forgejo/vendor/github.com/blevesearch/zapx/v15/build.go
2022-01-01 16:26:27 +08:00

186 lines
4 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 (
"bufio"
"fmt"
"io"
"math"
"os"
"github.com/blevesearch/vellum"
)
const Version uint32 = 15
const Type string = "zap"
const fieldNotUninverted = math.MaxUint64
func (sb *SegmentBase) Persist(path string) error {
return PersistSegmentBase(sb, path)
}
// WriteTo is an implementation of io.WriterTo interface.
func (sb *SegmentBase) WriteTo(w io.Writer) (int64, error) {
if w == nil {
return 0, fmt.Errorf("invalid writer found")
}
n, err := persistSegmentBaseToWriter(sb, w)
return int64(n), err
}
// 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)
}
_, err = persistSegmentBaseToWriter(sb, f)
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 err
}
type bufWriter struct {
w *bufio.Writer
n int
}
func (br *bufWriter) Write(in []byte) (int, error) {
n, err := br.w.Write(in)
br.n += n
return n, err
}
func persistSegmentBaseToWriter(sb *SegmentBase, w io.Writer) (int, error) {
br := &bufWriter{w: bufio.NewWriter(w)}
_, err := br.Write(sb.mem)
if err != nil {
return 0, err
}
err = persistFooter(sb.numDocs, sb.storedIndexOffset, sb.fieldsIndexOffset,
sb.docValueOffset, sb.chunkMode, sb.memCRC, br)
if err != nil {
return 0, err
}
err = br.w.Flush()
if err != nil {
return 0, err
}
return br.n, 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, chunkMode 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,
chunkMode: chunkMode,
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
}