1 files changed, 132 insertions, 0 deletions
diff --git a/examples/cmd/stats-client/stats_client.go b/examples/cmd/stats-client/stats_client.go
new file mode 100644
index 0000000..fc40b24
--- /dev/null
+++ b/examples/cmd/stats-client/stats_client.go
@@ -0,0 +1,132 @@
+// Copyright (c) 2017 Cisco and/or its affiliates.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at:
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Binary stats-client is an example VPP management application that exercises the
+// govpp API for interface counters together with asynchronous connection to VPP.
+package main
+
+// Generates Go bindings for all VPP APIs located in the json directory.
+//go:generate binapi-generator --input-dir=bin_api --output-dir=bin_api
+
+import (
+	"fmt"
+	"os"
+	"os/signal"
+
+	"git.fd.io/govpp.git"
+	"git.fd.io/govpp.git/api"
+	"git.fd.io/govpp.git/api/ifcounters"
+	"git.fd.io/govpp.git/core"
+	"git.fd.io/govpp.git/core/bin_api/vpe"
+	"git.fd.io/govpp.git/examples/bin_api/interfaces"
+)
+
+func main() {
+	fmt.Println("Starting stats VPP client...")
+
+	// async connect to VPP
+	conn, statCh, err := govpp.AsyncConnect()
+	if err != nil {
+		fmt.Println("Error:", err)
+		os.Exit(1)
+	}
+	defer conn.Disconnect()
+
+	// create an API channel that will be used in the examples
+	ch, err := conn.NewAPIChannel()
+	if err != nil {
+		fmt.Println("Error:", err)
+		os.Exit(1)
+	}
+	defer ch.Close()
+
+	// create channel for Interrupt signal
+	sigChan := make(chan os.Signal, 1)
+	signal.Notify(sigChan, os.Interrupt)
+
+	var subs *api.NotifSubscription
+	var notifChan chan api.Message
+
+	// loop until Interrupt signal is received
+loop:
+	for {
+		select {
+
+		case connEvent := <-statCh:
+			// VPP connection state change
+			switch connEvent.State {
+			case core.Connected:
+				fmt.Println("VPP connected.")
+				if subs == nil {
+					subs, notifChan = subscribeNotification(ch)
+				}
+				requestStatistics(ch)
+
+			case core.Disconnected:
+				fmt.Println("VPP disconnected.")
+			}
+
+		case notifMsg := <-notifChan:
+			// counter notification received
+			processCounters(notifMsg.(*interfaces.VnetInterfaceCounters))
+
+		case <-sigChan:
+			// interrupt received
+			fmt.Println("Interrupt received, exiting.")
+			break loop
+		}
+	}
+
+	ch.UnsubscribeNotification(subs)
+}
+
+// subscribeNotification subscribes for interface counters notifications.
+func subscribeNotification(ch *api.Channel) (*api.NotifSubscription, chan api.Message) {
+
+	notifChan := make(chan api.Message, 100)
+	subs, _ := ch.SubscribeNotification(notifChan, interfaces.NewVnetInterfaceCounters)
+
+	return subs, notifChan
+}
+
+// requestStatistics requests interface counters notifications from VPP.
+func requestStatistics(ch *api.Channel) {
+	ch.SendRequest(&vpe.WantStats{
+		Pid:           uint32(os.Getpid()),
+		EnableDisable: 1,
+	}).ReceiveReply(&vpe.WantStatsReply{})
+}
+
+// processCounters processes a counter message received from VPP.
+func processCounters(msg *interfaces.VnetInterfaceCounters) {
+	fmt.Printf("%+v\n", msg)
+
+	if msg.IsCombined == 0 {
+		// simple counter
+		counters, err := ifcounters.DecodeCounters(ifcounters.VnetInterfaceCounters(*msg))
+		if err != nil {
+			fmt.Println("Error:", err)
+		} else {
+			fmt.Printf("%+v\n", counters)
+		}
+	} else {
+		// combined counter
+		counters, err := ifcounters.DecodeCombinedCounters(ifcounters.VnetInterfaceCounters(*msg))
+		if err != nil {
+			fmt.Println("Error:", err)
+		} else {
+			fmt.Printf("%+v\n", counters)
+		}
+	}
+}