func NewTermPrefixSearcher(indexReader index.IndexReader, prefix string, field string, boost float64, explain bool) (*TermPrefixSearcher, error) {
// find the terms with this prefix
fieldReader, err := indexReader.FieldReader(field, []byte(prefix), []byte(prefix))
// enumerate all the terms in the range
qsearchers := make([]search.Searcher, 0, 25)
tfd, err := fieldReader.Next()
for err == nil && tfd != nil {
qsearcher, err := NewTermSearcher(indexReader, string(tfd.Term), field, 1.0, explain)
if err != nil {
return nil, err
}
qsearchers = append(qsearchers, qsearcher)
tfd, err = fieldReader.Next()
}
// build disjunction searcher of these ranges
searcher, err := NewDisjunctionSearcher(indexReader, qsearchers, 0, explain)
if err != nil {
return nil, err
}
return &TermPrefixSearcher{
indexReader: indexReader,
prefix: prefix,
field: field,
explain: explain,
searcher: searcher,
}, nil
}
func findRegexpCandidateTerms(indexReader index.IndexReader, pattern *regexp.Regexp, field, prefixTerm string) (rv []string, err error) {
rv = make([]string, 0)
var fieldDict index.FieldDict
if len(prefixTerm) > 0 {
fieldDict, err = indexReader.FieldDictPrefix(field, []byte(prefixTerm))
} else {
fieldDict, err = indexReader.FieldDict(field)
}
defer func() {
if cerr := fieldDict.Close(); cerr != nil && err == nil {
err = cerr
}
}()
// enumerate the terms and check against regexp
tfd, err := fieldDict.Next()
for err == nil && tfd != nil {
if pattern.MatchString(tfd.Term) {
rv = append(rv, tfd.Term)
if tooManyClauses(len(rv)) {
return rv, tooManyClausesErr()
}
}
tfd, err = fieldDict.Next()
}
return rv, err
}
func findFuzzyCandidateTerms(indexReader index.IndexReader, term *string, fuzziness int, field, prefixTerm string) (rv []string, err error) {
rv = make([]string, 0)
var fieldDict index.FieldDict
if len(prefixTerm) > 0 {
fieldDict, err = indexReader.FieldDictPrefix(field, []byte(prefixTerm))
} else {
fieldDict, err = indexReader.FieldDict(field)
}
defer func() {
if cerr := fieldDict.Close(); cerr != nil && err == nil {
err = cerr
}
}()
// enumerate terms and check levenshtein distance
tfd, err := fieldDict.Next()
for err == nil && tfd != nil {
ld, exceeded := search.LevenshteinDistanceMax(term, &tfd.Term, fuzziness)
if !exceeded && ld <= fuzziness {
rv = append(rv, tfd.Term)
if tooManyClauses(len(rv)) {
return rv, tooManyClausesErr()
}
}
tfd, err = fieldDict.Next()
}
return rv, err
}
func NewFuzzySearcher(indexReader index.IndexReader, term string, prefix, fuzziness int, field string, boost float64, explain bool) (*FuzzySearcher, error) {
prefixTerm := ""
for i, r := range term {
if i < prefix {
prefixTerm += string(r)
}
}
// find the terms with this prefix
var fieldDict index.FieldDict
var err error
if len(prefixTerm) > 0 {
fieldDict, err = indexReader.FieldDictPrefix(field, []byte(prefixTerm))
} else {
fieldDict, err = indexReader.FieldDict(field)
}
// enumerate terms and check levenshtein distance
candidateTerms := make([]string, 0)
tfd, err := fieldDict.Next()
for err == nil && tfd != nil {
ld, exceeded := search.LevenshteinDistanceMax(&term, &tfd.Term, fuzziness)
if !exceeded && ld <= fuzziness {
candidateTerms = append(candidateTerms, tfd.Term)
}
tfd, err = fieldDict.Next()
}
if err != nil {
return nil, err
}
// enumerate all the terms in the range
qsearchers := make([]search.Searcher, 0, 25)
for _, cterm := range candidateTerms {
qsearcher, err := NewTermSearcher(indexReader, cterm, field, boost, explain)
if err != nil {
return nil, err
}
qsearchers = append(qsearchers, qsearcher)
}
// build disjunction searcher of these ranges
searcher, err := NewDisjunctionSearcher(indexReader, qsearchers, 0, explain)
if err != nil {
return nil, err
}
return &FuzzySearcher{
indexReader: indexReader,
term: term,
prefix: prefix,
fuzziness: fuzziness,
field: field,
explain: explain,
searcher: searcher,
}, nil
}
func NewRegexpSearcher(indexReader index.IndexReader, pattern *regexp.Regexp, field string, boost float64, explain bool) (*RegexpSearcher, error) {
prefixTerm, complete := pattern.LiteralPrefix()
candidateTerms := make([]string, 0)
if complete {
// there is no pattern
candidateTerms = append(candidateTerms, prefixTerm)
} else {
var fieldDict index.FieldDict
var err error
if len(prefixTerm) > 0 {
fieldDict, err = indexReader.FieldDictPrefix(field, []byte(prefixTerm))
} else {
fieldDict, err = indexReader.FieldDict(field)
}
// enumerate the terms and check against regexp
tfd, err := fieldDict.Next()
for err == nil && tfd != nil {
if pattern.MatchString(tfd.Term) {
candidateTerms = append(candidateTerms, tfd.Term)
}
tfd, err = fieldDict.Next()
}
if err != nil {
return nil, err
}
}
// enumerate all the terms in the range
qsearchers := make([]search.Searcher, 0, 25)
for _, cterm := range candidateTerms {
qsearcher, err := NewTermSearcher(indexReader, cterm, field, boost, explain)
if err != nil {
return nil, err
}
qsearchers = append(qsearchers, qsearcher)
}
// build disjunction searcher of these ranges
searcher, err := NewDisjunctionSearcher(indexReader, qsearchers, 0, explain)
if err != nil {
return nil, err
}
return &RegexpSearcher{
indexReader: indexReader,
pattern: pattern,
field: field,
explain: explain,
searcher: searcher,
}, nil
}
func NewMatchAllSearcher(indexReader index.IndexReader, boost float64, explain bool) (*MatchAllSearcher, error) {
reader, err := indexReader.DocIDReader("", "")
if err != nil {
return nil, err
}
scorer := scorers.NewConstantScorer(1.0, boost, explain)
return &MatchAllSearcher{
indexReader: indexReader,
reader: reader,
scorer: scorer,
}, nil
}
func NewDocIDSearcher(indexReader index.IndexReader, ids []string, boost float64,
explain bool) (searcher *DocIDSearcher, err error) {
reader, err := indexReader.DocIDReaderOnly(ids)
if err != nil {
return nil, err
}
scorer := scorers.NewConstantScorer(1.0, boost, explain)
return &DocIDSearcher{
scorer: scorer,
reader: reader,
count: len(ids),
}, nil
}
func NewTermSearcher(indexReader index.IndexReader, term string, field string, boost float64, explain bool) (*TermSearcher, error) {
reader, err := indexReader.TermFieldReader([]byte(term), field)
if err != nil {
return nil, err
}
scorer := scorers.NewTermQueryScorer(term, field, boost, indexReader.DocCount(), reader.Count(), explain)
return &TermSearcher{
indexReader: indexReader,
term: term,
field: field,
explain: explain,
reader: reader,
scorer: scorer,
}, nil
}
// 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 NewMatchAllSearcher(indexReader index.IndexReader, boost float64, explain bool) (*MatchAllSearcher, error) {
reader, err := indexReader.DocIDReaderAll()
if err != nil {
return nil, err
}
count, err := indexReader.DocCount()
if err != nil {
_ = reader.Close()
return nil, err
}
scorer := scorer.NewConstantScorer(1.0, boost, explain)
return &MatchAllSearcher{
indexReader: indexReader,
reader: reader,
scorer: scorer,
count: count,
}, nil
}
func NewDocIDSearcher(indexReader index.IndexReader, ids []string, boost float64,
explain bool) (searcher *DocIDSearcher, err error) {
kept := make([]string, len(ids))
copy(kept, ids)
sort.Strings(kept)
if len(ids) > 0 {
var idReader index.DocIDReader
endTerm := string(incrementBytes([]byte(kept[len(kept)-1])))
idReader, err = indexReader.DocIDReader(kept[0], endTerm)
if err != nil {
return nil, err
}
defer func() {
if cerr := idReader.Close(); err == nil && cerr != nil {
err = cerr
}
}()
j := 0
for _, id := range kept {
doc, err := idReader.Advance(id)
if err != nil {
return nil, err
}
// Non-duplicate match
if doc == id && (j == 0 || kept[j-1] != id) {
kept[j] = id
j++
}
}
kept = kept[:j]
}
scorer := scorers.NewConstantScorer(1.0, boost, explain)
return &DocIDSearcher{
ids: kept,
scorer: scorer,
}, nil
}
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
}
