add current route

dispatcher.go

@@ -80,9 +80,16 @@
 package httpdispatch
 
 import (
+	"context"
 	"net/http"
 )
 
+type ContextKey int
+
+const (
+	ContextKeyRoute ContextKey = iota
+)
+
 // Handler is an interface that can be registered to a route to handle HTTP
 // requests. Like http.HandlerFunc, but has a third parameter for the values of
 // wildcards (variables).
@@ -235,7 +242,8 @@ func (d *Dispatcher) ServeFiles(path string, fs http.FileSystem) {
 // the same path with / without the trailing slash should be performed.
 func (d *Dispatcher) Lookup(method, path string) (Handler, Params, bool) {
 	if root := d.trees[method]; root != nil {
-		return root.getValue(path)
+		handler, params, tsr, _ := root.getValue(path)
+		return handler, params, tsr
 	}
 
 	return nil, nil, false
@@ -250,10 +258,11 @@ func (d *Dispatcher) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 	path := r.URL.Path
 
 	if root := d.trees[r.Method]; root != nil {
-		handler, params, tsr := root.getValue(path)
+		handler, params, tsr, route := root.getValue(path)
 
 		if handler != nil {
 			if !tsr || !d.RedirectTrailingSlash {
+				r = r.WithContext(context.WithValue(r.Context(), ContextKeyRoute, route))
 				handler.Handle(w, r, params)
 				return
 			}
@@ -382,7 +391,7 @@ func (d *Dispatcher) allowed(path, reqMethod string) (allow string) {
 				continue
 			}
 
-			handler, _, _ := d.trees[method].getValue(path)
+			handler, _, _, _ := d.trees[method].getValue(path)
 			if handler != nil {
 				// add request method to list of allowed methods
 				if len(allow) == 0 {

go.mod

@@ -0,0 +1,5 @@
+module github.com/dolab/httpdispatch
+
+go 1.12
+
+require github.com/golib/assert v1.3.0

go.sum

@@ -0,0 +1,13 @@
+github.com/buger/jsonparser v0.0.0-20181115193947-bf1c66bbce23 h1:D21IyuvjDCshj1/qq+pCNd3VZOAEI9jy6Bi131YlXgI=
+github.com/buger/jsonparser v0.0.0-20181115193947-bf1c66bbce23/go.mod h1:bbYlZJ7hK1yFx9hf58LP0zeX7UjIGs20ufpu3evjr+s=
+github.com/dolab/types v0.0.0-20181115071224-9f9f8147c117 h1:w7dIqNfQuaVBTSMCHx0q32k4gM3vN5ZRJKs73EhEnIA=
+github.com/dolab/types v0.0.0-20181115071224-9f9f8147c117/go.mod h1:ye5M9z0YlIxn/I+vU4MlK18SuRdSl62pxjMI6CdlFGg=
+github.com/golib/assert v1.3.0 h1:0zlb71NpB0q5FHMnYHyTnh+IS1+6YwW26ARpgN/0PA4=
+github.com/golib/assert v1.3.0/go.mod h1:hyMJSCLv/DFMNpTYmEaAd+OYj1KqmB5pZ7WlKGj7sGo=
+github.com/kr/pretty v0.1.0 h1:L/CwN0zerZDmRFUapSPitk6f+Q3+0za1rQkzVuMiMFI=
+github.com/kr/pretty v0.1.0/go.mod h1:dAy3ld7l9f0ibDNOQOHHMYYIIbhfbHSm3C4ZsoJORNo=
+github.com/kr/pty v1.1.1/go.mod h1:pFQYn66WHrOpPYNljwOMqo10TkYh1fy3cYio2l3bCsQ=
+github.com/kr/text v0.1.0 h1:45sCR5RtlFHMR4UwH9sdQ5TC8v0qDQCHnXt+kaKSTVE=
+github.com/kr/text v0.1.0/go.mod h1:4Jbv+DJW3UT/LiOwJeYQe1efqtUx/iVham/4vfdArNI=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=

tree.go

@@ -321,7 +321,8 @@ func (n *node) insertChild(numParams uint8, path, fullPath string, handle Handle
 // made if a handle exists with an extra (without the) trailing slash for the
 // given path.
 // It returns handle also if a TSR is true. Its useful for quick fallback strategy.
-func (n *node) getValue(path string) (handle Handler, p Params, tsr bool) {
+func (n *node) getValue(path string) (handle Handler, p Params, tsr bool, route string) {
+	route = "/"
 walk: // outer loop for walking the tree
 	for {
 		switch {
@@ -345,6 +346,7 @@ walk: // outer loop for walking the tree
 					for i := 0; i < len(n.indices); i++ {
 						if c == n.indices[i] {
 							n = n.children[i]
+							route += n.path
 							continue walk
 						}
 					}
@@ -354,6 +356,8 @@ walk: // outer loop for walking the tree
 
 				// handle wildcard child
 				n = n.children[0]
+				route += n.path
+
 				switch n.typo {
 				case param:
 					// save param value
@@ -387,6 +391,7 @@ walk: // outer loop for walking the tree
 						if len(n.children) > 0 {
 							path = path[end:]
 							n = n.children[0]
+							route += n.path
 
 							continue walk
 						}
@@ -404,6 +409,7 @@ walk: // outer loop for walking the tree
 					// trailing slash exists for TSR recommendation
 					if len(n.children) == 1 {
 						n = n.children[0]
+						route += n.path
 
 						tsr = (n.path == "/" && n.handle != nil)
 						if tsr {
@@ -457,6 +463,7 @@ walk: // outer loop for walking the tree
 			for i := 0; i < len(n.indices); i++ {
 				if n.indices[i] == '/' {
 					n = n.children[i]
+					route += n.path
 
 					tsr = (len(n.path) == 1 && n.handle != nil)
 					if tsr {

tree_test.go

@@ -42,7 +42,7 @@ type testRequests []struct {
 
 func checkRequests(t *testing.T, tree *node, requests testRequests) {
 	for _, request := range requests {
-		handler, ps, tsr := tree.getValue(request.path)
+		handler, ps, tsr, _ := tree.getValue(request.path)
 
 		if tsr {
 			if handler != nil {
@@ -470,7 +470,7 @@ func TestTreeTrailingSlashRedirect(t *testing.T) {
 		"/doc/",
 	}
 	for _, route := range tsrRoutes {
-		handler, _, tsr := tree.getValue(route)
+		handler, _, tsr, _ := tree.getValue(route)
 		if handler != nil && !tsr {
 			t.Fatalf("non-nil handler for TSR route '%s", route)
 		} else if !tsr {
@@ -487,7 +487,7 @@ func TestTreeTrailingSlashRedirect(t *testing.T) {
 		"/api/world/abc",
 	}
 	for _, route := range noTsrRoutes {
-		handler, _, tsr := tree.getValue(route)
+		handler, _, tsr, _ := tree.getValue(route)
 		if handler != nil {
 			t.Fatalf("non-nil handler for No-TSR route '%s", route)
 		} else if tsr {
@@ -506,7 +506,7 @@ func TestTreeRootTrailingSlashRedirect(t *testing.T) {
 		t.Fatalf("panic inserting test route: %v", recv)
 	}
 
-	handler, _, tsr := tree.getValue("/")
+	handler, _, tsr, _ := tree.getValue("/")
 	if handler != nil {
 		t.Fatalf("non-nil handler")
 	} else if tsr {