cmd/geth, eth/fetcher: initial metrics support

Conflicts:
	cmd/geth/admin.go

eth/fetcher/fetcher.go

@@ -7,6 +7,8 @@ import (
 	"math/rand"
 	"time"
 
+	"github.com/rcrowley/go-metrics"
+
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/core/types"
 	"github.com/ethereum/go-ethereum/logger"
@@ -96,6 +98,11 @@ type Fetcher struct {
 	// Testing hooks
 	fetchingHook func([]common.Hash) // Method to call upon starting a block fetch
 	importedHook func(*types.Block)  // Method to call upon successful block import
+
+	// Runtime metrics
+	announceStats  metrics.Meter
+	broadcastStats metrics.Meter
+	discardStats   metrics.Meter
 }
 
 // New creates a block fetcher to retrieve blocks based on hash announcements.
@@ -118,6 +125,9 @@ func New(getBlock blockRetrievalFn, validateBlock blockValidatorFn, broadcastBlo
 		chainHeight:    chainHeight,
 		insertChain:    insertChain,
 		dropPeer:       dropPeer,
+		announceStats:  metrics.GetOrRegisterMeter("eth/Announced Blocks", metrics.DefaultRegistry),
+		broadcastStats: metrics.GetOrRegisterMeter("eth/Propagated Blocks", metrics.DefaultRegistry),
+		discardStats:   metrics.GetOrRegisterMeter("eth/Discarded Blocks", metrics.DefaultRegistry),
 	}
 }
 
@@ -229,6 +239,8 @@ func (f *Fetcher) loop() {
 
 		case notification := <-f.notify:
 			// A block was announced, make sure the peer isn't DOSing us
+			f.announceStats.Mark(1)
+
 			count := f.announces[notification.origin] + 1
 			if count > hashLimit {
 				glog.V(logger.Debug).Infof("Peer %s: exceeded outstanding announces (%d)", notification.origin, hashLimit)
@@ -246,6 +258,7 @@ func (f *Fetcher) loop() {
 
 		case op := <-f.inject:
 			// A direct block insertion was requested, try and fill any pending gaps
+			f.broadcastStats.Mark(1)
 			f.enqueue(op.origin, op.block)
 
 		case hash := <-f.done:
@@ -364,6 +377,7 @@ func (f *Fetcher) enqueue(peer string, block *types.Block) {
 	// Discard any past or too distant blocks
 	if dist := int64(block.NumberU64()) - int64(f.chainHeight()); dist < -maxUncleDist || dist > maxQueueDist {
 		glog.V(logger.Debug).Infof("Peer %s: discarded block #%d [%x], distance %d", peer, block.NumberU64(), hash.Bytes()[:4], dist)
+		f.discardStats.Mark(1)
 		return
 	}
 	// Schedule the block for future importing