Fantom-foundation/go-lachesis

package poset

import (
    "github.com/ethereum/go-ethereum/common"

    "github.com/Fantom-foundation/go-lachesis/hash"
    "github.com/Fantom-foundation/go-lachesis/inter"
    "github.com/Fantom-foundation/go-lachesis/inter/idx"
    "github.com/Fantom-foundation/go-lachesis/poset/election"
    "github.com/Fantom-foundation/go-lachesis/vector"
)

// Checkpoint is for persistent storing.
type Checkpoint struct {
    // fields can change only after a frame is decided
    LastDecidedFrame idx.Frame
    LastBlockN       idx.Block
    LastAtropos      hash.Event
    AppHash          common.Hash
}

/*
 * Poset's methods:
 */

// State saves Checkpoint.
func (p *Poset) saveCheckpoint() {
    p.store.SetCheckpoint(p.Checkpoint)
}

// Bootstrap restores poset's state from store.
func (p *Poset) Bootstrap(callback inter.ConsensusCallbacks) {
    if p.Checkpoint != nil {
        return
    }
    // block handler must be set before p.handleElection
    p.callback = callback

    // restore Checkpoint
    p.Checkpoint = p.store.GetCheckpoint()
    if p.Checkpoint == nil {
        p.Log.Crit("Apply genesis for store first")
    }

    // restore current epoch
    p.loadEpoch()
    p.vecClock = vector.NewIndex(p.dag.VectorClockConfig, p.Validators, p.store.epochTable.VectorIndex, func(id hash.Event) *inter.EventHeaderData {
        return p.input.GetEventHeader(p.EpochN, id)
    })
    p.election = election.New(p.Validators, p.LastDecidedFrame+1, p.vecClock.ForklessCause, p.store.GetFrameRoots)

    // events reprocessing
    p.handleElection(nil)
}