Chore: Move remaining web framework code to pkg/web, remove macaron binding module (#43018)

* remove macaron binding dependency

* completely purge macaron binding

* move everything to pkg/web

* remove non-go files from pkg/web

* clean up leftovers of macaron imports

* make linter happy

pkg/web/router.go

@@ -0,0 +1,229 @@
+// Copyright 2014 The Macaron Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License"): you may
+// not use this file except in compliance with the License. You may obtain
+// a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+// WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+// License for the specific language governing permissions and limitations
+// under the License.
+
+package web
+
+import (
+	"net/http"
+	"strings"
+	"sync"
+)
+
+var (
+	// Known HTTP methods.
+	_HTTP_METHODS = map[string]bool{
+		"GET":     true,
+		"POST":    true,
+		"PUT":     true,
+		"DELETE":  true,
+		"PATCH":   true,
+		"OPTIONS": true,
+		"HEAD":    true,
+	}
+)
+
+// routeMap represents a thread-safe map for route tree.
+type routeMap struct {
+	lock   sync.RWMutex
+	routes map[string]map[string]*Leaf
+}
+
+// NewRouteMap initializes and returns a new routeMap.
+func newRouteMap() *routeMap {
+	rm := &routeMap{
+		routes: make(map[string]map[string]*Leaf),
+	}
+	for m := range _HTTP_METHODS {
+		rm.routes[m] = make(map[string]*Leaf)
+	}
+	return rm
+}
+
+// getLeaf returns Leaf object if a route has been registered.
+func (rm *routeMap) getLeaf(method, pattern string) *Leaf {
+	rm.lock.RLock()
+	defer rm.lock.RUnlock()
+
+	return rm.routes[method][pattern]
+}
+
+// add adds new route to route tree map.
+func (rm *routeMap) add(method, pattern string, leaf *Leaf) {
+	rm.lock.Lock()
+	defer rm.lock.Unlock()
+
+	rm.routes[method][pattern] = leaf
+}
+
+type group struct {
+	pattern  string
+	handlers []Handler
+}
+
+// Router represents a Macaron router layer.
+type Router struct {
+	m       *Macaron
+	routers map[string]*Tree
+	*routeMap
+	namedRoutes map[string]*Leaf
+
+	groups   []group
+	notFound http.HandlerFunc
+}
+
+func NewRouter() *Router {
+	return &Router{
+		routers:     make(map[string]*Tree),
+		routeMap:    newRouteMap(),
+		namedRoutes: make(map[string]*Leaf),
+	}
+}
+
+// Handle is a function 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).
+type Handle func(http.ResponseWriter, *http.Request, map[string]string)
+
+// handle adds new route to the router tree.
+func (r *Router) handle(method, pattern string, handle Handle) {
+	method = strings.ToUpper(method)
+
+	var leaf *Leaf
+	// Prevent duplicate routes.
+	if leaf = r.getLeaf(method, pattern); leaf != nil {
+		return
+	}
+
+	// Validate HTTP methods.
+	if !_HTTP_METHODS[method] && method != "*" {
+		panic("unknown HTTP method: " + method)
+	}
+
+	// Generate methods need register.
+	methods := make(map[string]bool)
+	if method == "*" {
+		for m := range _HTTP_METHODS {
+			methods[m] = true
+		}
+	} else {
+		methods[method] = true
+	}
+
+	// Add to router tree.
+	for m := range methods {
+		if t, ok := r.routers[m]; ok {
+			leaf = t.Add(pattern, handle)
+		} else {
+			t := NewTree()
+			leaf = t.Add(pattern, handle)
+			r.routers[m] = t
+		}
+		r.add(m, pattern, leaf)
+	}
+}
+
+// Handle registers a new request handle with the given pattern, method and handlers.
+func (r *Router) Handle(method string, pattern string, handlers []Handler) {
+	if len(r.groups) > 0 {
+		groupPattern := ""
+		h := make([]Handler, 0)
+		for _, g := range r.groups {
+			groupPattern += g.pattern
+			h = append(h, g.handlers...)
+		}
+
+		pattern = groupPattern + pattern
+		h = append(h, handlers...)
+		handlers = h
+	}
+	handlers = validateAndWrapHandlers(handlers)
+
+	r.handle(method, pattern, func(resp http.ResponseWriter, req *http.Request, params map[string]string) {
+		c := r.m.createContext(resp, SetURLParams(req, params))
+		c.handlers = make([]Handler, 0, len(r.m.handlers)+len(handlers))
+		c.handlers = append(c.handlers, r.m.handlers...)
+		c.handlers = append(c.handlers, handlers...)
+		c.run()
+	})
+}
+
+func (r *Router) Group(pattern string, fn func(), h ...Handler) {
+	r.groups = append(r.groups, group{pattern, h})
+	fn()
+	r.groups = r.groups[:len(r.groups)-1]
+}
+
+// Get is a shortcut for r.Handle("GET", pattern, handlers)
+func (r *Router) Get(pattern string, h ...Handler) {
+	r.Handle("GET", pattern, h)
+	r.Head(pattern, h...)
+}
+
+// Patch is a shortcut for r.Handle("PATCH", pattern, handlers)
+func (r *Router) Patch(pattern string, h ...Handler) { r.Handle("PATCH", pattern, h) }
+
+// Post is a shortcut for r.Handle("POST", pattern, handlers)
+func (r *Router) Post(pattern string, h ...Handler) { r.Handle("POST", pattern, h) }
+
+// Put is a shortcut for r.Handle("PUT", pattern, handlers)
+func (r *Router) Put(pattern string, h ...Handler) { r.Handle("PUT", pattern, h) }
+
+// Delete is a shortcut for r.Handle("DELETE", pattern, handlers)
+func (r *Router) Delete(pattern string, h ...Handler) { r.Handle("DELETE", pattern, h) }
+
+// Options is a shortcut for r.Handle("OPTIONS", pattern, handlers)
+func (r *Router) Options(pattern string, h ...Handler) { r.Handle("OPTIONS", pattern, h) }
+
+// Head is a shortcut for r.Handle("HEAD", pattern, handlers)
+func (r *Router) Head(pattern string, h ...Handler) { r.Handle("HEAD", pattern, h) }
+
+// Any is a shortcut for r.Handle("*", pattern, handlers)
+func (r *Router) Any(pattern string, h ...Handler) { r.Handle("*", pattern, h) }
+
+// NotFound configurates http.HandlerFunc which is called when no matching route is
+// found. If it is not set, http.NotFound is used.
+// Be sure to set 404 response code in your handler.
+func (r *Router) NotFound(handlers ...Handler) {
+	handlers = validateAndWrapHandlers(handlers)
+	r.notFound = func(rw http.ResponseWriter, req *http.Request) {
+		c := r.m.createContext(rw, req)
+		c.handlers = make([]Handler, 0, len(r.m.handlers)+len(handlers))
+		c.handlers = append(c.handlers, r.m.handlers...)
+		c.handlers = append(c.handlers, handlers...)
+		c.run()
+	}
+}
+
+func (r *Router) ServeHTTP(rw http.ResponseWriter, req *http.Request) {
+	if t, ok := r.routers[req.Method]; ok {
+		// Fast match for static routes
+		if !strings.ContainsAny(req.URL.Path, ":*") {
+			leaf := r.getLeaf(req.Method, req.URL.Path)
+			if leaf != nil {
+				leaf.handle(rw, req, nil)
+				return
+			}
+		}
+
+		h, p, ok := t.Match(req.URL.EscapedPath())
+		if ok {
+			if splat, ok := p["*0"]; ok {
+				p["*"] = splat // Easy name.
+			}
+			h(rw, req, p)
+			return
+		}
+	}
+
+	r.notFound(rw, req)
+}