Merge pull request ethereum#49 from lochjin/v1.14.5-qng

BUG:qng downloader

eth/downloader/downloader_qng.go

@@ -3,8 +3,12 @@
 package downloader
 
 import (
+	"fmt"
 	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/core/types"
+	"github.com/ethereum/go-ethereum/eth/protocols/eth"
 	"github.com/ethereum/go-ethereum/log"
+	"time"
 )
 
 func (d *Downloader) SyncQng(peerid string, mode SyncMode, hash common.Hash) error {
@@ -21,7 +25,7 @@ func (d *Downloader) SyncQng(peerid string, mode SyncMode, hash common.Hash) err
 		return errBadPeer
 	}
 	log.Info("Attempting to retrieve sync target", "peer", peer.id, "head", hash.String())
-	headers, metas, err := d.fetchHeadersByHash(peer, hash, 1, 0, false)
+	headers, metas, err := d.fetchQngHeadersByHash(peer, hash, 1, 0, false)
 	if err != nil || len(headers) != 1 {
 		log.Warn("Failed to fetch sync target", "headers", len(headers), "err", err)
 		return err
@@ -33,3 +37,45 @@ func (d *Downloader) SyncQng(peerid string, mode SyncMode, hash common.Hash) err
 	}
 	return d.BeaconSync(mode, headers[0], headers[0])
 }
+
+func (d *Downloader) fetchQngHeadersByHash(p *peerConnection, hash common.Hash, amount int, skip int, reverse bool) ([]*types.Header, []common.Hash, error) {
+	// Create the response sink and send the network request
+	start := time.Now()
+	resCh := make(chan *eth.Response)
+
+	req, err := p.peer.RequestHeadersByHash(hash, amount, skip, reverse, resCh)
+	if err != nil {
+		return nil, nil, err
+	}
+	defer func() {
+		fmt.Println(time.Now().String(), "测试3")
+		req.Close()
+	}()
+
+	// Wait until the response arrives, the request is cancelled or times out
+	ttl := d.peers.rates.TargetTimeout()
+
+	timeoutTimer := time.NewTimer(ttl)
+	defer timeoutTimer.Stop()
+
+	select {
+	case <-timeoutTimer.C:
+		// Header retrieval timed out, update the metrics
+		p.log.Debug("Header request timed out", "elapsed", ttl)
+		headerTimeoutMeter.Mark(1)
+
+		return nil, nil, errTimeout
+
+	case res := <-resCh:
+		// Headers successfully retrieved, update the metrics
+		headerReqTimer.Update(time.Since(start))
+		headerInMeter.Mark(int64(len(*res.Res.(*eth.BlockHeadersRequest))))
+
+		// Don't reject the packet even if it turns out to be bad, downloader will
+		// disconnect the peer on its own terms. Simply delivery the headers to
+		// be processed by the caller
+		res.Done <- nil
+
+		return *res.Res.(*eth.BlockHeadersRequest), res.Meta.([]common.Hash), nil
+	}
+}