proxy: Avoid sorting endpoints for every single request

The endpoints are no longer hashed by path name in the directors map since
that made iterating over the endpoints unstable. They are now stored in a
slice in the order in which the are defined in the configuration.

Closes: owncloud#4497

changelog/unreleased/refactor-proxy.md

@@ -3,4 +3,7 @@ Enhancement: Refactor the proxy service
 The routes of the proxy service now have a "unprotected" flag. This is used by the authentication middleware to determine if the request needs to be blocked when missing authentication or not. 
 
 https://github.com/owncloud/ocis/issues/4401
+https://github.com/owncloud/ocis/issues/4497
 https://github.com/owncloud/ocis/pull/4461
+https://github.com/owncloud/ocis/pull/4498
+https://github.com/owncloud/ocis/pull/4514

services/proxy/pkg/router/router.go

@@ -5,7 +5,6 @@ import (
 	"net/http"
 	"net/url"
 	"regexp"
-	"sort"
 	"strings"
 
 	"github.com/owncloud/ocis/v2/ocis-pkg/log"
@@ -58,7 +57,7 @@ func New(policySelector *config.PolicySelector, policies []config.Policy, logger
 
 	r := Router{
 		logger:         logger,
-		directors:      make(map[string]map[config.RouteType]map[string]map[string]RoutingInfo),
+		directors:      make(map[string]map[config.RouteType]map[string][]RoutingInfo),
 		policySelector: selector,
 	}
 	for _, pol := range policies {
@@ -87,6 +86,7 @@ func New(policySelector *config.PolicySelector, policies []config.Policy, logger
 // RoutingInfo contains the proxy director and some information about the route.
 type RoutingInfo struct {
 	director    func(*http.Request)
+	endpoint    string
 	unprotected bool
 }
 
@@ -103,30 +103,31 @@ func (r RoutingInfo) IsRouteUnprotected() bool {
 // Router handles the routing of HTTP requests according to the given policies.
 type Router struct {
 	logger         log.Logger
-	directors      map[string]map[config.RouteType]map[string]map[string]RoutingInfo
+	directors      map[string]map[config.RouteType]map[string][]RoutingInfo
 	policySelector policy.Selector
 }
 
 func (rt Router) addHost(policy string, target *url.URL, route config.Route) {
 	targetQuery := target.RawQuery
 	if rt.directors[policy] == nil {
-		rt.directors[policy] = make(map[config.RouteType]map[string]map[string]RoutingInfo)
+		rt.directors[policy] = make(map[config.RouteType]map[string][]RoutingInfo)
 	}
 	routeType := config.DefaultRouteType
 	if route.Type != "" {
 		routeType = route.Type
 	}
 	if rt.directors[policy][routeType] == nil {
-		rt.directors[policy][routeType] = make(map[string]map[string]RoutingInfo)
+		rt.directors[policy][routeType] = make(map[string][]RoutingInfo)
 	}
 	if rt.directors[policy][routeType][route.Method] == nil {
-		rt.directors[policy][routeType][route.Method] = make(map[string]RoutingInfo)
+		rt.directors[policy][routeType][route.Method] = make([]RoutingInfo, 0)
 	}
 
 	reg := registry.GetRegistry()
 	sel := selector.NewSelector(selector.Registry(reg))
 
-	rt.directors[policy][routeType][route.Method][route.Endpoint] = RoutingInfo{
+	rt.directors[policy][routeType][route.Method] = append(rt.directors[policy][routeType][route.Method], RoutingInfo{
+		endpoint:    route.Endpoint,
 		unprotected: route.Unprotected,
 		director: func(req *http.Request) {
 			if route.Service != "" {
@@ -170,7 +171,7 @@ func (rt Router) addHost(policy string, target *url.URL, route config.Route) {
 				req.Header.Set("User-Agent", "")
 			}
 		},
-	}
+	})
 }
 
 // Route is evaluating the policies on the request and returns the RoutingInfo if successful.
@@ -208,32 +209,25 @@ func (rt Router) Route(r *http.Request) (RoutingInfo, bool) {
 			method = r.Method
 		}
 
-		endpoints := make([]string, 0, len(rt.directors[pol][rtype][method]))
-		for endpoint := range rt.directors[pol][rtype][method] {
-			endpoints = append(endpoints, endpoint)
-		}
-		sort.Slice(endpoints, func(i, j int) bool {
-			return len(endpoints[j]) < len(endpoints[i])
-		})
-		for _, endpoint := range endpoints {
-			if handler(endpoint, *r.URL) {
+		for _, ri := range rt.directors[pol][rtype][method] {
+			if handler(ri.endpoint, *r.URL) {
 				rt.logger.Debug().
 					Str("policy", pol).
 					Str("method", r.Method).
-					Str("prefix", endpoint).
+					Str("prefix", ri.endpoint).
 					Str("path", r.URL.Path).
 					Str("routeType", string(rtype)).
 					Msg("director found")
 
-				return rt.directors[pol][rtype][method][endpoint], true
+				return ri, true
 			}
 		}
 	}
 
 	// override default director with root. If any
-	if ri, ok := rt.directors[pol][config.PrefixRoute][method]["/"]; ok { // try specific method
+	if ri := rt.directors[pol][config.PrefixRoute][method][0]; ri.endpoint == "/" { // try specific method
 		return ri, true
-	} else if ri, ok := rt.directors[pol][config.PrefixRoute][""]["/"]; ok { // fallback to unspecific method
+	} else if ri := rt.directors[pol][config.PrefixRoute][""][0]; ri.endpoint == "/" { // fallback to unspecific method
 		return ri, true
 	}