask |= 1 << i;
} else start[i] = RoleFiller.STOP; // prohibit setting
// we may eliminate some ConceptGroupGenerators
// those which would be used only by Queries which voted NO
if (voteMask != 0) // need to open up document
{
ConceptGroupGenerator gen;
// !!! don't gather Fillers for disinterested Queries
if (openDocumentIndex(_document)) // multi group
{
// set up all needed generators
int i = 0;
while ((_queryMasks.at(i) & voteMask) == 0) ++i;
// assert(i < index);
int c = _docConcepts.at(i);
int group = 0;
// find first group
while (c > _maxConcepts.at(group) && ++group < _limit) ;
gen = makeGenerator(group);
gen.addTerms(indexOf(c), _conceptData[i]);
for (++i; i < index; i++)
if ((_queryMasks.at(i) & voteMask) > 0) {
c = _docConcepts.at(i);
if (c > _max) // need to find another group
{
// assert(group < _limit);
while (c > _maxConcepts.at(group) && ++group < _limit) ;
gen = makeGenerator(group);
}
gen.addTerms(indexOf(c), _conceptData[i]);
}
return 0;
} else // single group
{
for (int i = 0; i < index; i++)
if ((_queryMasks.at(i) & voteMask) != 0)
_firstGenerator.addTerms(indexOf(_docConcepts.at(i)), _conceptData[i]);
return 1;
}
}
}
return 2;
}