githaven/vendor/github.com/blevesearch/bleve/index_meta.go
2017-01-25 10:43:02 +08:00

97 lines
2.4 KiB
Go

// Copyright (c) 2014 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 bleve
import (
"encoding/json"
"io/ioutil"
"os"
"github.com/blevesearch/bleve/index/upsidedown"
)
const metaFilename = "index_meta.json"
type indexMeta struct {
Storage string `json:"storage"`
IndexType string `json:"index_type"`
Config map[string]interface{} `json:"config,omitempty"`
}
func newIndexMeta(indexType string, storage string, config map[string]interface{}) *indexMeta {
return &indexMeta{
IndexType: indexType,
Storage: storage,
Config: config,
}
}
func openIndexMeta(path string) (*indexMeta, error) {
if _, err := os.Stat(path); os.IsNotExist(err) {
return nil, ErrorIndexPathDoesNotExist
}
indexMetaPath := indexMetaPath(path)
metaBytes, err := ioutil.ReadFile(indexMetaPath)
if err != nil {
return nil, ErrorIndexMetaMissing
}
var im indexMeta
err = json.Unmarshal(metaBytes, &im)
if err != nil {
return nil, ErrorIndexMetaCorrupt
}
if im.IndexType == "" {
im.IndexType = upsidedown.Name
}
return &im, nil
}
func (i *indexMeta) Save(path string) (err error) {
indexMetaPath := indexMetaPath(path)
// ensure any necessary parent directories exist
err = os.MkdirAll(path, 0700)
if err != nil {
if os.IsExist(err) {
return ErrorIndexPathExists
}
return err
}
metaBytes, err := json.Marshal(i)
if err != nil {
return err
}
indexMetaFile, err := os.OpenFile(indexMetaPath, os.O_RDWR|os.O_CREATE|os.O_EXCL, 0666)
if err != nil {
if os.IsExist(err) {
return ErrorIndexPathExists
}
return err
}
defer func() {
if ierr := indexMetaFile.Close(); err == nil && ierr != nil {
err = ierr
}
}()
_, err = indexMetaFile.Write(metaBytes)
if err != nil {
return err
}
return nil
}
func indexMetaPath(path string) string {
return path + string(os.PathSeparator) + metaFilename
}