forked from blevesearch/bleve
/
build.go
665 lines (563 loc) · 16.2 KB
/
build.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 zap
import (
"bufio"
"bytes"
"encoding/binary"
"math"
"os"
"sort"
"github.com/Smerity/govarint"
"github.com/blevesearch/bleve/index/scorch/segment/mem"
"github.com/couchbase/vellum"
"github.com/golang/snappy"
)
const version uint32 = 3
const fieldNotUninverted = math.MaxUint64
// PersistSegmentBase persists SegmentBase in the zap file format.
func PersistSegmentBase(sb *SegmentBase, path string) error {
flag := os.O_RDWR | os.O_CREATE
f, err := os.OpenFile(path, flag, 0600)
if err != nil {
return err
}
cleanup := func() {
_ = f.Close()
_ = os.Remove(path)
}
br := bufio.NewWriter(f)
_, err = br.Write(sb.mem)
if err != nil {
cleanup()
return err
}
err = persistFooter(sb.numDocs, sb.storedIndexOffset, sb.fieldsIndexOffset, sb.docValueOffset,
sb.chunkFactor, sb.memCRC, br)
if err != nil {
cleanup()
return err
}
err = br.Flush()
if err != nil {
cleanup()
return err
}
err = f.Sync()
if err != nil {
cleanup()
return err
}
err = f.Close()
if err != nil {
cleanup()
return err
}
return nil
}
// PersistSegment takes the in-memory segment and persists it to
// the specified path in the zap file format.
func PersistSegment(memSegment *mem.Segment, path string, chunkFactor uint32) error {
flag := os.O_RDWR | os.O_CREATE
f, err := os.OpenFile(path, flag, 0600)
if err != nil {
return err
}
cleanup := func() {
_ = f.Close()
_ = os.Remove(path)
}
// buffer the output
br := bufio.NewWriter(f)
// wrap it for counting (tracking offsets)
cr := NewCountHashWriter(br)
numDocs, storedIndexOffset, fieldsIndexOffset, docValueOffset, _, err :=
persistBase(memSegment, cr, chunkFactor)
if err != nil {
cleanup()
return err
}
err = persistFooter(numDocs, storedIndexOffset, fieldsIndexOffset, docValueOffset,
chunkFactor, cr.Sum32(), cr)
if err != nil {
cleanup()
return err
}
err = br.Flush()
if err != nil {
cleanup()
return err
}
err = f.Sync()
if err != nil {
cleanup()
return err
}
err = f.Close()
if err != nil {
cleanup()
return err
}
return nil
}
func persistBase(memSegment *mem.Segment, cr *CountHashWriter, chunkFactor uint32) (
numDocs, storedIndexOffset, fieldsIndexOffset, docValueOffset uint64,
dictLocs []uint64, err error) {
docValueOffset = uint64(fieldNotUninverted)
if len(memSegment.Stored) > 0 {
storedIndexOffset, err = persistStored(memSegment, cr)
if err != nil {
return 0, 0, 0, 0, nil, err
}
freqOffsets, locOffsets, err := persistPostingDetails(memSegment, cr, chunkFactor)
if err != nil {
return 0, 0, 0, 0, nil, err
}
postingsListLocs, err := persistPostingsLocs(memSegment, cr)
if err != nil {
return 0, 0, 0, 0, nil, err
}
postingsLocs, err := persistPostingsLists(memSegment, cr, postingsListLocs, freqOffsets, locOffsets)
if err != nil {
return 0, 0, 0, 0, nil, err
}
dictLocs, err = persistDictionary(memSegment, cr, postingsLocs)
if err != nil {
return 0, 0, 0, 0, nil, err
}
docValueOffset, err = persistFieldDocValues(memSegment, cr, chunkFactor)
if err != nil {
return 0, 0, 0, 0, nil, err
}
} else {
dictLocs = make([]uint64, len(memSegment.FieldsInv))
}
fieldsIndexOffset, err = persistFields(memSegment.FieldsInv, cr, dictLocs)
if err != nil {
return 0, 0, 0, 0, nil, err
}
return uint64(len(memSegment.Stored)), storedIndexOffset, fieldsIndexOffset, docValueOffset,
dictLocs, nil
}
func persistStored(memSegment *mem.Segment, w *CountHashWriter) (uint64, error) {
var curr int
var metaBuf bytes.Buffer
var data, compressed []byte
metaEncoder := govarint.NewU64Base128Encoder(&metaBuf)
docNumOffsets := make(map[int]uint64, len(memSegment.Stored))
for docNum, storedValues := range memSegment.Stored {
if docNum != 0 {
// reset buffer if necessary
curr = 0
metaBuf.Reset()
data = data[:0]
compressed = compressed[:0]
}
st := memSegment.StoredTypes[docNum]
sp := memSegment.StoredPos[docNum]
// encode fields in order
for fieldID := range memSegment.FieldsInv {
if storedFieldValues, ok := storedValues[uint16(fieldID)]; ok {
stf := st[uint16(fieldID)]
spf := sp[uint16(fieldID)]
var err2 error
curr, data, err2 = persistStoredFieldValues(fieldID,
storedFieldValues, stf, spf, curr, metaEncoder, data)
if err2 != nil {
return 0, err2
}
}
}
metaEncoder.Close()
metaBytes := metaBuf.Bytes()
// compress the data
compressed = snappy.Encode(compressed, data)
// record where we're about to start writing
docNumOffsets[docNum] = uint64(w.Count())
// write out the meta len and compressed data len
_, err := writeUvarints(w, uint64(len(metaBytes)), uint64(len(compressed)))
if err != nil {
return 0, err
}
// now write the meta
_, err = w.Write(metaBytes)
if err != nil {
return 0, err
}
// now write the compressed data
_, err = w.Write(compressed)
if err != nil {
return 0, err
}
}
// return value is the start of the stored index
rv := uint64(w.Count())
// now write out the stored doc index
for docNum := range memSegment.Stored {
err := binary.Write(w, binary.BigEndian, docNumOffsets[docNum])
if err != nil {
return 0, err
}
}
return rv, nil
}
func persistStoredFieldValues(fieldID int,
storedFieldValues [][]byte, stf []byte, spf [][]uint64,
curr int, metaEncoder *govarint.Base128Encoder, data []byte) (
int, []byte, error) {
for i := 0; i < len(storedFieldValues); i++ {
// encode field
_, err := metaEncoder.PutU64(uint64(fieldID))
if err != nil {
return 0, nil, err
}
// encode type
_, err = metaEncoder.PutU64(uint64(stf[i]))
if err != nil {
return 0, nil, err
}
// encode start offset
_, err = metaEncoder.PutU64(uint64(curr))
if err != nil {
return 0, nil, err
}
// end len
_, err = metaEncoder.PutU64(uint64(len(storedFieldValues[i])))
if err != nil {
return 0, nil, err
}
// encode number of array pos
_, err = metaEncoder.PutU64(uint64(len(spf[i])))
if err != nil {
return 0, nil, err
}
// encode all array positions
for _, pos := range spf[i] {
_, err = metaEncoder.PutU64(pos)
if err != nil {
return 0, nil, err
}
}
data = append(data, storedFieldValues[i]...)
curr += len(storedFieldValues[i])
}
return curr, data, nil
}
func persistPostingDetails(memSegment *mem.Segment, w *CountHashWriter, chunkFactor uint32) ([]uint64, []uint64, error) {
var freqOffsets, locOfffsets []uint64
tfEncoder := newChunkedIntCoder(uint64(chunkFactor), uint64(len(memSegment.Stored)-1))
for postingID := range memSegment.Postings {
if postingID != 0 {
tfEncoder.Reset()
}
freqs := memSegment.Freqs[postingID]
norms := memSegment.Norms[postingID]
postingsListItr := memSegment.Postings[postingID].Iterator()
var offset int
for postingsListItr.HasNext() {
docNum := uint64(postingsListItr.Next())
// put freq
err := tfEncoder.Add(docNum, freqs[offset])
if err != nil {
return nil, nil, err
}
// put norm
norm := norms[offset]
normBits := math.Float32bits(norm)
err = tfEncoder.Add(docNum, uint64(normBits))
if err != nil {
return nil, nil, err
}
offset++
}
// record where this postings freq info starts
freqOffsets = append(freqOffsets, uint64(w.Count()))
tfEncoder.Close()
_, err := tfEncoder.Write(w)
if err != nil {
return nil, nil, err
}
}
// now do it again for the locations
locEncoder := newChunkedIntCoder(uint64(chunkFactor), uint64(len(memSegment.Stored)-1))
for postingID := range memSegment.Postings {
if postingID != 0 {
locEncoder.Reset()
}
freqs := memSegment.Freqs[postingID]
locfields := memSegment.Locfields[postingID]
locpos := memSegment.Locpos[postingID]
locstarts := memSegment.Locstarts[postingID]
locends := memSegment.Locends[postingID]
locarraypos := memSegment.Locarraypos[postingID]
postingsListItr := memSegment.Postings[postingID].Iterator()
var offset int
var locOffset int
for postingsListItr.HasNext() {
docNum := uint64(postingsListItr.Next())
for i := 0; i < int(freqs[offset]); i++ {
if len(locfields) > 0 {
// put field
err := locEncoder.Add(docNum, uint64(locfields[locOffset]))
if err != nil {
return nil, nil, err
}
// put pos
err = locEncoder.Add(docNum, locpos[locOffset])
if err != nil {
return nil, nil, err
}
// put start
err = locEncoder.Add(docNum, locstarts[locOffset])
if err != nil {
return nil, nil, err
}
// put end
err = locEncoder.Add(docNum, locends[locOffset])
if err != nil {
return nil, nil, err
}
// put the number of array positions to follow
num := len(locarraypos[locOffset])
err = locEncoder.Add(docNum, uint64(num))
if err != nil {
return nil, nil, err
}
// put each array position
for _, pos := range locarraypos[locOffset] {
err = locEncoder.Add(docNum, pos)
if err != nil {
return nil, nil, err
}
}
}
locOffset++
}
offset++
}
// record where this postings loc info starts
locOfffsets = append(locOfffsets, uint64(w.Count()))
locEncoder.Close()
_, err := locEncoder.Write(w)
if err != nil {
return nil, nil, err
}
}
return freqOffsets, locOfffsets, nil
}
func persistPostingsLocs(memSegment *mem.Segment, w *CountHashWriter) (rv []uint64, err error) {
rv = make([]uint64, 0, len(memSegment.PostingsLocs))
var reuseBuf bytes.Buffer
reuseBufVarint := make([]byte, binary.MaxVarintLen64)
for postingID := range memSegment.PostingsLocs {
// record where we start this posting loc
rv = append(rv, uint64(w.Count()))
// write out the length and bitmap
_, err = writeRoaringWithLen(memSegment.PostingsLocs[postingID], w, &reuseBuf, reuseBufVarint)
if err != nil {
return nil, err
}
}
return rv, nil
}
func persistPostingsLists(memSegment *mem.Segment, w *CountHashWriter,
postingsListLocs, freqOffsets, locOffsets []uint64) (rv []uint64, err error) {
rv = make([]uint64, 0, len(memSegment.Postings))
var reuseBuf bytes.Buffer
reuseBufVarint := make([]byte, binary.MaxVarintLen64)
for postingID := range memSegment.Postings {
// record where we start this posting list
rv = append(rv, uint64(w.Count()))
// write out the term info, loc info, and loc posting list offset
_, err = writeUvarints(w, freqOffsets[postingID],
locOffsets[postingID], postingsListLocs[postingID])
if err != nil {
return nil, err
}
// write out the length and bitmap
_, err = writeRoaringWithLen(memSegment.Postings[postingID], w, &reuseBuf, reuseBufVarint)
if err != nil {
return nil, err
}
}
return rv, nil
}
func persistDictionary(memSegment *mem.Segment, w *CountHashWriter, postingsLocs []uint64) ([]uint64, error) {
rv := make([]uint64, 0, len(memSegment.DictKeys))
varintBuf := make([]byte, binary.MaxVarintLen64)
var buffer bytes.Buffer
for fieldID, fieldTerms := range memSegment.DictKeys {
if fieldID != 0 {
buffer.Reset()
}
// start a new vellum for this field
builder, err := vellum.New(&buffer, nil)
if err != nil {
return nil, err
}
dict := memSegment.Dicts[fieldID]
// now walk the dictionary in order of fieldTerms (already sorted)
for _, fieldTerm := range fieldTerms {
postingID := dict[fieldTerm] - 1
postingsAddr := postingsLocs[postingID]
err = builder.Insert([]byte(fieldTerm), postingsAddr)
if err != nil {
return nil, err
}
}
err = builder.Close()
if err != nil {
return nil, err
}
// record where this dictionary starts
rv = append(rv, uint64(w.Count()))
vellumData := buffer.Bytes()
// write out the length of the vellum data
n := binary.PutUvarint(varintBuf, uint64(len(vellumData)))
_, err = w.Write(varintBuf[:n])
if err != nil {
return nil, err
}
// write this vellum to disk
_, err = w.Write(vellumData)
if err != nil {
return nil, err
}
}
return rv, nil
}
type docIDRange []uint64
func (a docIDRange) Len() int { return len(a) }
func (a docIDRange) Swap(i, j int) { a[i], a[j] = a[j], a[i] }
func (a docIDRange) Less(i, j int) bool { return a[i] < a[j] }
func persistDocValues(memSegment *mem.Segment, w *CountHashWriter,
chunkFactor uint32) (map[uint16]uint64, error) {
fieldChunkOffsets := make(map[uint16]uint64, len(memSegment.FieldsInv))
fdvEncoder := newChunkedContentCoder(uint64(chunkFactor), uint64(len(memSegment.Stored)-1))
for fieldID := range memSegment.DocValueFields {
field := memSegment.FieldsInv[fieldID]
docTermMap := make(map[uint64][]byte, 0)
dict, err := memSegment.Dictionary(field)
if err != nil {
return nil, err
}
dictItr := dict.Iterator()
next, err := dictItr.Next()
for err == nil && next != nil {
postings, err1 := dict.PostingsList(next.Term, nil)
if err1 != nil {
return nil, err
}
postingsItr := postings.Iterator()
nextPosting, err2 := postingsItr.Next()
for err2 == nil && nextPosting != nil {
docNum := nextPosting.Number()
docTermMap[docNum] = append(docTermMap[docNum], []byte(next.Term)...)
docTermMap[docNum] = append(docTermMap[docNum], termSeparator)
nextPosting, err2 = postingsItr.Next()
}
if err2 != nil {
return nil, err2
}
next, err = dictItr.Next()
}
if err != nil {
return nil, err
}
// sort wrt to docIDs
var docNumbers docIDRange
for k := range docTermMap {
docNumbers = append(docNumbers, k)
}
sort.Sort(docNumbers)
for _, docNum := range docNumbers {
err = fdvEncoder.Add(docNum, docTermMap[docNum])
if err != nil {
return nil, err
}
}
fieldChunkOffsets[fieldID] = uint64(w.Count())
err = fdvEncoder.Close()
if err != nil {
return nil, err
}
// persist the doc value details for this field
_, err = fdvEncoder.Write(w)
if err != nil {
return nil, err
}
// reseting encoder for the next field
fdvEncoder.Reset()
}
return fieldChunkOffsets, nil
}
func persistFieldDocValues(memSegment *mem.Segment, w *CountHashWriter,
chunkFactor uint32) (uint64, error) {
fieldDvOffsets, err := persistDocValues(memSegment, w, chunkFactor)
if err != nil {
return 0, err
}
fieldDocValuesOffset := uint64(w.Count())
buf := make([]byte, binary.MaxVarintLen64)
offset := uint64(0)
ok := true
for fieldID := range memSegment.FieldsInv {
// if the field isn't configured for docValue, then mark
// the offset accordingly
if offset, ok = fieldDvOffsets[uint16(fieldID)]; !ok {
offset = fieldNotUninverted
}
n := binary.PutUvarint(buf, uint64(offset))
_, err := w.Write(buf[:n])
if err != nil {
return 0, err
}
}
return fieldDocValuesOffset, nil
}
func NewSegmentBase(memSegment *mem.Segment, chunkFactor uint32) (*SegmentBase, error) {
var br bytes.Buffer
cr := NewCountHashWriter(&br)
numDocs, storedIndexOffset, fieldsIndexOffset, docValueOffset, dictLocs, err :=
persistBase(memSegment, cr, chunkFactor)
if err != nil {
return nil, err
}
return InitSegmentBase(br.Bytes(), cr.Sum32(), chunkFactor,
memSegment.FieldsMap, memSegment.FieldsInv, numDocs,
storedIndexOffset, fieldsIndexOffset, docValueOffset, dictLocs)
}
func InitSegmentBase(mem []byte, memCRC uint32, chunkFactor uint32,
fieldsMap map[string]uint16, fieldsInv []string, numDocs uint64,
storedIndexOffset uint64, fieldsIndexOffset uint64, docValueOffset uint64,
dictLocs []uint64) (*SegmentBase, error) {
sb := &SegmentBase{
mem: mem,
memCRC: memCRC,
chunkFactor: chunkFactor,
fieldsMap: fieldsMap,
fieldsInv: fieldsInv,
numDocs: numDocs,
storedIndexOffset: storedIndexOffset,
fieldsIndexOffset: fieldsIndexOffset,
docValueOffset: docValueOffset,
dictLocs: dictLocs,
fieldDvIterMap: make(map[uint16]*docValueIterator),
}
err := sb.loadDvIterators()
if err != nil {
return nil, err
}
return sb, nil
}