path: root/swarm/network/simulation/node.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 simulation

import (
    "encoding/json"
    "errors"
    "io/ioutil"
    "math/rand"
    "os"
    "time"

    "github.com/ethereum/go-ethereum/log"
    "github.com/ethereum/go-ethereum/p2p/discover"
    "github.com/ethereum/go-ethereum/p2p/simulations"
    "github.com/ethereum/go-ethereum/p2p/simulations/adapters"
)

// NodeIDs returns NodeIDs for all nodes in the network.
func (s *Simulation) NodeIDs() (ids []discover.NodeID) {
    nodes := s.Net.GetNodes()
    ids = make([]discover.NodeID, len(nodes))
    for i, node := range nodes {
        ids[i] = node.ID()
    }
    return ids
}

// UpNodeIDs returns NodeIDs for nodes that are up in the network.
func (s *Simulation) UpNodeIDs() (ids []discover.NodeID) {
    nodes := s.Net.GetNodes()
    for _, node := range nodes {
        if node.Up {
            ids = append(ids, node.ID())
        }
    }
    return ids
}

// DownNodeIDs returns NodeIDs for nodes that are stopped in the network.
func (s *Simulation) DownNodeIDs() (ids []discover.NodeID) {
    nodes := s.Net.GetNodes()
    for _, node := range nodes {
        if !node.Up {
            ids = append(ids, node.ID())
        }
    }
    return ids
}

// AddNodeOption defines the option that can be passed
// to Simulation.AddNode method.
type AddNodeOption func(*adapters.NodeConfig)

// AddNodeWithMsgEvents sets the EnableMsgEvents option
// to NodeConfig.
func AddNodeWithMsgEvents(enable bool) AddNodeOption {
    return func(o *adapters.NodeConfig) {
        o.EnableMsgEvents = enable
    }
}

// AddNodeWithService specifies a service that should be
// started on a node. This option can be repeated as variadic
// argument toe AddNode and other add node related methods.
// If AddNodeWithService is not specified, all services will be started.
func AddNodeWithService(serviceName string) AddNodeOption {
    return func(o *adapters.NodeConfig) {
        o.Services = append(o.Services, serviceName)
    }
}

// AddNode creates a new node with random configuration,
// applies provided options to the config and adds the node to network.
// By default all services will be started on a node. If one or more
// AddNodeWithService option are provided, only specified services will be started.
func (s *Simulation) AddNode(opts ...AddNodeOption) (id discover.NodeID, err error) {
    conf := adapters.RandomNodeConfig()
    for _, o := range opts {
        o(conf)
    }
    if len(conf.Services) == 0 {
        conf.Services = s.serviceNames
    }
    node, err := s.Net.NewNodeWithConfig(conf)
    if err != nil {
        return id, err
    }
    return node.ID(), s.Net.Start(node.ID())
}

// AddNodes creates new nodes with random configurations,
// applies provided options to the config and adds nodes to network.
func (s *Simulation) AddNodes(count int, opts ...AddNodeOption) (ids []discover.NodeID, err error) {
    ids = make([]discover.NodeID, 0, count)
    for i := 0; i < count; i++ {
        id, err := s.AddNode(opts...)
        if err != nil {
            return nil, err
        }
        ids = append(ids, id)
    }
    return ids, nil
}

// AddNodesAndConnectFull is a helpper method that combines
// AddNodes and ConnectNodesFull. Only new nodes will be connected.
func (s *Simulation) AddNodesAndConnectFull(count int, opts ...AddNodeOption) (ids []discover.NodeID, err error) {
    if count < 2 {
        return nil, errors.New("count of nodes must be at least 2")
    }
    ids, err = s.AddNodes(count, opts...)
    if err != nil {
        return nil, err
    }
    err = s.ConnectNodesFull(ids)
    if err != nil {
        return nil, err
    }
    return ids, nil
}

// AddNodesAndConnectChain is a helpper method that combines
// AddNodes and ConnectNodesChain. The chain will be continued from the last
// added node, if there is one in simulation using ConnectToLastNode method.
func (s *Simulation) AddNodesAndConnectChain(count int, opts ...AddNodeOption) (ids []discover.NodeID, err error) {
    if count < 2 {
        return nil, errors.New("count of nodes must be at least 2")
    }
    id, err := s.AddNode(opts...)
    if err != nil {
        return nil, err
    }
    err = s.ConnectToLastNode(id)
    if err != nil {
        return nil, err
    }
    ids, err = s.AddNodes(count-1, opts...)
    if err != nil {
        return nil, err
    }
    ids = append([]discover.NodeID{id}, ids...)
    err = s.ConnectNodesChain(ids)
    if err != nil {
        return nil, err
    }
    return ids, nil
}

// AddNodesAndConnectRing is a helpper method that combines
// AddNodes and ConnectNodesRing.
func (s *Simulation) AddNodesAndConnectRing(count int, opts ...AddNodeOption) (ids []discover.NodeID, err error) {
    if count < 2 {
        return nil, errors.New("count of nodes must be at least 2")
    }
    ids, err = s.AddNodes(count, opts...)
    if err != nil {
        return nil, err
    }
    err = s.ConnectNodesRing(ids)
    if err != nil {
        return nil, err
    }
    return ids, nil
}

// AddNodesAndConnectStar is a helpper method that combines
// AddNodes and ConnectNodesStar.
func (s *Simulation) AddNodesAndConnectStar(count int, opts ...AddNodeOption) (ids []discover.NodeID, err error) {
    if count < 2 {
        return nil, errors.New("count of nodes must be at least 2")
    }
    ids, err = s.AddNodes(count, opts...)
    if err != nil {
        return nil, err
    }
    err = s.ConnectNodesStar(ids[0], ids[1:])
    if err != nil {
        return nil, err
    }
    return ids, nil
}

//UploadSnapshot uploads a snapshot to the simulation
//This method tries to open the json file provided, applies the config to all nodes
//and then loads the snapshot into the Simulation network
func (s *Simulation) UploadSnapshot(snapshotFile string, opts ...AddNodeOption) error {
    f, err := os.Open(snapshotFile)
    if err != nil {
        return err
    }
    defer func() {
        err := f.Close()
        if err != nil {
            log.Error("Error closing snapshot file", "err", err)
        }
    }()
    jsonbyte, err := ioutil.ReadAll(f)
    if err != nil {
        return err
    }
    var snap simulations.Snapshot
    err = json.Unmarshal(jsonbyte, &snap)
    if err != nil {
        return err
    }

    //the snapshot probably has the property EnableMsgEvents not set
    //just in case, set it to true!
    //(we need this to wait for messages before uploading)
    for _, n := range snap.Nodes {
        n.Node.Config.EnableMsgEvents = true
        n.Node.Config.Services = s.serviceNames
        for _, o := range opts {
            o(n.Node.Config)
        }
    }

    log.Info("Waiting for p2p connections to be established...")

    //now we can load the snapshot
    err = s.Net.Load(&snap)
    if err != nil {
        return err
    }
    log.Info("Snapshot loaded")
    return nil
}

// SetPivotNode sets the NodeID of the network's pivot node.
// Pivot node is just a specific node that should be treated
// differently then other nodes in test. SetPivotNode and
// PivotNodeID are just a convenient functions to set and
// retrieve it.
func (s *Simulation) SetPivotNode(id discover.NodeID) {
    s.mu.Lock()
    defer s.mu.Unlock()
    s.pivotNodeID = &id
}

// PivotNodeID returns NodeID of the pivot node set by
// Simulation.SetPivotNode method.
func (s *Simulation) PivotNodeID() (id *discover.NodeID) {
    s.mu.Lock()
    defer s.mu.Unlock()
    return s.pivotNodeID
}

// StartNode starts a node by NodeID.
func (s *Simulation) StartNode(id discover.NodeID) (err error) {
    return s.Net.Start(id)
}

// StartRandomNode starts a random node.
func (s *Simulation) StartRandomNode() (id discover.NodeID, err error) {
    n := s.randomDownNode()
    if n == nil {
        return id, ErrNodeNotFound
    }
    return n.ID, s.Net.Start(n.ID)
}

// StartRandomNodes starts random nodes.
func (s *Simulation) StartRandomNodes(count int) (ids []discover.NodeID, err error) {
    ids = make([]discover.NodeID, 0, count)
    downIDs := s.DownNodeIDs()
    for i := 0; i < count; i++ {
        n := s.randomNode(downIDs, ids...)
        if n == nil {
            return nil, ErrNodeNotFound
        }
        err = s.Net.Start(n.ID)
        if err != nil {
            return nil, err
        }
        ids = append(ids, n.ID)
    }
    return ids, nil
}

// StopNode stops a node by NodeID.
func (s *Simulation) StopNode(id discover.NodeID) (err error) {
    return s.Net.Stop(id)
}

// StopRandomNode stops a random node.
func (s *Simulation) StopRandomNode() (id discover.NodeID, err error) {
    n := s.RandomUpNode()
    if n == nil {
        return id, ErrNodeNotFound
    }
    return n.ID, s.Net.Stop(n.ID)
}

// StopRandomNodes stops random nodes.
func (s *Simulation) StopRandomNodes(count int) (ids []discover.NodeID, err error) {
    ids = make([]discover.NodeID, 0, count)
    upIDs := s.UpNodeIDs()
    for i := 0; i < count; i++ {
        n := s.randomNode(upIDs, ids...)
        if n == nil {
            return nil, ErrNodeNotFound
        }
        err = s.Net.Stop(n.ID)
        if err != nil {
            return nil, err
        }
        ids = append(ids, n.ID)
    }
    return ids, nil
}

// seed the random generator for Simulation.randomNode.
func init() {
    rand.Seed(time.Now().UnixNano())
}

// RandomUpNode returns a random SimNode that is up.
// Arguments are NodeIDs for nodes that should not be returned.
func (s *Simulation) RandomUpNode(exclude ...discover.NodeID) *adapters.SimNode {
    return s.randomNode(s.UpNodeIDs(), exclude...)
}

// randomDownNode returns a random SimNode that is not up.
func (s *Simulation) randomDownNode(exclude ...discover.NodeID) *adapters.SimNode {
    return s.randomNode(s.DownNodeIDs(), exclude...)
}

// randomNode returns a random SimNode from the slice of NodeIDs.
func (s *Simulation) randomNode(ids []discover.NodeID, exclude ...discover.NodeID) *adapters.SimNode {
    for _, e := range exclude {
        var i int
        for _, id := range ids {
            if id == e {
                ids = append(ids[:i], ids[i+1:]...)
            } else {
                i++
            }
        }
    }
    l := len(ids)
    if l == 0 {
        return nil
    }
    n := s.Net.GetNode(ids[rand.Intn(l)])
    node, _ := n.Node.(*adapters.SimNode)
    return node
}