Golang binary.Write函数代码示例

// bigIntToNetIPv6 is a helper function that correctly returns a net.IP with the
// correctly padded values.
func bigIntToNetIPv6(bi *big.Int) *net.IP {
	x := make(net.IP, IPv6len)
	ipv6Bytes := bi.Bytes()

	// It's possibe for ipv6Bytes to be less than IPv6len bytes in size.  If
	// they are different sizes we to pad the size of response.
	if len(ipv6Bytes) < IPv6len {
		buf := new(bytes.Buffer)
		buf.Grow(IPv6len)

		for i := len(ipv6Bytes); i < IPv6len; i++ {
			if err := binary.Write(buf, binary.BigEndian, byte(0)); err != nil {
				panic(fmt.Sprintf("Unable to pad byte %d of input %v: %v", i, bi, err))
			}
		}

		for _, b := range ipv6Bytes {
			if err := binary.Write(buf, binary.BigEndian, b); err != nil {
				panic(fmt.Sprintf("Unable to preserve endianness of input %v: %v", bi, err))
			}
		}

		ipv6Bytes = buf.Bytes()
	}
	i := copy(x, ipv6Bytes)
	if i != IPv6len {
		panic("IPv6 wrong size")
	}
	return &x
}

func (obj GCAddEffectPacket) Write(buf io.Writer, code uint8) error {

	binary.Write(buf, binary.LittleEndian, obj.ObjectID)
	binary.Write(buf, binary.LittleEndian, obj.EffectID)
	binary.Write(buf, binary.LittleEndian, obj.Duration)
	return nil
}

func (e *indexEntry) WriteTo(w io.Writer) (n int64, err error) {
	deleted := byte(0)
	if e.deleted {
		deleted = 1
	}

	if err = binary.Write(w, binary.BigEndian, deleted); err != nil {
		return 0, err
	}

	value_len := uint32(len(e.value))
	if err = binary.Write(w, binary.BigEndian, value_len); err != nil {
		return 0, err
	}

	if err = binary.Write(w, binary.BigEndian, []byte(e.value)); err != nil {
		return 0, err
	}

	if err = binary.Write(w, binary.BigEndian, e.id); err != nil {
		return 0, err
	}

	return int64(binary.Size(deleted) + binary.Size([]byte(e.value)) + binary.Size(e.id)), nil
}

func (client *Client) WriteEMessage(emsg *EMessage) []byte {
	buffer := new(bytes.Buffer)
	binary.Write(buffer, binary.BigEndian, emsg.msgid)
	binary.Write(buffer, binary.BigEndian, emsg.device_id)
	SendMessage(buffer, emsg.msg)
	return buffer.Bytes()
}

func serializeV1PrecertSCTSignatureInput(timestamp uint64, issuerKeyHash [issuerKeyHashLength]byte, tbs []byte, ext CTExtensions) ([]byte, error) {
	if err := checkCertificateFormat(tbs); err != nil {
		return nil, err
	}
	if err := checkExtensionsFormat(ext); err != nil {
		return nil, err
	}
	var buf bytes.Buffer
	if err := binary.Write(&buf, binary.BigEndian, V1); err != nil {
		return nil, err
	}
	if err := binary.Write(&buf, binary.BigEndian, CertificateTimestampSignatureType); err != nil {
		return nil, err
	}
	if err := binary.Write(&buf, binary.BigEndian, timestamp); err != nil {
		return nil, err
	}
	if err := binary.Write(&buf, binary.BigEndian, PrecertLogEntryType); err != nil {
		return nil, err
	}
	if _, err := buf.Write(issuerKeyHash[:]); err != nil {
		return nil, err
	}
	if err := writeVarBytes(&buf, tbs, CertificateLengthBytes); err != nil {
		return nil, err
	}
	if err := writeVarBytes(&buf, ext, ExtensionsLengthBytes); err != nil {
		return nil, err
	}
	return buf.Bytes(), nil
}

// SerializeTimestampedEntry writes timestamped entry to Writer.
// In case of error, w may contain garbage.
func SerializeTimestampedEntry(w io.Writer, t *TimestampedEntry) error {
	if err := binary.Write(w, binary.BigEndian, t.Timestamp); err != nil {
		return err
	}
	if err := binary.Write(w, binary.BigEndian, t.EntryType); err != nil {
		return err
	}
	switch t.EntryType {
	case X509LogEntryType:
		if err := writeVarBytes(w, t.X509Entry, CertificateLengthBytes); err != nil {
			return err
		}
	case PrecertLogEntryType:
		if err := binary.Write(w, binary.BigEndian, t.PrecertEntry.IssuerKeyHash); err != nil {
			return err
		}
		if err := writeVarBytes(w, t.PrecertEntry.TBSCertificate, PreCertificateLengthBytes); err != nil {
			return err
		}
	case XJSONLogEntryType:
		// TODO: Pending google/certificate-transparency#1243, replace
		// with ObjectHash once supported by CT server.
		//jsonhash := objecthash.CommonJSONHash(string(t.JSONData))
		if err := writeVarBytes(w, []byte(t.JSONData), JSONLengthBytes); err != nil {
			return err
		}
	default:
		return fmt.Errorf("unknown EntryType: %d", t.EntryType)
	}
	writeVarBytes(w, t.Extensions, ExtensionsLengthBytes)
	return nil
}

func MarshalPacket(pack interface{}) ([]byte, error) {
	et := typetest(pack)
	if et < EncodingTypeNil || et > EncodingTypeMax {
		return nil, errors.New("MarshalPacket unkown data type")
	}

	if encodingArray[et] == nil {
		return nil, errors.New("MarshalPacket unkown data type")
	}

	data, err := encodingArray[et].Marshal(pack)
	if err != nil {
		return nil, fmt.Errorf("%v %v", pack, err.Error())
	}

	packetid, err := getPacketId(pack)
	if err != nil {
		return nil, fmt.Errorf("%v %v", pack, err.Error())
	}

	ph := PacketHeader{
		EncodeType: int16(et),
		PacketId:   int16(packetid),
	}

	w := bytes.NewBuffer(nil)
	binary.Write(w, binary.LittleEndian, &ph)
	binary.Write(w, binary.LittleEndian, data)
	return w.Bytes(), nil
}

func (this *DataPackage) Package() []byte {
	buf := new(bytes.Buffer)
	binary.Write(buf, binary.BigEndian, this.Head)
	binary.Write(buf, binary.BigEndian, this.Body)
	binary.Write(buf, binary.BigEndian, this.Tail)
	return buf.Bytes()
}

func cipherPacket(cmd uint8, data []byte) []byte {
	buf := new(bytes.Buffer)
	binary.Write(buf, binary.BigEndian, cmd)
	binary.Write(buf, binary.BigEndian, uint16(len(data)))
	buf.Write(data)
	return buf.Bytes()
}

func (w *Writer) flushIndex() error {
	w.trailer.DataIndexOffset = w.curOffset
	w.trailer.DataIndexCount = uint32(len(w.blocks))

	w.fp.Write(IndexMagic)
	w.curOffset += uint64(len(IndexMagic))

	for _, b := range w.blocks {
		if err := binary.Write(w.fp, binary.BigEndian, b.offset); err != nil {
			return err
		}
		w.curOffset += uint64(binary.Size(b.offset))

		if err := binary.Write(w.fp, binary.BigEndian, b.size); err != nil {
			return err
		}
		w.curOffset += uint64(binary.Size(b.size))

		if i, err := writeUvarint(w.fp, uint64(len(b.firstKeyBytes))); err != nil {
			return err
		} else {
			w.curOffset += uint64(i)
		}

		if i, err := w.fp.Write(b.firstKeyBytes); err != nil {
			return err
		} else {
			w.curOffset += uint64(i)
		}
	}

	return nil
}

func (space *Space) Call(procName string, returnTuple bool, args ...TupleField) (tuples [][][]byte, err error) {
	body := new(bytes.Buffer)
	flags := BoxFlags

	if returnTuple == true {
		flags |= BoxReturnTuple
	}

	err = binary.Write(body, binary.LittleEndian, flags)
	if err != nil {
		return
	}

	err = String(procName).Pack(body)
	if err != nil {
		return
	}

	err = binary.Write(body, binary.LittleEndian, int32(len(args)))
	if err != nil {
		return
	}

	for _, field := range args {
		field.Pack(body)
	}

	tuples, err = space.request(CallOp, body)
	return
}

// Refactor: same as Insert but Op number
func (space *Space) Delete(tuple []TupleField, returnTuple bool) (tuples [][][]byte, err error) {
	body := new(bytes.Buffer)
	flags := BoxFlags

	if returnTuple == true {
		flags |= BoxReturnTuple
	}

	requestBody := []int32{space.spaceNo, flags}
	err = binary.Write(body, binary.LittleEndian, requestBody)
	if err != nil {
		return
	}

	err = binary.Write(body, binary.LittleEndian, int32(len(tuple)))
	if err != nil {
		return
	}

	for _, field := range tuple {
		field.Pack(body)
	}

	tuples, err = space.request(DeleteOp, body)
	return
}

func (m *EntryBlockResponse) MarshalForSignature() ([]byte, error) {
	var buf primitives.Buffer

	binary.Write(&buf, binary.BigEndian, m.Type())

	t := m.GetTimestamp()
	data, err := t.MarshalBinary()
	if err != nil {
		return nil, err
	}
	buf.Write(data)

	m.EBlockCount = uint32(len(m.EBlocks))
	binary.Write(&buf, binary.BigEndian, m.EBlockCount)
	for _, eb := range m.EBlocks {
		bin, err := eb.MarshalBinary()
		if err != nil {
			return nil, err
		}
		buf.Write(bin)
	}

	m.EntryCount = uint32(len(m.Entries))
	binary.Write(&buf, binary.BigEndian, m.EntryCount)
	for _, e := range m.Entries {
		bin, err := e.MarshalBinary()
		if err != nil {
			return nil, err
		}
		buf.Write(bin)
	}

	return buf.DeepCopyBytes(), nil
}

func writeNumber(b io.Writer, num int) (err error) {
	// The first two bits encode the size:
	// 00 = 1 byte
	// 01 = 2 bytes
	// 10 = 3 bytes
	// 11 = 4 bytes
	switch {
	case num < 64: // 2^(8-2)
		// Fits in one byte.
		binary.Write(b, binary.BigEndian, uint8(num))
	case num < 16384: // 2^(16-2)
		// Fits in two bytes.
		binary.Write(b, binary.BigEndian, uint16(num|0x4000)) // Set the size to 01.
	case num < 4194304: // 2^(24-2)
		// Fits in three bytes.
		// Drop the two least significant bytes and set the size to 10.
		binary.Write(b, binary.BigEndian, uint8((num>>16)|0x80))
		// Drop the two most significant bytes.
		binary.Write(b, binary.BigEndian, uint16(num&0xffff))
	case num < 1073741824: // 2^(32-2):
		// Fits in four bytes.
		// Set the size to 11.
		binary.Write(b, binary.BigEndian, uint32(num|0xc0000000))
	default:
		err = fmt.Errorf("Number is too big: %d", num)
	}
	return err
}

// Writes the tny_page to the specified writer.  We want to do this
// in Go so that we can write a page to local disk, Hadoop, S3, etc
func (self *TnyPage) WritePage(writer *bufio.Writer) {
	// Lets write out the page...

	// fmt.Printf("Writing page for %s (ptr: %p, len: %d):\n", self.Column.Name, self.cptr, self.Length())

	if err := binary.Write(writer, binary.LittleEndian, int32(self.Depth())); err != nil {
		panic("Unable to write page header (depth) (" + err.Error() + ")")
	}

	if err := binary.Write(writer, binary.LittleEndian, int32(self.Length())); err != nil {
		panic("Unable to write page header (length) (" + err.Error() + ")")
	}

	// fmt.Printf("Wrote header, writing data now...\n")

	for d := 0; d < int(self.Depth()); d++ {
		bmp := self.BitmapAtDepth(d)
		bmpSlice := bmp.Slice()

		// fmt.Printf("\t%s\n", bmp.BitString(100))

		// fmt.Printf("Writing slice %d...\n", d)

		if err := binary.Write(writer, binary.LittleEndian, bmpSlice); err != nil {
			panic("Unable to write page (" + err.Error() + ")")
		}

	}
	// fmt.Printf("Write Page (%d): ", depth)
	// for i := 0; i < 10; i++ {
	// 	fmt.Printf("%d, ", self.Access(i))
	// }
	// fmt.Printf("\n")
}