// ApplySnapshot applies the snapshot of the computation's persisted state
func (p *LevelDBPersister) ApplySnapshot(compID StreamID, snapshot []byte) error {
batch := new(leveldb.Batch)
log.Println("[persister] Applying snapshot") //, snapshot)
// clear data for this computation
keyPrefix := compID
iter := p.db.NewIterator(util.BytesPrefix([]byte(keyPrefix)), nil)
defer iter.Release()
for iter.Next() {
batch.Delete(iter.Key())
}
err := p.db.Write(batch, nil)
if err != nil {
return err
}
batch.Reset()
err = batch.Load(snapshot)
if err != nil {
return err
}
return p.db.Write(batch, nil)
}