Use gorilla/mux for middleware and extend

- Use gorilla/mux for middleware.
- Add Dumper, RequestID, and Logger middlewares.
- Add makeURL helper

vendor/github.com/gorilla/mux/mux.go

@@ -10,16 +10,19 @@ import (
 	"net/http"
 	"path"
 	"regexp"
-	"strings"
 )
 
 var (
+	// ErrMethodMismatch is returned when the method in the request does not match
+	// the method defined against the route.
 	ErrMethodMismatch = errors.New("method is not allowed")
+	// ErrNotFound is returned when no route match is found.
+	ErrNotFound = errors.New("no matching route was found")
 )
 
 // NewRouter returns a new router instance.
 func NewRouter() *Router {
-	return &Router{namedRoutes: make(map[string]*Route), KeepContext: false}
+	return &Router{namedRoutes: make(map[string]*Route)}
 }
 
 // Router registers routes to be matched and dispatches a handler.
@@ -47,42 +50,121 @@ type Router struct {
 	// Configurable Handler to be used when the request method does not match the route.
 	MethodNotAllowedHandler http.Handler
 
-	// Parent route, if this is a subrouter.
-	parent parentRoute
 	// Routes to be matched, in order.
 	routes []*Route
+
 	// Routes by name for URL building.
 	namedRoutes map[string]*Route
-	// See Router.StrictSlash(). This defines the flag for new routes.
-	strictSlash bool
-	// See Router.SkipClean(). This defines the flag for new routes.
-	skipClean bool
+
 	// If true, do not clear the request context after handling the request.
-	// This has no effect when go1.7+ is used, since the context is stored
+	//
+	// Deprecated: No effect when go1.7+ is used, since the context is stored
 	// on the request itself.
 	KeepContext bool
-	// see Router.UseEncodedPath(). This defines a flag for all routes.
-	useEncodedPath bool
+
+	// Slice of middlewares to be called after a match is found
+	middlewares []middleware
+
+	// configuration shared with `Route`
+	routeConf
 }
 
-// Match matches registered routes against the request.
+// common route configuration shared between `Router` and `Route`
+type routeConf struct {
+	// If true, "/path/foo%2Fbar/to" will match the path "/path/{var}/to"
+	useEncodedPath bool
+
+	// If true, when the path pattern is "/path/", accessing "/path" will
+	// redirect to the former and vice versa.
+	strictSlash bool
+
+	// If true, when the path pattern is "/path//to", accessing "/path//to"
+	// will not redirect
+	skipClean bool
+
+	// Manager for the variables from host and path.
+	regexp routeRegexpGroup
+
+	// List of matchers.
+	matchers []matcher
+
+	// The scheme used when building URLs.
+	buildScheme string
+
+	buildVarsFunc BuildVarsFunc
+}
+
+// returns an effective deep copy of `routeConf`
+func copyRouteConf(r routeConf) routeConf {
+	c := r
+
+	if r.regexp.path != nil {
+		c.regexp.path = copyRouteRegexp(r.regexp.path)
+	}
+
+	if r.regexp.host != nil {
+		c.regexp.host = copyRouteRegexp(r.regexp.host)
+	}
+
+	c.regexp.queries = make([]*routeRegexp, 0, len(r.regexp.queries))
+	for _, q := range r.regexp.queries {
+		c.regexp.queries = append(c.regexp.queries, copyRouteRegexp(q))
+	}
+
+	c.matchers = make([]matcher, 0, len(r.matchers))
+	for _, m := range r.matchers {
+		c.matchers = append(c.matchers, m)
+	}
+
+	return c
+}
+
+func copyRouteRegexp(r *routeRegexp) *routeRegexp {
+	c := *r
+	return &c
+}
+
+// Match attempts to match the given request against the router's registered routes.
+//
+// If the request matches a route of this router or one of its subrouters the Route,
+// Handler, and Vars fields of the the match argument are filled and this function
+// returns true.
+//
+// If the request does not match any of this router's or its subrouters' routes
+// then this function returns false. If available, a reason for the match failure
+// will be filled in the match argument's MatchErr field. If the match failure type
+// (eg: not found) has a registered handler, the handler is assigned to the Handler
+// field of the match argument.
 func (r *Router) Match(req *http.Request, match *RouteMatch) bool {
 	for _, route := range r.routes {
 		if route.Match(req, match) {
+			// Build middleware chain if no error was found
+			if match.MatchErr == nil {
+				for i := len(r.middlewares) - 1; i >= 0; i-- {
+					match.Handler = r.middlewares[i].Middleware(match.Handler)
+				}
+			}
 			return true
 		}
 	}
 
-	if match.MatchErr == ErrMethodMismatch && r.MethodNotAllowedHandler != nil {
-		match.Handler = r.MethodNotAllowedHandler
-		return true
+	if match.MatchErr == ErrMethodMismatch {
+		if r.MethodNotAllowedHandler != nil {
+			match.Handler = r.MethodNotAllowedHandler
+			return true
+		}
+
+		return false
 	}
 
 	// Closest match for a router (includes sub-routers)
 	if r.NotFoundHandler != nil {
 		match.Handler = r.NotFoundHandler
+		match.MatchErr = ErrNotFound
 		return true
 	}
+
+	match.MatchErr = ErrNotFound
 	return false
 }
 
@@ -94,7 +176,7 @@ func (r *Router) ServeHTTP(w http.ResponseWriter, req *http.Request) {
 	if !r.skipClean {
 		path := req.URL.Path
 		if r.useEncodedPath {
-			path = getPath(req)
+			path = req.URL.EscapedPath()
 		}
 		// Clean path to canonical form and redirect.
 		if p := cleanPath(path); p != path {
@@ -127,33 +209,35 @@ func (r *Router) ServeHTTP(w http.ResponseWriter, req *http.Request) {
 		handler = http.NotFoundHandler()
 	}
 
-	if !r.KeepContext {
-		defer contextClear(req)
-	}
 	handler.ServeHTTP(w, req)
 }
 
 // Get returns a route registered with the given name.
 func (r *Router) Get(name string) *Route {
-	return r.getNamedRoutes()[name]
+	return r.namedRoutes[name]
 }
 
 // GetRoute returns a route registered with the given name. This method
 // was renamed to Get() and remains here for backwards compatibility.
 func (r *Router) GetRoute(name string) *Route {
-	return r.getNamedRoutes()[name]
+	return r.namedRoutes[name]
 }
 
 // StrictSlash defines the trailing slash behavior for new routes. The initial
 // value is false.
 //
-// When true, if the route path is "/path/", accessing "/path" will redirect
+// When true, if the route path is "/path/", accessing "/path" will perform a redirect
 // to the former and vice versa. In other words, your application will always
 // see the path as specified in the route.
 //
 // When false, if the route path is "/path", accessing "/path/" will not match
 // this route and vice versa.
 //
+// The re-direct is a HTTP 301 (Moved Permanently). Note that when this is set for
+// routes with a non-idempotent method (e.g. POST, PUT), the subsequent re-directed
+// request will be made as a GET by most clients. Use middleware or client settings
+// to modify this behaviour as needed.
+//
 // Special case: when a route sets a path prefix using the PathPrefix() method,
 // strict slash is ignored for that route because the redirect behavior can't
 // be determined from a prefix alone. However, any subrouters created from that
@@ -179,10 +263,6 @@ func (r *Router) SkipClean(value bool) *Router {
 // UseEncodedPath tells the router to match the encoded original path
 // to the routes.
 // For eg. "/path/foo%2Fbar/to" will match the path "/path/{var}/to".
-// This behavior has the drawback of needing to match routes against
-// r.RequestURI instead of r.URL.Path. Any modifications (such as http.StripPrefix)
-// to r.URL.Path will not affect routing when this flag is on and thus may
-// induce unintended behavior.
 //
 // If not called, the router will match the unencoded path to the routes.
 // For eg. "/path/foo%2Fbar/to" will match the path "/path/foo/bar/to"
@@ -191,55 +271,24 @@ func (r *Router) UseEncodedPath() *Router {
 	return r
 }
 
-// ----------------------------------------------------------------------------
-// parentRoute
-// ----------------------------------------------------------------------------
-
-func (r *Router) getBuildScheme() string {
-	if r.parent != nil {
-		return r.parent.getBuildScheme()
-	}
-	return ""
-}
-
-// getNamedRoutes returns the map where named routes are registered.
-func (r *Router) getNamedRoutes() map[string]*Route {
-	if r.namedRoutes == nil {
-		if r.parent != nil {
-			r.namedRoutes = r.parent.getNamedRoutes()
-		} else {
-			r.namedRoutes = make(map[string]*Route)
-		}
-	}
-	return r.namedRoutes
-}
-
-// getRegexpGroup returns regexp definitions from the parent route, if any.
-func (r *Router) getRegexpGroup() *routeRegexpGroup {
-	if r.parent != nil {
-		return r.parent.getRegexpGroup()
-	}
-	return nil
-}
-
-func (r *Router) buildVars(m map[string]string) map[string]string {
-	if r.parent != nil {
-		m = r.parent.buildVars(m)
-	}
-	return m
-}
-
 // ----------------------------------------------------------------------------
 // Route factories
 // ----------------------------------------------------------------------------
 
 // NewRoute registers an empty route.
 func (r *Router) NewRoute() *Route {
-	route := &Route{parent: r, strictSlash: r.strictSlash, skipClean: r.skipClean, useEncodedPath: r.useEncodedPath}
+	// initialize a route with a copy of the parent router's configuration
+	route := &Route{routeConf: copyRouteConf(r.routeConf), namedRoutes: r.namedRoutes}
 	r.routes = append(r.routes, route)
 	return route
 }
 
+// Name registers a new route with a name.
+// See Route.Name().
+func (r *Router) Name(name string) *Route {
+	return r.NewRoute().Name(name)
+}
+
 // Handle registers a new route with a matcher for the URL path.
 // See Route.Path() and Route.Handler().
 func (r *Router) Handle(path string, handler http.Handler) *Route {
@@ -409,28 +458,6 @@ func setCurrentRoute(r *http.Request, val interface{}) *http.Request {
 // Helpers
 // ----------------------------------------------------------------------------
 
-// getPath returns the escaped path if possible; doing what URL.EscapedPath()
-// which was added in go1.5 does
-func getPath(req *http.Request) string {
-	if req.RequestURI != "" {
-		// Extract the path from RequestURI (which is escaped unlike URL.Path)
-		// as detailed here as detailed in https://golang.org/pkg/net/url/#URL
-		// for < 1.5 server side workaround
-		// http://localhost/path/here?v=1 -> /path/here
-		path := req.RequestURI
-		path = strings.TrimPrefix(path, req.URL.Scheme+`://`)
-		path = strings.TrimPrefix(path, req.URL.Host)
-		if i := strings.LastIndex(path, "?"); i > -1 {
-			path = path[:i]
-		}
-		if i := strings.LastIndex(path, "#"); i > -1 {
-			path = path[:i]
-		}
-		return path
-	}
-	return req.URL.Path
-}
-
 // cleanPath returns the canonical path for p, eliminating . and .. elements.
 // Borrowed from the net/http package.
 func cleanPath(p string) string {