func()

in src/go/configgenerator/routegen/helpers/backend_route.go [55:111]

• 46 lines of code
• 7 McCabe index (conditional complexity)

func (r *BackendRouteGenerator) GenRoutesForMethod(methodCfg *MethodCfg, filterGens []filtergen.FilterGenerator) ([]*routepb.Route, error) {
	methodName, err := util.SelectorToMethodName(methodCfg.OperationName)
	if err != nil {
		return nil, fmt.Errorf("fail to parse method short name from selector %q: %v", methodCfg.OperationName, err)
	}

	routeMatchers, err := MakePerMethodRouteMatchers(methodCfg.HTTPPattern, r.DisallowColonInWildcardPathSegment)
	if err != nil {
		return nil, fmt.Errorf("fail to make backend per-method route matchers for operation %q: %v", methodCfg.OperationName, err)
	}

	var routes []*routepb.Route
	for i, routeMatcher := range routeMatchers {
		routeAction := &routepb.RouteAction{
			ClusterSpecifier: &routepb.RouteAction_Cluster{
				Cluster: methodCfg.BackendClusterName,
			},
		}

		if methodCfg.HostRewrite != "" {
			routeAction.HostRewriteSpecifier = &routepb.RouteAction_HostRewriteLiteral{
				HostRewriteLiteral: methodCfg.HostRewrite,
			}
		}

		MaybeAddDeadlines(r.DeadlineCfg, routeAction, methodCfg.Deadline, methodCfg.IsStreaming)
		if err := MaybeAddRetryPolicy(r.RetryCfg, routeAction); err != nil {
			return nil, err
		}

		perFilterConfig, err := makePerRouteFilterConfig(methodCfg.OperationName, methodCfg.HTTPPattern, filterGens)
		if err != nil {
			return nil, fmt.Errorf("fail to make per-route filter config for route matcher %d: %v", i, err)
		}

		route := &routepb.Route{
			Name:  methodCfg.OperationName,
			Match: routeMatcher.RouteMatch,
			Action: &routepb.Route_Route{
				Route: routeAction,
			},
			Decorator: &routepb.Decorator{
				// TODO(taoxuy@): check if the generated span name length less than the limit.
				// Note we don't add ApiName to reduce the length of the span name.
				Operation: fmt.Sprintf("%s %s", util.SpanNamePrefix, methodName),
			},
			TypedPerFilterConfig: perFilterConfig,
		}

		MaybeAddHSTSHeader(r.HSTSCfg, route)
		MaybeAddOperationNameHeader(r.OperationNameCfg, route, methodCfg.OperationName)

		routes = append(routes, route)
	}

	return routes, nil
}