1 files changed, 310 insertions, 0 deletions
diff --git a/p2p/protocols/accounting_simulation_test.go b/p2p/protocols/accounting_simulation_test.go
new file mode 100644
index 000000000..65b737abe
--- /dev/null
+++ b/p2p/protocols/accounting_simulation_test.go
@@ -0,0 +1,310 @@
+// Copyright 2018 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package protocols
+
+import (
+	"context"
+	"flag"
+	"fmt"
+	"math/rand"
+	"reflect"
+	"sync"
+	"testing"
+	"time"
+
+	"github.com/mattn/go-colorable"
+
+	"github.com/ethereum/go-ethereum/log"
+	"github.com/ethereum/go-ethereum/rpc"
+
+	"github.com/ethereum/go-ethereum/node"
+	"github.com/ethereum/go-ethereum/p2p"
+	"github.com/ethereum/go-ethereum/p2p/enode"
+	"github.com/ethereum/go-ethereum/p2p/simulations"
+	"github.com/ethereum/go-ethereum/p2p/simulations/adapters"
+)
+
+const (
+	content = "123456789"
+)
+
+var (
+	nodes    = flag.Int("nodes", 30, "number of nodes to create (default 30)")
+	msgs     = flag.Int("msgs", 100, "number of messages sent by node (default 100)")
+	loglevel = flag.Int("loglevel", 0, "verbosity of logs")
+	rawlog   = flag.Bool("rawlog", false, "remove terminal formatting from logs")
+)
+
+func init() {
+	flag.Parse()
+	log.PrintOrigins(true)
+	log.Root().SetHandler(log.LvlFilterHandler(log.Lvl(*loglevel), log.StreamHandler(colorable.NewColorableStderr(), log.TerminalFormat(!*rawlog))))
+}
+
+//TestAccountingSimulation runs a p2p/simulations simulation
+//It creates a *nodes number of nodes, connects each one with each other,
+//then sends out a random selection of messages up to *msgs amount of messages
+//from the test protocol spec.
+//The spec has some accounted messages defined through the Prices interface.
+//The test does accounting for all the message exchanged, and then checks
+//that every node has the same balance with a peer, but with opposite signs.
+//Balance(AwithB) = 0 - Balance(BwithA) or Abs|Balance(AwithB)| == Abs|Balance(BwithA)|
+func TestAccountingSimulation(t *testing.T) {
+	//setup the balances objects for every node
+	bal := newBalances(*nodes)
+	//define the node.Service for this test
+	services := adapters.Services{
+		"accounting": func(ctx *adapters.ServiceContext) (node.Service, error) {
+			return bal.newNode(), nil
+		},
+	}
+	//setup the simulation
+	adapter := adapters.NewSimAdapter(services)
+	net := simulations.NewNetwork(adapter, &simulations.NetworkConfig{DefaultService: "accounting"})
+	defer net.Shutdown()
+
+	// we send msgs messages per node, wait for all messages to arrive
+	bal.wg.Add(*nodes * *msgs)
+	trigger := make(chan enode.ID)
+	go func() {
+		// wait for all of them to arrive
+		bal.wg.Wait()
+		// then trigger a check
+		// the selected node for the trigger is irrelevant,
+		// we just want to trigger the end of the simulation
+		trigger <- net.Nodes[0].ID()
+	}()
+
+	// create nodes and start them
+	for i := 0; i < *nodes; i++ {
+		conf := adapters.RandomNodeConfig()
+		bal.id2n[conf.ID] = i
+		if _, err := net.NewNodeWithConfig(conf); err != nil {
+			t.Fatal(err)
+		}
+		if err := net.Start(conf.ID); err != nil {
+			t.Fatal(err)
+		}
+	}
+	// fully connect nodes
+	for i, n := range net.Nodes {
+		for _, m := range net.Nodes[i+1:] {
+			if err := net.Connect(n.ID(), m.ID()); err != nil {
+				t.Fatal(err)
+			}
+		}
+	}
+
+	// empty action
+	action := func(ctx context.Context) error {
+		return nil
+	}
+	// 	check always checks out
+	check := func(ctx context.Context, id enode.ID) (bool, error) {
+		return true, nil
+	}
+
+	// run simulation
+	timeout := 30 * time.Second
+	ctx, cancel := context.WithTimeout(context.Background(), timeout)
+	defer cancel()
+	result := simulations.NewSimulation(net).Run(ctx, &simulations.Step{
+		Action:  action,
+		Trigger: trigger,
+		Expect: &simulations.Expectation{
+			Nodes: []enode.ID{net.Nodes[0].ID()},
+			Check: check,
+		},
+	})
+
+	if result.Error != nil {
+		t.Fatal(result.Error)
+	}
+
+	// check if balance matrix is symmetric
+	if err := bal.symmetric(); err != nil {
+		t.Fatal(err)
+	}
+}
+
+// matrix is a matrix of nodes and its balances
+// matrix is in fact a linear array of size n*n,
+// so the balance for any node A with B is at index
+// A*n + B, while the balance of node B with A is at
+// B*n + A
+// (n entries in the array will not be filled -
+//  the balance of a node with itself)
+type matrix struct {
+	n int     //number of nodes
+	m []int64 //array of balances
+}
+
+// create a new matrix
+func newMatrix(n int) *matrix {
+	return &matrix{
+		n: n,
+		m: make([]int64, n*n),
+	}
+}
+
+// called from the testBalance's Add accounting function: register balance change
+func (m *matrix) add(i, j int, v int64) error {
+	// index for the balance of local node i with remote nodde j is
+	// i * number of nodes + remote node
+	mi := i*m.n + j
+	// register that balance
+	m.m[mi] += v
+	return nil
+}
+
+// check that the balances are symmetric:
+// balance of node i with node j is the same as j with i but with inverted signs
+func (m *matrix) symmetric() error {
+	//iterate all nodes
+	for i := 0; i < m.n; i++ {
+		//iterate starting +1
+		for j := i + 1; j < m.n; j++ {
+			log.Debug("bal", "1", i, "2", j, "i,j", m.m[i*m.n+j], "j,i", m.m[j*m.n+i])
+			if m.m[i*m.n+j] != -m.m[j*m.n+i] {
+				return fmt.Errorf("value mismatch. m[%v, %v] = %v; m[%v, %v] = %v", i, j, m.m[i*m.n+j], j, i, m.m[j*m.n+i])
+			}
+		}
+	}
+	return nil
+}
+
+// all the balances
+type balances struct {
+	i int
+	*matrix
+	id2n map[enode.ID]int
+	wg   *sync.WaitGroup
+}
+
+func newBalances(n int) *balances {
+	return &balances{
+		matrix: newMatrix(n),
+		id2n:   make(map[enode.ID]int),
+		wg:     &sync.WaitGroup{},
+	}
+}
+
+// create a new testNode for every node created as part of the service
+func (b *balances) newNode() *testNode {
+	defer func() { b.i++ }()
+	return &testNode{
+		bal:   b,
+		i:     b.i,
+		peers: make([]*testPeer, b.n), //a node will be connected to n-1 peers
+	}
+}
+
+type testNode struct {
+	bal       *balances
+	i         int
+	lock      sync.Mutex
+	peers     []*testPeer
+	peerCount int
+}
+
+// do the accounting for the peer's test protocol
+// testNode implements protocols.Balance
+func (t *testNode) Add(a int64, p *Peer) error {
+	//get the index for the remote peer
+	remote := t.bal.id2n[p.ID()]
+	log.Debug("add", "local", t.i, "remote", remote, "amount", a)
+	return t.bal.add(t.i, remote, a)
+}
+
+//run the p2p protocol
+//for every node, represented by testNode, create a remote testPeer
+func (t *testNode) run(p *p2p.Peer, rw p2p.MsgReadWriter) error {
+	spec := createTestSpec()
+	//create accounting hook
+	spec.Hook = NewAccounting(t, &dummyPrices{})
+
+	//create a peer for this node
+	tp := &testPeer{NewPeer(p, rw, spec), t.i, t.bal.id2n[p.ID()], t.bal.wg}
+	t.lock.Lock()
+	t.peers[t.bal.id2n[p.ID()]] = tp
+	t.peerCount++
+	if t.peerCount == t.bal.n-1 {
+		//when all peer connections are established, start sending messages from this peer
+		go t.send()
+	}
+	t.lock.Unlock()
+	return tp.Run(tp.handle)
+}
+
+// p2p message receive handler function
+func (tp *testPeer) handle(ctx context.Context, msg interface{}) error {
+	tp.wg.Done()
+	log.Debug("receive", "from", tp.remote, "to", tp.local, "type", reflect.TypeOf(msg), "msg", msg)
+	return nil
+}
+
+type testPeer struct {
+	*Peer
+	local, remote int
+	wg            *sync.WaitGroup
+}
+
+func (t *testNode) send() {
+	log.Debug("start sending")
+	for i := 0; i < *msgs; i++ {
+		//determine randomly to which peer to send
+		whom := rand.Intn(t.bal.n - 1)
+		if whom >= t.i {
+			whom++
+		}
+		t.lock.Lock()
+		p := t.peers[whom]
+		t.lock.Unlock()
+
+		//determine a random message from the spec's messages to be sent
+		which := rand.Intn(len(p.spec.Messages))
+		msg := p.spec.Messages[which]
+		switch msg.(type) {
+		case *perBytesMsgReceiverPays:
+			msg = &perBytesMsgReceiverPays{Content: content[:rand.Intn(len(content))]}
+		case *perBytesMsgSenderPays:
+			msg = &perBytesMsgSenderPays{Content: content[:rand.Intn(len(content))]}
+		}
+		log.Debug("send", "from", t.i, "to", whom, "type", reflect.TypeOf(msg), "msg", msg)
+		p.Send(context.TODO(), msg)
+	}
+}
+
+// define the protocol
+func (t *testNode) Protocols() []p2p.Protocol {
+	return []p2p.Protocol{{
+		Length: 100,
+		Run:    t.run,
+	}}
+}
+
+func (t *testNode) APIs() []rpc.API {
+	return nil
+}
+
+func (t *testNode) Start(server *p2p.Server) error {
+	return nil
+}
+
+func (t *testNode) Stop() error {
+	return nil
+}