6f243a2a76
The main problem is to distinguish the case of initial initialization and update from version 0. We can't do this at `Open`, because of `resync_metabase` flag. Thus, the following approach was taken: 1. During `Open` check whether the metabase was initialized. 2. Check for the version in `Init` or write the new one if the metabase is new. 3. Update version in `Reset`. Signed-off-by: Evgenii Stratonikov <evgeniy@nspcc.ru>
41 lines
955 B
Go
41 lines
955 B
Go
package meta
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import (
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"encoding/binary"
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"fmt"
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"go.etcd.io/bbolt"
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)
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// version contains current metabase version.
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const version = 0
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var versionKey = []byte("version")
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func checkVersion(tx *bbolt.Tx, initialized bool) error {
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b := tx.Bucket(shardInfoBucket)
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if b != nil {
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data := b.Get(versionKey)
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if len(data) == 8 {
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stored := binary.LittleEndian.Uint64(data)
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if stored != version {
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return fmt.Errorf("invalid version: expected=%d, stored=%d", version, stored)
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}
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}
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}
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if !initialized { // new database, write version
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return updateVersion(tx, version)
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}
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return nil // return error here after the first version increase
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}
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func updateVersion(tx *bbolt.Tx, version uint64) error {
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data := make([]byte, 8)
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binary.LittleEndian.PutUint64(data, version)
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b, err := tx.CreateBucketIfNotExists(shardInfoBucket)
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if err != nil {
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return fmt.Errorf("can't create auxilliary bucket: %w", err)
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}
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return b.Put(versionKey, data)
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}
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