path: root/simulation/network.go

// Copyright 2018 The dexon-consensus-core Authors
// This file is part of the dexon-consensus-core library.
//
// The dexon-consensus-core 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 dexon-consensus-core 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 dexon-consensus-core library. If not, see
// <http://www.gnu.org/licenses/>.

package simulation

import (
    "context"
    "encoding/json"
    "fmt"
    "net"
    "strconv"
    "time"

    "github.com/dexon-foundation/dexon-consensus-core/common"
    "github.com/dexon-foundation/dexon-consensus-core/core/crypto"
    "github.com/dexon-foundation/dexon-consensus-core/core/test"
    "github.com/dexon-foundation/dexon-consensus-core/core/types"
    typesDKG "github.com/dexon-foundation/dexon-consensus-core/core/types/dkg"
    "github.com/dexon-foundation/dexon-consensus-core/simulation/config"
)

type messageType string

const (
    shutdownAck    messageType = "shutdownAck"
    blockTimestamp messageType = "blockTimestamps"
)

// message is a struct for peer sending message to server.
type message struct {
    Type    messageType     `json:"type"`
    Payload json.RawMessage `json:"payload"`
}

type timestampEvent string

const (
    blockSeen        timestampEvent = "blockSeen"
    timestampConfirm timestampEvent = "timestampConfirm"
    timestampAck     timestampEvent = "timestampAck"
)

// TimestampMessage is a struct for peer sending consensus timestamp information
// to server.
type timestampMessage struct {
    BlockHash common.Hash    `json:"hash"`
    Event     timestampEvent `json:"event"`
    Timestamp time.Time      `json:"timestamp"`
}

type infoStatus string

const (
    statusInit     infoStatus = "init"
    statusNormal   infoStatus = "normal"
    statusShutdown infoStatus = "shutdown"
)

// infoMessage is a struct used by peerServer's /info.
type infoMessage struct {
    Status infoStatus              `json:"status"`
    Peers  map[types.NodeID]string `json:"peers"`
}

// network implements core.Network interface and other methods for simulation
// based on test.TransportClient.
type network struct {
    cfg            config.Networking
    ctx            context.Context
    ctxCancel      context.CancelFunc
    trans          test.TransportClient
    fromTransport  <-chan *test.TransportEnvelope
    toConsensus    chan interface{}
    toNode         chan interface{}
    sentRandomness map[common.Hash]struct{}
    sentAgreement  map[common.Hash]struct{}
    blockCache     map[common.Hash]*types.Block
}

// newNetwork setup network stuffs for nodes, which provides an
// implementation of core.Network based on test.TransportClient.
func newNetwork(pubKey crypto.PublicKey, cfg config.Networking) (n *network) {
    // Construct latency model.
    latency := &test.NormalLatencyModel{
        Mean:  cfg.Mean,
        Sigma: cfg.Sigma,
    }
    // Construct basic network instance.
    n = &network{
        cfg:            cfg,
        toNode:         make(chan interface{}, 1000),
        toConsensus:    make(chan interface{}, 1000),
        sentRandomness: make(map[common.Hash]struct{}),
        sentAgreement:  make(map[common.Hash]struct{}),
        blockCache:     make(map[common.Hash]*types.Block),
    }
    n.ctx, n.ctxCancel = context.WithCancel(context.Background())
    // Construct transport layer.
    switch cfg.Type {
    case config.NetworkTypeTCPLocal:
        n.trans = test.NewTCPTransportClient(
            pubKey, latency, &jsonMarshaller{}, true)
    case config.NetworkTypeTCP:
        n.trans = test.NewTCPTransportClient(
            pubKey, latency, &jsonMarshaller{}, false)
    case config.NetworkTypeFake:
        n.trans = test.NewFakeTransportClient(pubKey, latency)
    default:
        panic(fmt.Errorf("unknown network type: %v", cfg.Type))
    }
    return
}

// PullBlock implements core.Network interface.
func (n *network) PullBlocks(hashes common.Hashes) {
    go func() {
        for _, hash := range hashes {
            // TODO(jimmy-dexon): request block from network instead of cache.
            if block, exist := n.blockCache[hash]; exist {
                n.toConsensus <- block
                continue
            }
            panic(fmt.Errorf("unknown block %s requested", hash))
        }
    }()
}

// BroadcastVote implements core.Network interface.
func (n *network) BroadcastVote(vote *types.Vote) {
    if err := n.trans.Broadcast(vote); err != nil {
        panic(err)
    }
}

// BroadcastBlock implements core.Network interface.
func (n *network) BroadcastBlock(block *types.Block) {
    if err := n.trans.Broadcast(block); err != nil {
        panic(err)
    }
}

// BroadcastAgreementResult implements core.Network interface.
func (n *network) BroadcastAgreementResult(
    randRequest *types.AgreementResult) {
    if _, exist := n.sentAgreement[randRequest.BlockHash]; exist {
        return
    }
    if len(n.sentAgreement) > 1000 {
        // Randomly drop one entry.
        for k := range n.sentAgreement {
            delete(n.sentAgreement, k)
            break
        }
    }
    n.sentAgreement[randRequest.BlockHash] = struct{}{}
    if err := n.trans.Broadcast(randRequest); err != nil {
        panic(err)
    }
}

// BroadcastRandomnessResult implements core.Network interface.
func (n *network) BroadcastRandomnessResult(
    randResult *types.BlockRandomnessResult) {
    if _, exist := n.sentRandomness[randResult.BlockHash]; exist {
        return
    }
    if len(n.sentRandomness) > 1000 {
        // Randomly drop one entry.
        for k := range n.sentRandomness {
            delete(n.sentRandomness, k)
            break
        }
    }
    n.sentRandomness[randResult.BlockHash] = struct{}{}
    if err := n.trans.Broadcast(randResult); err != nil {
        panic(err)
    }
}

// broadcast message to all other nodes in the network.
func (n *network) broadcast(message interface{}) {
    if err := n.trans.Broadcast(message); err != nil {
        panic(err)
    }
}

// SendDKGPrivateShare implements core.Network interface.
func (n *network) SendDKGPrivateShare(
    recv crypto.PublicKey, prvShare *typesDKG.PrivateShare) {
    if err := n.trans.Send(types.NewNodeID(recv), prvShare); err != nil {
        panic(err)
    }
}

// BroadcastDKGPrivateShare implements core.Network interface.
func (n *network) BroadcastDKGPrivateShare(
    prvShare *typesDKG.PrivateShare) {
    if err := n.trans.Broadcast(prvShare); err != nil {
        panic(err)
    }
}

// BroadcastDKGPartialSignature implements core.Network interface.
func (n *network) BroadcastDKGPartialSignature(
    psig *typesDKG.PartialSignature) {
    if err := n.trans.Broadcast(psig); err != nil {
        panic(err)
    }
}

// ReceiveChan implements core.Network interface.
func (n *network) ReceiveChan() <-chan interface{} {
    return n.toConsensus
}

// receiveChanForNode returns a channel for nodes' specific
// messages.
func (n *network) receiveChanForNode() <-chan interface{} {
    return n.toNode
}

// setup transport layer.
func (n *network) setup(serverEndpoint interface{}) (err error) {
    // Join the p2p network.
    switch n.cfg.Type {
    case config.NetworkTypeTCP, config.NetworkTypeTCPLocal:
        addr := net.JoinHostPort(n.cfg.PeerServer, strconv.Itoa(peerPort))
        n.fromTransport, err = n.trans.Join(addr)
    case config.NetworkTypeFake:
        n.fromTransport, err = n.trans.Join(serverEndpoint)
    default:
        err = fmt.Errorf("unknown network type: %v", n.cfg.Type)
    }
    if err != nil {
        return
    }
    return
}

// run the main loop.
func (n *network) run() {
    // The dispatcher declararion:
    // to consensus or node, that's the question.
    disp := func(e *test.TransportEnvelope) {
        if block, ok := e.Msg.(*types.Block); ok {
            if len(n.blockCache) > 500 {
                for k := range n.blockCache {
                    delete(n.blockCache, k)
                    break
                }
            }
            n.blockCache[block.Hash] = block
        }
        switch e.Msg.(type) {
        case *types.Block, *types.Vote,
            *types.AgreementResult, *types.BlockRandomnessResult,
            *typesDKG.PrivateShare, *typesDKG.PartialSignature:
            n.toConsensus <- e.Msg
        default:
            n.toNode <- e.Msg
        }
    }
MainLoop:
    for {
        select {
        case <-n.ctx.Done():
            break MainLoop
        default:
        }
        select {
        case <-n.ctx.Done():
            break MainLoop
        case e, ok := <-n.fromTransport:
            if !ok {
                break MainLoop
            }
            disp(e)
        }
    }
}

// Close stop the network.
func (n *network) Close() (err error) {
    n.ctxCancel()
    close(n.toConsensus)
    n.toConsensus = nil
    close(n.toNode)
    n.toNode = nil
    if err = n.trans.Close(); err != nil {
        return
    }
    return
}

// report exports 'Report' method of test.TransportClient.
func (n *network) report(msg interface{}) error {
    return n.trans.Report(msg)
}

// peers exports 'Peers' method of test.Transport.
func (n *network) peers() []crypto.PublicKey {
    return n.trans.Peers()
}