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

326 lines
8.5 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 upsidedown
import (
"bytes"
"sort"
"sync/atomic"
"github.com/blevesearch/bleve/index"
"github.com/blevesearch/bleve/index/store"
)
type UpsideDownCouchTermFieldReader struct {
count uint64
indexReader *IndexReader
iterator store.KVIterator
term []byte
tfrNext *TermFrequencyRow
keyBuf []byte
field uint16
}
func newUpsideDownCouchTermFieldReader(indexReader *IndexReader, term []byte, field uint16, includeFreq, includeNorm, includeTermVectors bool) (*UpsideDownCouchTermFieldReader, error) {
dictionaryRow := NewDictionaryRow(term, field, 0)
val, err := indexReader.kvreader.Get(dictionaryRow.Key())
if err != nil {
return nil, err
}
if val == nil {
atomic.AddUint64(&indexReader.index.stats.termSearchersStarted, uint64(1))
return &UpsideDownCouchTermFieldReader{
count: 0,
term: term,
tfrNext: &TermFrequencyRow{},
field: field,
}, nil
}
err = dictionaryRow.parseDictionaryV(val)
if err != nil {
return nil, err
}
tfr := NewTermFrequencyRow(term, field, []byte{}, 0, 0)
it := indexReader.kvreader.PrefixIterator(tfr.Key())
atomic.AddUint64(&indexReader.index.stats.termSearchersStarted, uint64(1))
return &UpsideDownCouchTermFieldReader{
indexReader: indexReader,
iterator: it,
count: dictionaryRow.count,
term: term,
field: field,
}, nil
}
func (r *UpsideDownCouchTermFieldReader) Count() uint64 {
return r.count
}
func (r *UpsideDownCouchTermFieldReader) Next(preAlloced *index.TermFieldDoc) (*index.TermFieldDoc, error) {
if r.iterator != nil {
// We treat tfrNext also like an initialization flag, which
// tells us whether we need to invoke the underlying
// iterator.Next(). The first time, don't call iterator.Next().
if r.tfrNext != nil {
r.iterator.Next()
} else {
r.tfrNext = &TermFrequencyRow{}
}
key, val, valid := r.iterator.Current()
if valid {
tfr := r.tfrNext
err := tfr.parseKDoc(key, r.term)
if err != nil {
return nil, err
}
err = tfr.parseV(val)
if err != nil {
return nil, err
}
rv := preAlloced
if rv == nil {
rv = &index.TermFieldDoc{}
}
rv.ID = append(rv.ID, tfr.doc...)
rv.Freq = tfr.freq
rv.Norm = float64(tfr.norm)
if tfr.vectors != nil {
rv.Vectors = r.indexReader.index.termFieldVectorsFromTermVectors(tfr.vectors)
}
return rv, nil
}
}
return nil, nil
}
func (r *UpsideDownCouchTermFieldReader) Advance(docID index.IndexInternalID, preAlloced *index.TermFieldDoc) (rv *index.TermFieldDoc, err error) {
if r.iterator != nil {
if r.tfrNext == nil {
r.tfrNext = &TermFrequencyRow{}
}
tfr := InitTermFrequencyRow(r.tfrNext, r.term, r.field, docID, 0, 0)
r.keyBuf, err = tfr.KeyAppendTo(r.keyBuf[:0])
if err != nil {
return nil, err
}
r.iterator.Seek(r.keyBuf)
key, val, valid := r.iterator.Current()
if valid {
err := tfr.parseKDoc(key, r.term)
if err != nil {
return nil, err
}
err = tfr.parseV(val)
if err != nil {
return nil, err
}
rv = preAlloced
if rv == nil {
rv = &index.TermFieldDoc{}
}
rv.ID = append(rv.ID, tfr.doc...)
rv.Freq = tfr.freq
rv.Norm = float64(tfr.norm)
if tfr.vectors != nil {
rv.Vectors = r.indexReader.index.termFieldVectorsFromTermVectors(tfr.vectors)
}
return rv, nil
}
}
return nil, nil
}
func (r *UpsideDownCouchTermFieldReader) Close() error {
if r.indexReader != nil {
atomic.AddUint64(&r.indexReader.index.stats.termSearchersFinished, uint64(1))
}
if r.iterator != nil {
return r.iterator.Close()
}
return nil
}
type UpsideDownCouchDocIDReader struct {
indexReader *IndexReader
iterator store.KVIterator
only []string
onlyPos int
onlyMode bool
}
func newUpsideDownCouchDocIDReader(indexReader *IndexReader) (*UpsideDownCouchDocIDReader, error) {
startBytes := []byte{0x0}
endBytes := []byte{0xff}
bisr := NewBackIndexRow(startBytes, nil, nil)
bier := NewBackIndexRow(endBytes, nil, nil)
it := indexReader.kvreader.RangeIterator(bisr.Key(), bier.Key())
return &UpsideDownCouchDocIDReader{
indexReader: indexReader,
iterator: it,
}, nil
}
func newUpsideDownCouchDocIDReaderOnly(indexReader *IndexReader, ids []string) (*UpsideDownCouchDocIDReader, error) {
// ensure ids are sorted
sort.Strings(ids)
startBytes := []byte{0x0}
if len(ids) > 0 {
startBytes = []byte(ids[0])
}
endBytes := []byte{0xff}
if len(ids) > 0 {
endBytes = incrementBytes([]byte(ids[len(ids)-1]))
}
bisr := NewBackIndexRow(startBytes, nil, nil)
bier := NewBackIndexRow(endBytes, nil, nil)
it := indexReader.kvreader.RangeIterator(bisr.Key(), bier.Key())
return &UpsideDownCouchDocIDReader{
indexReader: indexReader,
iterator: it,
only: ids,
onlyMode: true,
}, nil
}
func (r *UpsideDownCouchDocIDReader) Next() (index.IndexInternalID, error) {
key, val, valid := r.iterator.Current()
if r.onlyMode {
var rv index.IndexInternalID
for valid && r.onlyPos < len(r.only) {
br, err := NewBackIndexRowKV(key, val)
if err != nil {
return nil, err
}
if !bytes.Equal(br.doc, []byte(r.only[r.onlyPos])) {
ok := r.nextOnly()
if !ok {
return nil, nil
}
r.iterator.Seek(NewBackIndexRow([]byte(r.only[r.onlyPos]), nil, nil).Key())
key, val, valid = r.iterator.Current()
continue
} else {
rv = append([]byte(nil), br.doc...)
break
}
}
if valid && r.onlyPos < len(r.only) {
ok := r.nextOnly()
if ok {
r.iterator.Seek(NewBackIndexRow([]byte(r.only[r.onlyPos]), nil, nil).Key())
}
return rv, nil
}
} else {
if valid {
br, err := NewBackIndexRowKV(key, val)
if err != nil {
return nil, err
}
rv := append([]byte(nil), br.doc...)
r.iterator.Next()
return rv, nil
}
}
return nil, nil
}
func (r *UpsideDownCouchDocIDReader) Advance(docID index.IndexInternalID) (index.IndexInternalID, error) {
if r.onlyMode {
r.onlyPos = sort.SearchStrings(r.only, string(docID))
if r.onlyPos >= len(r.only) {
// advanced to key after our last only key
return nil, nil
}
r.iterator.Seek(NewBackIndexRow([]byte(r.only[r.onlyPos]), nil, nil).Key())
key, val, valid := r.iterator.Current()
var rv index.IndexInternalID
for valid && r.onlyPos < len(r.only) {
br, err := NewBackIndexRowKV(key, val)
if err != nil {
return nil, err
}
if !bytes.Equal(br.doc, []byte(r.only[r.onlyPos])) {
// the only key we seek'd to didn't exist
// now look for the closest key that did exist in only
r.onlyPos = sort.SearchStrings(r.only, string(br.doc))
if r.onlyPos >= len(r.only) {
// advanced to key after our last only key
return nil, nil
}
// now seek to this new only key
r.iterator.Seek(NewBackIndexRow([]byte(r.only[r.onlyPos]), nil, nil).Key())
key, val, valid = r.iterator.Current()
continue
} else {
rv = append([]byte(nil), br.doc...)
break
}
}
if valid && r.onlyPos < len(r.only) {
ok := r.nextOnly()
if ok {
r.iterator.Seek(NewBackIndexRow([]byte(r.only[r.onlyPos]), nil, nil).Key())
}
return rv, nil
}
} else {
bir := NewBackIndexRow(docID, nil, nil)
r.iterator.Seek(bir.Key())
key, val, valid := r.iterator.Current()
if valid {
br, err := NewBackIndexRowKV(key, val)
if err != nil {
return nil, err
}
rv := append([]byte(nil), br.doc...)
r.iterator.Next()
return rv, nil
}
}
return nil, nil
}
func (r *UpsideDownCouchDocIDReader) Close() error {
return r.iterator.Close()
}
// move the r.only pos forward one, skipping duplicates
// return true if there is more data, or false if we got to the end of the list
func (r *UpsideDownCouchDocIDReader) nextOnly() bool {
// advance 1 position, until we see a different key
// it's already sorted, so this skips duplicates
start := r.onlyPos
r.onlyPos++
for r.onlyPos < len(r.only) && r.only[r.onlyPos] == r.only[start] {
start = r.onlyPos
r.onlyPos++
}
// inidicate if we got to the end of the list
return r.onlyPos < len(r.only)
}