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bleve/index_meta.go
Marty Schoch dbb93b75a4 refactoring to allow pluggable index encodings
this lays the foundation for supporting the new firestorm
indexing scheme.  i'm merging these changes ahead of
the rest of the firestorm branch so i can continue
to make changes to the analysis pipeline in parallel
2015-09-02 13:12:08 -04:00

84 lines
2.2 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"
)
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
}
return &im, nil
}
func (i *indexMeta) Save(path string) (err error) {
indexMetaPath := indexMetaPath(path)
// ensure any necessary parent directories exist
err = os.Mkdir(path, 0700)
if err != nil {
return ErrorIndexPathExists
}
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
}