Adding upstream version 2.5.1.

Signed-off-by: Daniel Baumann <daniel@debian.org>

index_meta.go

@@ -0,0 +1,115 @@
+//  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 (
+	"fmt"
+	"os"
+	"path/filepath"
+
+	"github.com/blevesearch/bleve/v2/index/upsidedown"
+	"github.com/blevesearch/bleve/v2/util"
+	index "github.com/blevesearch/bleve_index_api"
+)
+
+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 := os.ReadFile(indexMetaPath)
+	if err != nil {
+		return nil, ErrorIndexMetaMissing
+	}
+	var im indexMeta
+	err = util.UnmarshalJSON(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 := util.MarshalJSON(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 (i *indexMeta) CopyTo(d index.Directory) (err error) {
+	metaBytes, err := util.MarshalJSON(i)
+	if err != nil {
+		return err
+	}
+
+	w, err := d.GetWriter(metaFilename)
+	if w == nil || err != nil {
+		return fmt.Errorf("invalid writer for file: %s, err: %v",
+			metaFilename, err)
+	}
+	defer w.Close()
+
+	_, err = w.Write(metaBytes)
+	return err
+}
+
+func indexMetaPath(path string) string {
+	return filepath.Join(path, metaFilename)
+}