peer: Combine stats struct into peer struct.

This defines the peer stat fields directly in the Peer struct instead of
defining them in a separate struct and embedding them.  It is slightly
more efficient this way and there is really no reason to have them
defined separately anyways since they are not passed around or otherwise
used independently.

peer/peer.go

@@ -322,23 +322,6 @@ type stallControlMsg struct {
 	message wire.Message
 }
 
-// stats is the collection of stats related to a peer.
-type stats struct {
-	statsMtx           sync.RWMutex // protects all statistics below here.
-	timeOffset         int64
-	timeConnected      time.Time
-	lastSend           time.Time
-	lastRecv           time.Time
-	bytesReceived      uint64
-	bytesSent          uint64
-	startingHeight     int32
-	lastBlock          int32
-	lastAnnouncedBlock *wire.ShaHash
-	lastPingNonce      uint64    // Set to nonce if we have a pending ping.
-	lastPingTime       time.Time // Time we sent last ping.
-	lastPingMicros     int64     // Time for last ping to return.
-}
-
 // StatsSnap is a snapshot of peer stats at a point in time.
 type StatsSnap struct {
 	ID             int32
@@ -428,6 +411,22 @@ type Peer struct {
 	prevGetHdrsBegin   *wire.ShaHash
 	prevGetHdrsStop    *wire.ShaHash
 
+	// These fields keep track of statistics for the peer and are protected
+	// by the statsMtx mutex.
+	statsMtx           sync.RWMutex
+	timeOffset         int64
+	timeConnected      time.Time
+	lastSend           time.Time
+	lastRecv           time.Time
+	bytesReceived      uint64
+	bytesSent          uint64
+	startingHeight     int32
+	lastBlock          int32
+	lastAnnouncedBlock *wire.ShaHash
+	lastPingNonce      uint64    // Set to nonce if we have a pending ping.
+	lastPingTime       time.Time // Time we sent last ping.
+	lastPingMicros     int64     // Time for last ping to return.
+
 	stallControl  chan stallControlMsg
 	outputQueue   chan outMsg
 	sendQueue     chan outMsg
@@ -437,8 +436,6 @@ type Peer struct {
 	queueQuit     chan struct{}
 	outQuit       chan struct{}
 	quit          chan struct{}
-
-	stats
 }
 
 // String returns the peer's address and directionality as a human-readable
@@ -2058,7 +2055,6 @@ func newPeerBase(cfg *Config, inbound bool) *Peer {
 		queueQuit:       make(chan struct{}),
 		outQuit:         make(chan struct{}),
 		quit:            make(chan struct{}),
-		stats:           stats{},
 		cfg:             *cfg, // Copy so caller can't mutate.
 		services:        cfg.Services,
 		protocolVersion: protocolVersion,