func (e *etcd) SaveRoute(route models.Route) error { key := generateHttpRouteKey(route) retries := 0 for retries <= maxRetries { response, err := e.keysAPI.Get(context.Background(), key, readOpts()) // Update if response != nil && err == nil { var existingRoute models.Route err = json.Unmarshal([]byte(response.Node.Value), &existingRoute) if err != nil { return err } route.ModificationTag = existingRoute.ModificationTag route.ModificationTag.Increment() routeJSON, _ := json.Marshal(route) _, err = e.keysAPI.Set(context.Background(), key, string(routeJSON), updateOptsWithTTL(route.TTL, response.Node.ModifiedIndex)) if err == nil { break } } else if cerr, ok := err.(client.Error); ok && cerr.Code == client.ErrorCodeKeyNotFound { //create // Delete came in between a read and an update if retries > 0 { return ErrorConflict } var tag models.ModificationTag tag, err = models.NewModificationTag() if err != nil { return err } route.ModificationTag = tag routeJSON, _ := json.Marshal(route) _, err = e.keysAPI.Set(ctx(), key, string(routeJSON), createOpts(route.TTL)) if err == nil { break } } // only retry on a compare and swap error if cerr, ok := err.(client.Error); ok && cerr.Code == client.ErrorCodeTestFailed { retries++ } else { return err } } if retries > maxRetries { return ErrorConflict } return nil }
func (e *etcd) SaveTcpRouteMapping(tcpMapping models.TcpRouteMapping) error { key := generateTcpRouteMappingKey(tcpMapping) retries := 0 for retries <= maxRetries { response, err := e.keysAPI.Get(context.Background(), key, readOpts()) // Update if response != nil && err == nil { var existingTcpRouteMapping models.TcpRouteMapping err = json.Unmarshal([]byte(response.Node.Value), &existingTcpRouteMapping) if err != nil { return err } tcpMapping.ModificationTag = existingTcpRouteMapping.ModificationTag tcpMapping.ModificationTag.Increment() tcpRouteJSON, _ := json.Marshal(tcpMapping) _, err = e.keysAPI.Set(ctx(), key, string(tcpRouteJSON), updateOptsWithTTL(int(tcpMapping.TTL), response.Node.ModifiedIndex)) } else if cerr, ok := err.(client.Error); ok && cerr.Code == client.ErrorCodeKeyNotFound { //create // Delete came in between a read and update if retries > 0 { return ErrorConflict } var tag models.ModificationTag tag, err = models.NewModificationTag() if err != nil { return err } tcpMapping.ModificationTag = tag tcpRouteMappingJSON, _ := json.Marshal(tcpMapping) _, err = e.keysAPI.Set(ctx(), key, string(tcpRouteMappingJSON), createOpts(int(tcpMapping.TTL))) } // return when create or update is successful if err == nil { return nil } // only retry on a compare and swap error if cerr, ok := err.(client.Error); ok && cerr.Code == client.ErrorCodeTestFailed { retries++ } else { return err } } // number of retries exceeded return ErrorConflict }