path: root/simulation/node.go

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

package simulation

import (
    "encoding/json"
    "fmt"
    "time"

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

type infoStatus string

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

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"`
}

// node represents a node in DexCon.
type node struct {
    app       core.Application
    db        blockdb.BlockDatabase
    gov       *test.Governance
    netModule *test.Network
    ID        types.NodeID
    prvKey    crypto.PrivateKey
    consensus *core.Consensus
}

// newNode returns a new empty node.
func newNode(
    prvKey crypto.PrivateKey,
    config config.Config) *node {
    pubKey := prvKey.PublicKey()
    netModule := test.NewNetwork(
        pubKey,
        &test.NormalLatencyModel{
            Mean:  config.Networking.Mean,
            Sigma: config.Networking.Sigma,
        },
        test.NewDefaultMarshaller(&jsonMarshaller{}),
        test.NetworkConfig{
            Type:       config.Networking.Type,
            PeerServer: config.Networking.PeerServer,
            PeerPort:   peerPort,
        })
    id := types.NewNodeID(pubKey)
    db, err := blockdb.NewMemBackedBlockDB(id.String() + ".blockdb")
    if err != nil {
        panic(err)
    }
    // Sync config to state in governance.
    cConfig := config.Node.Consensus
    gov, err := test.NewGovernance(
        test.NewState(
            []crypto.PublicKey{pubKey},
            time.Millisecond,
            &common.NullLogger{},
            true),
        core.ConfigRoundShift)
    if err != nil {
        panic(err)
    }
    gov.State().RequestChange(test.StateChangeK, cConfig.K)
    gov.State().RequestChange(test.StateChangePhiRatio, cConfig.PhiRatio)
    gov.State().RequestChange(test.StateChangeNumChains, cConfig.ChainNum)
    gov.State().RequestChange(
        test.StateChangeNotarySetSize, cConfig.NotarySetSize)
    gov.State().RequestChange(test.StateChangeDKGSetSize, cConfig.DKGSetSize)
    gov.State().RequestChange(test.StateChangeLambdaBA, time.Duration(
        cConfig.LambdaBA)*time.Millisecond)
    gov.State().RequestChange(test.StateChangeLambdaDKG, time.Duration(
        cConfig.LambdaDKG)*time.Millisecond)
    gov.State().RequestChange(test.StateChangeRoundInterval, time.Duration(
        cConfig.RoundInterval)*time.Millisecond)
    gov.State().RequestChange(
        test.StateChangeMinBlockInterval,
        3*time.Duration(cConfig.LambdaBA)*time.Millisecond)
    gov.State().ProposeCRS(0, crypto.Keccak256Hash([]byte(cConfig.GenesisCRS)))
    return &node{
        ID:        id,
        prvKey:    prvKey,
        app:       newSimApp(id, netModule, gov.State()),
        gov:       gov,
        db:        db,
        netModule: netModule,
    }
}

// GetID returns the ID of node.
func (n *node) GetID() types.NodeID {
    return n.ID
}

// run starts the node.
func (n *node) run(
    serverEndpoint interface{}, dMoment time.Time, logger common.Logger) {
    // Run network.
    if err := n.netModule.Setup(serverEndpoint); err != nil {
        panic(err)
    }
    msgChannel := n.netModule.ReceiveChanForNode()
    peers := n.netModule.Peers()
    go n.netModule.Run()
    // Run consensus.
    hashes := make(common.Hashes, 0, len(peers))
    for _, pubKey := range peers {
        nID := types.NewNodeID(pubKey)
        n.gov.State().RequestChange(test.StateAddNode, pubKey)
        hashes = append(hashes, nID.Hash)
    }
    // This notification is implictly called in full node.
    n.gov.NotifyRoundHeight(0, 0)
    // Setup of governance is ready, can be switched to remote mode.
    n.gov.SwitchToRemoteMode(n.netModule)
    // Setup Consensus.
    n.consensus = core.NewConsensus(
        dMoment,
        n.app,
        n.gov,
        n.db,
        n.netModule,
        n.prvKey,
        logger)
    go n.consensus.Run()

    // Blocks forever.
MainLoop:
    for {
        msg := <-msgChannel
        switch val := msg.(type) {
        case infoStatus:
            if val == statusShutdown {
                break MainLoop
            }
        default:
            panic(fmt.Errorf("unexpected message from server: %v", val))
        }
    }
    // Cleanup.
    n.consensus.Stop()
    if err := n.db.Close(); err != nil {
        fmt.Println(err)
    }
    n.netModule.Report(&message{
        Type: shutdownAck,
    })
    // TODO(mission): once we have a way to know if consensus is stopped, stop
    //                the network module.
    return
}