package route import ( "net/http" "sync" "github.com/julienschmidt/httprouter" "golang.org/x/net/context" ) var ( mtx = sync.RWMutex{} ctxts = map[*http.Request]context.Context{} ) // Context returns the context for the request. func Context(r *http.Request) context.Context { mtx.RLock() defer mtx.RUnlock() return ctxts[r] } type param string // Param returns param p for the context. func Param(ctx context.Context, p string) string { return ctx.Value(param(p)).(string) } // WithParam returns a new context with param p set to v. func WithParam(ctx context.Context, p, v string) context.Context { return context.WithValue(ctx, param(p), v) } // handle turns a Handle into httprouter.Handle func handle(h http.HandlerFunc) httprouter.Handle { return func(w http.ResponseWriter, r *http.Request, params httprouter.Params) { ctx, cancel := context.WithCancel(context.Background()) defer cancel() for _, p := range params { ctx = context.WithValue(ctx, param(p.Key), p.Value) } mtx.Lock() ctxts[r] = ctx mtx.Unlock() h(w, r) mtx.Lock() delete(ctxts, r) mtx.Unlock() } } // Router wraps httprouter.Router and adds support for prefixed sub-routers. type Router struct { rtr *httprouter.Router prefix string } // New returns a new Router. func New() *Router { return &Router{rtr: httprouter.New()} } // WithPrefix returns a router that prefixes all registered routes with prefix. func (r *Router) WithPrefix(prefix string) *Router { return &Router{rtr: r.rtr, prefix: r.prefix + prefix} } // Get registers a new GET route. func (r *Router) Get(path string, h http.HandlerFunc) { r.rtr.GET(r.prefix+path, handle(h)) } // Del registers a new DELETE route. func (r *Router) Del(path string, h http.HandlerFunc) { r.rtr.DELETE(r.prefix+path, handle(h)) } // Post registers a new POST route. func (r *Router) Post(path string, h http.HandlerFunc) { r.rtr.POST(r.prefix+path, handle(h)) } // ServeHTTP implements http.Handler. func (r *Router) ServeHTTP(w http.ResponseWriter, req *http.Request) { r.rtr.ServeHTTP(w, req) } // FileServe returns a new http.HandlerFunc that serves files from dir. // Using routes must provide the *filepath parameter. func FileServe(dir string) http.HandlerFunc { fs := http.FileServer(http.Dir(dir)) return func(w http.ResponseWriter, r *http.Request) { r.URL.Path = Param(Context(r), "filepath") fs.ServeHTTP(w, r) } }