- // 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"
- "math"
- "os"
-
- "github.com/blevesearch/vellum"
- )
-
- const Version uint32 = 11
-
- const Type string = "zap"
-
- const fieldNotUninverted = math.MaxUint64
-
- func (sb *SegmentBase) Persist(path string) error {
- return PersistSegmentBase(sb, path)
- }
-
- // 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
- }
-
- func persistStoredFieldValues(fieldID int,
- storedFieldValues [][]byte, stf []byte, spf [][]uint64,
- curr int, metaEncode varintEncoder, data []byte) (
- int, []byte, error) {
- for i := 0; i < len(storedFieldValues); i++ {
- // encode field
- _, err := metaEncode(uint64(fieldID))
- if err != nil {
- return 0, nil, err
- }
- // encode type
- _, err = metaEncode(uint64(stf[i]))
- if err != nil {
- return 0, nil, err
- }
- // encode start offset
- _, err = metaEncode(uint64(curr))
- if err != nil {
- return 0, nil, err
- }
- // end len
- _, err = metaEncode(uint64(len(storedFieldValues[i])))
- if err != nil {
- return 0, nil, err
- }
- // encode number of array pos
- _, err = metaEncode(uint64(len(spf[i])))
- if err != nil {
- return 0, nil, err
- }
- // encode all array positions
- for _, pos := range spf[i] {
- _, err = metaEncode(pos)
- if err != nil {
- return 0, nil, err
- }
- }
-
- data = append(data, storedFieldValues[i]...)
- curr += len(storedFieldValues[i])
- }
-
- return curr, data, nil
- }
-
- 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,
- fieldDvReaders: make(map[uint16]*docValueReader),
- fieldFSTs: make(map[uint16]*vellum.FST),
- }
- sb.updateSize()
-
- err := sb.loadDvReaders()
- if err != nil {
- return nil, err
- }
-
- return sb, nil
- }
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