Beispiel #1
0
// SetPhase implements ModelMigration.
func (mig *modelMigration) SetPhase(nextPhase migration.Phase) error {
	now := GetClock().Now().UnixNano()

	phase, err := mig.Phase()
	if err != nil {
		return errors.Trace(err)
	}

	if nextPhase == phase {
		return nil // Already at that phase. Nothing to do.
	}
	if !phase.CanTransitionTo(nextPhase) {
		return errors.Errorf("illegal phase change: %s -> %s", phase, nextPhase)
	}

	nextDoc := mig.statusDoc
	nextDoc.Phase = nextPhase.String()
	nextDoc.PhaseChangedTime = now
	update := bson.M{
		"phase":              nextDoc.Phase,
		"phase-changed-time": now,
	}
	if nextPhase == migration.SUCCESS {
		nextDoc.SuccessTime = now
		update["success-time"] = now
	}
	var ops []txn.Op
	if nextPhase.IsTerminal() {
		nextDoc.EndTime = now
		update["end-time"] = now
		ops = append(ops, txn.Op{
			C:      migrationsActiveC,
			Id:     mig.doc.ModelUUID,
			Assert: txn.DocExists,
			Remove: true,
		})
	}

	ops = append(ops, txn.Op{
		C:      migrationsStatusC,
		Id:     mig.statusDoc.Id,
		Update: bson.M{"$set": update},
		// Ensure phase hasn't changed underneath us
		Assert: bson.M{"phase": mig.statusDoc.Phase},
	})

	if err := mig.st.runTransaction(ops); err == txn.ErrAborted {
		return errors.New("phase already changed")
	} else if err != nil {
		return errors.Annotate(err, "failed to update phase")
	}

	mig.statusDoc = nextDoc
	return nil
}
Beispiel #2
0
// IsTerminal returns true when the given phase means a migration has
// finished (successfully or otherwise).
func IsTerminal(phase migration.Phase) bool {
	return phase.IsTerminal()
}