forked from blevesearch/bleve
/
snapshot_index.go
503 lines (437 loc) · 12.2 KB
/
snapshot_index.go
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// Copyright (c) 2017 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 scorch
import (
"bytes"
"container/heap"
"encoding/binary"
"fmt"
"sort"
"sync"
"sync/atomic"
"github.com/RoaringBitmap/roaring"
"github.com/blevesearch/bleve/document"
"github.com/blevesearch/bleve/index"
"github.com/blevesearch/bleve/index/scorch/segment"
)
type asynchSegmentResult struct {
dictItr segment.DictionaryIterator
index int
docs *roaring.Bitmap
postings segment.PostingsList
err error
}
type IndexSnapshot struct {
parent *Scorch
segment []*SegmentSnapshot
offsets []uint64
internal map[string][]byte
epoch uint64
m sync.Mutex // Protects the fields that follow.
refs int64
}
func (i *IndexSnapshot) Segments() []*SegmentSnapshot {
return i.segment
}
func (i *IndexSnapshot) Internal() map[string][]byte {
return i.internal
}
func (i *IndexSnapshot) AddRef() {
i.m.Lock()
i.refs++
i.m.Unlock()
}
func (i *IndexSnapshot) DecRef() (err error) {
i.m.Lock()
i.refs--
if i.refs == 0 {
for _, s := range i.segment {
if s != nil {
err2 := s.segment.DecRef()
if err == nil {
err = err2
}
}
}
if i.parent != nil {
go i.parent.AddEligibleForRemoval(i.epoch)
}
}
i.m.Unlock()
return err
}
func (i *IndexSnapshot) newIndexSnapshotFieldDict(field string, makeItr func(i segment.TermDictionary) segment.DictionaryIterator) (*IndexSnapshotFieldDict, error) {
results := make(chan *asynchSegmentResult)
for index, segment := range i.segment {
go func(index int, segment *SegmentSnapshot) {
dict, err := segment.Dictionary(field)
if err != nil {
results <- &asynchSegmentResult{err: err}
} else {
results <- &asynchSegmentResult{dictItr: makeItr(dict)}
}
}(index, segment)
}
var err error
rv := &IndexSnapshotFieldDict{
snapshot: i,
cursors: make([]*segmentDictCursor, 0, len(i.segment)),
}
for count := 0; count < len(i.segment); count++ {
asr := <-results
if asr.err != nil && err == nil {
err = asr.err
} else {
next, err2 := asr.dictItr.Next()
if err2 != nil && err == nil {
err = err2
}
if next != nil {
rv.cursors = append(rv.cursors, &segmentDictCursor{
itr: asr.dictItr,
curr: next,
})
}
}
}
// after ensuring we've read all items on channel
if err != nil {
return nil, err
}
// prepare heap
heap.Init(rv)
return rv, nil
}
func (i *IndexSnapshot) FieldDict(field string) (index.FieldDict, error) {
return i.newIndexSnapshotFieldDict(field, func(i segment.TermDictionary) segment.DictionaryIterator {
return i.Iterator()
})
}
func (i *IndexSnapshot) FieldDictRange(field string, startTerm []byte,
endTerm []byte) (index.FieldDict, error) {
return i.newIndexSnapshotFieldDict(field, func(i segment.TermDictionary) segment.DictionaryIterator {
return i.RangeIterator(string(startTerm), string(endTerm))
})
}
func (i *IndexSnapshot) FieldDictPrefix(field string,
termPrefix []byte) (index.FieldDict, error) {
return i.newIndexSnapshotFieldDict(field, func(i segment.TermDictionary) segment.DictionaryIterator {
return i.PrefixIterator(string(termPrefix))
})
}
func (i *IndexSnapshot) DocIDReaderAll() (index.DocIDReader, error) {
results := make(chan *asynchSegmentResult)
for index, segment := range i.segment {
go func(index int, segment *SegmentSnapshot) {
results <- &asynchSegmentResult{
index: index,
docs: segment.DocNumbersLive(),
}
}(index, segment)
}
return i.newDocIDReader(results)
}
func (i *IndexSnapshot) DocIDReaderOnly(ids []string) (index.DocIDReader, error) {
results := make(chan *asynchSegmentResult)
for index, segment := range i.segment {
go func(index int, segment *SegmentSnapshot) {
docs, err := segment.DocNumbers(ids)
if err != nil {
results <- &asynchSegmentResult{err: err}
} else {
results <- &asynchSegmentResult{
index: index,
docs: docs,
}
}
}(index, segment)
}
return i.newDocIDReader(results)
}
func (i *IndexSnapshot) newDocIDReader(results chan *asynchSegmentResult) (index.DocIDReader, error) {
rv := &IndexSnapshotDocIDReader{
snapshot: i,
iterators: make([]roaring.IntIterable, len(i.segment)),
}
var err error
for count := 0; count < len(i.segment); count++ {
asr := <-results
if asr.err != nil && err != nil {
err = asr.err
} else {
rv.iterators[asr.index] = asr.docs.Iterator()
}
}
if err != nil {
return nil, err
}
return rv, nil
}
func (i *IndexSnapshot) Fields() ([]string, error) {
// FIXME not making this concurrent for now as it's not used in hot path
// of any searches at the moment (just a debug aid)
fieldsMap := map[string]struct{}{}
for _, segment := range i.segment {
fields := segment.Fields()
for _, field := range fields {
fieldsMap[field] = struct{}{}
}
}
rv := make([]string, 0, len(fieldsMap))
for k := range fieldsMap {
rv = append(rv, k)
}
return rv, nil
}
func (i *IndexSnapshot) GetInternal(key []byte) ([]byte, error) {
return i.internal[string(key)], nil
}
func (i *IndexSnapshot) DocCount() (uint64, error) {
var rv uint64
for _, segment := range i.segment {
rv += segment.Count()
}
return rv, nil
}
func (i *IndexSnapshot) Document(id string) (rv *document.Document, err error) {
// FIXME could be done more efficiently directly, but reusing for simplicity
tfr, err := i.TermFieldReader([]byte(id), "_id", false, false, false)
if err != nil {
return nil, err
}
defer func() {
if cerr := tfr.Close(); err == nil && cerr != nil {
err = cerr
}
}()
next, err := tfr.Next(nil)
if err != nil {
return nil, err
}
if next == nil {
// no such doc exists
return nil, nil
}
docNum, err := docInternalToNumber(next.ID)
if err != nil {
return nil, err
}
segmentIndex, localDocNum := i.segmentIndexAndLocalDocNumFromGlobal(docNum)
rv = document.NewDocument(id)
err = i.segment[segmentIndex].VisitDocument(localDocNum, func(name string, typ byte, value []byte, pos []uint64) bool {
if name == "_id" {
return true
}
switch typ {
case 't':
rv.AddField(document.NewTextField(name, pos, value))
case 'n':
rv.AddField(document.NewNumericFieldFromBytes(name, pos, value))
case 'd':
rv.AddField(document.NewDateTimeFieldFromBytes(name, pos, value))
case 'b':
rv.AddField(document.NewBooleanFieldFromBytes(name, pos, value))
case 'g':
rv.AddField(document.NewGeoPointFieldFromBytes(name, pos, value))
}
return true
})
if err != nil {
return nil, err
}
return rv, nil
}
func (i *IndexSnapshot) segmentIndexAndLocalDocNumFromGlobal(docNum uint64) (int, uint64) {
segmentIndex := sort.Search(len(i.offsets),
func(x int) bool {
return i.offsets[x] > docNum
}) - 1
localDocNum := docNum - i.offsets[segmentIndex]
return int(segmentIndex), localDocNum
}
func (i *IndexSnapshot) ExternalID(id index.IndexInternalID) (string, error) {
docNum, err := docInternalToNumber(id)
if err != nil {
return "", err
}
segmentIndex, localDocNum := i.segmentIndexAndLocalDocNumFromGlobal(docNum)
var found bool
var rv string
err = i.segment[segmentIndex].VisitDocument(localDocNum, func(field string, typ byte, value []byte, pos []uint64) bool {
if field == "_id" {
found = true
rv = string(value)
return false
}
return true
})
if err != nil {
return "", err
}
if found {
return rv, nil
}
return "", fmt.Errorf("document number %d not found", docNum)
}
func (i *IndexSnapshot) InternalID(id string) (rv index.IndexInternalID, err error) {
// FIXME could be done more efficiently directly, but reusing for simplicity
tfr, err := i.TermFieldReader([]byte(id), "_id", false, false, false)
if err != nil {
return nil, err
}
defer func() {
if cerr := tfr.Close(); err == nil && cerr != nil {
err = cerr
}
}()
next, err := tfr.Next(nil)
if err != nil || next == nil {
return nil, err
}
return next.ID, nil
}
func (i *IndexSnapshot) TermFieldReader(term []byte, field string, includeFreq,
includeNorm, includeTermVectors bool) (index.TermFieldReader, error) {
rv := &IndexSnapshotTermFieldReader{
term: term,
field: field,
snapshot: i,
postings: make([]segment.PostingsList, len(i.segment)),
iterators: make([]segment.PostingsIterator, len(i.segment)),
includeFreq: includeFreq,
includeNorm: includeNorm,
includeTermVectors: includeTermVectors,
}
for i, segment := range i.segment {
dict, err := segment.Dictionary(field)
if err != nil {
return nil, err
}
pl, err := dict.PostingsList(string(term), nil)
if err != nil {
return nil, err
}
rv.postings[i] = pl
rv.iterators[i] = pl.Iterator()
}
atomic.AddUint64(&i.parent.stats.termSearchersStarted, uint64(1))
return rv, nil
}
func docNumberToBytes(buf []byte, in uint64) []byte {
if len(buf) != 8 {
if cap(buf) >= 8 {
buf = buf[0:8]
} else {
buf = make([]byte, 8)
}
}
binary.BigEndian.PutUint64(buf, in)
return buf
}
func docInternalToNumber(in index.IndexInternalID) (uint64, error) {
var res uint64
err := binary.Read(bytes.NewReader(in), binary.BigEndian, &res)
if err != nil {
return 0, err
}
return res, nil
}
func (i *IndexSnapshot) DocumentVisitFieldTerms(id index.IndexInternalID,
fields []string, visitor index.DocumentFieldTermVisitor) error {
docNum, err := docInternalToNumber(id)
if err != nil {
return err
}
segmentIndex, localDocNum := i.segmentIndexAndLocalDocNumFromGlobal(docNum)
if segmentIndex >= len(i.segment) {
return nil
}
ss := i.segment[segmentIndex]
if zaps, ok := ss.segment.(segment.DocumentFieldTermVisitable); ok {
// get the list of doc value persisted fields
pFields, err := zaps.VisitableDocValueFields()
if err != nil {
return err
}
// assort the fields for which terms look up have to
// be performed runtime
dvPendingFields := extractDvPendingFields(fields, pFields)
if len(dvPendingFields) == 0 {
// all fields are doc value persisted
return zaps.VisitDocumentFieldTerms(localDocNum, fields, visitor)
}
// concurrently trigger the runtime doc value preparations for
// pending fields as well as the visit of the persisted doc values
errCh := make(chan error, 1)
go func() {
defer close(errCh)
err := ss.cachedDocs.prepareFields(fields, ss)
if err != nil {
errCh <- err
}
}()
// visit the persisted dv while the cache preparation is in progress
err = zaps.VisitDocumentFieldTerms(localDocNum, fields, visitor)
if err != nil {
return err
}
// err out if fieldCache preparation failed
err = <-errCh
if err != nil {
return err
}
visitDocumentFieldCacheTerms(localDocNum, dvPendingFields, ss, visitor)
return nil
}
return prepareCacheVisitDocumentFieldTerms(localDocNum, fields, ss, visitor)
}
func prepareCacheVisitDocumentFieldTerms(localDocNum uint64, fields []string,
ss *SegmentSnapshot, visitor index.DocumentFieldTermVisitor) error {
err := ss.cachedDocs.prepareFields(fields, ss)
if err != nil {
return err
}
visitDocumentFieldCacheTerms(localDocNum, fields, ss, visitor)
return nil
}
func visitDocumentFieldCacheTerms(localDocNum uint64, fields []string,
ss *SegmentSnapshot, visitor index.DocumentFieldTermVisitor) {
for _, field := range fields {
if cachedFieldDocs, exists := ss.cachedDocs.cache[field]; exists {
if tlist, exists := cachedFieldDocs.docs[localDocNum]; exists {
for {
i := bytes.Index(tlist, TermSeparatorSplitSlice)
if i < 0 {
break
}
visitor(field, tlist[0:i])
tlist = tlist[i+1:]
}
}
}
}
}
func extractDvPendingFields(requestedFields, persistedFields []string) []string {
removeMap := map[string]struct{}{}
for _, str := range persistedFields {
removeMap[str] = struct{}{}
}
rv := make([]string, 0, len(requestedFields))
for _, s := range requestedFields {
if _, ok := removeMap[s]; !ok {
rv = append(rv, s)
}
}
return rv
}