123 lines
		
	
	
		
			3.8 KiB
		
	
	
	
		
			Go
		
	
	
	
	
	
			
		
		
	
	
			123 lines
		
	
	
		
			3.8 KiB
		
	
	
	
		
			Go
		
	
	
	
	
	
package eth
 | 
						|
 | 
						|
import (
 | 
						|
	"math"
 | 
						|
	"sync/atomic"
 | 
						|
	"time"
 | 
						|
 | 
						|
	"github.com/ethereum/go-ethereum/core/types"
 | 
						|
	"github.com/ethereum/go-ethereum/eth/downloader"
 | 
						|
	"github.com/ethereum/go-ethereum/logger"
 | 
						|
	"github.com/ethereum/go-ethereum/logger/glog"
 | 
						|
)
 | 
						|
 | 
						|
// update periodically tries to synchronise with the network, both downloading
 | 
						|
// hashes and blocks as well as retrieving cached ones.
 | 
						|
func (pm *ProtocolManager) update() {
 | 
						|
	forceSync := time.Tick(forceSyncCycle)
 | 
						|
	blockProc := time.Tick(blockProcCycle)
 | 
						|
	blockProcPend := int32(0)
 | 
						|
 | 
						|
	for {
 | 
						|
		select {
 | 
						|
		case <-pm.newPeerCh:
 | 
						|
			// Make sure we have peers to select from, then sync
 | 
						|
			if pm.peers.Len() < minDesiredPeerCount {
 | 
						|
				break
 | 
						|
			}
 | 
						|
			go pm.synchronise(pm.peers.BestPeer())
 | 
						|
 | 
						|
		case <-forceSync:
 | 
						|
			// Force a sync even if not enough peers are present
 | 
						|
			go pm.synchronise(pm.peers.BestPeer())
 | 
						|
 | 
						|
		case <-blockProc:
 | 
						|
			// Try to pull some blocks from the downloaded
 | 
						|
			if atomic.CompareAndSwapInt32(&blockProcPend, 0, 1) {
 | 
						|
				go func() {
 | 
						|
					pm.processBlocks()
 | 
						|
					atomic.StoreInt32(&blockProcPend, 0)
 | 
						|
				}()
 | 
						|
			}
 | 
						|
 | 
						|
		case <-pm.quitSync:
 | 
						|
			return
 | 
						|
		}
 | 
						|
	}
 | 
						|
}
 | 
						|
 | 
						|
// processBlocks retrieves downloaded blocks from the download cache and tries
 | 
						|
// to construct the local block chain with it. Note, since the block retrieval
 | 
						|
// order matters, access to this function *must* be synchronized/serialized.
 | 
						|
func (pm *ProtocolManager) processBlocks() error {
 | 
						|
	pm.wg.Add(1)
 | 
						|
	defer pm.wg.Done()
 | 
						|
 | 
						|
	// Short circuit if no blocks are available for insertion
 | 
						|
	blocks := pm.downloader.TakeBlocks()
 | 
						|
	if len(blocks) == 0 {
 | 
						|
		return nil
 | 
						|
	}
 | 
						|
	glog.V(logger.Debug).Infof("Inserting chain with %d blocks (#%v - #%v)\n", len(blocks), blocks[0].RawBlock.Number(), blocks[len(blocks)-1].RawBlock.Number())
 | 
						|
 | 
						|
	for len(blocks) != 0 && !pm.quit {
 | 
						|
		// Retrieve the first batch of blocks to insert
 | 
						|
		max := int(math.Min(float64(len(blocks)), float64(blockProcAmount)))
 | 
						|
		raw := make(types.Blocks, 0, max)
 | 
						|
		for _, block := range blocks[:max] {
 | 
						|
			raw = append(raw, block.RawBlock)
 | 
						|
		}
 | 
						|
		// Try to inset the blocks, drop the originating peer if there's an error
 | 
						|
		index, err := pm.chainman.InsertChain(raw)
 | 
						|
		if err != nil {
 | 
						|
			glog.V(logger.Debug).Infoln("Downloaded block import failed:", err)
 | 
						|
			pm.removePeer(blocks[index].OriginPeer)
 | 
						|
			pm.downloader.Cancel()
 | 
						|
			return err
 | 
						|
		}
 | 
						|
		blocks = blocks[max:]
 | 
						|
	}
 | 
						|
	return nil
 | 
						|
}
 | 
						|
 | 
						|
// synchronise tries to sync up our local block chain with a remote peer, both
 | 
						|
// adding various sanity checks as well as wrapping it with various log entries.
 | 
						|
func (pm *ProtocolManager) synchronise(peer *peer) {
 | 
						|
	// Short circuit if no peers are available
 | 
						|
	if peer == nil {
 | 
						|
		return
 | 
						|
	}
 | 
						|
	// Make sure the peer's TD is higher than our own. If not drop.
 | 
						|
	if peer.td.Cmp(pm.chainman.Td()) <= 0 {
 | 
						|
		return
 | 
						|
	}
 | 
						|
	// FIXME if we have the hash in our chain and the TD of the peer is
 | 
						|
	// much higher than ours, something is wrong with us or the peer.
 | 
						|
	// Check if the hash is on our own chain
 | 
						|
	if pm.chainman.HasBlock(peer.recentHash) {
 | 
						|
		glog.V(logger.Debug).Infoln("Synchronisation canceled: head already known")
 | 
						|
		return
 | 
						|
	}
 | 
						|
	// Get the hashes from the peer (synchronously)
 | 
						|
	glog.V(logger.Debug).Infof("Attempting synchronisation: %v, 0x%x", peer.id, peer.recentHash)
 | 
						|
 | 
						|
	err := pm.downloader.Synchronise(peer.id, peer.recentHash)
 | 
						|
	switch err {
 | 
						|
	case nil:
 | 
						|
		glog.V(logger.Debug).Infof("Synchronisation completed")
 | 
						|
 | 
						|
	case downloader.ErrBusy:
 | 
						|
		glog.V(logger.Debug).Infof("Synchronisation already in progress")
 | 
						|
 | 
						|
	case downloader.ErrTimeout, downloader.ErrBadPeer, downloader.ErrEmptyHashSet, downloader.ErrInvalidChain, downloader.ErrCrossCheckFailed:
 | 
						|
		glog.V(logger.Debug).Infof("Removing peer %v: %v", peer.id, err)
 | 
						|
		pm.removePeer(peer.id)
 | 
						|
 | 
						|
	case downloader.ErrPendingQueue:
 | 
						|
		glog.V(logger.Debug).Infoln("Synchronisation aborted:", err)
 | 
						|
 | 
						|
	default:
 | 
						|
		glog.V(logger.Warn).Infof("Synchronisation failed: %v", err)
 | 
						|
	}
 | 
						|
}
 |