path: root/p2p/simulations/mocker_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 simulations simulates p2p networks.
// A mocker simulates starting and stopping real nodes in a network.
package simulations

import (
    "encoding/json"
    "net/http"
    "net/url"
    "strconv"
    "sync"
    "testing"
    "time"

    "github.com/ethereum/go-ethereum/p2p/enode"
)

func TestMocker(t *testing.T) {
    //start the simulation HTTP server
    _, s := testHTTPServer(t)
    defer s.Close()

    //create a client
    client := NewClient(s.URL)

    //start the network
    err := client.StartNetwork()
    if err != nil {
        t.Fatalf("Could not start test network: %s", err)
    }
    //stop the network to terminate
    defer func() {
        err = client.StopNetwork()
        if err != nil {
            t.Fatalf("Could not stop test network: %s", err)
        }
    }()

    //get the list of available mocker types
    resp, err := http.Get(s.URL + "/mocker")
    if err != nil {
        t.Fatalf("Could not get mocker list: %s", err)
    }
    defer resp.Body.Close()

    if resp.StatusCode != 200 {
        t.Fatalf("Invalid Status Code received, expected 200, got %d", resp.StatusCode)
    }

    //check the list is at least 1 in size
    var mockerlist []string
    err = json.NewDecoder(resp.Body).Decode(&mockerlist)
    if err != nil {
        t.Fatalf("Error decoding JSON mockerlist: %s", err)
    }

    if len(mockerlist) < 1 {
        t.Fatalf("No mockers available")
    }

    nodeCount := 10
    var wg sync.WaitGroup

    events := make(chan *Event, 10)
    var opts SubscribeOpts
    sub, err := client.SubscribeNetwork(events, opts)
    defer sub.Unsubscribe()
    //wait until all nodes are started and connected
    //store every node up event in a map (value is irrelevant, mimic Set datatype)
    nodemap := make(map[enode.ID]bool)
    wg.Add(1)
    nodesComplete := false
    connCount := 0
    go func() {
        for {
            select {
            case event := <-events:
                if isNodeUp(event) {
                    //add the correspondent node ID to the map
                    nodemap[event.Node.Config.ID] = true
                    //this means all nodes got a nodeUp event, so we can continue the test
                    if len(nodemap) == nodeCount {
                        nodesComplete = true
                    }
                } else if event.Conn != nil && nodesComplete {
                    connCount += 1
                    if connCount == (nodeCount-1)*2 {
                        wg.Done()
                        return
                    }
                }
            case <-time.After(30 * time.Second):
                wg.Done()
                t.Fatalf("Timeout waiting for nodes being started up!")
            }
        }
    }()

    //take the last element of the mockerlist as the default mocker-type to ensure one is enabled
    mockertype := mockerlist[len(mockerlist)-1]
    //still, use hardcoded "probabilistic" one if available ;)
    for _, m := range mockerlist {
        if m == "probabilistic" {
            mockertype = m
            break
        }
    }
    //start the mocker with nodeCount number of nodes
    resp, err = http.PostForm(s.URL+"/mocker/start", url.Values{"mocker-type": {mockertype}, "node-count": {strconv.Itoa(nodeCount)}})
    if err != nil {
        t.Fatalf("Could not start mocker: %s", err)
    }
    if resp.StatusCode != 200 {
        t.Fatalf("Invalid Status Code received for starting mocker, expected 200, got %d", resp.StatusCode)
    }

    wg.Wait()

    //check there are nodeCount number of nodes in the network
    nodesInfo, err := client.GetNodes()
    if err != nil {
        t.Fatalf("Could not get nodes list: %s", err)
    }

    if len(nodesInfo) != nodeCount {
        t.Fatalf("Expected %d number of nodes, got: %d", nodeCount, len(nodesInfo))
    }

    //stop the mocker
    resp, err = http.Post(s.URL+"/mocker/stop", "", nil)
    if err != nil {
        t.Fatalf("Could not stop mocker: %s", err)
    }
    if resp.StatusCode != 200 {
        t.Fatalf("Invalid Status Code received for stopping mocker, expected 200, got %d", resp.StatusCode)
    }

    //reset the network
    _, err = http.Post(s.URL+"/reset", "", nil)
    if err != nil {
        t.Fatalf("Could not reset network: %s", err)
    }

    //now the number of nodes in the network should be zero
    nodesInfo, err = client.GetNodes()
    if err != nil {
        t.Fatalf("Could not get nodes list: %s", err)
    }

    if len(nodesInfo) != 0 {
        t.Fatalf("Expected empty list of nodes, got: %d", len(nodesInfo))
    }
}

func isNodeUp(event *Event) bool {
    return event.Node != nil && event.Node.Up()
}