Implement getnettotals RPC.

Also, change the display handler for getnettotals in btcctl to the JSON
display handler for better display.

Closes #84.

rpcserver.go

@@ -64,6 +64,7 @@ var rpcHandlersBeforeInit = map[string]commandHandler{
 	"getgenerate":          handleGetGenerate,
 	"gethashespersec":      handleGetHashesPerSec,
 	"getinfo":              handleGetInfo,
+	"getnettotals":         handleGetNetTotals,
 	"getpeerinfo":          handleGetPeerInfo,
 	"getrawmempool":        handleGetRawMempool,
 	"getrawtransaction":    handleGetRawTransaction,
@@ -133,7 +134,6 @@ var rpcAskWallet = map[string]bool{
 // Commands that are temporarily unimplemented.
 var rpcUnimplemented = map[string]bool{
 	"getmininginfo":    true,
-	"getnettotals":     true,
 	"getnetworkhashps": true,
 }
 
@@ -727,8 +727,8 @@ func handleGetAddedNodeInfo(s *rpcServer, cmd btcjson.Cmd) (interface{}, error)
 		}
 	}
 
-	// Without the dns flag, the result is just a slice of the adddresses
-	// as strings.
+	// Without the dns flag, the result is just a slice of the addresses as
+	// strings.
 	if !c.Dns {
 		results := make([]string, 0, len(peers))
 		for _, peer := range peers {
@@ -978,6 +978,17 @@ func handleGetInfo(s *rpcServer, cmd btcjson.Cmd) (interface{}, error) {
 	return ret, nil
 }
 
+// handleGetNetTotals implements the getnettotals command.
+func handleGetNetTotals(s *rpcServer, cmd btcjson.Cmd) (interface{}, error) {
+	netTotals := s.server.NetTotals()
+	reply := &btcjson.GetNetTotalsResult{
+		TotalBytesRecv: netTotals.TotalBytesRecv,
+		TotalBytesSent: netTotals.TotalBytesSent,
+		TimeMillis:     time.Now().UnixNano() / 1000,
+	}
+	return reply, nil
+}
+
 // handleGetPeerInfo implements the getpeerinfo command.
 func handleGetPeerInfo(s *rpcServer, cmd btcjson.Cmd) (interface{}, error) {
 	return s.server.PeerInfo(), nil

server.go

@@ -300,6 +300,19 @@ type getAddedNodesMsg struct {
 	reply chan []*peer
 }
 
+// NetTotals contains information about the total bytes received and sent across
+// the network.
+type NetTotals struct {
+	TotalBytesRecv uint64
+	TotalBytesSent uint64
+}
+
+// getNetTotals is a message type to be sent across the query channel for
+// retrieving the current total bytes sent and received from all peers.
+type getNetTotals struct {
+	reply chan *NetTotals
+}
+
 // handleQuery is the central handler for all queries and commands from other
 // goroutines related to peer state.
 func (s *server) handleQuery(querymsg interface{}, state *peerState) {
@@ -403,6 +416,18 @@ func (s *server) handleQuery(querymsg interface{}, state *peerState) {
 			peers = append(peers, peer)
 		}
 		msg.reply <- peers
+
+	// Request the total bytes sent and received.
+	case getNetTotals:
+		// Respond with a ....
+		netTotals := NetTotals{}
+		state.forAllPeers(func(p *peer) {
+			if p.Connected() {
+				netTotals.TotalBytesRecv += p.bytesReceived
+				netTotals.TotalBytesSent += p.bytesSent
+			}
+		})
+		msg.reply <- &netTotals
 	}
 }
 
@@ -694,6 +719,14 @@ func (s *server) RemoveAddr(addr string) error {
 	return <-replyChan
 }
 
+// NetTotals returns the sum of all bytes received and sent across the network
+// for all peers.
+func (s *server) NetTotals() *NetTotals {
+	reply := make(chan *NetTotals)
+	s.query <- getNetTotals{reply: reply}
+	return <-reply
+}
+
 // Start begins accepting connections from peers.
 func (s *server) Start() {
 	// Already started?

util/btcctl/btcctl.go

@@ -66,7 +66,7 @@ var commandHandlers = map[string]*handlerData{
 	"getgenerate":           {0, 0, displayGeneric, nil, makeGetGenerate, ""},
 	"gethashespersec":       {0, 0, displayGeneric, nil, makeGetHashesPerSec, ""},
 	"getinfo":               {0, 0, displayJSONDump, nil, makeGetInfo, ""},
-	"getnettotals":          {0, 0, displayGeneric, nil, makeGetNetTotals, ""},
+	"getnettotals":          {0, 0, displayJSONDump, nil, makeGetNetTotals, ""},
 	"getnewaddress":         {0, 1, displayGeneric, nil, makeGetNewAddress, "[account]"},
 	"getpeerinfo":           {0, 0, displayJSONDump, nil, makeGetPeerInfo, ""},
 	"getrawchangeaddress":   {0, 0, displayGeneric, nil, makeGetRawChangeAddress, ""},