path: root/les/freeclient_test.go

// Copyright 2017 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 light implements on-demand retrieval capable state and chain objects
// for the Ethereum Light Client.
package les

import (
    "fmt"
    "math/rand"
    "testing"
    "time"

    "github.com/dexon-foundation/dexon/common/mclock"
    "github.com/dexon-foundation/dexon/ethdb"
)

func TestFreeClientPoolL10C100(t *testing.T) {
    testFreeClientPool(t, 10, 100)
}

func TestFreeClientPoolL40C200(t *testing.T) {
    testFreeClientPool(t, 40, 200)
}

func TestFreeClientPoolL100C300(t *testing.T) {
    testFreeClientPool(t, 100, 300)
}

const testFreeClientPoolTicks = 500000

func testFreeClientPool(t *testing.T, connLimit, clientCount int) {
    var (
        clock     mclock.Simulated
        db        = ethdb.NewMemDatabase()
        pool      = newFreeClientPool(db, connLimit, 10000, &clock)
        connected = make([]bool, clientCount)
        connTicks = make([]int, clientCount)
        disconnCh = make(chan int, clientCount)
    )
    peerId := func(i int) string {
        return fmt.Sprintf("test peer #%d", i)
    }
    disconnFn := func(i int) func() {
        return func() {
            disconnCh <- i
        }
    }

    // pool should accept new peers up to its connected limit
    for i := 0; i < connLimit; i++ {
        if pool.connect(peerId(i), disconnFn(i)) {
            connected[i] = true
        } else {
            t.Fatalf("Test peer #%d rejected", i)
        }
    }
    // since all accepted peers are new and should not be kicked out, the next one should be rejected
    if pool.connect(peerId(connLimit), disconnFn(connLimit)) {
        connected[connLimit] = true
        t.Fatalf("Peer accepted over connected limit")
    }

    // randomly connect and disconnect peers, expect to have a similar total connection time at the end
    for tickCounter := 0; tickCounter < testFreeClientPoolTicks; tickCounter++ {
        clock.Run(1 * time.Second)

        i := rand.Intn(clientCount)
        if connected[i] {
            pool.disconnect(peerId(i))
            connected[i] = false
            connTicks[i] += tickCounter
        } else {
            if pool.connect(peerId(i), disconnFn(i)) {
                connected[i] = true
                connTicks[i] -= tickCounter
            }
        }
    pollDisconnects:
        for {
            select {
            case i := <-disconnCh:
                pool.disconnect(peerId(i))
                if connected[i] {
                    connTicks[i] += tickCounter
                    connected[i] = false
                }
            default:
                break pollDisconnects
            }
        }
    }

    expTicks := testFreeClientPoolTicks * connLimit / clientCount
    expMin := expTicks - expTicks/10
    expMax := expTicks + expTicks/10

    // check if the total connected time of peers are all in the expected range
    for i, c := range connected {
        if c {
            connTicks[i] += testFreeClientPoolTicks
        }
        if connTicks[i] < expMin || connTicks[i] > expMax {
            t.Errorf("Total connected time of test node #%d (%d) outside expected range (%d to %d)", i, connTicks[i], expMin, expMax)
        }
    }

    // a previously unknown peer should be accepted now
    if !pool.connect("newPeer", func() {}) {
        t.Fatalf("Previously unknown peer rejected")
    }

    // close and restart pool
    pool.stop()
    pool = newFreeClientPool(db, connLimit, 10000, &clock)

    // try connecting all known peers (connLimit should be filled up)
    for i := 0; i < clientCount; i++ {
        pool.connect(peerId(i), func() {})
    }
    // expect pool to remember known nodes and kick out one of them to accept a new one
    if !pool.connect("newPeer2", func() {}) {
        t.Errorf("Previously unknown peer rejected after restarting pool")
    }
    pool.stop()
}