Golang ByteOrder.Uint64方法代碼示例

// Open a CDataFile
func OpenRawDataFile(name string, readOnly bool, byteOrder binary.ByteOrder, byteAlignment uint64, valueSize int) (*RawDataFile, error) {
	flag := os.O_RDWR
	if readOnly {
		flag = os.O_RDONLY
	}

	file, err := os.OpenFile(name, flag, 0644)
	if err != nil {
		return nil, err
	}

	var univalToBytes func([]byte, unival)
	var bytesToUnival func([]byte) unival
	switch valueSize {
	case 8:
		univalToBytes = func(dst []byte, src unival) {
			byteOrder.PutUint64(dst, src.AsUnsignedLong())
		}
		bytesToUnival = func(src []byte) unival {
			return unival(byteOrder.Uint64(src))
		}
	default:
		return nil, errors.Errorf("Invalid value size %d", valueSize)
	}
	return &RawDataFile{
		file: file,
		//		byteOrder:     byteOrder,
		byteAlignment: byteAlignment,
		valueSize:     valueSize,
		univalToBytes: univalToBytes,
		bytesToUnival: bytesToUnival,
	}, nil
}

func (b *Buffer) ReadUint64(order binary.ByteOrder) (uint64, error) {
	if b.readPos >= len(b.Buf)-8 {
		return 0, io.EOF
	}
	u := order.Uint64(b.Buf[b.readPos:])
	b.readPos += 8
	return u, nil
}

// Uint64 reads eight bytes from the provided reader using a buffer from the
// free list, converts it to a number using the provided byte order, and returns
// the resulting uint64.
func (l binaryFreeList) Uint64(r io.Reader, byteOrder binary.ByteOrder) (uint64, error) {
	buf := l.Borrow()[:8]
	if _, err := io.ReadFull(r, buf); err != nil {
		l.Return(buf)
		return 0, err
	}
	rv := byteOrder.Uint64(buf)
	l.Return(buf)
	return rv, nil
}

func walksymtab(data []byte, ptrsz int, fn func(sym) error) error {
	var order binary.ByteOrder = binary.BigEndian
	var s sym
	p := data
	for len(p) >= 4 {
		// Symbol type, value.
		if len(p) < ptrsz {
			return &formatError{len(data), "unexpected EOF", nil}
		}
		// fixed-width value
		if ptrsz == 8 {
			s.value = order.Uint64(p[0:8])
			p = p[8:]
		} else {
			s.value = uint64(order.Uint32(p[0:4]))
			p = p[4:]
		}

		var typ byte
		typ = p[0] & 0x7F
		s.typ = typ
		p = p[1:]

		// Name.
		var i int
		var nnul int
		for i = 0; i < len(p); i++ {
			if p[i] == 0 {
				nnul = 1
				break
			}
		}
		switch typ {
		case 'z', 'Z':
			p = p[i+nnul:]
			for i = 0; i+2 <= len(p); i += 2 {
				if p[i] == 0 && p[i+1] == 0 {
					nnul = 2
					break
				}
			}
		}
		if len(p) < i+nnul {
			return &formatError{len(data), "unexpected EOF", nil}
		}
		s.name = p[0:i]
		i += nnul
		p = p[i:]

		fn(s)
	}
	return nil
}

func newSimpleProtocol(n int, byteOrder binary.ByteOrder) *simpleProtocol {
	protocol := &simpleProtocol{
		n:  n,
		bo: byteOrder,
	}

	switch n {
	case 1:
		protocol.encodeHead = func(buffer []byte) {
			buffer[0] = byte(len(buffer) - n)
		}
		protocol.decodeHead = func(buffer []byte) int {
			return int(buffer[0])
		}
	case 2:
		protocol.encodeHead = func(buffer []byte) {
			byteOrder.PutUint16(buffer, uint16(len(buffer)-n))
		}
		protocol.decodeHead = func(buffer []byte) int {
			return int(byteOrder.Uint16(buffer))
		}
	case 4:
		protocol.encodeHead = func(buffer []byte) {
			byteOrder.PutUint32(buffer, uint32(len(buffer)-n))
		}
		protocol.decodeHead = func(buffer []byte) int {
			return int(byteOrder.Uint32(buffer))
		}
	case 8:
		protocol.encodeHead = func(buffer []byte) {
			byteOrder.PutUint64(buffer, uint64(len(buffer)-n))
		}
		protocol.decodeHead = func(buffer []byte) int {
			return int(byteOrder.Uint64(buffer))
		}
	default:
		panic("unsupported packet head size")
	}

	return protocol
}

func walksymtab(data []byte, fn func(sym) error) error {
	if len(data) == 0 { // missing symtab is okay
		return nil
	}
	var order binary.ByteOrder = binary.BigEndian
	newTable := false
	switch {
	case bytes.HasPrefix(data, oldLittleEndianSymtab):
		// Same as Go 1.0, but little endian.
		// Format was used during interim development between Go 1.0 and Go 1.1.
		// Should not be widespread, but easy to support.
		data = data[6:]
		order = binary.LittleEndian
	case bytes.HasPrefix(data, bigEndianSymtab):
		newTable = true
	case bytes.HasPrefix(data, littleEndianSymtab):
		newTable = true
		order = binary.LittleEndian
	}
	var ptrsz int
	if newTable {
		if len(data) < 8 {
			return &DecodingError{len(data), "unexpected EOF", nil}
		}
		ptrsz = int(data[7])
		if ptrsz != 4 && ptrsz != 8 {
			return &DecodingError{7, "invalid pointer size", ptrsz}
		}
		data = data[8:]
	}
	var s sym
	p := data
	for len(p) >= 4 {
		var typ byte
		if newTable {
			// Symbol type, value, Go type.
			typ = p[0] & 0x3F
			wideValue := p[0]&0x40 != 0
			goType := p[0]&0x80 != 0
			if typ < 26 {
				typ += 'A'
			} else {
				typ += 'a' - 26
			}
			s.typ = typ
			p = p[1:]
			if wideValue {
				if len(p) < ptrsz {
					return &DecodingError{len(data), "unexpected EOF", nil}
				}
				// fixed-width value
				if ptrsz == 8 {
					s.value = order.Uint64(p[0:8])
					p = p[8:]
				} else {
					s.value = uint64(order.Uint32(p[0:4]))
					p = p[4:]
				}
			} else {
				// varint value
				s.value = 0
				shift := uint(0)
				for len(p) > 0 && p[0]&0x80 != 0 {
					s.value |= uint64(p[0]&0x7F) << shift
					shift += 7
					p = p[1:]
				}
				if len(p) == 0 {
					return &DecodingError{len(data), "unexpected EOF", nil}
				}
				s.value |= uint64(p[0]) << shift
				p = p[1:]
			}
			if goType {
				if len(p) < ptrsz {
					return &DecodingError{len(data), "unexpected EOF", nil}
				}
				// fixed-width go type
				if ptrsz == 8 {
					s.gotype = order.Uint64(p[0:8])
					p = p[8:]
				} else {
					s.gotype = uint64(order.Uint32(p[0:4]))
					p = p[4:]
				}
			}
		} else {
			// Value, symbol type.
			s.value = uint64(order.Uint32(p[0:4]))
			if len(p) < 5 {
				return &DecodingError{len(data), "unexpected EOF", nil}
			}
			typ = p[4]
			if typ&0x80 == 0 {
				return &DecodingError{len(data) - len(p) + 4, "bad symbol type", typ}
			}
			typ &^= 0x80
			s.typ = typ
			p = p[5:]
		}
//.........這裏部分代碼省略.........

func (s *Stream) readSectionHeaderBlockBody(headerData []byte) (header *SectionHeaderBlock, err error) {
	//
	// read byte-order magic, version and section length
	//
	bodyData, err := s.read(16)
	if err != nil {
		return nil, err
	}

	//
	// read byte-order magic
	//
	var byteOrder binary.ByteOrder

	if bodyData[0] == 0x1A && bodyData[1] == 0x2B && bodyData[2] == 0x3C && bodyData[3] == 0x4D {
		byteOrder = binary.BigEndian
	} else if bodyData[3] == 0x1A && bodyData[2] == 0x2B && bodyData[1] == 0x3C && bodyData[0] == 0x4D {
		byteOrder = binary.LittleEndian
	} else {
		return nil, errors.New("invalid byte order mark")
	}

	//
	// read other fields
	//
	versionMajor := byteOrder.Uint16(bodyData[4:6])
	versionMinor := byteOrder.Uint16(bodyData[6:8])
	sectionLength := int64(byteOrder.Uint64(bodyData[8:16]))

	//
	// Read options
	//
	totalLength := byteOrder.Uint32(headerData[4:8])
	optsLen := totalLength - 28
	rawOpts, err := s.readOptions(optsLen, byteOrder)
	if err != nil {
		return nil, err
	}

	opts, err := parseSectionHeaderOptions(rawOpts)
	if err != nil {
		return nil, err
	}

	//
	// Read last block total length
	//
	_, err = s.readExactly(4)
	if err != nil {
		return nil, err
	}

	retval := &SectionHeaderBlock{
		totalLength:   totalLength,
		ByteOrder:     byteOrder,
		VersionMajor:  versionMajor,
		VersionMinor:  versionMinor,
		SectionLength: sectionLength,
		RawOptions:    rawOpts,
		Options:       opts,
	}

	s.sectionHeader = retval
	return retval, nil
}

// Convert raw image data into a 2d array of 64-bit labels
func (d *Data) convertTo64bit(geom dvid.Geometry, data []uint8, bytesPerVoxel, stride int) ([]byte, error) {
	nx := int(geom.Size().Value(0))
	ny := int(geom.Size().Value(1))
	numBytes := nx * ny * 8
	data64 := make([]byte, numBytes, numBytes)

	var byteOrder binary.ByteOrder
	if geom.DataShape().ShapeDimensions() == 2 {
		byteOrder = binary.BigEndian // This is the default for PNG
	} else {
		byteOrder = binary.LittleEndian
	}

	switch bytesPerVoxel {
	case 1:
		dstI := 0
		for y := 0; y < ny; y++ {
			srcI := y * stride
			for x := 0; x < nx; x++ {
				binary.LittleEndian.PutUint64(data64[dstI:dstI+8], uint64(data[srcI]))
				srcI++
				dstI += 8
			}
		}
	case 2:
		dstI := 0
		for y := 0; y < ny; y++ {
			srcI := y * stride
			for x := 0; x < nx; x++ {
				value := byteOrder.Uint16(data[srcI : srcI+2])
				binary.LittleEndian.PutUint64(data64[dstI:dstI+8], uint64(value))
				srcI += 2
				dstI += 8
			}
		}
	case 4:
		dstI := 0
		for y := 0; y < ny; y++ {
			srcI := y * stride
			for x := 0; x < nx; x++ {
				value := byteOrder.Uint32(data[srcI : srcI+4])
				binary.LittleEndian.PutUint64(data64[dstI:dstI+8], uint64(value))
				srcI += 4
				dstI += 8
			}
		}
	case 8:
		dstI := 0
		for y := 0; y < ny; y++ {
			srcI := y * stride
			for x := 0; x < nx; x++ {
				value := byteOrder.Uint64(data[srcI : srcI+8])
				binary.LittleEndian.PutUint64(data64[dstI:dstI+8], uint64(value))
				srcI += 8
				dstI += 8
			}
		}
	default:
		return nil, fmt.Errorf("could not convert to 64-bit label given %d bytes/voxel", bytesPerVoxel)
	}
	return data64, nil
}

func reprDouble(in []byte, bo binary.ByteOrder) string {
	return fmt.Sprintf("%f", math.Float64frombits(bo.Uint64(in)))
}

func rvalSLong8(in []byte, bo binary.ByteOrder) reflect.Value {
	return reflect.ValueOf(int64(bo.Uint64(in)))
}

func reprSLong8(in []byte, bo binary.ByteOrder) string { return fmt.Sprintf("%d", int64(bo.Uint64(in))) }

// decodeNumeric decodes a simple stream of numeric or character data
func decodeNumeric(de dataElement, bo binary.ByteOrder) (interface{}, error) {
	var b [8]byte
	var bs []byte
	if int(de.nBytes) > len(b) {
		bs = make([]byte, de.nBytes)
	} else {
		bs = b[:de.nBytes]
	}
	_, err := de.r.ReadAt(bs, 0)
	if err != nil {
		return nil, err
	}
	switch de.dataType {
	case miINT8:
		val := make([]int8, de.nBytes)
		for i, x := range bs {
			val[i] = int8(x)
		}
		return val, nil
	case miUINT8:
		val := make([]uint8, de.nBytes)
		copy(val, bs)
		return val, nil
	case miINT16:
		val := make([]int16, de.nBytes/2)
		for i := range bs {
			val[i] = int16(bo.Uint16(bs[2*i:]))
		}
		return val, nil
	case miUINT16:
		val := make([]uint16, de.nBytes/2)
		for i := range bs {
			val[i] = bo.Uint16(bs[2*i:])
		}
		return val, nil
	case miINT32:
		val := make([]int32, de.nBytes/4)
		for i := range bs {
			val[i] = int32(bo.Uint32(bs[4*i:]))
		}
		return val, nil
	case miUINT32:
		val := make([]uint32, de.nBytes/4)
		for i := range bs {
			val[i] = bo.Uint32(bs[4*i:])
		}
		return val, nil
	case miINT64:
		val := make([]int64, de.nBytes/8)
		for i := range bs {
			val[i] = int64(bo.Uint64(bs[8*i:]))
		}
		return val, nil
	case miUINT64:
		val := make([]uint64, de.nBytes/8)
		for i := range bs {
			val[i] = bo.Uint64(bs[8*i:])
		}
		return val, nil
	case miSINGLE:
		val := make([]float32, de.nBytes/4)
		for i := range bs {
			val[i] = math.Float32frombits(bo.Uint32(bs[4*i:]))
		}
		return val, nil
	case miDOUBLE:
		val := make([]float64, de.nBytes/8)
		for i := range bs {
			val[i] = math.Float64frombits(bo.Uint64(bs[8*i:]))
		}
		return val, nil
	case miUTF8:
		return string(bs), nil
	case miUTF16:
		x := make([]uint16, de.nBytes/2)
		for i := range bs {
			x[i] = bo.Uint16(bs[2*i:])
		}
		return string(utf16.Decode(x)), nil
	case miUTF32:
		runes := make([]rune, de.nBytes/4)
		for i := range runes {
			runes[i] = rune(bo.Uint32(bs[4*i:]))
		}
		return string(runes), nil
	}
	return nil, nil
}

func readFloat(buf []byte, byteOrder binary.ByteOrder) float64 {
	u := byteOrder.Uint64(buf)
	return math.Float64frombits(u)
}

func NewCpuProfParser(r io.Reader) (*CpuProfParser, error) {
	b := bufio.NewReader(r)
	chunk, err := b.Peek(16)
	if err != nil {
		return nil, err
	}
	// A CPU profile starts with integers 0, and 3, with program's
	// word size and endianness.
	size := 32
	first := binary.LittleEndian.Uint64(chunk[:8])
	if first == 0 {
		size = 64
	}
	var order binary.ByteOrder
	if size == 32 {
		n := binary.LittleEndian.Uint32(chunk[4:8])
		if n == 3 {
			order = binary.LittleEndian
		} else {
			order = binary.BigEndian
		}
	} else {
		n := binary.LittleEndian.Uint64(chunk[8:16])
		if n == 3 {
			order = binary.LittleEndian
		} else {
			order = binary.BigEndian
		}
	}
	p := &CpuProfParser{R: b, Order: order, Size: size}
	if size == 32 {
		p.read = func() (n uint64, err error) {
			s, err := b.Peek(4)
			if err == nil {
				n = uint64(order.Uint32(s[:]))
			}
			b.Read(s)
			return
		}
	} else {
		p.read = func() (n uint64, err error) {
			s, err := b.Peek(8)
			if err == nil {
				n = order.Uint64(s)
			}
			b.Read(s)
			return
		}
	}

	headerCount, _ := p.read()
	headerWords, _ := p.read()
	version, _ := p.read()
	period, _ := p.read()
	padding, err := p.read()
	if err != nil {
		return nil, err
	}

	if headerCount != 0 || headerWords != 3 || version != 0 || padding != 0 {
		return nil, errBadProfileHeader
	}
	p.Period = period
	return p, nil
}

func rvalDouble(in []byte, bo binary.ByteOrder) reflect.Value {
	return reflect.ValueOf(math.Float64frombits(bo.Uint64(in)))
}