go http包 DefaultServeMux 有關匹配規則的幾個函數

這是一個建立於 的文章，其中的資訊可能已經有所發展或是發生改變。

func (mux *ServeMux) match(path string) Handler {var h Handlervar n = 0for k, v := range mux.m {if !pathMatch(k, path) {continue}if h == nil || len(k) > n {n = len(k)h = v.h}}return h}

func pathMatch(pattern, path string) bool {if len(pattern) == 0 {// should not happenreturn false}n := len(pattern)if pattern[n-1] != '/' {return pattern == path}return len(path) >= n && path[0:n] == pattern}

func (mux *ServeMux) handler(r *Request) Handler {mux.mu.RLock()defer mux.mu.RUnlock()// Host-specific pattern takes precedence over generic onesh := mux.match(r.Host + r.URL.Path)if h == nil {h = mux.match(r.URL.Path)}if h == nil {h = NotFoundHandler()}return h}

總是會請求一個 "/favicon.ico" 所以總是會出現 "/" 被請求了兩次