From 9ed166c196b07047299579e5ea2b6ece26aec5c6 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?P=C3=A9ter=20Szil=C3=A1gyi?= <peterke@gmail.com>
Date: Mon, 8 Jun 2015 20:38:39 +0300
Subject: eth: split and handle explicitly vs. download requested blocks

---
 eth/sync.go | 56 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 56 insertions(+)

(limited to 'eth/sync.go')

diff --git a/eth/sync.go b/eth/sync.go
index 1a1cbdb47..f761f3cd1 100644
--- a/eth/sync.go
+++ b/eth/sync.go
@@ -12,6 +12,16 @@ import (
 	"github.com/ethereum/go-ethereum/logger/glog"
 )
 
+const (
+	forceSyncCycle      = 10 * time.Second       // Time interval to force syncs, even if few peers are available
+	blockProcCycle      = 500 * time.Millisecond // Time interval to check for new blocks to process
+	notifyCheckCycle    = 100 * time.Millisecond // Time interval to allow hash notifies to fulfill before hard fetching
+	notifyArriveTimeout = 500 * time.Millisecond // Time allowance before an announced block is explicitly requested
+	notifyFetchTimeout  = 5 * time.Second        // Maximum alloted time to return an explicitly requested block
+	minDesiredPeerCount = 5                      // Amount of peers desired to start syncing
+	blockProcAmount     = 256
+)
+
 // blockAnnounce is the hash notification of the availability of a new block in
 // the network.
 type blockAnnounce struct {
@@ -25,6 +35,7 @@ type blockAnnounce struct {
 func (pm *ProtocolManager) fetcher() {
 	announces := make(map[common.Hash]*blockAnnounce)
 	request := make(map[*peer][]common.Hash)
+	pending := make(map[common.Hash]*blockAnnounce)
 	cycle := time.Tick(notifyCheckCycle)
 
 	// Iterate the block fetching until a quit is requested
@@ -38,11 +49,18 @@ func (pm *ProtocolManager) fetcher() {
 			}
 
 		case <-cycle:
+			// Clean up any expired block fetches
+			for hash, announce := range pending {
+				if time.Since(announce.time) > notifyFetchTimeout {
+					delete(pending, hash)
+				}
+			}
 			// Check if any notified blocks failed to arrive
 			for hash, announce := range announces {
 				if time.Since(announce.time) > notifyArriveTimeout {
 					if !pm.chainman.HasBlock(hash) {
 						request[announce.peer] = append(request[announce.peer], hash)
+						pending[hash] = announce
 					}
 					delete(announces, hash)
 				}
@@ -57,6 +75,44 @@ func (pm *ProtocolManager) fetcher() {
 			}
 			request = make(map[*peer][]common.Hash)
 
+		case filter := <-pm.newBlockCh:
+			// Blocks arrived, extract any explicit requests, return all else
+			var blocks types.Blocks
+			select {
+			case blocks = <-filter:
+			case <-pm.quitSync:
+				return
+			}
+
+			fetch, sync := []*types.Block{}, []*types.Block{}
+			for _, block := range blocks {
+				hash := block.Hash()
+				if _, ok := pending[hash]; ok {
+					fetch = append(fetch, block)
+				} else {
+					sync = append(sync, block)
+				}
+			}
+
+			select {
+			case filter <- sync:
+			case <-pm.quitSync:
+				return
+			}
+			// If any explicit fetches were replied to, import them
+			if len(fetch) > 0 {
+				go func() {
+					for _, block := range fetch {
+						if announce := pending[block.Hash()]; announce != nil {
+							if err := pm.importBlock(announce.peer, block, nil); err != nil {
+								glog.V(logger.Detail).Infof("Failed to import explicitly fetched block: %v", err)
+								return
+							}
+						}
+					}
+				}()
+			}
+
 		case <-pm.quitSync:
 			return
 		}
-- 
cgit v1.2.3