570 lines
14 KiB
Go
Vendored
570 lines
14 KiB
Go
Vendored
// 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 (
|
|
"bytes"
|
|
"encoding/binary"
|
|
"fmt"
|
|
"io"
|
|
"os"
|
|
"sync"
|
|
"unsafe"
|
|
|
|
"github.com/RoaringBitmap/roaring"
|
|
mmap "github.com/blevesearch/mmap-go"
|
|
segment "github.com/blevesearch/scorch_segment_api/v2"
|
|
"github.com/blevesearch/vellum"
|
|
"github.com/golang/snappy"
|
|
)
|
|
|
|
var reflectStaticSizeSegmentBase int
|
|
|
|
func init() {
|
|
var sb SegmentBase
|
|
reflectStaticSizeSegmentBase = int(unsafe.Sizeof(sb))
|
|
}
|
|
|
|
// Open returns a zap impl of a segment
|
|
func (*ZapPlugin) Open(path string) (segment.Segment, error) {
|
|
f, err := os.Open(path)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
mm, err := mmap.Map(f, mmap.RDONLY, 0)
|
|
if err != nil {
|
|
// mmap failed, try to close the file
|
|
_ = f.Close()
|
|
return nil, err
|
|
}
|
|
|
|
rv := &Segment{
|
|
SegmentBase: SegmentBase{
|
|
mem: mm[0 : len(mm)-FooterSize],
|
|
fieldsMap: make(map[string]uint16),
|
|
fieldDvReaders: make(map[uint16]*docValueReader),
|
|
fieldFSTs: make(map[uint16]*vellum.FST),
|
|
},
|
|
f: f,
|
|
mm: mm,
|
|
path: path,
|
|
refs: 1,
|
|
}
|
|
rv.SegmentBase.updateSize()
|
|
|
|
err = rv.loadConfig()
|
|
if err != nil {
|
|
_ = rv.Close()
|
|
return nil, err
|
|
}
|
|
|
|
err = rv.loadFields()
|
|
if err != nil {
|
|
_ = rv.Close()
|
|
return nil, err
|
|
}
|
|
|
|
err = rv.loadDvReaders()
|
|
if err != nil {
|
|
_ = rv.Close()
|
|
return nil, err
|
|
}
|
|
|
|
return rv, nil
|
|
}
|
|
|
|
// SegmentBase is a memory only, read-only implementation of the
|
|
// segment.Segment interface, using zap's data representation.
|
|
type SegmentBase struct {
|
|
mem []byte
|
|
memCRC uint32
|
|
chunkMode uint32
|
|
fieldsMap map[string]uint16 // fieldName -> fieldID+1
|
|
fieldsInv []string // fieldID -> fieldName
|
|
numDocs uint64
|
|
storedIndexOffset uint64
|
|
fieldsIndexOffset uint64
|
|
docValueOffset uint64
|
|
dictLocs []uint64
|
|
fieldDvReaders map[uint16]*docValueReader // naive chunk cache per field
|
|
fieldDvNames []string // field names cached in fieldDvReaders
|
|
size uint64
|
|
|
|
m sync.Mutex
|
|
fieldFSTs map[uint16]*vellum.FST
|
|
}
|
|
|
|
func (sb *SegmentBase) Size() int {
|
|
return int(sb.size)
|
|
}
|
|
|
|
func (sb *SegmentBase) updateSize() {
|
|
sizeInBytes := reflectStaticSizeSegmentBase +
|
|
cap(sb.mem)
|
|
|
|
// fieldsMap
|
|
for k := range sb.fieldsMap {
|
|
sizeInBytes += (len(k) + SizeOfString) + SizeOfUint16
|
|
}
|
|
|
|
// fieldsInv, dictLocs
|
|
for _, entry := range sb.fieldsInv {
|
|
sizeInBytes += len(entry) + SizeOfString
|
|
}
|
|
sizeInBytes += len(sb.dictLocs) * SizeOfUint64
|
|
|
|
// fieldDvReaders
|
|
for _, v := range sb.fieldDvReaders {
|
|
sizeInBytes += SizeOfUint16 + SizeOfPtr
|
|
if v != nil {
|
|
sizeInBytes += v.size()
|
|
}
|
|
}
|
|
|
|
sb.size = uint64(sizeInBytes)
|
|
}
|
|
|
|
func (sb *SegmentBase) AddRef() {}
|
|
func (sb *SegmentBase) DecRef() (err error) { return nil }
|
|
func (sb *SegmentBase) Close() (err error) { return nil }
|
|
|
|
// Segment implements a persisted segment.Segment interface, by
|
|
// embedding an mmap()'ed SegmentBase.
|
|
type Segment struct {
|
|
SegmentBase
|
|
|
|
f *os.File
|
|
mm mmap.MMap
|
|
path string
|
|
version uint32
|
|
crc uint32
|
|
|
|
m sync.Mutex // Protects the fields that follow.
|
|
refs int64
|
|
}
|
|
|
|
func (s *Segment) Size() int {
|
|
// 8 /* size of file pointer */
|
|
// 4 /* size of version -> uint32 */
|
|
// 4 /* size of crc -> uint32 */
|
|
sizeOfUints := 16
|
|
|
|
sizeInBytes := (len(s.path) + SizeOfString) + sizeOfUints
|
|
|
|
// mutex, refs -> int64
|
|
sizeInBytes += 16
|
|
|
|
// do not include the mmap'ed part
|
|
return sizeInBytes + s.SegmentBase.Size() - cap(s.mem)
|
|
}
|
|
|
|
func (s *Segment) AddRef() {
|
|
s.m.Lock()
|
|
s.refs++
|
|
s.m.Unlock()
|
|
}
|
|
|
|
func (s *Segment) DecRef() (err error) {
|
|
s.m.Lock()
|
|
s.refs--
|
|
if s.refs == 0 {
|
|
err = s.closeActual()
|
|
}
|
|
s.m.Unlock()
|
|
return err
|
|
}
|
|
|
|
func (s *Segment) loadConfig() error {
|
|
crcOffset := len(s.mm) - 4
|
|
s.crc = binary.BigEndian.Uint32(s.mm[crcOffset : crcOffset+4])
|
|
|
|
verOffset := crcOffset - 4
|
|
s.version = binary.BigEndian.Uint32(s.mm[verOffset : verOffset+4])
|
|
if s.version != Version {
|
|
return fmt.Errorf("unsupported version %d", s.version)
|
|
}
|
|
|
|
chunkOffset := verOffset - 4
|
|
s.chunkMode = binary.BigEndian.Uint32(s.mm[chunkOffset : chunkOffset+4])
|
|
|
|
docValueOffset := chunkOffset - 8
|
|
s.docValueOffset = binary.BigEndian.Uint64(s.mm[docValueOffset : docValueOffset+8])
|
|
|
|
fieldsIndexOffset := docValueOffset - 8
|
|
s.fieldsIndexOffset = binary.BigEndian.Uint64(s.mm[fieldsIndexOffset : fieldsIndexOffset+8])
|
|
|
|
storedIndexOffset := fieldsIndexOffset - 8
|
|
s.storedIndexOffset = binary.BigEndian.Uint64(s.mm[storedIndexOffset : storedIndexOffset+8])
|
|
|
|
numDocsOffset := storedIndexOffset - 8
|
|
s.numDocs = binary.BigEndian.Uint64(s.mm[numDocsOffset : numDocsOffset+8])
|
|
return nil
|
|
}
|
|
|
|
func (s *SegmentBase) loadFields() error {
|
|
// NOTE for now we assume the fields index immediately precedes
|
|
// the footer, and if this changes, need to adjust accordingly (or
|
|
// store explicit length), where s.mem was sliced from s.mm in Open().
|
|
fieldsIndexEnd := uint64(len(s.mem))
|
|
|
|
// iterate through fields index
|
|
var fieldID uint64
|
|
for s.fieldsIndexOffset+(8*fieldID) < fieldsIndexEnd {
|
|
addr := binary.BigEndian.Uint64(s.mem[s.fieldsIndexOffset+(8*fieldID) : s.fieldsIndexOffset+(8*fieldID)+8])
|
|
|
|
dictLoc, read := binary.Uvarint(s.mem[addr:fieldsIndexEnd])
|
|
n := uint64(read)
|
|
s.dictLocs = append(s.dictLocs, dictLoc)
|
|
|
|
var nameLen uint64
|
|
nameLen, read = binary.Uvarint(s.mem[addr+n : fieldsIndexEnd])
|
|
n += uint64(read)
|
|
|
|
name := string(s.mem[addr+n : addr+n+nameLen])
|
|
s.fieldsInv = append(s.fieldsInv, name)
|
|
s.fieldsMap[name] = uint16(fieldID + 1)
|
|
|
|
fieldID++
|
|
}
|
|
return nil
|
|
}
|
|
|
|
// Dictionary returns the term dictionary for the specified field
|
|
func (s *SegmentBase) Dictionary(field string) (segment.TermDictionary, error) {
|
|
dict, err := s.dictionary(field)
|
|
if err == nil && dict == nil {
|
|
return emptyDictionary, nil
|
|
}
|
|
return dict, err
|
|
}
|
|
|
|
func (sb *SegmentBase) dictionary(field string) (rv *Dictionary, err error) {
|
|
fieldIDPlus1 := sb.fieldsMap[field]
|
|
if fieldIDPlus1 > 0 {
|
|
rv = &Dictionary{
|
|
sb: sb,
|
|
field: field,
|
|
fieldID: fieldIDPlus1 - 1,
|
|
}
|
|
|
|
dictStart := sb.dictLocs[rv.fieldID]
|
|
if dictStart > 0 {
|
|
var ok bool
|
|
sb.m.Lock()
|
|
if rv.fst, ok = sb.fieldFSTs[rv.fieldID]; !ok {
|
|
// read the length of the vellum data
|
|
vellumLen, read := binary.Uvarint(sb.mem[dictStart : dictStart+binary.MaxVarintLen64])
|
|
fstBytes := sb.mem[dictStart+uint64(read) : dictStart+uint64(read)+vellumLen]
|
|
rv.fst, err = vellum.Load(fstBytes)
|
|
if err != nil {
|
|
sb.m.Unlock()
|
|
return nil, fmt.Errorf("dictionary field %s vellum err: %v", field, err)
|
|
}
|
|
|
|
sb.fieldFSTs[rv.fieldID] = rv.fst
|
|
}
|
|
|
|
sb.m.Unlock()
|
|
rv.fstReader, err = rv.fst.Reader()
|
|
if err != nil {
|
|
return nil, fmt.Errorf("dictionary field %s vellum reader err: %v", field, err)
|
|
}
|
|
}
|
|
}
|
|
|
|
return rv, nil
|
|
}
|
|
|
|
// visitDocumentCtx holds data structures that are reusable across
|
|
// multiple VisitDocument() calls to avoid memory allocations
|
|
type visitDocumentCtx struct {
|
|
buf []byte
|
|
reader bytes.Reader
|
|
arrayPos []uint64
|
|
}
|
|
|
|
var visitDocumentCtxPool = sync.Pool{
|
|
New: func() interface{} {
|
|
reuse := &visitDocumentCtx{}
|
|
return reuse
|
|
},
|
|
}
|
|
|
|
// VisitStoredFields invokes the StoredFieldValueVisitor for each stored field
|
|
// for the specified doc number
|
|
func (s *SegmentBase) VisitStoredFields(num uint64, visitor segment.StoredFieldValueVisitor) error {
|
|
vdc := visitDocumentCtxPool.Get().(*visitDocumentCtx)
|
|
defer visitDocumentCtxPool.Put(vdc)
|
|
return s.visitStoredFields(vdc, num, visitor)
|
|
}
|
|
|
|
func (s *SegmentBase) visitStoredFields(vdc *visitDocumentCtx, num uint64,
|
|
visitor segment.StoredFieldValueVisitor) error {
|
|
// first make sure this is a valid number in this segment
|
|
if num < s.numDocs {
|
|
meta, compressed := s.getDocStoredMetaAndCompressed(num)
|
|
|
|
vdc.reader.Reset(meta)
|
|
|
|
// handle _id field special case
|
|
idFieldValLen, err := binary.ReadUvarint(&vdc.reader)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
idFieldVal := compressed[:idFieldValLen]
|
|
|
|
keepGoing := visitor("_id", byte('t'), idFieldVal, nil)
|
|
if !keepGoing {
|
|
visitDocumentCtxPool.Put(vdc)
|
|
return nil
|
|
}
|
|
|
|
// handle non-"_id" fields
|
|
compressed = compressed[idFieldValLen:]
|
|
|
|
uncompressed, err := snappy.Decode(vdc.buf[:cap(vdc.buf)], compressed)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
|
|
for keepGoing {
|
|
field, err := binary.ReadUvarint(&vdc.reader)
|
|
if err == io.EOF {
|
|
break
|
|
}
|
|
if err != nil {
|
|
return err
|
|
}
|
|
typ, err := binary.ReadUvarint(&vdc.reader)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
offset, err := binary.ReadUvarint(&vdc.reader)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
l, err := binary.ReadUvarint(&vdc.reader)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
numap, err := binary.ReadUvarint(&vdc.reader)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
var arrayPos []uint64
|
|
if numap > 0 {
|
|
if cap(vdc.arrayPos) < int(numap) {
|
|
vdc.arrayPos = make([]uint64, numap)
|
|
}
|
|
arrayPos = vdc.arrayPos[:numap]
|
|
for i := 0; i < int(numap); i++ {
|
|
ap, err := binary.ReadUvarint(&vdc.reader)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
arrayPos[i] = ap
|
|
}
|
|
}
|
|
|
|
value := uncompressed[offset : offset+l]
|
|
keepGoing = visitor(s.fieldsInv[field], byte(typ), value, arrayPos)
|
|
}
|
|
|
|
vdc.buf = uncompressed
|
|
}
|
|
return nil
|
|
}
|
|
|
|
// DocID returns the value of the _id field for the given docNum
|
|
func (s *SegmentBase) DocID(num uint64) ([]byte, error) {
|
|
if num >= s.numDocs {
|
|
return nil, nil
|
|
}
|
|
|
|
vdc := visitDocumentCtxPool.Get().(*visitDocumentCtx)
|
|
|
|
meta, compressed := s.getDocStoredMetaAndCompressed(num)
|
|
|
|
vdc.reader.Reset(meta)
|
|
|
|
// handle _id field special case
|
|
idFieldValLen, err := binary.ReadUvarint(&vdc.reader)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
idFieldVal := compressed[:idFieldValLen]
|
|
|
|
visitDocumentCtxPool.Put(vdc)
|
|
|
|
return idFieldVal, nil
|
|
}
|
|
|
|
// Count returns the number of documents in this segment.
|
|
func (s *SegmentBase) Count() uint64 {
|
|
return s.numDocs
|
|
}
|
|
|
|
// DocNumbers returns a bitset corresponding to the doc numbers of all the
|
|
// provided _id strings
|
|
func (s *SegmentBase) DocNumbers(ids []string) (*roaring.Bitmap, error) {
|
|
rv := roaring.New()
|
|
|
|
if len(s.fieldsMap) > 0 {
|
|
idDict, err := s.dictionary("_id")
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
postingsList := emptyPostingsList
|
|
|
|
sMax, err := idDict.fst.GetMaxKey()
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
sMaxStr := string(sMax)
|
|
filteredIds := make([]string, 0, len(ids))
|
|
for _, id := range ids {
|
|
if id <= sMaxStr {
|
|
filteredIds = append(filteredIds, id)
|
|
}
|
|
}
|
|
|
|
for _, id := range filteredIds {
|
|
postingsList, err = idDict.postingsList([]byte(id), nil, postingsList)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
postingsList.OrInto(rv)
|
|
}
|
|
}
|
|
|
|
return rv, nil
|
|
}
|
|
|
|
// Fields returns the field names used in this segment
|
|
func (s *SegmentBase) Fields() []string {
|
|
return s.fieldsInv
|
|
}
|
|
|
|
// Path returns the path of this segment on disk
|
|
func (s *Segment) Path() string {
|
|
return s.path
|
|
}
|
|
|
|
// Close releases all resources associated with this segment
|
|
func (s *Segment) Close() (err error) {
|
|
return s.DecRef()
|
|
}
|
|
|
|
func (s *Segment) closeActual() (err error) {
|
|
if s.mm != nil {
|
|
err = s.mm.Unmap()
|
|
}
|
|
// try to close file even if unmap failed
|
|
if s.f != nil {
|
|
err2 := s.f.Close()
|
|
if err == nil {
|
|
// try to return first error
|
|
err = err2
|
|
}
|
|
}
|
|
return
|
|
}
|
|
|
|
// some helpers i started adding for the command-line utility
|
|
|
|
// Data returns the underlying mmaped data slice
|
|
func (s *Segment) Data() []byte {
|
|
return s.mm
|
|
}
|
|
|
|
// CRC returns the CRC value stored in the file footer
|
|
func (s *Segment) CRC() uint32 {
|
|
return s.crc
|
|
}
|
|
|
|
// Version returns the file version in the file footer
|
|
func (s *Segment) Version() uint32 {
|
|
return s.version
|
|
}
|
|
|
|
// ChunkFactor returns the chunk factor in the file footer
|
|
func (s *Segment) ChunkMode() uint32 {
|
|
return s.chunkMode
|
|
}
|
|
|
|
// FieldsIndexOffset returns the fields index offset in the file footer
|
|
func (s *Segment) FieldsIndexOffset() uint64 {
|
|
return s.fieldsIndexOffset
|
|
}
|
|
|
|
// StoredIndexOffset returns the stored value index offset in the file footer
|
|
func (s *Segment) StoredIndexOffset() uint64 {
|
|
return s.storedIndexOffset
|
|
}
|
|
|
|
// DocValueOffset returns the docValue offset in the file footer
|
|
func (s *Segment) DocValueOffset() uint64 {
|
|
return s.docValueOffset
|
|
}
|
|
|
|
// NumDocs returns the number of documents in the file footer
|
|
func (s *Segment) NumDocs() uint64 {
|
|
return s.numDocs
|
|
}
|
|
|
|
// DictAddr is a helper function to compute the file offset where the
|
|
// dictionary is stored for the specified field.
|
|
func (s *Segment) DictAddr(field string) (uint64, error) {
|
|
fieldIDPlus1, ok := s.fieldsMap[field]
|
|
if !ok {
|
|
return 0, fmt.Errorf("no such field '%s'", field)
|
|
}
|
|
|
|
return s.dictLocs[fieldIDPlus1-1], nil
|
|
}
|
|
|
|
func (s *SegmentBase) loadDvReaders() error {
|
|
if s.docValueOffset == fieldNotUninverted || s.numDocs == 0 {
|
|
return nil
|
|
}
|
|
|
|
var read uint64
|
|
for fieldID, field := range s.fieldsInv {
|
|
var fieldLocStart, fieldLocEnd uint64
|
|
var n int
|
|
fieldLocStart, n = binary.Uvarint(s.mem[s.docValueOffset+read : s.docValueOffset+read+binary.MaxVarintLen64])
|
|
if n <= 0 {
|
|
return fmt.Errorf("loadDvReaders: failed to read the docvalue offset start for field %d", fieldID)
|
|
}
|
|
read += uint64(n)
|
|
fieldLocEnd, n = binary.Uvarint(s.mem[s.docValueOffset+read : s.docValueOffset+read+binary.MaxVarintLen64])
|
|
if n <= 0 {
|
|
return fmt.Errorf("loadDvReaders: failed to read the docvalue offset end for field %d", fieldID)
|
|
}
|
|
read += uint64(n)
|
|
|
|
fieldDvReader, err := s.loadFieldDocValueReader(field, fieldLocStart, fieldLocEnd)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
if fieldDvReader != nil {
|
|
s.fieldDvReaders[uint16(fieldID)] = fieldDvReader
|
|
s.fieldDvNames = append(s.fieldDvNames, field)
|
|
}
|
|
}
|
|
|
|
return nil
|
|
}
|