func Read()

in patches/gopsutil/v3/internal/common/binary.go [138:221]
81 lines of code
31 McCabe index (conditional complexity)

func Read(r io.Reader, order ByteOrder, data interface{}) error {
	// Fast path for basic types and slices.
	if n := intDataSize(data); n != 0 {
		var b [8]byte
		var bs []byte
		if n > len(b) {
			bs = make([]byte, n)
		} else {
			bs = b[:n]
		}
		if _, err := io.ReadFull(r, bs); err != nil {
			return err
		}
		switch data := data.(type) {
		case *int8:
			*data = int8(b[0])
		case *uint8:
			*data = b[0]
		case *int16:
			*data = int16(order.Uint16(bs))
		case *uint16:
			*data = order.Uint16(bs)
		case *int32:
			*data = int32(order.Uint32(bs))
		case *uint32:
			*data = order.Uint32(bs)
		case *int64:
			*data = int64(order.Uint64(bs))
		case *uint64:
			*data = order.Uint64(bs)
		case []int8:
			for i, x := range bs { // Easier to loop over the input for 8-bit values.
				data[i] = int8(x)
			}
		case []uint8:
			copy(data, bs)
		case []int16:
			for i := range data {
				data[i] = int16(order.Uint16(bs[2*i:]))
			}
		case []uint16:
			for i := range data {
				data[i] = order.Uint16(bs[2*i:])
			}
		case []int32:
			for i := range data {
				data[i] = int32(order.Uint32(bs[4*i:]))
			}
		case []uint32:
			for i := range data {
				data[i] = order.Uint32(bs[4*i:])
			}
		case []int64:
			for i := range data {
				data[i] = int64(order.Uint64(bs[8*i:]))
			}
		case []uint64:
			for i := range data {
				data[i] = order.Uint64(bs[8*i:])
			}
		}
		return nil
	}

	// Fallback to reflect-based decoding.
	v := reflect.ValueOf(data)
	size := -1
	switch v.Kind() {
	case reflect.Ptr:
		v = v.Elem()
		size = dataSize(v)
	case reflect.Slice:
		size = dataSize(v)
	}
	if size < 0 {
		return errors.New("binary.Read: invalid type " + reflect.TypeOf(data).String())
	}
	d := &decoder{order: order, buf: make([]byte, size)}
	if _, err := io.ReadFull(r, d.buf); err != nil {
		return err
	}
	d.value(v)
	return nil
}