Golang io.WriteCloser類代碼示例

func revc(conn net.Conn, w io.WriteCloser) {
	defer w.Write([]byte("exit\n\r"))
	defer conn.Close()
	var b [100]byte
	conn.Write([]byte("welcome\n"))
	var s string
	for {
		n, err := conn.Read(b[0:100])
		if err != nil {
			break
		}
		//退格刪除字符
		if b[0] == 8 {
			s = s[0 : len(s)-1]
			continue
		}
		s += string(b[0:n])
		//回車提交
		if b[n-1] == 10 {
			//fmt.Print("接收:", n, s, b[1])
			w.Write([]byte(s))
			s = ""
		}
	}
}

// Start the link with the specified toxics
func (link *ToxicLink) Start(name string, source io.Reader, dest io.WriteCloser) {
	go func() {
		bytes, err := io.Copy(link.input, source)
		if err != nil {
			logrus.WithFields(logrus.Fields{
				"name":     link.proxy.Name,
				"upstream": link.proxy.Upstream,
				"bytes":    bytes,
				"err":      err,
			}).Warn("Source terminated")
		}
		link.input.Close()
	}()
	for i, toxic := range link.toxics.chain {
		go link.stubs[i].Run(toxic)
	}
	go func() {
		bytes, err := io.Copy(dest, link.output)
		if err != nil {
			logrus.WithFields(logrus.Fields{
				"name":     link.proxy.Name,
				"upstream": link.proxy.Upstream,
				"bytes":    bytes,
				"err":      err,
			}).Warn("Destination terminated")
		}
		dest.Close()
		link.toxics.RemoveLink(name)
		link.proxy.RemoveConnection(name)
	}()
}

func PGPKeyRawToArmored(raw []byte, priv bool) (ret string, err error) {

	var writer io.WriteCloser
	var out bytes.Buffer
	var which string

	if priv {
		which = "PRIVATE"
	} else {
		which = "PUBLIC"
	}
	hdr := fmt.Sprintf("PGP %s KEY BLOCK", which)

	writer, err = armor.Encode(&out, hdr, PGPArmorHeaders)

	if err != nil {
		return
	}
	if _, err = writer.Write(raw); err != nil {
		return
	}
	writer.Close()
	ret = out.String()
	return
}

func saltpackSign(g *GlobalContext, source io.ReadCloser, sink io.WriteCloser, key NaclSigningKeyPair, streamer streamfn) error {
	defer func() {
		if err := source.Close(); err != nil {
			g.Log.Warning("error closing source: %s", err)
		}
		if err := sink.Close(); err != nil {
			g.Log.Warning("error closing sink: %s", err)
		}
	}()

	stream, err := streamer(sink, saltSigner{key}, KeybaseSaltpackBrand)
	if err != nil {
		return err
	}

	if _, err := io.Copy(stream, source); err != nil {
		return err
	}

	if err = stream.Close(); err != nil {
		return err
	}

	return nil
}

//Backup - method to execute backup
func (s *MysqlPlugin) Backup() (err error) {
	lo.G.Debug("Starting backup of mysql-tile")
	var writer io.WriteCloser
	var persistanceBackuper cfbackup.PersistanceBackup
	var mysqlUserName, mysqlPassword string
	var sshConfigs []command.SshConfig

	if sshConfigs, err = s.getSSHConfig(); err == nil {
		//take first node to execute backup on
		sshConfig := sshConfigs[0]
		if mysqlUserName, mysqlPassword, err = s.getMysqlCredentials(); err == nil {
			lo.G.Debug("Successfully got mysqlCredentials")
			if persistanceBackuper, err = s.GetPersistanceBackup(mysqlUserName, mysqlPassword, sshConfig); err == nil {
				if writer, err = s.PivotalCF.NewArchiveWriter(outputFileName); err == nil {
					defer writer.Close()
					lo.G.Debug("Starting mysql dump")
					err = persistanceBackuper.Dump(writer)
					lo.G.Debug("Dump finished", err)
				}
			}
		}
	}
	lo.G.Debug("Finished backup of mysql-tile", err)
	return
}

func HandleWrite(ctx syncer.Context, l uri.Uri, r uri.Uri) error {
	if l.ModTime().Sub(r.ModTime()) < 0 {
		return ctx.Finish()
	}
	var (
		reader io.ReadCloser
		writer io.WriteCloser
		err    error
	)

	for {
		reader, err = l.OpenRead()
		if err == nil {
			break
		}
		time.Sleep(time.Second * 20)
	}
	for {
		writer, err = r.OpenWrite()
		if err == nil {
			break
		}
		time.Sleep(time.Minute * 10)
	}
	defer reader.Close()
	defer writer.Close()
	_, err = io.Copy(writer, reader)
	if err != nil {
		ctx.EmitLog(syncer.TypeError, err)
	}
	ctx.EmitLog(syncer.TypeInfo, "write to ", r.Uri())
	return err
}

func migrateCommandFunc(cmd *cobra.Command, args []string) {
	var (
		writer io.WriteCloser
		reader io.ReadCloser
		errc   chan error
	)
	if migrateTransformer != "" {
		writer, reader, errc = startTransformer()
	} else {
		fmt.Println("using default transformer")
		writer, reader, errc = defaultTransformer()
	}

	st, index := rebuildStoreV2()
	be := prepareBackend()
	defer be.Close()

	go func() {
		writeStore(writer, st)
		writer.Close()
	}()

	readKeys(reader, be)
	mvcc.UpdateConsistentIndex(be, index)
	err := <-errc
	if err != nil {
		fmt.Println("failed to transform keys")
		ExitWithError(ExitError, err)
	}

	fmt.Println("finished transforming keys")
}

func dump(args ...string) error {
	var w io.WriteCloser

	if len(args) == 0 {
		w = hex.Dumper(os.Stdout)
	} else {
		var err error

		w, err = os.Create(args[0])
		if err != nil {
			return err
		}
	}
	defer w.Close()

	d, err := openDevice()
	if err != nil {
		return err
	}
	defer d.Close()

	if dumpCount == 0 {
		dumpCount = eeprom.MaxBytes - dumpStart
	}
	data := make([]byte, dumpCount)
	if err := d.Read(uint16(dumpStart), data); err != nil {
		d.Reset()
		return err
	}
	_, err = w.Write(data)
	return err
}

func fakeEngine(r io.Reader, w io.WriteCloser) {
	buf := bufio.NewReader(r)
	for {
		line, _, err := buf.ReadLine()
		if err != nil {
			return
		}
		switch field := tokenise(string(line)); field.next() {
		case "uci":
			for _, o := range optionTests {
				fmt.Fprintf(w, "option name %s type %s %s\n", o.name, o.typ, o.other)
			}
			fmt.Fprintln(w, "uciok")
		case "isready":
			fmt.Fprintln(w, "readyok")
		case "setoption":
			// ignore
		case "go":
			for _, i := range infoTests {
				fmt.Fprintln(w, i.line)
			}
		case "quit":
			w.Close()
			return
		}
	}
}

func (c *Client) Stream(path string, headers map[string]string, in io.Reader, out io.WriteCloser) error {
	origin := fmt.Sprintf("https://%s", c.Host)
	endpoint := fmt.Sprintf("wss://%s%s", c.Host, path)

	config, err := websocket.NewConfig(endpoint, origin)

	if err != nil {
		return err
	}

	config.TlsConfig = &tls.Config{
		InsecureSkipVerify: true,
	}

	config.Header.Set("Version", c.Version)

	userpass := fmt.Sprintf("convox:%s", c.Password)
	userpass_encoded := base64.StdEncoding.EncodeToString([]byte(userpass))

	config.Header.Add("Authorization", fmt.Sprintf("Basic %s", userpass_encoded))

	for k, v := range headers {
		config.Header.Add(k, v)
	}

	config.TlsConfig = &tls.Config{
		InsecureSkipVerify: true,
	}

	var ws *websocket.Conn

	if proxy := os.Getenv("HTTPS_PROXY"); proxy != "" {
		ws, err = c.proxyWebsocket(config, proxy)
	} else {
		ws, err = websocket.DialConfig(config)
	}

	if err != nil {
		return err
	}

	defer ws.Close()

	var wg sync.WaitGroup

	if in != nil {
		go io.Copy(ws, in)
	}

	if out != nil {
		wg.Add(1)
		go copyAsync(out, ws, &wg)
	}

	wg.Wait()

	out.Close()

	return nil
}

func write(w io.WriteCloser) error {
	if _, err := io.Copy(w, strings.NewReader(poem)); err != nil {
		return err
	}

	return w.Close()
}

func (context *ElasticRuntime) readWriterArchive(dbInfo SystemDump, databaseDir string, action int) (err error) {
	filename := fmt.Sprintf(ER_BACKUP_FILE_FORMAT, dbInfo.Get(SD_COMPONENT))
	filepath := path.Join(databaseDir, filename)

	var pb PersistanceBackup

	if pb, err = dbInfo.GetPersistanceBackup(); err == nil {
		switch action {
		case IMPORT_ARCHIVE:
			lo.G.Debug("we are doing something here now")
			var backupReader io.ReadCloser
			if backupReader, err = context.Reader(filepath); err == nil {
				defer backupReader.Close()
				err = pb.Import(backupReader)
			}
		case EXPORT_ARCHIVE:
			lo.G.Info("Dumping database to file")
			var backupWriter io.WriteCloser
			if backupWriter, err = context.Writer(filepath); err == nil {
				defer backupWriter.Close()
				err = pb.Dump(backupWriter)
			}
		}
	}
	return
}

// ??
func SniffClose(name string, sink io.WriteCloser, source io.Reader, eof func()) {
	sniffer := newSniffer(name)
	z1, z2 := make(chan struct{}), make(chan struct{})
	go func() {
		io.Copy(sniffer, source)
		sniffer.warn("SRC=>EVE⋅⋅SINK", "closing")
		sniffer.Close()
		close(z1)
	}()
	go func() {
		io.Copy(sink, sniffer)
		sniffer.warn("SRC⋅⋅EVE=>SINK", "closing")
		sink.Close()
		close(z2)
	}()
	go func() {
		<-z1
		sniffer.warn("SRC=>EVE⋅⋅SINK", "closed")
		<-z2
		sniffer.warn("SRC⋅⋅EVE=>SINK", "closed")
		if eof != nil {
			eof()
		}
	}()
}

func inLoop(pipe io.WriteCloser, stdin io.Reader, done chan bool) {
	buf := make([]byte, 2)
	logger.Println("Entering stdin loop")
	done <- true
	for {
		bytes_read, read_err := io.ReadFull(stdin, buf)
		if read_err == io.EOF && bytes_read == 0 {
			break
		}
		fatal_if(read_err)

		length := read16_be(buf)
		logger.Printf("in: packet length = %v\n", length)
		if length == 0 {
			// this is how Porcelain signals EOF from Elixir
			break
		}

		bytes_written, write_err := io.CopyN(pipe, stdin, int64(length))
		logger.Printf("in: copied %v bytes\n", bytes_written)
		fatal_if(write_err)
	}
	pipe.Close()
	done <- true
}

func copyAndClose(wg *sync.WaitGroup, dest io.WriteCloser, src io.Reader) {
	_, _ = io.Copy(dest, src)
	_ = dest.Close()
	if wg != nil {
		wg.Done()
	}
}