gitea/vendor/github.com/blevesearch/bleve/index/upsidedown/field_dict.go
2017-01-25 10:43:02 +08:00

78 lines
2.2 KiB
Go
Vendored

// 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 upsidedown
import (
"fmt"
"github.com/blevesearch/bleve/index"
"github.com/blevesearch/bleve/index/store"
)
type UpsideDownCouchFieldDict struct {
indexReader *IndexReader
iterator store.KVIterator
dictRow *DictionaryRow
dictEntry *index.DictEntry
field uint16
}
func newUpsideDownCouchFieldDict(indexReader *IndexReader, field uint16, startTerm, endTerm []byte) (*UpsideDownCouchFieldDict, error) {
startKey := NewDictionaryRow(startTerm, field, 0).Key()
if endTerm == nil {
endTerm = []byte{ByteSeparator}
} else {
endTerm = incrementBytes(endTerm)
}
endKey := NewDictionaryRow(endTerm, field, 0).Key()
it := indexReader.kvreader.RangeIterator(startKey, endKey)
return &UpsideDownCouchFieldDict{
indexReader: indexReader,
iterator: it,
dictRow: &DictionaryRow{}, // Pre-alloced, reused row.
dictEntry: &index.DictEntry{}, // Pre-alloced, reused entry.
field: field,
}, nil
}
func (r *UpsideDownCouchFieldDict) Next() (*index.DictEntry, error) {
key, val, valid := r.iterator.Current()
if !valid {
return nil, nil
}
err := r.dictRow.parseDictionaryK(key)
if err != nil {
return nil, fmt.Errorf("unexpected error parsing dictionary row key: %v", err)
}
err = r.dictRow.parseDictionaryV(val)
if err != nil {
return nil, fmt.Errorf("unexpected error parsing dictionary row val: %v", err)
}
r.dictEntry.Term = string(r.dictRow.term)
r.dictEntry.Count = r.dictRow.count
// advance the iterator to the next term
r.iterator.Next()
return r.dictEntry, nil
}
func (r *UpsideDownCouchFieldDict) Close() error {
return r.iterator.Close()
}