announce payment threshold through pricing protocol (#585)

pkg/accounting/accounting.go

@@ -15,6 +15,7 @@ import (
 
 	"github.com/ethersphere/bee/pkg/logging"
 	"github.com/ethersphere/bee/pkg/p2p"
+	"github.com/ethersphere/bee/pkg/pricing"
 	"github.com/ethersphere/bee/pkg/settlement"
 	"github.com/ethersphere/bee/pkg/storage"
 	"github.com/ethersphere/bee/pkg/swarm"
@@ -47,20 +48,9 @@ type Interface interface {
 
 // accountingPeer holds all in-memory accounting information for one peer.
 type accountingPeer struct {
-	// Lock to be held during any accounting action for this peer.
-	lock sync.Mutex
-	// Amount currently reserved for active peer interaction
-	reservedBalance uint64
-}
-
-// Options are options provided to Accounting.
-type Options struct {
-	PaymentThreshold uint64
-	PaymentTolerance uint64
-	EarlyPayment     uint64
-	Logger           logging.Logger
-	Store            storage.StateStorer
-	Settlement       settlement.Interface
+	lock             sync.Mutex // lock to be held during any accounting action for this peer
+	reservedBalance  uint64     // amount currently reserved for active peer interaction
+	paymentThreshold uint64     // the threshold at which the peer expects us to pay
 }
 
 // Accounting is the main implementation of the accounting interface.
@@ -77,6 +67,7 @@ type Accounting struct {
 	paymentTolerance uint64
 	earlyPayment     uint64
 	settlement       settlement.Interface
+	pricing          pricing.Interface
 	metrics          metrics
 }
 
@@ -95,23 +86,32 @@ var (
 )
 
 // NewAccounting creates a new Accounting instance with the provided options.
-func NewAccounting(o Options) (*Accounting, error) {
-	if o.PaymentTolerance+o.PaymentThreshold > math.MaxInt64 {
+func NewAccounting(
+	PaymentThreshold uint64,
+	PaymentTolerance uint64,
+	EarlyPayment uint64,
+	Logger logging.Logger,
+	Store storage.StateStorer,
+	Settlement settlement.Interface,
+	Pricing pricing.Interface,
+) (*Accounting, error) {
+	if PaymentTolerance+PaymentThreshold > math.MaxInt64 {
 		return nil, fmt.Errorf("tolerance plus threshold too big: %w", ErrOverflow)
 	}
 
-	if o.PaymentTolerance > o.PaymentThreshold/2 {
+	if PaymentTolerance > PaymentThreshold/2 {
 		return nil, ErrInvalidPaymentTolerance
 	}
 
 	return &Accounting{
 		accountingPeers:  make(map[string]*accountingPeer),
-		paymentThreshold: o.PaymentThreshold,
-		paymentTolerance: o.PaymentTolerance,
-		earlyPayment:     o.EarlyPayment,
-		logger:           o.Logger,
-		store:            o.Store,
-		settlement:       o.Settlement,
+		paymentThreshold: PaymentThreshold,
+		paymentTolerance: PaymentTolerance,
+		earlyPayment:     EarlyPayment,
+		logger:           Logger,
+		store:            Store,
+		settlement:       Settlement,
+		pricing:          Pricing,
 		metrics:          newMetrics(),
 	}, nil
 }
@@ -233,7 +233,7 @@ func (a *Accounting) Credit(peer swarm.Address, price uint64) error {
 	// If our expected debt is less than earlyPayment away from our payment threshold (which we assume is
 	// also the peers payment threshold), trigger settlement.
 	// we pay early to avoid needlessly blocking request later when concurrent requests occur and we are already close to the payment threshold
-	threshold := a.paymentThreshold
+	threshold := accountingPeer.paymentThreshold
 	if threshold > a.earlyPayment {
 		threshold -= a.earlyPayment
 	} else {
@@ -370,6 +370,8 @@ func (a *Accounting) getAccountingPeer(peer swarm.Address) (*accountingPeer, err
 	if !ok {
 		peerData = &accountingPeer{
 			reservedBalance: 0,
+			// initially assume the peer has the same threshold as us
+			paymentThreshold: a.paymentThreshold,
 		}
 		a.accountingPeers[peer.String()] = peerData
 	}
@@ -506,3 +508,17 @@ func addI64pU64(a int64, b uint64) (result int64, err error) {
 
 	return result, nil
 }
+
+// NotifyPaymentThreshold should be called to notify accounting of changes in the payment threshold
+func (a *Accounting) NotifyPaymentThreshold(peer swarm.Address, paymentThreshold uint64) error {
+	accountingPeer, err := a.getAccountingPeer(peer)
+	if err != nil {
+		return err
+	}
+
+	accountingPeer.lock.Lock()
+	defer accountingPeer.lock.Unlock()
+
+	accountingPeer.paymentThreshold = paymentThreshold
+	return nil
+}

pkg/accounting/accounting_test.go

@@ -40,11 +40,7 @@ func TestAccountingAddBalance(t *testing.T) {
 	store := mock.NewStateStore()
 	defer store.Close()
 
-	acc, err := accounting.NewAccounting(accounting.Options{
-		PaymentThreshold: testPaymentThreshold,
-		Logger:           logger,
-		Store:            store,
-	})
+	acc, err := accounting.NewAccounting(testPaymentThreshold, 1000, 1000, logger, store, nil, nil)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -105,11 +101,7 @@ func TestAccountingAdd_persistentBalances(t *testing.T) {
 	store := mock.NewStateStore()
 	defer store.Close()
 
-	acc, err := accounting.NewAccounting(accounting.Options{
-		PaymentThreshold: testPaymentThreshold,
-		Logger:           logger,
-		Store:            store,
-	})
+	acc, err := accounting.NewAccounting(testPaymentThreshold, 1000, 1000, logger, store, nil, nil)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -136,10 +128,7 @@ func TestAccountingAdd_persistentBalances(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	acc, err = accounting.NewAccounting(accounting.Options{
-		Logger: logger,
-		Store:  store,
-	})
+	acc, err = accounting.NewAccounting(testPaymentThreshold, 1000, 1000, logger, store, nil, nil)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -170,11 +159,7 @@ func TestAccountingReserve(t *testing.T) {
 	store := mock.NewStateStore()
 	defer store.Close()
 
-	acc, err := accounting.NewAccounting(accounting.Options{
-		PaymentThreshold: testPaymentThreshold,
-		Logger:           logger,
-		Store:            store,
-	})
+	acc, err := accounting.NewAccounting(testPaymentThreshold, 1000, 1000, logger, store, nil, nil)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -208,12 +193,7 @@ func TestAccountingOverflowReserve(t *testing.T) {
 
 	settlement := &settlementMock{}
 
-	acc, err := accounting.NewAccounting(accounting.Options{
-		PaymentThreshold: testPaymentThresholdLarge,
-		Logger:           logger,
-		Store:            store,
-		Settlement:       settlement,
-	})
+	acc, err := accounting.NewAccounting(testPaymentThresholdLarge, 0, 0, logger, store, settlement, nil)
 
 	if err != nil {
 		t.Fatal(err)
@@ -263,12 +243,7 @@ func TestAccountingOverflowNotifyPayment(t *testing.T) {
 
 	settlement := &settlementMock{}
 
-	acc, err := accounting.NewAccounting(accounting.Options{
-		PaymentThreshold: testPaymentThresholdLarge,
-		Logger:           logger,
-		Store:            store,
-		Settlement:       settlement,
-	})
+	acc, err := accounting.NewAccounting(testPaymentThresholdLarge, 0, 0, logger, store, settlement, nil)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -299,12 +274,7 @@ func TestAccountingOverflowDebit(t *testing.T) {
 	store := mock.NewStateStore()
 	defer store.Close()
 
-	acc, err := accounting.NewAccounting(accounting.Options{
-		PaymentThreshold: testPaymentThresholdLarge,
-		Logger:           logger,
-		Store:            store,
-	})
-
+	acc, err := accounting.NewAccounting(testPaymentThresholdLarge, 0, 0, logger, store, nil, nil)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -345,12 +315,7 @@ func TestAccountingOverflowCredit(t *testing.T) {
 	store := mock.NewStateStore()
 	defer store.Close()
 
-	acc, err := accounting.NewAccounting(accounting.Options{
-		PaymentThreshold: testPaymentThresholdLarge,
-		Logger:           logger,
-		Store:            store,
-	})
-
+	acc, err := accounting.NewAccounting(testPaymentThresholdLarge, 0, 0, logger, store, nil, nil)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -396,12 +361,7 @@ func TestAccountingDisconnect(t *testing.T) {
 	store := mock.NewStateStore()
 	defer store.Close()
 
-	acc, err := accounting.NewAccounting(accounting.Options{
-		PaymentThreshold: testPaymentThreshold,
-		PaymentTolerance: testPaymentTolerance,
-		Logger:           logger,
-		Store:            store,
-	})
+	acc, err := accounting.NewAccounting(testPaymentThreshold, 1000, 1000, logger, store, nil, nil)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -468,13 +428,7 @@ func TestAccountingCallSettlement(t *testing.T) {
 
 	settlement := &settlementMock{}
 
-	acc, err := accounting.NewAccounting(accounting.Options{
-		PaymentThreshold: testPaymentThreshold,
-		PaymentTolerance: testPaymentTolerance,
-		Logger:           logger,
-		Store:            store,
-		Settlement:       settlement,
-	})
+	acc, err := accounting.NewAccounting(testPaymentThreshold, 1000, 1000, logger, store, settlement, nil)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -550,14 +504,7 @@ func TestAccountingCallSettlementEarly(t *testing.T) {
 	settlement := &settlementMock{}
 	earlyPayment := uint64(1000)
 
-	acc, err := accounting.NewAccounting(accounting.Options{
-		PaymentThreshold: testPaymentThreshold,
-		PaymentTolerance: testPaymentTolerance,
-		EarlyPayment:     earlyPayment,
-		Logger:           logger,
-		Store:            store,
-		Settlement:       settlement,
-	})
+	acc, err := accounting.NewAccounting(testPaymentThreshold, testPaymentTolerance, earlyPayment, logger, store, settlement, nil)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -605,12 +552,7 @@ func TestAccountingNotifyPayment(t *testing.T) {
 	store := mock.NewStateStore()
 	defer store.Close()
 
-	acc, err := accounting.NewAccounting(accounting.Options{
-		PaymentThreshold: testPaymentThreshold,
-		PaymentTolerance: testPaymentTolerance,
-		Logger:           logger,
-		Store:            store,
-	})
+	acc, err := accounting.NewAccounting(testPaymentThreshold, testPaymentTolerance, 1000, logger, store, nil, nil)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -648,12 +590,7 @@ func TestAccountingInvalidPaymentTolerance(t *testing.T) {
 	store := mock.NewStateStore()
 	defer store.Close()
 
-	_, err := accounting.NewAccounting(accounting.Options{
-		PaymentThreshold: testPaymentThreshold,
-		PaymentTolerance: testPaymentThreshold/2 + 1,
-		Logger:           logger,
-		Store:            store,
-	})
+	_, err := accounting.NewAccounting(testPaymentThreshold, testPaymentThreshold/2+1, 1000, logger, store, nil, nil)
 	if err == nil {
 		t.Fatal("expected error")
 	}
@@ -662,3 +599,93 @@ func TestAccountingInvalidPaymentTolerance(t *testing.T) {
 		t.Fatalf("got wrong error. got %v wanted %v", err, accounting.ErrInvalidPaymentTolerance)
 	}
 }
+
+type pricingMock struct {
+	called           bool
+	peer             swarm.Address
+	paymentThreshold uint64
+}
+
+func (p *pricingMock) AnnouncePaymentThreshold(ctx context.Context, peer swarm.Address, paymentThreshold uint64) error {
+	p.called = true
+	p.peer = peer
+	p.paymentThreshold = paymentThreshold
+	return nil
+}
+
+func TestAccountingConnected(t *testing.T) {
+	logger := logging.New(ioutil.Discard, 0)
+
+	store := mock.NewStateStore()
+	defer store.Close()
+
+	pricing := &pricingMock{}
+
+	_, err := accounting.NewAccounting(testPaymentThreshold, 1000, 1000, logger, store, nil, pricing)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	peer1Addr, err := swarm.ParseHexAddress("00112233")
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	err = pricing.AnnouncePaymentThreshold(context.Background(), peer1Addr, testPaymentThreshold)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if !pricing.called {
+		t.Fatal("expected pricing to be called")
+	}
+
+	if !pricing.peer.Equal(peer1Addr) {
+		t.Fatalf("paid to wrong peer. got %v wanted %v", pricing.peer, peer1Addr)
+	}
+
+	if pricing.paymentThreshold != testPaymentThreshold {
+		t.Fatalf("paid wrong amount. got %d wanted %d", pricing.paymentThreshold, testPaymentThreshold)
+	}
+}
+
+func TestAccountingNotifyPaymentThreshold(t *testing.T) {
+	logger := logging.New(ioutil.Discard, 0)
+
+	store := mock.NewStateStore()
+	defer store.Close()
+
+	pricing := &pricingMock{}
+	settlement := &settlementMock{}
+
+	acc, err := accounting.NewAccounting(testPaymentThreshold, 1000, 0, logger, store, settlement, pricing)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	peer1Addr, err := swarm.ParseHexAddress("00112233")
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	lowerThreshold := uint64(100)
+
+	err = acc.NotifyPaymentThreshold(peer1Addr, lowerThreshold)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	err = acc.Reserve(peer1Addr, lowerThreshold)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	err = acc.Credit(peer1Addr, lowerThreshold)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if settlement.paidAmount != lowerThreshold {
+		t.Fatalf("settled wrong amount. wanted %d, got %d", lowerThreshold, settlement.paidAmount)
+	}
+}

pkg/node/node.go

@@ -33,6 +33,7 @@ import (
 	"github.com/ethersphere/bee/pkg/netstore"
 	"github.com/ethersphere/bee/pkg/p2p/libp2p"
 	"github.com/ethersphere/bee/pkg/pingpong"
+	"github.com/ethersphere/bee/pkg/pricing"
 	"github.com/ethersphere/bee/pkg/pss"
 	"github.com/ethersphere/bee/pkg/puller"
 	"github.com/ethersphere/bee/pkg/pullsync"
@@ -290,19 +291,18 @@ func NewBee(addr string, swarmAddress swarm.Address, publicKey ecdsa.PublicKey,
 		settlement = pseudosettleService
 	}
 
-	acc, err := accounting.NewAccounting(accounting.Options{
-		Logger:           logger,
-		Store:            stateStore,
-		PaymentThreshold: o.PaymentThreshold,
-		PaymentTolerance: o.PaymentTolerance,
-		EarlyPayment:     o.PaymentEarly,
-		Settlement:       settlement,
-	})
+	pricing := pricing.New(p2ps, logger, o.PaymentThreshold)
+	if err = p2ps.AddProtocol(pricing.Protocol()); err != nil {
+		return nil, fmt.Errorf("pricing service: %w", err)
+	}
+
+	acc, err := accounting.NewAccounting(o.PaymentThreshold, o.PaymentTolerance, o.PaymentEarly, logger, stateStore, settlement, pricing)
 	if err != nil {
 		return nil, fmt.Errorf("accounting: %w", err)
 	}
 
 	settlement.SetPaymentObserver(acc)
+	pricing.SetPaymentThresholdObserver(acc)
 
 	kad := kademlia.New(swarmAddress, addressbook, hive, p2ps, logger, kademlia.Options{Bootnodes: bootnodes, Standalone: o.Standalone})
 	b.topologyCloser = kad

pkg/pricing/pb/doc.go

+// Copyright 2020 The Swarm Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:generate sh -c "protoc -I . -I \"$(go list -f '{{ .Dir }}' -m github.com/gogo/protobuf)/protobuf\" --gogofaster_out=. pricing.proto"
+
+package pb

pkg/pricing/pb/pricing.pb.go

+// Code generated by protoc-gen-gogo. DO NOT EDIT.
+// source: pricing.proto
+
+package pb
+
+import (
+	fmt "fmt"
+	proto "github.com/gogo/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.GoGoProtoPackageIsVersion3 // please upgrade the proto package
+
+type AnnouncePaymentThreshold struct {
+	PaymentThreshold uint64 `protobuf:"varint,1,opt,name=PaymentThreshold,proto3" json:"PaymentThreshold,omitempty"`
+}
+
+func (m *AnnouncePaymentThreshold) Reset()         { *m = AnnouncePaymentThreshold{} }
+func (m *AnnouncePaymentThreshold) String() string { return proto.CompactTextString(m) }
+func (*AnnouncePaymentThreshold) ProtoMessage()    {}
+func (*AnnouncePaymentThreshold) Descriptor() ([]byte, []int) {
+	return fileDescriptor_ec4cc93d045d43d0, []int{0}
+}
+func (m *AnnouncePaymentThreshold) XXX_Unmarshal(b []byte) error {
+	return m.Unmarshal(b)
+}
+func (m *AnnouncePaymentThreshold) XXX_Marshal(b []byte, deterministic bool) ([]byte, error) {
+	if deterministic {
+		return xxx_messageInfo_AnnouncePaymentThreshold.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 *AnnouncePaymentThreshold) XXX_Merge(src proto.Message) {
+	xxx_messageInfo_AnnouncePaymentThreshold.Merge(m, src)
+}
+func (m *AnnouncePaymentThreshold) XXX_Size() int {
+	return m.Size()
+}
+func (m *AnnouncePaymentThreshold) XXX_DiscardUnknown() {
+	xxx_messageInfo_AnnouncePaymentThreshold.DiscardUnknown(m)
+}
+
+var xxx_messageInfo_AnnouncePaymentThreshold proto.InternalMessageInfo
+
+func (m *AnnouncePaymentThreshold) GetPaymentThreshold() uint64 {
+	if m != nil {
+		return m.PaymentThreshold
+	}
+	return 0
+}
+
+func init() {
+	proto.RegisterType((*AnnouncePaymentThreshold)(nil), "pricing.AnnouncePaymentThreshold")
+}
+
+func init() { proto.RegisterFile("pricing.proto", fileDescriptor_ec4cc93d045d43d0) }
+
+var fileDescriptor_ec4cc93d045d43d0 = []byte{
+	// 122 bytes of a gzipped FileDescriptorProto
+	0x1f, 0x8b, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0xff, 0xe2, 0xe2, 0x2d, 0x28, 0xca, 0x4c,
+	0xce, 0xcc, 0x4b, 0xd7, 0x2b, 0x28, 0xca, 0x2f, 0xc9, 0x17, 0x62, 0x87, 0x72, 0x95, 0xdc, 0xb8,
+	0x24, 0x1c, 0xf3, 0xf2, 0xf2, 0x4b, 0xf3, 0x92, 0x53, 0x03, 0x12, 0x2b, 0x73, 0x53, 0xf3, 0x4a,
+	0x42, 0x32, 0x8a, 0x52, 0x8b, 0x33, 0xf2, 0x73, 0x52, 0x84, 0xb4, 0xb8, 0x04, 0xd0, 0xc5, 0x24,
+	0x18, 0x15, 0x18, 0x35, 0x58, 0x82, 0x30, 0xc4, 0x9d, 0x64, 0x4e, 0x3c, 0x92, 0x63, 0xbc, 0xf0,
+	0x48, 0x8e, 0xf1, 0xc1, 0x23, 0x39, 0xc6, 0x09, 0x8f, 0xe5, 0x18, 0x2e, 0x3c, 0x96, 0x63, 0xb8,
+	0xf1, 0x58, 0x8e, 0x21, 0x8a, 0xa9, 0x20, 0x29, 0x89, 0x0d, 0x6c, 0xab, 0x31, 0x20, 0x00, 0x00,
+	0xff, 0xff, 0x70, 0x59, 0x58, 0xcf, 0x86, 0x00, 0x00, 0x00,
+}
+
+func (m *AnnouncePaymentThreshold) 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 *AnnouncePaymentThreshold) MarshalTo(dAtA []byte) (int, error) {
+	size := m.Size()
+	return m.MarshalToSizedBuffer(dAtA[:size])
+}
+
+func (m *AnnouncePaymentThreshold) MarshalToSizedBuffer(dAtA []byte) (int, error) {
+	i := len(dAtA)
+	_ = i
+	var l int
+	_ = l
+	if m.PaymentThreshold != 0 {
+		i = encodeVarintPricing(dAtA, i, uint64(m.PaymentThreshold))
+		i--
+		dAtA[i] = 0x8
+	}
+	return len(dAtA) - i, nil
+}
+
+func encodeVarintPricing(dAtA []byte, offset int, v uint64) int {
+	offset -= sovPricing(v)
+	base := offset
+	for v >= 1<<7 {
+		dAtA[offset] = uint8(v&0x7f | 0x80)
+		v >>= 7
+		offset++
+	}
+	dAtA[offset] = uint8(v)
+	return base
+}
+func (m *AnnouncePaymentThreshold) Size() (n int) {
+	if m == nil {
+		return 0
+	}
+	var l int
+	_ = l
+	if m.PaymentThreshold != 0 {
+		n += 1 + sovPricing(uint64(m.PaymentThreshold))
+	}
+	return n
+}
+
+func sovPricing(x uint64) (n int) {
+	return (math_bits.Len64(x|1) + 6) / 7
+}
+func sozPricing(x uint64) (n int) {
+	return sovPricing(uint64((x << 1) ^ uint64((int64(x) >> 63))))
+}
+func (m *AnnouncePaymentThreshold) 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 ErrIntOverflowPricing
+			}
+			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: AnnouncePaymentThreshold: wiretype end group for non-group")
+		}
+		if fieldNum <= 0 {
+			return fmt.Errorf("proto: AnnouncePaymentThreshold: illegal tag %d (wire type %d)", fieldNum, wire)
+		}
+		switch fieldNum {
+		case 1:
+			if wireType != 0 {
+				return fmt.Errorf("proto: wrong wireType = %d for field PaymentThreshold", wireType)
+			}
+			m.PaymentThreshold = 0
+			for shift := uint(0); ; shift += 7 {
+				if shift >= 64 {
+					return ErrIntOverflowPricing
+				}
+				if iNdEx >= l {
+					return io.ErrUnexpectedEOF
+				}
+				b := dAtA[iNdEx]
+				iNdEx++
+				m.PaymentThreshold |= uint64(b&0x7F) << shift
+				if b < 0x80 {
+					break
+				}
+			}
+		default:
+			iNdEx = preIndex
+			skippy, err := skipPricing(dAtA[iNdEx:])
+			if err != nil {
+				return err
+			}
+			if skippy < 0 {
+				return ErrInvalidLengthPricing
+			}
+			if (iNdEx + skippy) < 0 {
+				return ErrInvalidLengthPricing
+			}
+			if (iNdEx + skippy) > l {
+				return io.ErrUnexpectedEOF
+			}
+			iNdEx += skippy
+		}
+	}
+
+	if iNdEx > l {
+		return io.ErrUnexpectedEOF
+	}
+	return nil
+}
+func skipPricing(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, ErrIntOverflowPricing
+			}
+			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, ErrIntOverflowPricing
+				}
+				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, ErrIntOverflowPricing
+				}
+				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, ErrInvalidLengthPricing
+			}
+			iNdEx += length
+		case 3:
+			depth++
+		case 4:
+			if depth == 0 {
+				return 0, ErrUnexpectedEndOfGroupPricing
+			}
+			depth--
+		case 5:
+			iNdEx += 4
+		default:
+			return 0, fmt.Errorf("proto: illegal wireType %d", wireType)
+		}
+		if iNdEx < 0 {
+			return 0, ErrInvalidLengthPricing
+		}
+		if depth == 0 {
+			return iNdEx, nil
+		}
+	}
+	return 0, io.ErrUnexpectedEOF
+}
+
+var (
+	ErrInvalidLengthPricing        = fmt.Errorf("proto: negative length found during unmarshaling")
+	ErrIntOverflowPricing          = fmt.Errorf("proto: integer overflow")
+	ErrUnexpectedEndOfGroupPricing = fmt.Errorf("proto: unexpected end of group")
+)

pkg/pricing/pb/pricing.proto

+// Copyright 2020 The Swarm Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+syntax = "proto3";
+
+package pricing;
+
+option go_package = "pb";
+
+message AnnouncePaymentThreshold {
+  uint64 PaymentThreshold = 1;
+}

pkg/pricing/pricing.go

+// Copyright 2020 The Swarm Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package pricing
+
+import (
+	"context"
+	"fmt"
+	"time"
+
+	"github.com/ethersphere/bee/pkg/logging"
+	"github.com/ethersphere/bee/pkg/p2p"
+	"github.com/ethersphere/bee/pkg/p2p/protobuf"
+	"github.com/ethersphere/bee/pkg/pricing/pb"
+	"github.com/ethersphere/bee/pkg/swarm"
+)
+
+const (
+	protocolName    = "pricing"
+	protocolVersion = "1.0.0"
+	streamName      = "pricing"
+)
+
+var _ Interface = (*Service)(nil)
+
+// Interface is the main interface of the pricing protocol
+type Interface interface {
+	AnnouncePaymentThreshold(ctx context.Context, peer swarm.Address, paymentThreshold uint64) error
+}
+
+// PaymentThresholdObserver is used for being notified of payment threshold updates
+type PaymentThresholdObserver interface {
+	NotifyPaymentThreshold(peer swarm.Address, paymentThreshold uint64) error
+}
+
+type Service struct {
+	streamer                 p2p.Streamer
+	logger                   logging.Logger
+	paymentThreshold         uint64
+	paymentThresholdObserver PaymentThresholdObserver
+}
+
+func New(streamer p2p.Streamer, logger logging.Logger, paymentThreshold uint64) *Service {
+	return &Service{
+		streamer:         streamer,
+		logger:           logger,
+		paymentThreshold: paymentThreshold,
+	}
+}
+
+func (s *Service) Protocol() p2p.ProtocolSpec {
+	return p2p.ProtocolSpec{
+		Name:    protocolName,
+		Version: protocolVersion,
+		StreamSpecs: []p2p.StreamSpec{
+			{
+				Name:    streamName,
+				Handler: s.handler,
+			},
+		},
+		ConnectIn:  s.init,
+		ConnectOut: s.init,
+	}
+}
+
+func (s *Service) handler(ctx context.Context, p p2p.Peer, stream p2p.Stream) (err error) {
+	r := protobuf.NewReader(stream)
+	defer func() {
+		if err != nil {
+			_ = stream.Reset()
+		} else {
+			_ = stream.FullClose()
+		}
+	}()
+	s.logger.Infof("receiving payment threshold announcement from peer %v", p.Address)
+	var req pb.AnnouncePaymentThreshold
+	if err := r.ReadMsg(&req); err != nil {
+		s.logger.Debugf("error receiving payment threshold announcement from peer %v", p.Address)
+		return fmt.Errorf("read request from peer %v: %w", p.Address, err)
+	}
+	s.logger.Infof("received payment threshold announcement from peer %v of %d", p.Address, req.PaymentThreshold)
+
+	return s.paymentThresholdObserver.NotifyPaymentThreshold(p.Address, req.PaymentThreshold)
+}
+
+func (s *Service) init(ctx context.Context, p p2p.Peer) error {
+	s.logger.Infof("sending payment threshold announcement to peer %v", p.Address)
+	err := s.AnnouncePaymentThreshold(ctx, p.Address, s.paymentThreshold)
+	if err != nil {
+		s.logger.Warningf("error sending payment threshold announcement to peer %v", p.Address)
+	}
+	return err
+}
+
+// AnnouncePaymentThreshold announces the payment threshold to per
+func (s *Service) AnnouncePaymentThreshold(ctx context.Context, peer swarm.Address, paymentThreshold uint64) error {
+	ctx, cancel := context.WithTimeout(ctx, 5*time.Second)
+	defer cancel()
+
+	stream, err := s.streamer.NewStream(ctx, peer, nil, protocolName, protocolVersion, streamName)
+	if err != nil {
+		return err
+	}
+	defer func() {
+		if err != nil {
+			_ = stream.Reset()
+		} else {
+			go stream.FullClose()
+		}
+	}()
+
+	s.logger.Tracef("sending payment threshold announcement to peer %v of %d", peer, paymentThreshold)
+	w := protobuf.NewWriter(stream)
+	err = w.WriteMsgWithContext(ctx, &pb.AnnouncePaymentThreshold{
+		PaymentThreshold: paymentThreshold,
+	})
+
+	return err
+}
+
+// SetPaymentThresholdObserver sets the PaymentThresholdObserver to be used when receiving a new payment threshold
+func (s *Service) SetPaymentThresholdObserver(observer PaymentThresholdObserver) {
+	s.paymentThresholdObserver = observer
+}

pkg/pricing/pricing_test.go

+// Copyright 2020 The Swarm Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package pricing_test
+
+import (
+	"bytes"
+	"context"
+	"io/ioutil"
+	"testing"
+
+	"github.com/ethersphere/bee/pkg/logging"
+	"github.com/ethersphere/bee/pkg/p2p/protobuf"
+	"github.com/ethersphere/bee/pkg/p2p/streamtest"
+	"github.com/ethersphere/bee/pkg/pricing"
+	"github.com/ethersphere/bee/pkg/pricing/pb"
+	"github.com/ethersphere/bee/pkg/swarm"
+)
+
+type testObserver struct {
+	called           bool
+	peer             swarm.Address
+	paymentThreshold uint64
+}
+
+func (t *testObserver) NotifyPaymentThreshold(peer swarm.Address, paymentThreshold uint64) error {
+	t.called = true
+	t.peer = peer
+	t.paymentThreshold = paymentThreshold
+	return nil
+}
+
+func TestAnnouncePaymentThreshold(t *testing.T) {
+	logger := logging.New(ioutil.Discard, 0)
+	testThreshold := uint64(100000)
+	observer := &testObserver{}
+
+	recipient := pricing.New(nil, logger, testThreshold)
+	recipient.SetPaymentThresholdObserver(observer)
+
+	recorder := streamtest.New(
+		streamtest.WithProtocols(recipient.Protocol()),
+	)
+
+	payer := pricing.New(recorder, logger, testThreshold)
+
+	peerID := swarm.MustParseHexAddress("9ee7add7")
+	paymentThreshold := uint64(10000)
+
+	err := payer.AnnouncePaymentThreshold(context.Background(), peerID, paymentThreshold)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	records, err := recorder.Records(peerID, "pricing", "1.0.0", "pricing")
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if l := len(records); l != 1 {
+		t.Fatalf("got %v records, want %v", l, 1)
+	}
+
+	record := records[0]
+
+	messages, err := protobuf.ReadMessages(
+		bytes.NewReader(record.In()),
+		func() protobuf.Message { return new(pb.AnnouncePaymentThreshold) },
+	)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if len(messages) != 1 {
+		t.Fatalf("got %v messages, want %v", len(messages), 1)
+	}
+
+	sentPaymentThreshold := messages[0].(*pb.AnnouncePaymentThreshold).PaymentThreshold
+	if sentPaymentThreshold != paymentThreshold {
+		t.Fatalf("got message with amount %v, want %v", sentPaymentThreshold, paymentThreshold)
+	}
+
+	if !observer.called {
+		t.Fatal("expected observer to be called")
+	}
+
+	if observer.paymentThreshold != paymentThreshold {
+		t.Fatalf("observer called with wrong paymentThreshold. got %d, want %d", observer.paymentThreshold, paymentThreshold)
+	}
+
+	if !observer.peer.Equal(peerID) {
+		t.Fatalf("observer called with wrong peer. got %v, want %v", observer.peer, peerID)
+	}
+}