Golang log.Stderr函数代码示例

// Handle the data from a single imported data stream, which will
// have the form
//	(response, data)*
// The response identifies by name which channel is receiving data.
// TODO: allow an importer to send.
func (imp *Importer) run() {
	// Loop on responses; requests are sent by ImportNValues()
	resp := new(response)
	for {
		if err := imp.decode(resp); err != nil {
			log.Stderr("importer response decode:", err)
			break
		}
		if resp.error != "" {
			log.Stderr("importer response error:", resp.error)
			// TODO: tear down connection
			break
		}
		imp.chanLock.Lock()
		ich, ok := imp.chans[resp.name]
		imp.chanLock.Unlock()
		if !ok {
			log.Stderr("unknown name in request:", resp.name)
			break
		}
		if ich.dir != Recv {
			log.Stderr("TODO: import send unimplemented")
			break
		}
		// Create a new value for each received item.
		val := reflect.MakeZero(ich.ptr.Type().(*reflect.PtrType).Elem())
		ich.ptr.PointTo(val)
		if err := imp.decode(ich.ptr.Interface()); err != nil {
			log.Stderr("importer value decode:", err)
			return
		}
		ich.ch.Send(val)
	}
}

func main() {

	// create the client.  Here we are using a synchronous client.
	// Using the default ConnectionSpec, we are specifying the client to connect
	// to db 13 (e.g. SELECT 13), and a password of go-redis (e.g. AUTH go-redis)

	spec := redis.DefaultSpec().Db(13).Password("go-redis")
	client, e := redis.NewSynchClientWithSpec(spec)
	if e != nil {
		log.Stderr("failed to create the client", e)
		return
	}

	key := "examples/hello/user.name"
	value, e := client.Get(key)
	if e != nil {
		log.Stderr("error on Get", e)
		return
	}

	if value == nil {
		fmt.Printf("\nHello, don't believe we've met before!\nYour name? ")
		reader := bufio.NewReader(os.Stdin)
		user, _ := reader.ReadString(byte('\n'))
		if len(user) > 1 {
			user = user[0 : len(user)-1]
			value = []byte(user)
			client.Set(key, value)
		} else {
			fmt.Printf("vafanculo!\n")
			return
		}
	}
	fmt.Printf("Hey, ciao %s!\n", fmt.Sprintf("%s", value))
}

// WriteHeader sends an HTTP response header with status code.
// If WriteHeader is not called explicitly, the first call to Write
// will trigger an implicit WriteHeader(http.StatusOK).
// Thus explicit calls to WriteHeader are mainly used to
// send error codes.
func (c *Conn) WriteHeader(code int) {
	if c.hijacked {
		log.Stderr("http: Conn.WriteHeader on hijacked connection")
		return
	}
	if c.wroteHeader {
		log.Stderr("http: multiple Conn.WriteHeader calls")
		return
	}
	c.wroteHeader = true
	c.status = code
	c.written = 0
	if !c.Req.ProtoAtLeast(1, 0) {
		return
	}
	proto := "HTTP/1.0"
	if c.Req.ProtoAtLeast(1, 1) {
		proto = "HTTP/1.1"
	}
	codestring := strconv.Itoa(code)
	text, ok := statusText[code]
	if !ok {
		text = "status code " + codestring
	}
	io.WriteString(c.buf, proto+" "+codestring+" "+text+"\r\n")
	for k, v := range c.header {
		io.WriteString(c.buf, k+": "+v+"\r\n")
	}
	io.WriteString(c.buf, "\r\n")
}

// Send all the data on a single channel to a client asking for a Recv
func (client *expClient) serveRecv(req *request) {
	exp := client.exp
	resp := new(response)
	resp.name = req.name
	var ok bool
	exp.chanLock.Lock()
	ech, ok := exp.chans[req.name]
	exp.chanLock.Unlock()
	if !ok {
		resp.error = "no such channel: " + req.name
		log.Stderr("export:", resp.error)
		client.encode(resp, nil) // ignore any encode error, hope client gets it
		return
	}
	for {
		if ech.dir != Send {
			log.Stderr("TODO: recv export unimplemented")
			break
		}
		val := ech.ch.Recv()
		if err := client.encode(resp, val.Interface()); err != nil {
			log.Stderr("error encoding client response:", err)
			break
		}
		if req.count > 0 {
			req.count--
			if req.count == 0 {
				break
			}
		}
	}
}

// WriteHeader sends an HTTP response header with status code.
// If WriteHeader is not called explicitly, the first call to Write
// will trigger an implicit WriteHeader(http.StatusOK).
// Thus explicit calls to WriteHeader are mainly used to
// send error codes.
func (c *Conn) WriteHeader(code int) {
	if c.hijacked {
		log.Stderr("http: Conn.WriteHeader on hijacked connection")
		return
	}
	if c.wroteHeader {
		log.Stderr("http: multiple Conn.WriteHeader calls")
		return
	}
	c.wroteHeader = true
	c.status = code
	if code == StatusNotModified {
		// Must not have body.
		c.header["Content-Type"] = "", false
		c.header["Transfer-Encoding"] = "", false
	}
	c.written = 0
	if !c.Req.ProtoAtLeast(1, 0) {
		return
	}
	proto := "HTTP/1.0"
	if c.Req.ProtoAtLeast(1, 1) {
		proto = "HTTP/1.1"
	}
	codestring := strconv.Itoa(code)
	text, ok := statusText[code]
	if !ok {
		text = "status code " + codestring
	}
	io.WriteString(c.buf, proto+" "+codestring+" "+text+"\r\n")
	for k, v := range c.header {
		io.WriteString(c.buf, k+": "+v+"\r\n")
	}
	io.WriteString(c.buf, "\r\n")
}

func proxyMuxer() {
	proxyMap := make(map[string]*proxy)
	for {
		select {
		case pp := <-queue:
			key := make([]byte, keyLen)
			// read key
			n, err := pp.r.Body.Read(key)
			if n != keyLen || err != nil {
				log.Stderr("Couldn't read key", key)
				continue
			}
			// find proxy
			p, ok := proxyMap[string(key)]
			if !ok {
				log.Stderr("Couldn't find proxy", key)
				continue
			}
			// handle
			p.handle(pp)
		case p := <-createQueue:
			proxyMap[p.key] = p
		}
	}
}

func serveConnection(serverName string, secure bool, handler web.Handler, netConn net.Conn) {
	br := bufio.NewReader(netConn)
	for {
		c := conn{
			serverName: serverName,
			secure:     secure,
			netConn:    netConn,
			br:         br}
		if err := c.prepare(); err != nil {
			if err != os.EOF {
				log.Stderr("twister/sever: prepare failed", err)
			}
			break
		}
		handler.ServeWeb(c.req)
		if c.hijacked {
			return
		}
		if err := c.finish(); err != nil {
			log.Stderr("twister/sever: finish failed", err)
			break
		}
		if c.closeAfterResponse {
			break
		}
	}
	netConn.Close()
}

func managementTask (c *asyncConnHdl, ctl workerCtl) (sig *interrupt_code, te *taskStatus) {
/* TODO:
connected:
	clearChannels();
	startWokers();
disconnected:
	?
on_fault:
	disconnect();
	goto disconnected;
on_exit:
	?
*/
	log.Stderr("MGR: do task ...");
	select {
		case stat:= <-c.feedback:
		log.Stderr("MGR: Feedback from one of my minions: ", stat);
		// do the shutdown for now -- TODO: try reconnect
		if stat.event == faulted {
			log.Stderr("MGR: Shutting down due to fault in ", stat.id);
			go func() { c.reqProcCtl <- stop; } ();
			go func() { c.rspProcCtl <- stop; } ();
			go func() { c.heartbeatCtl <- stop; } ();
			
			log.Stderr("MGR: Signal SHUTDOWN ... ");
			c.shutdown <- true;
			// stop self // TODO: should manager really be a task or a FSM?
			c.managerCtl <- stop;
		}
	case s := <- ctl:
		return &s, &ok_status;
	}
	
	return nil, &ok_status;
}

// Manage sends and receives for a single client.  For each (client Recv) request,
// this will launch a serveRecv goroutine to deliver the data for that channel,
// while (client Send) requests are handled as data arrives from the client.
func (client *expClient) run() {
	hdr := new(header)
	req := new(request)
	error := new(error)
	for {
		if err := client.decode(hdr); err != nil {
			log.Stderr("error decoding client header:", err)
			// TODO: tear down connection
			return
		}
		switch hdr.payloadType {
		case payRequest:
			if err := client.decode(req); err != nil {
				log.Stderr("error decoding client request:", err)
				// TODO: tear down connection
				return
			}
			switch req.dir {
			case Recv:
				go client.serveRecv(*hdr, req.count)
			case Send:
				// Request to send is clear as a matter of protocol
				// but not actually used by the implementation.
				// The actual sends will have payload type payData.
				// TODO: manage the count?
			default:
				error.error = "export request: can't handle channel direction"
				log.Stderr(error.error, req.dir)
				client.encode(hdr, payError, error)
			}
		case payData:
			client.serveSend(*hdr)
		}
	}
}

func handleMessage(s net.Conn, reqChannel chan MCRequest) (ret bool) {
	log.Stdoutf("Handling a message...")
	hdrBytes := make([]byte, HDR_LEN)
	ret = false

	log.Stdoutf("Reading header...")
	bytesRead, err := io.ReadFull(s, hdrBytes)
	if err != nil || bytesRead != HDR_LEN {
		log.Stderr("Error reading message: %s (%d bytes)", err, bytesRead)
		return
	}

	req := grokHeader(hdrBytes)

	readContents(s, req)

	log.Stdout("Processing message %s", req)
	req.ResponseChannel = make(chan MCResponse)
	reqChannel <- req
	res := <-req.ResponseChannel
	ret = !res.Fatal
	if ret {
		log.Stdoutf("Got response %s", res)
		transmitResponse(s, req, res)
	} else {
		log.Stderr("Something went wrong, hanging up...")
	}

	return
}

func main() {
	flag.Parse()

	listener, err := net.Listen("tcp", *listenAddr)
	if err != nil {
		panic(err)
	}

	conn, err := listener.Accept()
	if err != nil {
		panic(err)
	}

	buf := new(bytes.Buffer)

	// initiate new session and read key
	log.Stderr("Attempting connect", *destAddr)
	buf.Write([]byte(*destAddr))
	resp, err := http.Post(
		"http://"+*httpAddr+"/create",
		"text/plain",
		buf)
	if err != nil {
		panic(err)
	}
	key, _ := ioutil.ReadAll(resp.Body)
	resp.Body.Close()

	log.Stderr("Connected, key", key)

	// ticker to set a rate at which to hit the server
	tick := time.NewTicker(int64(*tickInterval) * 1e6)
	read := makeReadChan(conn, bufSize)
	buf.Reset()
	for {
		select {
		case <-tick.C:
			// write buf to new http request
			req := bytes.NewBuffer(key)
			buf.WriteTo(req)
			resp, err := http.Post(
				"http://"+*httpAddr+"/ping",
				"application/octet-stream",
				req)
			if err != nil {
				log.Stderr(err.String())
				continue
			}
			// write http response response to conn
			io.Copy(conn, resp.Body)
			resp.Body.Close()
		case b := <-read:
			buf.Write(b)
		}
	}
}

// This could find a happy home in a generalized worker package ...
// TODO
func (c *asyncConnHdl) worker(id int, name string, task workerTask, ctl workerCtl, fb chan workerStatus) {
	var signal interrupt_code
	var tstat *taskStatus

	// todo: add startup hook for worker

await_signal:
	log.Stdout(name, "_worker: await_signal.")
	signal = <-ctl

on_interrupt:
	//		log.Stdout(name, "_worker: on_interrupt: ", signal);
	switch signal {
	case stop:
		goto before_stop
	case pause:
		goto await_signal
	case start:
		goto work
	}

work:
	//		log.Stdout(name, "_worker: work!");
	select {
	case signal = <-ctl:
		goto on_interrupt
	default:
		is, stat := task(c, ctl) // todo is a task context type
		if stat == nil {
			log.Stderr("<BUG> nil stat from worker ", name)
		}
		if stat.code != ok {
			log.Stdout(name, "_worker: task error!")
			tstat = stat
			goto on_error
		} else if is != nil {
			signal = *is
			goto on_interrupt
		}
		goto work
	}

on_error:
	log.Stdout(name, "_worker: on_error!")
	// TODO: log it, send it, and go back to wait_start:
	log.Stderr(name, "_worker task raised error: ", tstat)
	fb <- workerStatus{id, faulted, tstat, &ctl}
	goto await_signal

before_stop:
	log.Stdout(name, "_worker: before_stop!")
	// TODO: add shutdown hook for worker

	log.Stdout(name, "_worker: STOPPED!")
}

func NewProxy(key, destAddr string) (p *proxy, err os.Error) {
	p = &proxy{C: make(chan proxyPacket), key: key}
	log.Stderr("Attempting connect", destAddr)
	p.conn, err = net.Dial("tcp", "", destAddr)
	if err != nil {
		return
	}
	p.conn.SetReadTimeout(readTimeout)
	log.Stderr("Connected", destAddr)
	return
}

func signalListener(end chan bool) {
	for {
		if n := <-signal.Incoming; strings.HasPrefix(n.String(), "SIGINT") {
			log.Stderr("Received SIGINT, ending execution")
			end <- true
			return
		} else {
			log.Stderr("Received singal", n, "ignoring")
		}
	}
}

func main() {
	var m int
	var user g9p.User
	var file *g9pc.File

	flag.Parse()
	user = g9p.OsUsers.Uid2User(os.Geteuid())
	c, err := g9pc.Mount("tcp", *addr, "", user, nil)
	if err != nil {
		goto error
	}

	if flag.NArg() != 1 {
		log.Stderr("invalid arguments")
		return
	}

	file, err = c.FOpen(flag.Arg(0), g9p.OWRITE|g9p.OTRUNC)
	if err != nil {
		file, err = c.FCreate(flag.Arg(0), 0666, g9p.OWRITE)
		if err != nil {
			goto error
		}
	}

	buf := make([]byte, 8192)
	for {
		n, oserr := os.Stdin.Read(buf)
		if oserr != nil && oserr != io.EOF {
			err = &g9p.Error{oserr.String(), 0}
			goto error
		}

		if n == 0 {
			break
		}

		m, err = file.Write(buf[0:n])
		if err != nil {
			goto error
		}

		if m != n {
			err = &g9p.Error{"short write", 0}
			goto error
		}
	}

	file.Close()
	return

error:
	log.Stderr(fmt.Sprintf("Error: %v", err))
}