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bleve/search/searchers/search_term_prefix.go
Marty Schoch 522f9d5cc7 significant change to index format, support dictionary rows
this introduces disk format v4
now the summary rows for a term are stored in their own
"dictionary row" format, previously the same information
was stored in special term frequency rows
this now allows us to easily iterate all the terms for a field
in sorted order (useful for many other fuzzy data structures)

at the top-level of bleve you can now browse terms within a field
using the following api on the Index interface:

  FieldDict(field string) (index.FieldDict, error)
  FieldDictRange(field string, startTerm []byte, endTerm []byte) (index.FieldDict, error)
  FieldDictPrefix(field string, termPrefix []byte) (index.FieldDict, error)

fixes #127
2015-03-10 16:22:19 -04:00

82 lines
2.3 KiB
Go

// Copyright (c) 2014 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 (
"github.com/blevesearch/bleve/index"
"github.com/blevesearch/bleve/search"
)
type TermPrefixSearcher struct {
indexReader index.IndexReader
prefix string
field string
explain bool
searcher *DisjunctionSearcher
}
func NewTermPrefixSearcher(indexReader index.IndexReader, prefix string, field string, boost float64, explain bool) (*TermPrefixSearcher, error) {
// find the terms with this prefix
fieldDict, err := indexReader.FieldDictPrefix(field, []byte(prefix))
// enumerate all the terms in the range
qsearchers := make([]search.Searcher, 0, 25)
tfd, err := fieldDict.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 = fieldDict.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 (s *TermPrefixSearcher) Count() uint64 {
return s.searcher.Count()
}
func (s *TermPrefixSearcher) Weight() float64 {
return s.searcher.Weight()
}
func (s *TermPrefixSearcher) SetQueryNorm(qnorm float64) {
s.searcher.SetQueryNorm(qnorm)
}
func (s *TermPrefixSearcher) Next() (*search.DocumentMatch, error) {
return s.searcher.Next()
}
func (s *TermPrefixSearcher) Advance(ID string) (*search.DocumentMatch, error) {
return s.searcher.Next()
}
func (s *TermPrefixSearcher) Close() error {
return s.searcher.Close()
}
func (s *TermPrefixSearcher) Min() int {
return 0
}