69 lines
1.7 KiB
Go
69 lines
1.7 KiB
Go
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package rupture
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import (
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"encoding/json"
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"io/ioutil"
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"os"
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"path/filepath"
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)
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const metaFilename = "rupture_meta.json"
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func indexMetadataPath(dir string) string {
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return filepath.Join(dir, metaFilename)
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}
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// IndexMetadata contains metadata about a bleve index.
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type IndexMetadata struct {
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// The version of the data in the index. This can be useful for tracking
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// schema changes or data migrations.
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Version int `json:"version"`
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}
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// in addition to the user-exposed metadata, we keep additional, internal-only
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// metadata for sharded indices.
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const shardedMetadataFilename = "rupture_sharded_meta.json"
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func shardedIndexMetadataPath(dir string) string {
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return filepath.Join(dir, shardedMetadataFilename)
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}
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type shardedIndexMetadata struct {
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NumShards int `json:"num_shards"`
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}
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func readJSON(path string, meta interface{}) error {
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metaBytes, err := ioutil.ReadFile(path)
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if err != nil {
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return err
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}
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return json.Unmarshal(metaBytes, meta)
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}
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func writeJSON(path string, meta interface{}) error {
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metaBytes, err := json.Marshal(meta)
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if err != nil {
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return err
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}
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return ioutil.WriteFile(path, metaBytes, 0666)
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}
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// ReadIndexMetadata returns the metadata for the index at the specified path.
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// If no such index metadata exists, an empty metadata and a nil error are
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// returned.
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func ReadIndexMetadata(path string) (*IndexMetadata, error) {
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meta := &IndexMetadata{}
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metaPath := indexMetadataPath(path)
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if _, err := os.Stat(metaPath); os.IsNotExist(err) {
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return meta, nil
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} else if err != nil {
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return nil, err
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}
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return meta, readJSON(metaPath, meta)
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}
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// WriteIndexMetadata writes metadata for the index at the specified path.
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func WriteIndexMetadata(path string, meta *IndexMetadata) error {
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return writeJSON(indexMetadataPath(path), meta)
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}
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