Add proto marshal helper for bytes

Signed-off-by: Alex Vanin <alexey@nspcc.ru>

util/proto/marshal.go

@@ -0,0 +1,44 @@
+/*
+This package contains help functions for stable marshaller. Their usage is
+totally optional. One can implement fast stable marshaller without these
+runtime function calls.
+*/
+
+package proto
+
+import (
+	"encoding/binary"
+	"math/bits"
+)
+
+func BytesMarshal(field int, buf, v []byte) (int, error) {
+	if len(v) == 0 {
+		return 0, nil
+	}
+
+	// buf length check can prevent panic at PutUvarint, but it will make
+	// marshaller a bit slower.
+
+	prefix := field<<3 | 0x2
+	i := binary.PutUvarint(buf, uint64(prefix))
+	i += binary.PutUvarint(buf[i:], uint64(len(v)))
+	i += copy(buf[i:], v)
+
+	return i, nil
+}
+
+func BytesSize(field int, v []byte) int {
+	ln := len(v)
+	if ln == 0 {
+		return 0
+	}
+
+	prefix := field<<3 | 0x2
+
+	return VarUIntSize(uint64(prefix)) + VarUIntSize(uint64(ln)) + ln
+}
+
+// varUIntSize returns length of varint byte sequence for uint64 value 'x'.
+func VarUIntSize(x uint64) int {
+	return (bits.Len64(x|1) + 6) / 7
+}

util/proto/marshal_test.go

@@ -0,0 +1,118 @@
+package proto_test
+
+import (
+	"testing"
+
+	"github.com/nspcc-dev/neofs-api-go/util/proto"
+	"github.com/nspcc-dev/neofs-api-go/util/proto/test"
+	"github.com/pkg/errors"
+	"github.com/stretchr/testify/require"
+)
+
+type stablePrimitives struct {
+	FieldA []byte
+}
+
+func (s *stablePrimitives) stableMarshal(buf []byte) ([]byte, error) {
+	if s == nil {
+		return []byte{}, nil
+	}
+
+	if buf == nil {
+		buf = make([]byte, s.stableSize())
+	}
+
+	var (
+		i, offset int
+	)
+
+	offset, err := proto.BytesMarshal(1, buf, s.FieldA)
+	if err != nil {
+		return nil, errors.Wrap(err, "can't marshal field a")
+	}
+	i += offset
+
+	return buf, nil
+}
+
+func (s *stablePrimitives) stableMarshalWrongFieldNum(buf []byte) ([]byte, error) {
+	if s == nil {
+		return []byte{}, nil
+	}
+
+	if buf == nil {
+		buf = make([]byte, s.stableSize())
+	}
+
+	var (
+		i, offset int
+	)
+
+	offset, err := proto.BytesMarshal(1+1, buf, s.FieldA)
+	if err != nil {
+		return nil, errors.Wrap(err, "can't marshal field a")
+	}
+	i += offset
+
+	return buf, nil
+}
+
+func (s *stablePrimitives) stableSize() int {
+	return proto.BytesSize(1, s.FieldA)
+}
+
+func TestBytesMarshal(t *testing.T) {
+	t.Run("not empty", func(t *testing.T) {
+		data := []byte("Hello World")
+		testBytesMarshal(t, data, false)
+		testBytesMarshal(t, data, true)
+	})
+
+	t.Run("empty", func(t *testing.T) {
+		testBytesMarshal(t, []byte{}, false)
+	})
+
+	t.Run("nil", func(t *testing.T) {
+		testBytesMarshal(t, nil, false)
+	})
+}
+
+func testBytesMarshal(t *testing.T, data []byte, wrongField bool) {
+	var (
+		wire []byte
+		err  error
+
+		custom    = stablePrimitives{FieldA: data}
+		transport = test.Primitives{FieldA: data}
+	)
+
+	if !wrongField {
+		wire, err = custom.stableMarshal(nil)
+	} else {
+		wire, err = custom.stableMarshalWrongFieldNum(nil)
+	}
+	require.NoError(t, err)
+
+	wireGen, err := transport.Marshal()
+	require.NoError(t, err)
+
+	if !wrongField {
+		// we can check equality because single field cannot be unstable marshalled
+		require.Equal(t, wireGen, wire)
+	} else {
+		require.NotEqual(t, wireGen, wire)
+	}
+
+	result := new(test.Primitives)
+	err = result.Unmarshal(wire)
+	require.NoError(t, err)
+
+	if !wrongField {
+		require.Len(t, result.FieldA, len(data))
+		if len(data) > 0 {
+			require.Equal(t, data, result.FieldA)
+		}
+	} else {
+		require.Len(t, result.FieldA, 0)
+	}
+}

util/proto/test/test.pb.go

@@ -0,0 +1,327 @@
+// Code generated by protoc-gen-gogo. DO NOT EDIT.
+// source: util/proto/test/test.proto
+
+package test
+
+import (
+	fmt "fmt"
+	proto "github.com/golang/protobuf/proto"
+	io "io"
+	math "math"
+	math_bits "math/bits"
+)
+
+// Reference imports to suppress errors if they are not otherwise used.
+var _ = proto.Marshal
+var _ = fmt.Errorf
+var _ = math.Inf
+
+// This is a compile-time assertion to ensure that this generated file
+// is compatible with the proto package it is being compiled against.
+// A compilation error at this line likely means your copy of the
+// proto package needs to be updated.
+const _ = proto.ProtoPackageIsVersion3 // please upgrade the proto package
+
+type Primitives struct {
+	FieldA               []byte   `protobuf:"bytes,1,opt,name=field_a,json=fieldA,proto3" json:"field_a,omitempty"`
+	XXX_NoUnkeyedLiteral struct{} `json:"-"`
+	XXX_unrecognized     []byte   `json:"-"`
+	XXX_sizecache        int32    `json:"-"`
+}
+
+func (m *Primitives) Reset()         { *m = Primitives{} }
+func (m *Primitives) String() string { return proto.CompactTextString(m) }
+func (*Primitives) ProtoMessage()    {}
+func (*Primitives) Descriptor() ([]byte, []int) {
+	return fileDescriptor_998ad0e1a3de8558, []int{0}
+}
+func (m *Primitives) XXX_Unmarshal(b []byte) error {
+	return m.Unmarshal(b)
+}
+func (m *Primitives) XXX_Marshal(b []byte, deterministic bool) ([]byte, error) {
+	if deterministic {
+		return xxx_messageInfo_Primitives.Marshal(b, m, deterministic)
+	} else {
+		b = b[:cap(b)]
+		n, err := m.MarshalToSizedBuffer(b)
+		if err != nil {
+			return nil, err
+		}
+		return b[:n], nil
+	}
+}
+func (m *Primitives) XXX_Merge(src proto.Message) {
+	xxx_messageInfo_Primitives.Merge(m, src)
+}
+func (m *Primitives) XXX_Size() int {
+	return m.Size()
+}
+func (m *Primitives) XXX_DiscardUnknown() {
+	xxx_messageInfo_Primitives.DiscardUnknown(m)
+}
+
+var xxx_messageInfo_Primitives proto.InternalMessageInfo
+
+func (m *Primitives) GetFieldA() []byte {
+	if m != nil {
+		return m.FieldA
+	}
+	return nil
+}
+
+func init() {
+	proto.RegisterType((*Primitives)(nil), "test.Primitives")
+}
+
+func init() { proto.RegisterFile("util/proto/test/test.proto", fileDescriptor_998ad0e1a3de8558) }
+
+var fileDescriptor_998ad0e1a3de8558 = []byte{
+	// 109 bytes of a gzipped FileDescriptorProto
+	0x1f, 0x8b, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0xff, 0xe2, 0x92, 0x2a, 0x2d, 0xc9, 0xcc,
+	0xd1, 0x2f, 0x28, 0xca, 0x2f, 0xc9, 0xd7, 0x2f, 0x49, 0x2d, 0x2e, 0x01, 0x13, 0x7a, 0x60, 0xbe,
+	0x10, 0x0b, 0x88, 0xad, 0xa4, 0xca, 0xc5, 0x15, 0x50, 0x94, 0x99, 0x9b, 0x59, 0x92, 0x59, 0x96,
+	0x5a, 0x2c, 0x24, 0xce, 0xc5, 0x9e, 0x96, 0x99, 0x9a, 0x93, 0x12, 0x9f, 0x28, 0xc1, 0xa8, 0xc0,
+	0xa8, 0xc1, 0x13, 0xc4, 0x06, 0xe6, 0x3a, 0x3a, 0x09, 0x9c, 0x78, 0x24, 0xc7, 0x78, 0xe1, 0x91,
+	0x1c, 0xe3, 0x83, 0x47, 0x72, 0x8c, 0x33, 0x1e, 0xcb, 0x31, 0x24, 0xb1, 0x81, 0x4d, 0x31, 0x06,
+	0x04, 0x00, 0x00, 0xff, 0xff, 0xe5, 0xa7, 0x6b, 0x1f, 0x63, 0x00, 0x00, 0x00,
+}
+
+func (m *Primitives) Marshal() (dAtA []byte, err error) {
+	size := m.Size()
+	dAtA = make([]byte, size)
+	n, err := m.MarshalToSizedBuffer(dAtA[:size])
+	if err != nil {
+		return nil, err
+	}
+	return dAtA[:n], nil
+}
+
+func (m *Primitives) MarshalTo(dAtA []byte) (int, error) {
+	size := m.Size()
+	return m.MarshalToSizedBuffer(dAtA[:size])
+}
+
+func (m *Primitives) MarshalToSizedBuffer(dAtA []byte) (int, error) {
+	i := len(dAtA)
+	_ = i
+	var l int
+	_ = l
+	if m.XXX_unrecognized != nil {
+		i -= len(m.XXX_unrecognized)
+		copy(dAtA[i:], m.XXX_unrecognized)
+	}
+	if len(m.FieldA) > 0 {
+		i -= len(m.FieldA)
+		copy(dAtA[i:], m.FieldA)
+		i = encodeVarintTest(dAtA, i, uint64(len(m.FieldA)))
+		i--
+		dAtA[i] = 0xa
+	}
+	return len(dAtA) - i, nil
+}
+
+func encodeVarintTest(dAtA []byte, offset int, v uint64) int {
+	offset -= sovTest(v)
+	base := offset
+	for v >= 1<<7 {
+		dAtA[offset] = uint8(v&0x7f | 0x80)
+		v >>= 7
+		offset++
+	}
+	dAtA[offset] = uint8(v)
+	return base
+}
+func (m *Primitives) Size() (n int) {
+	if m == nil {
+		return 0
+	}
+	var l int
+	_ = l
+	l = len(m.FieldA)
+	if l > 0 {
+		n += 1 + l + sovTest(uint64(l))
+	}
+	if m.XXX_unrecognized != nil {
+		n += len(m.XXX_unrecognized)
+	}
+	return n
+}
+
+func sovTest(x uint64) (n int) {
+	return (math_bits.Len64(x|1) + 6) / 7
+}
+func sozTest(x uint64) (n int) {
+	return sovTest(uint64((x << 1) ^ uint64((int64(x) >> 63))))
+}
+func (m *Primitives) Unmarshal(dAtA []byte) error {
+	l := len(dAtA)
+	iNdEx := 0
+	for iNdEx < l {
+		preIndex := iNdEx
+		var wire uint64
+		for shift := uint(0); ; shift += 7 {
+			if shift >= 64 {
+				return ErrIntOverflowTest
+			}
+			if iNdEx >= l {
+				return io.ErrUnexpectedEOF
+			}
+			b := dAtA[iNdEx]
+			iNdEx++
+			wire |= uint64(b&0x7F) << shift
+			if b < 0x80 {
+				break
+			}
+		}
+		fieldNum := int32(wire >> 3)
+		wireType := int(wire & 0x7)
+		if wireType == 4 {
+			return fmt.Errorf("proto: Primitives: wiretype end group for non-group")
+		}
+		if fieldNum <= 0 {
+			return fmt.Errorf("proto: Primitives: illegal tag %d (wire type %d)", fieldNum, wire)
+		}
+		switch fieldNum {
+		case 1:
+			if wireType != 2 {
+				return fmt.Errorf("proto: wrong wireType = %d for field FieldA", wireType)
+			}
+			var byteLen int
+			for shift := uint(0); ; shift += 7 {
+				if shift >= 64 {
+					return ErrIntOverflowTest
+				}
+				if iNdEx >= l {
+					return io.ErrUnexpectedEOF
+				}
+				b := dAtA[iNdEx]
+				iNdEx++
+				byteLen |= int(b&0x7F) << shift
+				if b < 0x80 {
+					break
+				}
+			}
+			if byteLen < 0 {
+				return ErrInvalidLengthTest
+			}
+			postIndex := iNdEx + byteLen
+			if postIndex < 0 {
+				return ErrInvalidLengthTest
+			}
+			if postIndex > l {
+				return io.ErrUnexpectedEOF
+			}
+			m.FieldA = append(m.FieldA[:0], dAtA[iNdEx:postIndex]...)
+			if m.FieldA == nil {
+				m.FieldA = []byte{}
+			}
+			iNdEx = postIndex
+		default:
+			iNdEx = preIndex
+			skippy, err := skipTest(dAtA[iNdEx:])
+			if err != nil {
+				return err
+			}
+			if skippy < 0 {
+				return ErrInvalidLengthTest
+			}
+			if (iNdEx + skippy) < 0 {
+				return ErrInvalidLengthTest
+			}
+			if (iNdEx + skippy) > l {
+				return io.ErrUnexpectedEOF
+			}
+			m.XXX_unrecognized = append(m.XXX_unrecognized, dAtA[iNdEx:iNdEx+skippy]...)
+			iNdEx += skippy
+		}
+	}
+
+	if iNdEx > l {
+		return io.ErrUnexpectedEOF
+	}
+	return nil
+}
+func skipTest(dAtA []byte) (n int, err error) {
+	l := len(dAtA)
+	iNdEx := 0
+	depth := 0
+	for iNdEx < l {
+		var wire uint64
+		for shift := uint(0); ; shift += 7 {
+			if shift >= 64 {
+				return 0, ErrIntOverflowTest
+			}
+			if iNdEx >= l {
+				return 0, io.ErrUnexpectedEOF
+			}
+			b := dAtA[iNdEx]
+			iNdEx++
+			wire |= (uint64(b) & 0x7F) << shift
+			if b < 0x80 {
+				break
+			}
+		}
+		wireType := int(wire & 0x7)
+		switch wireType {
+		case 0:
+			for shift := uint(0); ; shift += 7 {
+				if shift >= 64 {
+					return 0, ErrIntOverflowTest
+				}
+				if iNdEx >= l {
+					return 0, io.ErrUnexpectedEOF
+				}
+				iNdEx++
+				if dAtA[iNdEx-1] < 0x80 {
+					break
+				}
+			}
+		case 1:
+			iNdEx += 8
+		case 2:
+			var length int
+			for shift := uint(0); ; shift += 7 {
+				if shift >= 64 {
+					return 0, ErrIntOverflowTest
+				}
+				if iNdEx >= l {
+					return 0, io.ErrUnexpectedEOF
+				}
+				b := dAtA[iNdEx]
+				iNdEx++
+				length |= (int(b) & 0x7F) << shift
+				if b < 0x80 {
+					break
+				}
+			}
+			if length < 0 {
+				return 0, ErrInvalidLengthTest
+			}
+			iNdEx += length
+		case 3:
+			depth++
+		case 4:
+			if depth == 0 {
+				return 0, ErrUnexpectedEndOfGroupTest
+			}
+			depth--
+		case 5:
+			iNdEx += 4
+		default:
+			return 0, fmt.Errorf("proto: illegal wireType %d", wireType)
+		}
+		if iNdEx < 0 {
+			return 0, ErrInvalidLengthTest
+		}
+		if depth == 0 {
+			return iNdEx, nil
+		}
+	}
+	return 0, io.ErrUnexpectedEOF
+}
+
+var (
+	ErrInvalidLengthTest        = fmt.Errorf("proto: negative length found during unmarshaling")
+	ErrIntOverflowTest          = fmt.Errorf("proto: integer overflow")
+	ErrUnexpectedEndOfGroupTest = fmt.Errorf("proto: unexpected end of group")
+)

util/proto/test/test.proto

@@ -0,0 +1,7 @@
+syntax = "proto3";
+
+package test;
+
+message Primitives {
+    bytes field_a = 1;
+}