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bleve/search/searchers/search_regexp.go
Marty Schoch 5aa9e95468 major refactor of index/search API
index id's are now opaque (until finally returned to top-level user)
 - the TermFieldDoc's returned by TermFieldReader no longer contain doc id
 - instead they return an opaque IndexInternalID
 - items returned are still in the "natural index order"
 - but that is no longer guaranteed to be "doc id order"
 - correct behavior requires that they all follow the same order
 - but not any particular order

 - new API FinalizeDocID which converts index internal ID's to public string ID

 - APIs used internally which previously took doc id now take IndexInternalID
     - that is DocumentFieldTerms() and DocumentFieldTermsForFields()
 - however, APIs that are used externally do not reflect this change
     - that is Document()

 - DocumentIDReader follows the same changes, but this is less obvious
     - behavior clarified, used to iterate doc ids, BUT NOT in doc id order
     - method STILL available to iterate doc ids in range
     - but again, you won't get them in any meaningful order
     - new method to iterate actual doc ids from list of possible ids
         - this was introduced to make the DocIDSearcher continue working

searchers now work with the new opaque index internal doc ids
 - they return new DocumentMatchInternal (which does not have string ID)
scorerers also work with these opaque index internal doc ids
 - they return DocumentMatchInternal (which does not have string ID)
collectors now also perform a final step of converting the final result
 - they STILL return traditional DocumentMatch (with string ID)
 - but they now also require an IndexReader (so that they can do the conversion)
2016-07-31 13:46:18 -04:00

125 lines
3.4 KiB
Go

// Copyright (c) 2015 Couchbase, Inc.
// Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file
// except in compliance with the License. You may obtain a copy of the License at
// http://www.apache.org/licenses/LICENSE-2.0
// Unless required by applicable law or agreed to in writing, software distributed under the
// License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
// either express or implied. See the License for the specific language governing permissions
// and limitations under the License.
package searchers
import (
"regexp"
"github.com/blevesearch/bleve/index"
"github.com/blevesearch/bleve/search"
)
type RegexpSearcher struct {
indexReader index.IndexReader
pattern *regexp.Regexp
field string
explain bool
searcher *DisjunctionSearcher
}
func NewRegexpSearcher(indexReader index.IndexReader, pattern *regexp.Regexp, field string, boost float64, explain bool) (*RegexpSearcher, error) {
prefixTerm, complete := pattern.LiteralPrefix()
var candidateTerms []string
if complete {
// there is no pattern
candidateTerms = []string{prefixTerm}
} else {
var err error
candidateTerms, err = findRegexpCandidateTerms(indexReader, pattern, field, prefixTerm)
if err != nil {
return nil, err
}
}
// enumerate all the terms in the range
qsearchers := make([]search.Searcher, 0, len(candidateTerms))
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 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 (s *RegexpSearcher) Count() uint64 {
return s.searcher.Count()
}
func (s *RegexpSearcher) Weight() float64 {
return s.searcher.Weight()
}
func (s *RegexpSearcher) SetQueryNorm(qnorm float64) {
s.searcher.SetQueryNorm(qnorm)
}
func (s *RegexpSearcher) Next(preAllocated *search.DocumentMatchInternal) (*search.DocumentMatchInternal, error) {
return s.searcher.Next(preAllocated)
}
func (s *RegexpSearcher) Advance(ID index.IndexInternalID, preAllocated *search.DocumentMatchInternal) (*search.DocumentMatchInternal, error) {
return s.searcher.Advance(ID, preAllocated)
}
func (s *RegexpSearcher) Close() error {
return s.searcher.Close()
}
func (s *RegexpSearcher) Min() int {
return 0
}