path: root/simulation/node.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 (
    "fmt"
    "sort"
    "time"

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

// node represents a node in DexCon.
type node struct {
    app *simApp
    gov *simGovernance
    db  blockdb.BlockDatabase

    config    config.Node
    netModule *network

    ID        types.NodeID
    chainID   uint64
    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 := newNetwork(pubKey, config.Networking)
    id := types.NewNodeID(pubKey)
    db, err := blockdb.NewMemBackedBlockDB(
        id.String() + ".blockdb")
    if err != nil {
        panic(err)
    }
    gov := newSimGovernance(id, config.Node.Num, config.Node.Consensus)
    return &node{
        ID:        id,
        prvKey:    prvKey,
        config:    config.Node,
        app:       newSimApp(id, netModule),
        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) {
    // Run network.
    if err := n.netModule.setup(serverEndpoint); err != nil {
        panic(err)
    }
    msgChannel := n.netModule.receiveChanForNode()
    peers := n.netModule.peers()
    go n.netModule.run()
    n.gov.setNetwork(n.netModule)
    // Run consensus.
    hashes := make(common.Hashes, 0, len(peers))
    for _, pubKey := range peers {
        nID := types.NewNodeID(pubKey)
        n.gov.addNode(pubKey)
        hashes = append(hashes, nID.Hash)
    }
    sort.Sort(hashes)
    for i, hash := range hashes {
        if hash == n.ID.Hash {
            n.chainID = uint64(i)
            break
        }
    }
    n.consensus = core.NewConsensus(
        dMoment, n.app, n.gov, n.db, n.netModule, n.prvKey)
    go n.consensus.Run()

    // Blocks forever.
MainLoop:
    for {
        msg := <-msgChannel
        switch val := msg.(type) {
        case infoStatus:
            if val == statusShutdown {
                break MainLoop
            }
        case *types.DKGComplaint:
            n.gov.AddDKGComplaint(val.Round, val)
        case *types.DKGMasterPublicKey:
            n.gov.AddDKGMasterPublicKey(val.Round, val)
        case *types.DKGFinalize:
            n.gov.AddDKGFinalize(val.Round, val)
        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
}