feat: init swap protocol

* Add proto files
* Add options
* Add credit/debit for soft mode

README.md

@@ -55,7 +55,7 @@ Examples of usage of go-waku as a library can be found in the examples folder. T
 |[15/WAKU2-BRIDGE](https://rfc.vac.dev/spec/15)|⛔|
 |[16/WAKU2-RPC](https://rfc.vac.dev/spec/16)|🚧|
 |[17/WAKU2-RLNRELAY](https://rfc.vac.dev/spec/17)||
-|[18/WAKU2-SWAP](https://rfc.vac.dev/spec/18)||
+|[18/WAKU2-SWAP](https://rfc.vac.dev/spec/18)|🚧|
 |[21/WAKU2-FTSTORE](https://rfc.vac.dev/spec/21)|✔|
 |[22/TOY-CHAT](https://rfc.vac.dev/spec/22)|✔|
 |[23/TOPICS](https://rfc.vac.dev/spec/22)|✔|

waku/v2/protocol/pb/generate.go

@@ -4,3 +4,4 @@ package pb
 //go:generate protoc -I. --gofast_out=. ./waku_lightpush.proto
 //go:generate protoc -I. --gofast_out=. ./waku_message.proto
 //go:generate protoc -I. --gofast_out=. ./waku_store.proto
+//go:generate protoc -I. --gofast_out=. ./waku_swap.proto

waku/v2/protocol/pb/waku_swap.pb.go

@@ -0,0 +1,687 @@
+// Code generated by protoc-gen-gogo. DO NOT EDIT.
+// source: waku_swap.proto
+
+package pb
+
+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 Cheque struct {
+	IssuerAddress        string   `protobuf:"bytes,1,opt,name=issuerAddress,proto3" json:"issuerAddress,omitempty"`
+	Beneficiary          []byte   `protobuf:"bytes,2,opt,name=beneficiary,proto3" json:"beneficiary,omitempty"`
+	Date                 uint32   `protobuf:"varint,3,opt,name=date,proto3" json:"date,omitempty"`
+	Amount               uint32   `protobuf:"varint,4,opt,name=amount,proto3" json:"amount,omitempty"`
+	Signature            []byte   `protobuf:"bytes,5,opt,name=signature,proto3" json:"signature,omitempty"`
+	XXX_NoUnkeyedLiteral struct{} `json:"-"`
+	XXX_unrecognized     []byte   `json:"-"`
+	XXX_sizecache        int32    `json:"-"`
+}
+
+func (m *Cheque) Reset()         { *m = Cheque{} }
+func (m *Cheque) String() string { return proto.CompactTextString(m) }
+func (*Cheque) ProtoMessage()    {}
+func (*Cheque) Descriptor() ([]byte, []int) {
+	return fileDescriptor_8ec987fcc28cf932, []int{0}
+}
+func (m *Cheque) XXX_Unmarshal(b []byte) error {
+	return m.Unmarshal(b)
+}
+func (m *Cheque) XXX_Marshal(b []byte, deterministic bool) ([]byte, error) {
+	if deterministic {
+		return xxx_messageInfo_Cheque.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 *Cheque) XXX_Merge(src proto.Message) {
+	xxx_messageInfo_Cheque.Merge(m, src)
+}
+func (m *Cheque) XXX_Size() int {
+	return m.Size()
+}
+func (m *Cheque) XXX_DiscardUnknown() {
+	xxx_messageInfo_Cheque.DiscardUnknown(m)
+}
+
+var xxx_messageInfo_Cheque proto.InternalMessageInfo
+
+func (m *Cheque) GetIssuerAddress() string {
+	if m != nil {
+		return m.IssuerAddress
+	}
+	return ""
+}
+
+func (m *Cheque) GetBeneficiary() []byte {
+	if m != nil {
+		return m.Beneficiary
+	}
+	return nil
+}
+
+func (m *Cheque) GetDate() uint32 {
+	if m != nil {
+		return m.Date
+	}
+	return 0
+}
+
+func (m *Cheque) GetAmount() uint32 {
+	if m != nil {
+		return m.Amount
+	}
+	return 0
+}
+
+func (m *Cheque) GetSignature() []byte {
+	if m != nil {
+		return m.Signature
+	}
+	return nil
+}
+
+type Handshake struct {
+	Beneficiary          []byte   `protobuf:"bytes,1,opt,name=beneficiary,proto3" json:"beneficiary,omitempty"`
+	XXX_NoUnkeyedLiteral struct{} `json:"-"`
+	XXX_unrecognized     []byte   `json:"-"`
+	XXX_sizecache        int32    `json:"-"`
+}
+
+func (m *Handshake) Reset()         { *m = Handshake{} }
+func (m *Handshake) String() string { return proto.CompactTextString(m) }
+func (*Handshake) ProtoMessage()    {}
+func (*Handshake) Descriptor() ([]byte, []int) {
+	return fileDescriptor_8ec987fcc28cf932, []int{1}
+}
+func (m *Handshake) XXX_Unmarshal(b []byte) error {
+	return m.Unmarshal(b)
+}
+func (m *Handshake) XXX_Marshal(b []byte, deterministic bool) ([]byte, error) {
+	if deterministic {
+		return xxx_messageInfo_Handshake.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 *Handshake) XXX_Merge(src proto.Message) {
+	xxx_messageInfo_Handshake.Merge(m, src)
+}
+func (m *Handshake) XXX_Size() int {
+	return m.Size()
+}
+func (m *Handshake) XXX_DiscardUnknown() {
+	xxx_messageInfo_Handshake.DiscardUnknown(m)
+}
+
+var xxx_messageInfo_Handshake proto.InternalMessageInfo
+
+func (m *Handshake) GetBeneficiary() []byte {
+	if m != nil {
+		return m.Beneficiary
+	}
+	return nil
+}
+
+func init() {
+	proto.RegisterType((*Cheque)(nil), "pb.Cheque")
+	proto.RegisterType((*Handshake)(nil), "pb.Handshake")
+}
+
+func init() { proto.RegisterFile("waku_swap.proto", fileDescriptor_8ec987fcc28cf932) }
+
+var fileDescriptor_8ec987fcc28cf932 = []byte{
+	// 200 bytes of a gzipped FileDescriptorProto
+	0x1f, 0x8b, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0xff, 0xe2, 0xe2, 0x2f, 0x4f, 0xcc, 0x2e,
+	0x8d, 0x2f, 0x2e, 0x4f, 0x2c, 0xd0, 0x2b, 0x28, 0xca, 0x2f, 0xc9, 0x17, 0x62, 0x2a, 0x48, 0x52,
+	0x9a, 0xc5, 0xc8, 0xc5, 0xe6, 0x9c, 0x91, 0x5a, 0x58, 0x9a, 0x2a, 0xa4, 0xc2, 0xc5, 0x9b, 0x59,
+	0x5c, 0x5c, 0x9a, 0x5a, 0xe4, 0x98, 0x92, 0x52, 0x94, 0x5a, 0x5c, 0x2c, 0xc1, 0xa8, 0xc0, 0xa8,
+	0xc1, 0x19, 0x84, 0x2a, 0x28, 0xa4, 0xc0, 0xc5, 0x9d, 0x94, 0x9a, 0x97, 0x9a, 0x96, 0x99, 0x9c,
+	0x99, 0x58, 0x54, 0x29, 0xc1, 0xa4, 0xc0, 0xa8, 0xc1, 0x13, 0x84, 0x2c, 0x24, 0x24, 0xc4, 0xc5,
+	0x92, 0x92, 0x58, 0x92, 0x2a, 0xc1, 0xac, 0xc0, 0xa8, 0xc1, 0x1b, 0x04, 0x66, 0x0b, 0x89, 0x71,
+	0xb1, 0x25, 0xe6, 0xe6, 0x97, 0xe6, 0x95, 0x48, 0xb0, 0x80, 0x45, 0xa1, 0x3c, 0x21, 0x19, 0x2e,
+	0xce, 0xe2, 0xcc, 0xf4, 0xbc, 0xc4, 0x92, 0xd2, 0xa2, 0x54, 0x09, 0x56, 0xb0, 0x59, 0x08, 0x01,
+	0x25, 0x5d, 0x2e, 0x4e, 0x8f, 0xc4, 0xbc, 0x94, 0xe2, 0x8c, 0xc4, 0xec, 0x54, 0x74, 0x8b, 0x19,
+	0x31, 0x2c, 0x76, 0x12, 0x38, 0xf1, 0x48, 0x8e, 0xf1, 0xc2, 0x23, 0x39, 0xc6, 0x07, 0x8f, 0xe4,
+	0x18, 0x67, 0x3c, 0x96, 0x63, 0x48, 0x62, 0x03, 0x7b, 0xd4, 0x18, 0x10, 0x00, 0x00, 0xff, 0xff,
+	0xce, 0x34, 0x72, 0xd2, 0xfb, 0x00, 0x00, 0x00,
+}
+
+func (m *Cheque) 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 *Cheque) MarshalTo(dAtA []byte) (int, error) {
+	size := m.Size()
+	return m.MarshalToSizedBuffer(dAtA[:size])
+}
+
+func (m *Cheque) 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.Signature) > 0 {
+		i -= len(m.Signature)
+		copy(dAtA[i:], m.Signature)
+		i = encodeVarintWakuSwap(dAtA, i, uint64(len(m.Signature)))
+		i--
+		dAtA[i] = 0x2a
+	}
+	if m.Amount != 0 {
+		i = encodeVarintWakuSwap(dAtA, i, uint64(m.Amount))
+		i--
+		dAtA[i] = 0x20
+	}
+	if m.Date != 0 {
+		i = encodeVarintWakuSwap(dAtA, i, uint64(m.Date))
+		i--
+		dAtA[i] = 0x18
+	}
+	if len(m.Beneficiary) > 0 {
+		i -= len(m.Beneficiary)
+		copy(dAtA[i:], m.Beneficiary)
+		i = encodeVarintWakuSwap(dAtA, i, uint64(len(m.Beneficiary)))
+		i--
+		dAtA[i] = 0x12
+	}
+	if len(m.IssuerAddress) > 0 {
+		i -= len(m.IssuerAddress)
+		copy(dAtA[i:], m.IssuerAddress)
+		i = encodeVarintWakuSwap(dAtA, i, uint64(len(m.IssuerAddress)))
+		i--
+		dAtA[i] = 0xa
+	}
+	return len(dAtA) - i, nil
+}
+
+func (m *Handshake) 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 *Handshake) MarshalTo(dAtA []byte) (int, error) {
+	size := m.Size()
+	return m.MarshalToSizedBuffer(dAtA[:size])
+}
+
+func (m *Handshake) 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.Beneficiary) > 0 {
+		i -= len(m.Beneficiary)
+		copy(dAtA[i:], m.Beneficiary)
+		i = encodeVarintWakuSwap(dAtA, i, uint64(len(m.Beneficiary)))
+		i--
+		dAtA[i] = 0xa
+	}
+	return len(dAtA) - i, nil
+}
+
+func encodeVarintWakuSwap(dAtA []byte, offset int, v uint64) int {
+	offset -= sovWakuSwap(v)
+	base := offset
+	for v >= 1<<7 {
+		dAtA[offset] = uint8(v&0x7f | 0x80)
+		v >>= 7
+		offset++
+	}
+	dAtA[offset] = uint8(v)
+	return base
+}
+func (m *Cheque) Size() (n int) {
+	if m == nil {
+		return 0
+	}
+	var l int
+	_ = l
+	l = len(m.IssuerAddress)
+	if l > 0 {
+		n += 1 + l + sovWakuSwap(uint64(l))
+	}
+	l = len(m.Beneficiary)
+	if l > 0 {
+		n += 1 + l + sovWakuSwap(uint64(l))
+	}
+	if m.Date != 0 {
+		n += 1 + sovWakuSwap(uint64(m.Date))
+	}
+	if m.Amount != 0 {
+		n += 1 + sovWakuSwap(uint64(m.Amount))
+	}
+	l = len(m.Signature)
+	if l > 0 {
+		n += 1 + l + sovWakuSwap(uint64(l))
+	}
+	if m.XXX_unrecognized != nil {
+		n += len(m.XXX_unrecognized)
+	}
+	return n
+}
+
+func (m *Handshake) Size() (n int) {
+	if m == nil {
+		return 0
+	}
+	var l int
+	_ = l
+	l = len(m.Beneficiary)
+	if l > 0 {
+		n += 1 + l + sovWakuSwap(uint64(l))
+	}
+	if m.XXX_unrecognized != nil {
+		n += len(m.XXX_unrecognized)
+	}
+	return n
+}
+
+func sovWakuSwap(x uint64) (n int) {
+	return (math_bits.Len64(x|1) + 6) / 7
+}
+func sozWakuSwap(x uint64) (n int) {
+	return sovWakuSwap(uint64((x << 1) ^ uint64((int64(x) >> 63))))
+}
+func (m *Cheque) 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 ErrIntOverflowWakuSwap
+			}
+			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: Cheque: wiretype end group for non-group")
+		}
+		if fieldNum <= 0 {
+			return fmt.Errorf("proto: Cheque: illegal tag %d (wire type %d)", fieldNum, wire)
+		}
+		switch fieldNum {
+		case 1:
+			if wireType != 2 {
+				return fmt.Errorf("proto: wrong wireType = %d for field IssuerAddress", wireType)
+			}
+			var stringLen uint64
+			for shift := uint(0); ; shift += 7 {
+				if shift >= 64 {
+					return ErrIntOverflowWakuSwap
+				}
+				if iNdEx >= l {
+					return io.ErrUnexpectedEOF
+				}
+				b := dAtA[iNdEx]
+				iNdEx++
+				stringLen |= uint64(b&0x7F) << shift
+				if b < 0x80 {
+					break
+				}
+			}
+			intStringLen := int(stringLen)
+			if intStringLen < 0 {
+				return ErrInvalidLengthWakuSwap
+			}
+			postIndex := iNdEx + intStringLen
+			if postIndex < 0 {
+				return ErrInvalidLengthWakuSwap
+			}
+			if postIndex > l {
+				return io.ErrUnexpectedEOF
+			}
+			m.IssuerAddress = string(dAtA[iNdEx:postIndex])
+			iNdEx = postIndex
+		case 2:
+			if wireType != 2 {
+				return fmt.Errorf("proto: wrong wireType = %d for field Beneficiary", wireType)
+			}
+			var byteLen int
+			for shift := uint(0); ; shift += 7 {
+				if shift >= 64 {
+					return ErrIntOverflowWakuSwap
+				}
+				if iNdEx >= l {
+					return io.ErrUnexpectedEOF
+				}
+				b := dAtA[iNdEx]
+				iNdEx++
+				byteLen |= int(b&0x7F) << shift
+				if b < 0x80 {
+					break
+				}
+			}
+			if byteLen < 0 {
+				return ErrInvalidLengthWakuSwap
+			}
+			postIndex := iNdEx + byteLen
+			if postIndex < 0 {
+				return ErrInvalidLengthWakuSwap
+			}
+			if postIndex > l {
+				return io.ErrUnexpectedEOF
+			}
+			m.Beneficiary = append(m.Beneficiary[:0], dAtA[iNdEx:postIndex]...)
+			if m.Beneficiary == nil {
+				m.Beneficiary = []byte{}
+			}
+			iNdEx = postIndex
+		case 3:
+			if wireType != 0 {
+				return fmt.Errorf("proto: wrong wireType = %d for field Date", wireType)
+			}
+			m.Date = 0
+			for shift := uint(0); ; shift += 7 {
+				if shift >= 64 {
+					return ErrIntOverflowWakuSwap
+				}
+				if iNdEx >= l {
+					return io.ErrUnexpectedEOF
+				}
+				b := dAtA[iNdEx]
+				iNdEx++
+				m.Date |= uint32(b&0x7F) << shift
+				if b < 0x80 {
+					break
+				}
+			}
+		case 4:
+			if wireType != 0 {
+				return fmt.Errorf("proto: wrong wireType = %d for field Amount", wireType)
+			}
+			m.Amount = 0
+			for shift := uint(0); ; shift += 7 {
+				if shift >= 64 {
+					return ErrIntOverflowWakuSwap
+				}
+				if iNdEx >= l {
+					return io.ErrUnexpectedEOF
+				}
+				b := dAtA[iNdEx]
+				iNdEx++
+				m.Amount |= uint32(b&0x7F) << shift
+				if b < 0x80 {
+					break
+				}
+			}
+		case 5:
+			if wireType != 2 {
+				return fmt.Errorf("proto: wrong wireType = %d for field Signature", wireType)
+			}
+			var byteLen int
+			for shift := uint(0); ; shift += 7 {
+				if shift >= 64 {
+					return ErrIntOverflowWakuSwap
+				}
+				if iNdEx >= l {
+					return io.ErrUnexpectedEOF
+				}
+				b := dAtA[iNdEx]
+				iNdEx++
+				byteLen |= int(b&0x7F) << shift
+				if b < 0x80 {
+					break
+				}
+			}
+			if byteLen < 0 {
+				return ErrInvalidLengthWakuSwap
+			}
+			postIndex := iNdEx + byteLen
+			if postIndex < 0 {
+				return ErrInvalidLengthWakuSwap
+			}
+			if postIndex > l {
+				return io.ErrUnexpectedEOF
+			}
+			m.Signature = append(m.Signature[:0], dAtA[iNdEx:postIndex]...)
+			if m.Signature == nil {
+				m.Signature = []byte{}
+			}
+			iNdEx = postIndex
+		default:
+			iNdEx = preIndex
+			skippy, err := skipWakuSwap(dAtA[iNdEx:])
+			if err != nil {
+				return err
+			}
+			if (skippy < 0) || (iNdEx+skippy) < 0 {
+				return ErrInvalidLengthWakuSwap
+			}
+			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 (m *Handshake) 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 ErrIntOverflowWakuSwap
+			}
+			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: Handshake: wiretype end group for non-group")
+		}
+		if fieldNum <= 0 {
+			return fmt.Errorf("proto: Handshake: illegal tag %d (wire type %d)", fieldNum, wire)
+		}
+		switch fieldNum {
+		case 1:
+			if wireType != 2 {
+				return fmt.Errorf("proto: wrong wireType = %d for field Beneficiary", wireType)
+			}
+			var byteLen int
+			for shift := uint(0); ; shift += 7 {
+				if shift >= 64 {
+					return ErrIntOverflowWakuSwap
+				}
+				if iNdEx >= l {
+					return io.ErrUnexpectedEOF
+				}
+				b := dAtA[iNdEx]
+				iNdEx++
+				byteLen |= int(b&0x7F) << shift
+				if b < 0x80 {
+					break
+				}
+			}
+			if byteLen < 0 {
+				return ErrInvalidLengthWakuSwap
+			}
+			postIndex := iNdEx + byteLen
+			if postIndex < 0 {
+				return ErrInvalidLengthWakuSwap
+			}
+			if postIndex > l {
+				return io.ErrUnexpectedEOF
+			}
+			m.Beneficiary = append(m.Beneficiary[:0], dAtA[iNdEx:postIndex]...)
+			if m.Beneficiary == nil {
+				m.Beneficiary = []byte{}
+			}
+			iNdEx = postIndex
+		default:
+			iNdEx = preIndex
+			skippy, err := skipWakuSwap(dAtA[iNdEx:])
+			if err != nil {
+				return err
+			}
+			if (skippy < 0) || (iNdEx+skippy) < 0 {
+				return ErrInvalidLengthWakuSwap
+			}
+			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 skipWakuSwap(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, ErrIntOverflowWakuSwap
+			}
+			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, ErrIntOverflowWakuSwap
+				}
+				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, ErrIntOverflowWakuSwap
+				}
+				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, ErrInvalidLengthWakuSwap
+			}
+			iNdEx += length
+		case 3:
+			depth++
+		case 4:
+			if depth == 0 {
+				return 0, ErrUnexpectedEndOfGroupWakuSwap
+			}
+			depth--
+		case 5:
+			iNdEx += 4
+		default:
+			return 0, fmt.Errorf("proto: illegal wireType %d", wireType)
+		}
+		if iNdEx < 0 {
+			return 0, ErrInvalidLengthWakuSwap
+		}
+		if depth == 0 {
+			return iNdEx, nil
+		}
+	}
+	return 0, io.ErrUnexpectedEOF
+}
+
+var (
+	ErrInvalidLengthWakuSwap        = fmt.Errorf("proto: negative length found during unmarshaling")
+	ErrIntOverflowWakuSwap          = fmt.Errorf("proto: integer overflow")
+	ErrUnexpectedEndOfGroupWakuSwap = fmt.Errorf("proto: unexpected end of group")
+)

waku/v2/protocol/pb/waku_swap.proto

@@ -0,0 +1,15 @@
+syntax = "proto3";
+
+package pb;
+
+message Cheque {
+  string issuerAddress = 1;
+  bytes beneficiary = 2;
+  uint32 date = 3;
+  uint32 amount = 4;
+  bytes signature = 5;
+}
+
+message Handshake {
+  bytes beneficiary = 1;
+}

waku/v2/protocol/swap/waku_swap.go

@@ -0,0 +1,74 @@
+package swap
+
+import (
+	"sync"
+
+	logging "github.com/ipfs/go-log"
+
+	"github.com/libp2p/go-libp2p-core/protocol"
+)
+
+const (
+	SoftMode int = 0
+	MockMode int = 1
+	HardMode int = 2
+)
+
+const WakuSwapID_v200 = protocol.ID("/vac/waku/swap/2.0.0-beta1")
+
+var log = logging.Logger("wakuswap")
+
+type WakuSwap struct {
+	params *SwapParameters
+
+	Accounting      map[string]int
+	accountingMutex sync.RWMutex
+}
+
+func NewWakuSwap(opts ...SwapOption) *WakuSwap {
+	params := &SwapParameters{}
+
+	optList := DefaultOptions()
+	optList = append(optList, opts...)
+	for _, opt := range optList {
+		opt(params)
+	}
+
+	return &WakuSwap{
+		params:     params,
+		Accounting: make(map[string]int),
+	}
+}
+
+func (s *WakuSwap) sendCheque(peerId string) {
+	log.Debug("not yet implemented")
+}
+
+func (s *WakuSwap) applyPolicy(peerId string) {
+	if s.Accounting[peerId] <= s.params.disconnectThreshold {
+		log.Warnf("Disconnect threshhold has been reached for %s at %d", peerId, s.Accounting[peerId])
+	}
+
+	if s.Accounting[peerId] >= s.params.paymentThreshold {
+		log.Warnf("Disconnect threshhold has been reached for %s at %d", peerId, s.Accounting[peerId])
+		if s.params.mode != HardMode {
+			s.sendCheque(peerId)
+		}
+	}
+}
+
+func (s *WakuSwap) Credit(peerId string, n int) {
+	s.accountingMutex.Lock()
+	defer s.accountingMutex.Unlock()
+
+	s.Accounting[peerId] -= n
+	s.applyPolicy(peerId)
+}
+
+func (s *WakuSwap) Debit(peerId string, n int) {
+	s.accountingMutex.Lock()
+	defer s.accountingMutex.Unlock()
+
+	s.Accounting[peerId] += n
+	s.applyPolicy(peerId)
+}

waku/v2/protocol/swap/waku_swap_option.go

@@ -0,0 +1,29 @@
+package swap
+
+type SwapParameters struct {
+	mode                int
+	paymentThreshold    int
+	disconnectThreshold int
+}
+
+type SwapOption func(*SwapParameters)
+
+func WithMode(mode int) SwapOption {
+	return func(params *SwapParameters) {
+		params.mode = mode
+	}
+}
+
+func WithThreshold(payment, disconnect int) SwapOption {
+	return func(params *SwapParameters) {
+		params.disconnectThreshold = disconnect
+		params.paymentThreshold = payment
+	}
+}
+
+func DefaultOptions() []SwapOption {
+	return []SwapOption{
+		WithMode(SoftMode),
+		WithThreshold(100, -100),
+	}
+}

waku/v2/protocol/swap/waku_swap_option_test.go

@@ -0,0 +1,24 @@
+package swap
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestSwapOption(t *testing.T) {
+	options := []SwapOption{
+		WithMode(SoftMode),
+		WithThreshold(10, 0),
+	}
+
+	params := &SwapParameters{}
+
+	for _, opt := range options {
+		opt(params)
+	}
+
+	require.Equal(t, SoftMode, params.mode)
+	require.Equal(t, 10, params.paymentThreshold)
+	require.Equal(t, 0, params.disconnectThreshold)
+}

waku/v2/protocol/swap/waku_swap_test.go

@@ -0,0 +1,20 @@
+package swap
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestSwapCreditDebit(t *testing.T) {
+	swap := NewWakuSwap([]SwapOption{
+		WithMode(SoftMode),
+		WithThreshold(0, 0),
+	}...)
+
+	swap.Credit("1", 1)
+	require.Equal(t, -1, swap.Accounting["1"])
+
+	swap.Debit("1", 2)
+	require.Equal(t, 1, swap.Accounting["1"])
+}