go-ethereum/consensus/merger.go

111 lines
3.2 KiB
Go

// Copyright 2021 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 consensus
import (
"fmt"
"sync"
"github.com/ethereum/go-ethereum/core/rawdb"
"github.com/ethereum/go-ethereum/ethdb"
"github.com/ethereum/go-ethereum/log"
"github.com/ethereum/go-ethereum/rlp"
)
// transitionStatus describes the status of eth1/2 transition. This switch
// between modes is a one-way action which is triggered by corresponding
// consensus-layer message.
type transitionStatus struct {
LeftPoW bool // The flag is set when the first NewHead message received
EnteredPoS bool // The flag is set when the first FinalisedBlock message received
}
// Merger is an internal help structure used to track the eth1/2 transition status.
// It's a common structure can be used in both full node and light client.
type Merger struct {
db ethdb.KeyValueStore
status transitionStatus
mu sync.RWMutex
}
// NewMerger creates a new Merger which stores its transition status in the provided db.
func NewMerger(db ethdb.KeyValueStore) *Merger {
var status transitionStatus
blob := rawdb.ReadTransitionStatus(db)
if len(blob) != 0 {
if err := rlp.DecodeBytes(blob, &status); err != nil {
log.Crit("Failed to decode the transition status", "err", err)
}
}
return &Merger{
db: db,
status: status,
}
}
// ReachTTD is called whenever the first NewHead message received
// from the consensus-layer.
func (m *Merger) ReachTTD() {
m.mu.Lock()
defer m.mu.Unlock()
if m.status.LeftPoW {
return
}
m.status = transitionStatus{LeftPoW: true}
blob, err := rlp.EncodeToBytes(m.status)
if err != nil {
panic(fmt.Sprintf("Failed to encode the transition status: %v", err))
}
rawdb.WriteTransitionStatus(m.db, blob)
log.Info("Left PoW stage")
}
// FinalizePoS is called whenever the first FinalisedBlock message received
// from the consensus-layer.
func (m *Merger) FinalizePoS() {
m.mu.Lock()
defer m.mu.Unlock()
if m.status.EnteredPoS {
return
}
m.status = transitionStatus{LeftPoW: true, EnteredPoS: true}
blob, err := rlp.EncodeToBytes(m.status)
if err != nil {
panic(fmt.Sprintf("Failed to encode the transition status: %v", err))
}
rawdb.WriteTransitionStatus(m.db, blob)
log.Info("Entered PoS stage")
}
// TDDReached reports whether the chain has left the PoW stage.
func (m *Merger) TDDReached() bool {
m.mu.RLock()
defer m.mu.RUnlock()
return m.status.LeftPoW
}
// PoSFinalized reports whether the chain has entered the PoS stage.
func (m *Merger) PoSFinalized() bool {
m.mu.RLock()
defer m.mu.RUnlock()
return m.status.EnteredPoS
}