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

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2017-02-07 21:33:23 +00:00
// Copyright 2012 The Gorilla Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package mux
import (
"fmt"
"net/http"
"path"
"github.com/gorilla/context"
)
// NewRouter returns a new router instance.
func NewRouter() *Router {
return &Router{namedRoutes: make(map[string]*Route), KeepContext: false}
}
// Router registers routes to be matched and dispatches a handler.
//
// It implements the http.Handler interface, so it can be registered to serve
// requests:
//
// var router = mux.NewRouter()
//
// func main() {
// http.Handle("/", router)
// }
//
// Or, for Google App Engine, register it in a init() function:
//
// func init() {
// http.Handle("/", router)
// }
//
// This will send all incoming requests to the router.
type Router struct {
// Configurable Handler to be used when no route matches.
NotFoundHandler 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
// If true, do not clear the request context after handling the request
KeepContext bool
}
// Match matches registered routes against the request.
func (r *Router) Match(req *http.Request, match *RouteMatch) bool {
for _, route := range r.routes {
if route.Match(req, match) {
return true
}
}
return false
}
// ServeHTTP dispatches the handler registered in the matched route.
//
// When there is a match, the route variables can be retrieved calling
// mux.Vars(request).
func (r *Router) ServeHTTP(w http.ResponseWriter, req *http.Request) {
// Clean path to canonical form and redirect.
if p := cleanPath(req.URL.Path); p != req.URL.Path {
// Added 3 lines (Philip Schlump) - It was droping the query string and #whatever from query.
// This matches with fix in go 1.2 r.c. 4 for same problem. Go Issue:
// http://code.google.com/p/go/issues/detail?id=5252
url := *req.URL
url.Path = p
p = url.String()
w.Header().Set("Location", p)
w.WriteHeader(http.StatusMovedPermanently)
return
}
var match RouteMatch
var handler http.Handler
if r.Match(req, &match) {
handler = match.Handler
setVars(req, match.Vars)
setCurrentRoute(req, match.Route)
}
if handler == nil {
handler = r.NotFoundHandler
if handler == nil {
handler = http.NotFoundHandler()
}
}
if !r.KeepContext {
defer context.Clear(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]
}
// 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]
}
// 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
// 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.
//
// 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
// route inherit the original StrictSlash setting.
func (r *Router) StrictSlash(value bool) *Router {
r.strictSlash = value
return r
}
// ----------------------------------------------------------------------------
// parentRoute
// ----------------------------------------------------------------------------
// 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
}
// ----------------------------------------------------------------------------
// Route factories
// ----------------------------------------------------------------------------
// NewRoute registers an empty route.
func (r *Router) NewRoute() *Route {
route := &Route{parent: r, strictSlash: r.strictSlash}
r.routes = append(r.routes, route)
return route
}
// 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 {
return r.NewRoute().Path(path).Handler(handler)
}
// HandleFunc registers a new route with a matcher for the URL path.
// See Route.Path() and Route.HandlerFunc().
func (r *Router) HandleFunc(path string, f func(http.ResponseWriter,
*http.Request)) *Route {
return r.NewRoute().Path(path).HandlerFunc(f)
}
// Headers registers a new route with a matcher for request header values.
// See Route.Headers().
func (r *Router) Headers(pairs ...string) *Route {
return r.NewRoute().Headers(pairs...)
}
// Host registers a new route with a matcher for the URL host.
// See Route.Host().
func (r *Router) Host(tpl string) *Route {
return r.NewRoute().Host(tpl)
}
// MatcherFunc registers a new route with a custom matcher function.
// See Route.MatcherFunc().
func (r *Router) MatcherFunc(f MatcherFunc) *Route {
return r.NewRoute().MatcherFunc(f)
}
// Methods registers a new route with a matcher for HTTP methods.
// See Route.Methods().
func (r *Router) Methods(methods ...string) *Route {
return r.NewRoute().Methods(methods...)
}
// Path registers a new route with a matcher for the URL path.
// See Route.Path().
func (r *Router) Path(tpl string) *Route {
return r.NewRoute().Path(tpl)
}
// PathPrefix registers a new route with a matcher for the URL path prefix.
// See Route.PathPrefix().
func (r *Router) PathPrefix(tpl string) *Route {
return r.NewRoute().PathPrefix(tpl)
}
// Queries registers a new route with a matcher for URL query values.
// See Route.Queries().
func (r *Router) Queries(pairs ...string) *Route {
return r.NewRoute().Queries(pairs...)
}
// Schemes registers a new route with a matcher for URL schemes.
// See Route.Schemes().
func (r *Router) Schemes(schemes ...string) *Route {
return r.NewRoute().Schemes(schemes...)
}
// ----------------------------------------------------------------------------
// Context
// ----------------------------------------------------------------------------
// RouteMatch stores information about a matched route.
type RouteMatch struct {
Route *Route
Handler http.Handler
Vars map[string]string
}
type contextKey int
const (
varsKey contextKey = iota
routeKey
)
// Vars returns the route variables for the current request, if any.
func Vars(r *http.Request) map[string]string {
if rv := context.Get(r, varsKey); rv != nil {
return rv.(map[string]string)
}
return nil
}
// CurrentRoute returns the matched route for the current request, if any.
func CurrentRoute(r *http.Request) *Route {
if rv := context.Get(r, routeKey); rv != nil {
return rv.(*Route)
}
return nil
}
func setVars(r *http.Request, val interface{}) {
context.Set(r, varsKey, val)
}
func setCurrentRoute(r *http.Request, val interface{}) {
context.Set(r, routeKey, val)
}
// ----------------------------------------------------------------------------
// Helpers
// ----------------------------------------------------------------------------
// cleanPath returns the canonical path for p, eliminating . and .. elements.
// Borrowed from the net/http package.
func cleanPath(p string) string {
if p == "" {
return "/"
}
if p[0] != '/' {
p = "/" + p
}
np := path.Clean(p)
// path.Clean removes trailing slash except for root;
// put the trailing slash back if necessary.
if p[len(p)-1] == '/' && np != "/" {
np += "/"
}
return np
}
// uniqueVars returns an error if two slices contain duplicated strings.
func uniqueVars(s1, s2 []string) error {
for _, v1 := range s1 {
for _, v2 := range s2 {
if v1 == v2 {
return fmt.Errorf("mux: duplicated route variable %q", v2)
}
}
}
return nil
}
// mapFromPairs converts variadic string parameters to a string map.
func mapFromPairs(pairs ...string) (map[string]string, error) {
length := len(pairs)
if length%2 != 0 {
return nil, fmt.Errorf(
"mux: number of parameters must be multiple of 2, got %v", pairs)
}
m := make(map[string]string, length/2)
for i := 0; i < length; i += 2 {
m[pairs[i]] = pairs[i+1]
}
return m, nil
}
// matchInArray returns true if the given string value is in the array.
func matchInArray(arr []string, value string) bool {
for _, v := range arr {
if v == value {
return true
}
}
return false
}
// matchMap returns true if the given key/value pairs exist in a given map.
func matchMap(toCheck map[string]string, toMatch map[string][]string,
canonicalKey bool) bool {
for k, v := range toCheck {
// Check if key exists.
if canonicalKey {
k = http.CanonicalHeaderKey(k)
}
if values := toMatch[k]; values == nil {
return false
} else if v != "" {
// If value was defined as an empty string we only check that the
// key exists. Otherwise we also check for equality.
valueExists := false
for _, value := range values {
if v == value {
valueExists = true
break
}
}
if !valueExists {
return false
}
}
}
return true
}