Add stable marshal for accounting package

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

v2/accounting/marshal.go

@@ -0,0 +1,116 @@
+package accounting
+
+import (
+	"github.com/nspcc-dev/neofs-api-go/util/proto"
+)
+
+const (
+	decimalValueField     = 1
+	decimalPrecisionField = 2
+
+	balanceReqBodyOwnerField = 1
+
+	balanceRespBodyDecimalField = 1
+)
+
+func (d *Decimal) StableMarshal(buf []byte) ([]byte, error) {
+	if d == nil {
+		return []byte{}, nil
+	}
+
+	if buf == nil {
+		buf = make([]byte, d.StableSize())
+	}
+
+	var (
+		offset, n int
+		err       error
+	)
+
+	n, err = proto.Int64Marshal(decimalValueField, buf[offset:], d.val)
+	if err != nil {
+		return nil, err
+	}
+
+	offset += n
+
+	n, err = proto.UInt32Marshal(decimalPrecisionField, buf[offset:], d.prec)
+	if err != nil {
+		return nil, err
+	}
+
+	return buf, nil
+}
+
+func (d *Decimal) StableSize() (size int) {
+	if d == nil {
+		return 0
+	}
+
+	size += proto.Int64Size(decimalValueField, d.val)
+	size += proto.UInt32Size(decimalPrecisionField, d.prec)
+
+	return size
+}
+
+func (b *BalanceRequestBody) StableMarshal(buf []byte) ([]byte, error) {
+	if b == nil {
+		return []byte{}, nil
+	}
+
+	if buf == nil {
+		buf = make([]byte, b.StableSize())
+	}
+
+	if b.ownerID != nil {
+		_, err := proto.NestedStructureMarshal(balanceReqBodyOwnerField, buf, b.ownerID)
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	return buf, nil
+}
+
+func (b *BalanceRequestBody) StableSize() (size int) {
+	if b == nil {
+		return 0
+	}
+
+	if b.ownerID != nil {
+		size = proto.NestedStructureSize(balanceReqBodyOwnerField, b.ownerID)
+	}
+
+	return size
+}
+
+func (br *BalanceResponseBody) StableMarshal(buf []byte) ([]byte, error) {
+	if br == nil {
+		return []byte{}, nil
+	}
+
+	if buf == nil {
+		buf = make([]byte, br.StableSize())
+	}
+
+	if br.bal != nil {
+		_, err := proto.NestedStructureMarshal(balanceRespBodyDecimalField, buf, br.bal)
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	return buf, nil
+}
+
+func (br *BalanceResponseBody) StableSize() (size int) {
+	if br == nil {
+		return 0
+	}
+
+	if br.bal != nil {
+		size = proto.NestedStructureSize(balanceRespBodyDecimalField, br.bal)
+	}
+
+	return size
+}