server.go

package main

import (
    "http"
    "net"
    "io"
    "log"
    "os"
    "bufio"
)

type application interface {
    Route(s string) Handler
}

type handlerFunc func(io.Writer, *http.Request)

type Handler interface {
    ServeHTTP(io.Writer, *http.Request)
}

func (f handlerFunc) ServeHTTP(w io.Writer, r *http.Request){
    f(w, r)
}

type Application struct {
    handlers map[string] Handler
}

func (a *Application) Route(s string) Handler {
    if handler, ok := a.handlers[s]; ok {
        return handler
    }
    return handlerFunc(helloHandler)
}

func (a *Application) Handle(s string, h Handler) {
    a.handlers[s] = h
}

func helloHandler(w io.Writer, req *http.Request) {
    io.WriteString(w, "HTTP/1.1 200 OK\r\nContent-Length: 5\r\n\r\nhello")
}

func newConn(conn net.Conn) *bufio.ReadWriter {
    br := bufio.NewReader(conn)
    bw := bufio.NewWriter(conn)
    return bufio.NewReadWriter(br, bw)
}

func serve(listener net.Listener, app application) os.Error {
    for {
        rw, e := listener.Accept()
        if e != nil {
            return e
        }
        conn := newConn(rw)
        request, _ := http.ReadRequest(conn.Reader)
        app.Route(request.URL.Path).ServeHTTP(conn.Writer, request)
        //helloHandler(conn.Writer, request)
        conn.Flush()
        rw.Close()
    }
    panic("not reached")
}

func ServeApplication(app application, addr string) {
    listener, err := net.Listen("tcp", addr)
    if err != nil {
        log.Exit("can't listen: ", err.String())
    }
    serve(listener, app)
}

func main() {
    app := new(Application)
    //app.Handle("/", handlerFunc(helloHandler))
    ServeApplication(app, ":8000")
}