69 lines
1.8 KiB
Go
69 lines
1.8 KiB
Go
package lmdb
|
|
|
|
import (
|
|
"encoding/binary"
|
|
"fmt"
|
|
|
|
"github.com/PowerDNS/lmdb-go/lmdb"
|
|
)
|
|
|
|
const (
|
|
DB_VERSION byte = 'v'
|
|
)
|
|
|
|
func (b *LMDBBackend) runMigrations() error {
|
|
return b.lmdbEnv.Update(func(txn *lmdb.Txn) error {
|
|
var version uint16
|
|
v, err := txn.Get(b.settingsStore, []byte{DB_VERSION})
|
|
if err != nil {
|
|
if lmdbErr, ok := err.(*lmdb.OpError); ok && lmdbErr.Errno == lmdb.NotFound {
|
|
version = 0
|
|
} else if v == nil {
|
|
return fmt.Errorf("failed to read database version: %w", err)
|
|
}
|
|
} else {
|
|
version = binary.BigEndian.Uint16(v)
|
|
}
|
|
|
|
// do the migrations in increasing steps (there is no rollback)
|
|
//
|
|
|
|
// the 4 first migrations go to trash because on version 3 we need to export and import all the data anyway
|
|
if version < 4 {
|
|
// if there is any data in the relay we will stop and notify the user,
|
|
// otherwise we just set version to 3 and proceed
|
|
|
|
cursor, err := txn.OpenCursor(b.indexId)
|
|
if err != nil {
|
|
return fmt.Errorf("failed to open cursor in migration 4: %w", err)
|
|
}
|
|
defer cursor.Close()
|
|
|
|
hasAnyEntries := false
|
|
_, _, err = cursor.Get(nil, nil, lmdb.First)
|
|
for err == nil {
|
|
hasAnyEntries = true
|
|
break
|
|
}
|
|
|
|
if hasAnyEntries {
|
|
return fmt.Errorf("your database is at version %d, but in order to migrate up to version 4 you must manually export all the events and then import again: run an old version of this software, export the data, then delete the database files, run the new version, import the data back in.", version)
|
|
}
|
|
|
|
b.bumpVersion(txn, 4)
|
|
}
|
|
|
|
if version < 5 {
|
|
// ...
|
|
}
|
|
|
|
return nil
|
|
})
|
|
}
|
|
|
|
func (b *LMDBBackend) bumpVersion(txn *lmdb.Txn, version uint16) error {
|
|
buf, err := txn.PutReserve(b.settingsStore, []byte{DB_VERSION}, 4, 0)
|
|
binary.BigEndian.PutUint16(buf, version)
|
|
return err
|
|
}
|