path: root/p2p/protocols/accounting_simulation_test.go

// 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"
    "io/ioutil"
    "math/rand"
    "os"
    "path/filepath"
    "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)
    //setup the metrics system or tests will fail trying to write metrics
    dir, err := ioutil.TempDir("", "account-sim")
    if err != nil {
        t.Fatal(err)
    }
    defer os.RemoveAll(dir)
    SetupAccountingMetrics(1*time.Second, filepath.Join(dir, "metrics.db"))
    //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
}