// finalizeResults starts with the heap containing the final top size+skip
// it now throws away the results to be skipped
// and does final doc id lookup (if necessary)
func (hc *TopNCollector) finalizeResults(r index.IndexReader) error {
var err error
hc.results, err = hc.store.Final(hc.skip, func(doc *search.DocumentMatch) error {
if doc.ID == "" {
// look up the id since we need it for lookup
var err error
doc.ID, err = r.ExternalID(doc.IndexInternalID)
if err != nil {
return err
}
}
return nil
})
return err
}
func (hc *TopNCollector) collectSingle(ctx *search.SearchContext, reader index.IndexReader, d *search.DocumentMatch) error {
// increment total hits
hc.total++
d.HitNumber = hc.total
// update max score
if d.Score > hc.maxScore {
hc.maxScore = d.Score
}
var err error
// see if we need to load ID (at this early stage, for example to sort on it)
if hc.needDocIds {
d.ID, err = reader.ExternalID(d.IndexInternalID)
if err != nil {
return err
}
}
// see if we need to load the stored fields
if len(hc.neededFields) > 0 {
// find out which fields haven't been loaded yet
fieldsToLoad := d.CachedFieldTerms.FieldsNotYetCached(hc.neededFields)
// look them up
fieldTerms, err := reader.DocumentFieldTerms(d.IndexInternalID, fieldsToLoad)
if err != nil {
return err
}
// cache these as well
if d.CachedFieldTerms == nil {
d.CachedFieldTerms = make(map[string][]string)
}
d.CachedFieldTerms.Merge(fieldTerms)
}
// compute this hits sort value
if len(hc.sort) == 1 && hc.cachedScoring[0] {
d.Sort = sortByScoreOpt
} else {
hc.sort.Value(d)
}
// optimization, we track lowest sorting hit already removed from heap
// with this one comparison, we can avoid all heap operations if
// this hit would have been added and then immediately removed
if hc.lowestMatchOutsideResults != nil {
cmp := hc.sort.Compare(hc.cachedScoring, hc.cachedDesc, d, hc.lowestMatchOutsideResults)
if cmp >= 0 {
// this hit can't possibly be in the result set, so avoid heap ops
ctx.DocumentMatchPool.Put(d)
return nil
}
}
hc.store.Add(d)
if hc.store.Len() > hc.size+hc.skip {
removed := hc.store.RemoveLast()
if hc.lowestMatchOutsideResults == nil {
hc.lowestMatchOutsideResults = removed
} else {
cmp := hc.sort.Compare(hc.cachedScoring, hc.cachedDesc, removed, hc.lowestMatchOutsideResults)
if cmp < 0 {
tmp := hc.lowestMatchOutsideResults
hc.lowestMatchOutsideResults = removed
ctx.DocumentMatchPool.Put(tmp)
}
}
}
return nil
}