eth, eth/downloader: moved peer selection to protocol handler

pull/805/head
obscuren 10 years ago
parent 9caf880ff9
commit b86e7526e1
  1. 91
      eth/downloader/downloader.go
  2. 79
      eth/downloader/synchronous.go
  3. 65
      eth/handler.go
  4. 18
      eth/peer.go

@ -89,7 +89,7 @@ func New(hasBlock hashCheckFn, insertChain chainInsertFn, currentTd currentTdFn)
blockCh: make(chan blockPack, 1),
quit: make(chan struct{}),
}
go downloader.peerHandler()
//go downloader.peerHandler()
go downloader.update()
return downloader
@ -110,7 +110,6 @@ func (d *Downloader) RegisterPeer(id string, td *big.Int, hash common.Hash, getH
// add peer to our peer set
d.peers[id] = peer
// broadcast new peer
d.newPeerCh <- peer
return nil
}
@ -125,72 +124,78 @@ func (d *Downloader) UnregisterPeer(id string) {
delete(d.peers, id)
}
func (d *Downloader) peerHandler() {
// itimer is used to determine when to start ignoring `minDesiredPeerCount`
itimer := time.NewTimer(peerCountTimeout)
func (d *Downloader) update() {
out:
for {
select {
case <-d.newPeerCh:
// Meet the `minDesiredPeerCount` before we select our best peer
if len(d.peers) < minDesiredPeerCount {
case sync := <-d.syncCh:
var peer *peer = sync.peer
err := d.getFromPeer(peer, sync.hash, sync.ignoreInitial)
if err != nil {
glog.V(logger.Detail).Infoln(err)
break
}
itimer.Stop()
d.selectPeer(d.peers.bestPeer())
case <-itimer.C:
// The timer will make sure that the downloader keeps an active state
// in which it attempts to always check the network for highest td peers
// Either select the peer or restart the timer if no peers could
// be selected.
if peer := d.peers.bestPeer(); peer != nil {
d.selectPeer(d.peers.bestPeer())
} else {
itimer.Reset(5 * time.Second)
}
d.process()
case <-d.quit:
break out
}
}
}
func (d *Downloader) selectPeer(p *peer) {
// SynchroniseWithPeer will select the peer and use it for synchronising. If an empty string is given
// it will use the best peer possible and synchronise if it's TD is higher than our own. If any of the
// checks fail an error will be returned. This method is synchronous
func (d *Downloader) Synchronise(id string, hash common.Hash) (types.Blocks, error) {
// Make sure it's doing neither. Once done we can restart the
// downloading process if the TD is higher. For now just get on
// with whatever is going on. This prevents unecessary switching.
if d.isBusy() {
return
return nil, errBusy
}
// selected peer must be better than our own
// XXX we also check the peer's recent hash to make sure we
// don't have it. Some peers report (i think) incorrect TD.
if p.td.Cmp(d.currentTd()) <= 0 || d.hasBlock(p.recentHash) {
return
// Fetch the peer using the id or throw an error if the peer couldn't be found
p := d.peers[id]
if p == nil {
return nil, errUnknownPeer
}
glog.V(logger.Detail).Infoln("New peer with highest TD =", p.td)
d.syncCh <- syncPack{p, p.recentHash, false}
// Get the hash from the peer and initiate the downloading progress.
err := d.getFromPeer(p, hash, false)
if err != nil {
return nil, err
}
return d.queue.blocks, nil
}
func (d *Downloader) update() {
out:
for {
select {
case sync := <-d.syncCh:
var peer *peer = sync.peer
err := d.getFromPeer(peer, sync.hash, sync.ignoreInitial)
if err != nil {
glog.V(logger.Detail).Infoln(err)
break
func (d *Downloader) getFromPeer(p *peer, hash common.Hash, ignoreInitial bool) error {
d.activePeer = p.id
glog.V(logger.Detail).Infoln("Synchronising with the network using:", p.id)
// Start the fetcher. This will block the update entirely
// interupts need to be send to the appropriate channels
// respectively.
if err := d.startFetchingHashes(p, hash, ignoreInitial); err != nil {
// handle error
glog.V(logger.Debug).Infoln("Error fetching hashes:", err)
// XXX Reset
return err
}
d.process()
case <-d.quit:
break out
}
// Start fetching blocks in paralel. The strategy is simple
// take any available peers, seserve a chunk for each peer available,
// let the peer deliver the chunkn and periodically check if a peer
// has timedout. When done downloading, process blocks.
if err := d.startFetchingBlocks(p); err != nil {
glog.V(logger.Debug).Infoln("Error downloading blocks:", err)
// XXX reset
return err
}
glog.V(logger.Detail).Infoln("Sync completed")
return nil
}
// XXX Make synchronous

@ -1,79 +0,0 @@
package downloader
import (
"github.com/ethereum/go-ethereum/common"
"github.com/ethereum/go-ethereum/core/types"
"github.com/ethereum/go-ethereum/logger"
"github.com/ethereum/go-ethereum/logger/glog"
)
// THIS IS PENDING AND TO DO CHANGES FOR MAKING THE DOWNLOADER SYNCHRONOUS
// SynchroniseWithPeer will select the peer and use it for synchronising. If an empty string is given
// it will use the best peer possible and synchronise if it's TD is higher than our own. If any of the
// checks fail an error will be returned. This method is synchronous
func (d *Downloader) SynchroniseWithPeer(id string) (types.Blocks, error) {
// Check if we're busy
if d.isBusy() {
return nil, errBusy
}
// Attempt to select a peer. This can either be nothing, which returns, best peer
// or selected peer. If no peer could be found an error will be returned
var p *peer
if len(id) == 0 {
p = d.peers[id]
if p == nil {
return nil, errUnknownPeer
}
} else {
p = d.peers.bestPeer()
}
// Make sure our td is lower than the peer's td
if p.td.Cmp(d.currentTd()) <= 0 || d.hasBlock(p.recentHash) {
return nil, errLowTd
}
// Get the hash from the peer and initiate the downloading progress.
err := d.getFromPeer(p, p.recentHash, false)
if err != nil {
return nil, err
}
return d.queue.blocks, nil
}
// Synchronise will synchronise using the best peer.
func (d *Downloader) Synchronise() (types.Blocks, error) {
return d.SynchroniseWithPeer("")
}
func (d *Downloader) getFromPeer(p *peer, hash common.Hash, ignoreInitial bool) error {
d.activePeer = p.id
glog.V(logger.Detail).Infoln("Synchronising with the network using:", p.id)
// Start the fetcher. This will block the update entirely
// interupts need to be send to the appropriate channels
// respectively.
if err := d.startFetchingHashes(p, hash, ignoreInitial); err != nil {
// handle error
glog.V(logger.Debug).Infoln("Error fetching hashes:", err)
// XXX Reset
return err
}
// Start fetching blocks in paralel. The strategy is simple
// take any available peers, seserve a chunk for each peer available,
// let the peer deliver the chunkn and periodically check if a peer
// has timedout. When done downloading, process blocks.
if err := d.startFetchingBlocks(p); err != nil {
glog.V(logger.Debug).Infoln("Error downloading blocks:", err)
// XXX reset
return err
}
glog.V(logger.Detail).Infoln("Sync completed")
return nil
}

@ -39,6 +39,7 @@ import (
"math"
"math/big"
"sync"
"time"
"github.com/ethereum/go-ethereum/common"
"github.com/ethereum/go-ethereum/core"
@ -51,6 +52,11 @@ import (
"github.com/ethereum/go-ethereum/rlp"
)
const (
peerCountTimeout = 12 * time.Second // Amount of time it takes for the peer handler to ignore minDesiredPeerCount
minDesiredPeerCount = 5 // Amount of peers desired to start syncing
)
func errResp(code errCode, format string, v ...interface{}) error {
return fmt.Errorf("%v - %v", code, fmt.Sprintf(format, v...))
}
@ -82,6 +88,9 @@ type ProtocolManager struct {
eventMux *event.TypeMux
txSub event.Subscription
minedBlockSub event.Subscription
newPeerCh chan *peer
quit chan struct{}
}
// NewProtocolManager returns a new ethereum sub protocol manager. The Ethereum sub protocol manages peers capable
@ -93,7 +102,10 @@ func NewProtocolManager(protocolVersion, networkId int, mux *event.TypeMux, txpo
chainman: chainman,
downloader: downloader,
peers: make(map[string]*peer),
newPeerCh: make(chan *peer, 1),
quit: make(chan struct{}),
}
go manager.peerHandler()
manager.SubProtocol = p2p.Protocol{
Name: "eth",
@ -101,16 +113,61 @@ func NewProtocolManager(protocolVersion, networkId int, mux *event.TypeMux, txpo
Length: ProtocolLength,
Run: func(p *p2p.Peer, rw p2p.MsgReadWriter) error {
peer := manager.newPeer(protocolVersion, networkId, p, rw)
err := manager.handle(peer)
//glog.V(logger.Detail).Infof("[%s]: %v\n", peer.id, err)
return err
manager.newPeerCh <- peer
return manager.handle(peer)
},
}
return manager
}
func (pm *ProtocolManager) peerHandler() {
// itimer is used to determine when to start ignoring `minDesiredPeerCount`
itimer := time.NewTimer(peerCountTimeout)
out:
for {
select {
case <-pm.newPeerCh:
// Meet the `minDesiredPeerCount` before we select our best peer
if len(pm.peers) < minDesiredPeerCount {
break
}
itimer.Stop()
// Find the best peer
peer := getBestPeer(pm.peers)
if peer == nil {
glog.V(logger.Debug).Infoln("Sync attempt cancelled. No peers available")
return
}
go pm.synchronise(peer)
case <-itimer.C:
// The timer will make sure that the downloader keeps an active state
// in which it attempts to always check the network for highest td peers
// Either select the peer or restart the timer if no peers could
// be selected.
if peer := getBestPeer(pm.peers); peer != nil {
go pm.synchronise(peer)
} else {
itimer.Reset(5 * time.Second)
}
case <-pm.quit:
break out
}
}
}
func (pm *ProtocolManager) synchronise(peer *peer) {
// Get the hashes from the peer (synchronously)
_, err := pm.downloader.Synchronise(peer.id, peer.recentHash)
if err != nil {
// handle error
glog.V(logger.Debug).Infoln("error downloading:", err)
}
}
func (pm *ProtocolManager) Start() {
// broadcast transactions
pm.txSub = pm.eventMux.Subscribe(core.TxPreEvent{})
@ -141,7 +198,7 @@ func (pm *ProtocolManager) handle(p *peer) error {
pm.peers[p.id] = p
pm.pmu.Unlock()
pm.downloader.RegisterPeer(p.id, p.td, p.currentHash, p.requestHashes, p.requestBlocks)
pm.downloader.RegisterPeer(p.id, p.td, p.recentHash, p.requestHashes, p.requestBlocks)
defer func() {
pm.pmu.Lock()
defer pm.pmu.Unlock()

@ -25,6 +25,16 @@ type getBlockHashesMsgData struct {
Amount uint64
}
func getBestPeer(peers map[string]*peer) *peer {
var peer *peer
for _, cp := range peers {
if peer == nil || cp.td.Cmp(peer.td) > 0 {
peer = cp
}
}
return peer
}
type peer struct {
*p2p.Peer
@ -32,7 +42,7 @@ type peer struct {
protv, netid int
currentHash common.Hash
recentHash common.Hash
id string
td *big.Int
@ -43,14 +53,14 @@ type peer struct {
blockHashes *set.Set
}
func newPeer(protv, netid int, genesis, currentHash common.Hash, td *big.Int, p *p2p.Peer, rw p2p.MsgReadWriter) *peer {
func newPeer(protv, netid int, genesis, recentHash common.Hash, td *big.Int, p *p2p.Peer, rw p2p.MsgReadWriter) *peer {
id := p.ID()
return &peer{
Peer: p,
rw: rw,
genesis: genesis,
ourHash: currentHash,
ourHash: recentHash,
ourTd: td,
protv: protv,
netid: netid,
@ -145,7 +155,7 @@ func (p *peer) handleStatus() error {
// Set the total difficulty of the peer
p.td = status.TD
// set the best hash of the peer
p.currentHash = status.CurrentBlock
p.recentHash = status.CurrentBlock
return <-errc
}

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