Golang io.Writer類代碼示例

func UploadFromFileToUrl(url, fileName string, w io.Writer) (http.Header, error) {
	if url == "" {
		return http.Header{}, fmt.Errorf("To upload from a file to a url, I need a URL.")
	}
	w.Write([]byte("Uploading =>\t\t\t" + fileName + ":" + url + "\n"))

	input, err := os.Open(fileName)
	if err != nil {
		return http.Header{}, err
	}
	defer input.Close()

	request, err := http.NewRequest("POST", url, input)
	if err != nil {
		return http.Header{}, err
	}
	request.Header.Set("Content-Type", "application/json")

	client := &http.Client{}
	response, err := client.Do(request)
	if err != nil {
		return http.Header{}, err
	}
	defer response.Body.Close()

	return response.Header, nil
}

func (server *SocksServer) handleSocks4(reader io.Reader, writer io.Writer, auth protocol.Socks4AuthenticationRequest) error {
	result := protocol.Socks4RequestGranted
	if auth.Command == protocol.CmdBind {
		result = protocol.Socks4RequestRejected
	}
	socks4Response := protocol.NewSocks4AuthenticationResponse(result, auth.Port, auth.IP[:])

	responseBuffer := alloc.NewSmallBuffer().Clear()
	socks4Response.Write(responseBuffer)
	writer.Write(responseBuffer.Value)
	responseBuffer.Release()

	if result == protocol.Socks4RequestRejected {
		log.Warning("Unsupported socks 4 command %d", auth.Command)
		return UnsupportedSocksCommand
	}

	dest := v2net.NewTCPDestination(v2net.IPAddress(auth.IP[:], auth.Port))
	data, err := v2net.ReadFrom(reader, nil)
	if err != nil {
		return err
	}

	packet := v2net.NewPacket(dest, data, true)
	server.transport(reader, writer, packet)
	return nil
}

// serializeWithoutHeaders marshals the PublicKey to w in the form of an
// OpenPGP public key packet, not including the packet header.
func (pk *PublicKeyV3) serializeWithoutHeaders(w io.Writer) (err error) {
	var buf [8]byte
	// Version 3
	buf[0] = 3
	// Creation time
	t := uint32(pk.CreationTime.Unix())
	buf[1] = byte(t >> 24)
	buf[2] = byte(t >> 16)
	buf[3] = byte(t >> 8)
	buf[4] = byte(t)
	// Days to expire
	buf[5] = byte(pk.DaysToExpire >> 8)
	buf[6] = byte(pk.DaysToExpire)
	// Public key algorithm
	buf[7] = byte(pk.PubKeyAlgo)

	if _, err = w.Write(buf[:]); err != nil {
		return
	}

	switch pk.PubKeyAlgo {
	case PubKeyAlgoRSA, PubKeyAlgoRSAEncryptOnly, PubKeyAlgoRSASignOnly:
		return writeMPIs(w, pk.n, pk.e)
	}
	return errors.InvalidArgumentError("bad public-key algorithm")
}

func debugFailf(out io.Writer, body bool, s string, v ...interface{}) func(*http.Response) os.Error {
	return func(in *http.Response) os.Error {
		ob, _ := http.DumpResponse(in, body)
		out.Write(ob)
		return os.NewError(fmt.Sprintf(s, v...))
	}
}

// EncodeToStream serializes the provided object to the given writer. Overrides is ignored.
func (s *Serializer) EncodeToStream(obj runtime.Object, w io.Writer, overrides ...unversioned.GroupVersion) error {
	if s.yaml {
		json, err := json.Marshal(obj)
		if err != nil {
			return err
		}
		data, err := yaml.JSONToYAML(json)
		if err != nil {
			return err
		}
		_, err = w.Write(data)
		return err
	}

	if s.pretty {
		data, err := json.MarshalIndent(obj, "", "  ")
		if err != nil {
			return err
		}
		_, err = w.Write(data)
		return err
	}
	encoder := json.NewEncoder(w)
	return encoder.Encode(obj)
}

// emitCDATA writes to w the CDATA-wrapped plain text data s.
// It escapes CDATA directives nested in s.
func emitCDATA(w io.Writer, s []byte) error {
	if len(s) == 0 {
		return nil
	}
	if _, err := w.Write(cdataStart); err != nil {
		return err
	}
	for {
		i := bytes.Index(s, cdataEnd)
		if i >= 0 && i+len(cdataEnd) <= len(s) {
			// Found a nested CDATA directive end.
			if _, err := w.Write(s[:i]); err != nil {
				return err
			}
			if _, err := w.Write(cdataEscape); err != nil {
				return err
			}
			i += len(cdataEnd)
		} else {
			if _, err := w.Write(s); err != nil {
				return err
			}
			break
		}
		s = s[i:]
	}
	if _, err := w.Write(cdataEnd); err != nil {
		return err
	}
	return nil
}

func (par field) WriteValue(out io.Writer, valueOf reflect.Value) error {
	if (par.Flags & (fieldNotAny | fieldFollowedBy)) != 0 {
		return nil
	}

	if par.Index < 0 { // We can not out this value in all cases but if it was literal we can do it
		// TODO: Check if it is string and output only in case it is literal
		p := par.Parse
		v := valueOf
		for {
			switch tp := p.(type) {
			case *ptrParser:
				p = tp.Parser
				if v.IsNil() {
					if tp.Optional {
						return nil
					}
					return errors.New("Ptr value is nil")
				}
				v = v.Elem()
				break

			case *literalParser:
				_, err := out.Write([]byte(tp.Literal))
				return err
			default:
				return errors.New("Could not out anonymous field if it is not literal")
			}
		}
	} else {
		f := valueOf.Field(par.Index)
		return par.Parse.WriteValue(out, f)
	}
}

func (c *ClickWindow) write(ww io.Writer) (err error) {
	var tmp [2]byte
	tmp[0] = byte(c.ID >> 0)
	if _, err = ww.Write(tmp[:1]); err != nil {
		return
	}
	tmp[0] = byte(c.Slot >> 8)
	tmp[1] = byte(c.Slot >> 0)
	if _, err = ww.Write(tmp[:2]); err != nil {
		return
	}
	tmp[0] = byte(c.Button >> 0)
	if _, err = ww.Write(tmp[:1]); err != nil {
		return
	}
	tmp[0] = byte(c.ActionNumber >> 8)
	tmp[1] = byte(c.ActionNumber >> 0)
	if _, err = ww.Write(tmp[:2]); err != nil {
		return
	}
	tmp[0] = byte(c.Mode >> 0)
	if _, err = ww.Write(tmp[:1]); err != nil {
		return
	}
	if err = c.ClickedItem.Serialize(ww); err != nil {
		return
	}
	return
}

func (vs *Vertexes) Print(w io.Writer, xPos, zPos int) (count int) {
	var buf = make([]byte, 64)
	copy(buf[0:2], "v ")

	count = 0
	for i := 0; i < len(*vs); i += 129 {
		var x, z = (i / 129) / 17, (i / 129) % 17

		var column = (*vs)[i : i+129]
		for y, offset := range column {
			if offset != -1 {

				count++

				var (
					xa = x + xPos*16
					ya = y - 64
					za = z + zPos*16
				)

				buf = buf[:2]
				buf = appendCoord(buf, xa)
				buf = append(buf, ' ')
				buf = appendCoord(buf, ya)
				buf = append(buf, ' ')
				buf = appendCoord(buf, za)
				buf = append(buf, '\n')

				w.Write(buf)
			}
		}
	}
	return
}

// writeTxIn encodes ti to the bitcoin protocol encoding for a transaction
// input (TxIn) to w.
func writeTxIn(w io.Writer, pver uint32, version uint32, ti *TxIn) error {
	err := writeOutPoint(w, pver, version, &ti.PreviousOutpoint)
	if err != nil {
		return err
	}

	slen := uint64(len(ti.SignatureScript))
	err = writeVarInt(w, pver, slen)
	if err != nil {
		return err
	}

	b := []byte(ti.SignatureScript)
	_, err = w.Write(b)
	if err != nil {
		return err
	}

	err = writeElement(w, &ti.Sequence)
	if err != nil {
		return err
	}

	return nil
}

func pipe(r io.Reader, w io.Writer) {
	var err error
	defer func() {
		if err != nil && err != io.EOF {
			log.Print(err)
		}
	}()

	firstChunk := true
	buf := make([]byte, cmdline.bufsize)
	for {
		var n int
		n, err = r.Read(buf)
		if n <= 0 {
			return
		}

		if firstChunk {
			firstChunk = false
		} else if cmdline.maxPostDelay > 0 {
			delay(cmdline.minPostDelay, cmdline.maxPostDelay)
		}

		_, err = w.Write(buf[:n])
		if err != nil {
			return
		}
	}
}

// Write text to w; optionally html-escaped.
func writeText(w io.Writer, text []byte, html bool) {
	if html {
		template.HTMLEscape(w, text)
		return
	}
	w.Write(text)
}

// writeMPI serializes a big integer to w.
func writeMPI(w io.Writer, bitLength uint16, mpiBytes []byte) (err error) {
	_, err = w.Write([]byte{byte(bitLength >> 8), byte(bitLength)})
	if err == nil {
		_, err = w.Write(mpiBytes)
	}
	return
}

// serializeHeader writes an OpenPGP packet header to w. See RFC 4880, section
// 4.2.
func serializeHeader(w io.Writer, ptype packetType, length int) (err error) {
	var buf [6]byte
	var n int

	buf[0] = 0x80 | 0x40 | byte(ptype)
	if length < 192 {
		buf[1] = byte(length)
		n = 2
	} else if length < 8384 {
		length -= 192
		buf[1] = 192 + byte(length>>8)
		buf[2] = byte(length)
		n = 3
	} else {
		buf[1] = 255
		buf[2] = byte(length >> 24)
		buf[3] = byte(length >> 16)
		buf[4] = byte(length >> 8)
		buf[5] = byte(length)
		n = 6
	}

	_, err = w.Write(buf[:n])
	return
}

func (srv *Server) ImageInsert(name, url, path string, out io.Writer, sf *utils.StreamFormatter) (string, error) {
	out = utils.NewWriteFlusher(out)
	img, err := srv.runtime.repositories.LookupImage(name)
	if err != nil {
		return "", err
	}

	file, err := utils.Download(url, out)
	if err != nil {
		return "", err
	}
	defer file.Body.Close()

	config, _, _, err := ParseRun([]string{img.ID, "echo", "insert", url, path}, srv.runtime.capabilities)
	if err != nil {
		return "", err
	}

	b := NewBuilder(srv.runtime)
	c, err := b.Create(config)
	if err != nil {
		return "", err
	}

	if err := c.Inject(utils.ProgressReader(file.Body, int(file.ContentLength), out, sf.FormatProgress("Downloading", "%v/%v (%v)"), sf), path); err != nil {
		return "", err
	}
	// FIXME: Handle custom repo, tag comment, author
	img, err = b.Commit(c, "", "", img.Comment, img.Author, nil)
	if err != nil {
		return "", err
	}
	out.Write(sf.FormatStatus(img.ID))
	return img.ShortID(), nil
}