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forked from cerc-io/plugeth
plugeth/eth/discovery.go
Péter Szilágyi 017831dd5b
core, eth: split eth package, implement snap protocol ()
This commit splits the eth package, separating the handling of eth and snap protocols. It also includes the capability to run snap sync (https://github.com/ethereum/devp2p/blob/master/caps/snap.md) , but does not enable it by default. 

Co-authored-by: Marius van der Wijden <m.vanderwijden@live.de>
Co-authored-by: Martin Holst Swende <martin@swende.se>
2020-12-14 10:27:15 +01:00

75 lines
2.3 KiB
Go

// Copyright 2019 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 eth
import (
"github.com/ethereum/go-ethereum/core"
"github.com/ethereum/go-ethereum/core/forkid"
"github.com/ethereum/go-ethereum/p2p/dnsdisc"
"github.com/ethereum/go-ethereum/p2p/enode"
"github.com/ethereum/go-ethereum/rlp"
)
// ethEntry is the "eth" ENR entry which advertises eth protocol
// on the discovery network.
type ethEntry struct {
ForkID forkid.ID // Fork identifier per EIP-2124
// Ignore additional fields (for forward compatibility).
Rest []rlp.RawValue `rlp:"tail"`
}
// ENRKey implements enr.Entry.
func (e ethEntry) ENRKey() string {
return "eth"
}
// startEthEntryUpdate starts the ENR updater loop.
func (eth *Ethereum) startEthEntryUpdate(ln *enode.LocalNode) {
var newHead = make(chan core.ChainHeadEvent, 10)
sub := eth.blockchain.SubscribeChainHeadEvent(newHead)
go func() {
defer sub.Unsubscribe()
for {
select {
case <-newHead:
ln.Set(eth.currentEthEntry())
case <-sub.Err():
// Would be nice to sync with eth.Stop, but there is no
// good way to do that.
return
}
}
}()
}
func (eth *Ethereum) currentEthEntry() *ethEntry {
return &ethEntry{ForkID: forkid.NewID(eth.blockchain.Config(), eth.blockchain.Genesis().Hash(),
eth.blockchain.CurrentHeader().Number.Uint64())}
}
// setupDiscovery creates the node discovery source for the `eth` and `snap`
// protocols.
func setupDiscovery(urls []string) (enode.Iterator, error) {
if len(urls) == 0 {
return nil, nil
}
client := dnsdisc.NewClient(dnsdisc.Config{})
return client.NewIterator(urls...)
}