do not unwind/prune l1 sync data

As we unwind now on sequencer restart this process can take a long time on each sequencer restart.  As we only sync finalised data from the L1 this will not change anyway so no point unwinding it

zk/stages/stage_l1syncer.go

@@ -280,80 +280,13 @@ func parseLogType(l1RollupId uint64, log *ethTypes.Log) (l1BatchInfo types.L1Bat
 }
 
 func UnwindL1SyncerStage(u *stagedsync.UnwindState, tx kv.RwTx, cfg L1SyncerCfg, ctx context.Context) (err error) {
-	useExternalTx := tx != nil
-	if !useExternalTx {
-		tx, err = cfg.db.BeginRw(ctx)
-		if err != nil {
-			return err
-		}
-		defer tx.Rollback()
-	}
-	log.Debug("l1 sync: unwinding")
-
-	/*
-		1. unwind sequences table
-		2. unwind verifications table
-		3. update l1verifications batchno and l1syncer stage progress
-	*/
-
-	err = tx.ClearBucket(hermez_db.L1SEQUENCES)
-	if err != nil {
-		return err
-	}
-	err = tx.ClearBucket(hermez_db.L1VERIFICATIONS)
-	if err != nil {
-		return err
-	}
-
-	// the below are very inefficient due to key layout
-	//hermezDb := hermez_db.NewHermezDb(tx)
-	//err = hermezDb.TruncateSequences(u.UnwindPoint)
-	//if err != nil {
-	//	return err
-	//}
-	//
-	//err = hermezDb.TruncateVerifications(u.UnwindPoint)
-	//if err != nil {
-	//	return err
-	//}
-	// get the now latest l1 verification
-	//v, err := hermezDb.GetLatestVerification()
-	//if err != nil {
-	//	return err
-	//}
-
-	if err := stages.SaveStageProgress(tx, stages.L1VerificationsBatchNo, 0); err != nil {
-		return fmt.Errorf("failed to save stage progress, %w", err)
-	}
-	if err := stages.SaveStageProgress(tx, stages.L1Syncer, 0); err != nil {
-		return fmt.Errorf("failed to save stage progress, %w", err)
-	}
-
-	if !useExternalTx {
-		if err := tx.Commit(); err != nil {
-			return err
-		}
-	}
+	// we want to keep L1 data during an unwind, as we only sync finalised data there should be
+	// no need to unwind here
 	return nil
 }
 
 func PruneL1SyncerStage(s *stagedsync.PruneState, tx kv.RwTx, cfg L1SyncerCfg, ctx context.Context) (err error) {
-	useExternalTx := tx != nil
-	if !useExternalTx {
-		tx, err = cfg.db.BeginRw(ctx)
-		if err != nil {
-			return err
-		}
-		defer tx.Rollback()
-	}
-
-	// TODO: implement prune L1 Verifications stage! (if required)
-
-	if !useExternalTx {
-		if err := tx.Commit(); err != nil {
-			return err
-		}
-	}
+	// no need to prune this data
 	return nil
 }