Gorilla mux 源码阅读

//只要实现了Handler的接口就可以当作自定义的路由来用,也就是带上ServerHttp的方法就可以了。
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()
        //根据HTTP的协议重定向
　　　　 //设置Http的头Location,就可以告知服务器重定向到p这个地址

        w.Header().Set("Location", p)
        w.WriteHeader(http.StatusMovedPermanently)
        return
    }
    var match RouteMatch
    var handler http.Handler
　　//路由匹配对应的处理方式
   //handler获得处理方式
   //把req的一些值带上
   //把req的路由也给带上
   //调用handler的接口就可以啦
    if r.Match(req, &match) {
        handler = match.Handler
　　　　　　
        setVars(req, match.Vars)
   
        setCurrentRoute(req, match.Route)
    }
    if handler == nil {
        if r.NotFoundHandler == nil {
            r.NotFoundHandler = http.NotFoundHandler()
        }
        handler = r.NotFoundHandler
    }
    if !r.KeepContext {
        defer context.Clear(req)
    }
    handler.ServeHTTP(w, req)
}

 

// Match matches the route against the request.
func (r *Route) Match(req *http.Request, match *RouteMatch) bool {
    if r.buildOnly || r.err != nil {
　　　　　//带了buildOnly就表示这个路由仅仅是用来制作url的，不是用来处理request的。
        return false
    }
    // Match everything.
    //match 是匹配的路由的结果，作为参数传进来是可以对结果进行预设的
    for _, m := range r.matchers {
        if matched := m.Match(req, match); !matched {
            return false
        }
    }
    // Yay, we have a match. Let's collect some info about it.
    if match.Route == nil {
        match.Route = r
    }
    if match.Handler == nil {
        match.Handler = r.handler
    }
    if match.Vars == nil {
        match.Vars = make(map[string]string)
    }
    // Set variables.
    if r.regexp != nil {
        r.regexp.setMatch(req, match, r)
    }
    return true
}