Simplify subscribing to events and fix events

- there is no need for sending subscription requests through channels,
  since all the messages are registered and no communication with VPP
  is needed

Change-Id: Ibc29957be02a32e26309f66c369a071559b822a9
Signed-off-by: Ondrej Fabry <ofabry@cisco.com>

11 files changed, 64 insertions, 61 deletions

diff --git a/examples/bin_api/acl/acl.ba.go b/examples/bin_api/acl/acl.ba.go
index ff80173..0dfd335 100644
--- a/examples/bin_api/acl/acl.ba.go
+++ b/examples/bin_api/acl/acl.ba.go
@@ -19,6 +19,7 @@ import "github.com/lunixbochs/struc"
 import "bytes"
 
 // Reference imports to suppress errors if they are not otherwise used.
+var _ = api.RegisterMessage
 var _ = struc.Pack
 var _ = bytes.NewBuffer
 
diff --git a/examples/bin_api/af_packet/af_packet.ba.go b/examples/bin_api/af_packet/af_packet.ba.go
index a6bdc93..144bf74 100644
--- a/examples/bin_api/af_packet/af_packet.ba.go
+++ b/examples/bin_api/af_packet/af_packet.ba.go
@@ -18,6 +18,7 @@ import "github.com/lunixbochs/struc"
 import "bytes"
 
 // Reference imports to suppress errors if they are not otherwise used.
+var _ = api.RegisterMessage
 var _ = struc.Pack
 var _ = bytes.NewBuffer
 
diff --git a/examples/bin_api/interfaces/interfaces.ba.go b/examples/bin_api/interfaces/interfaces.ba.go
index 5ef58ed..38bbb6b 100644
--- a/examples/bin_api/interfaces/interfaces.ba.go
+++ b/examples/bin_api/interfaces/interfaces.ba.go
@@ -19,6 +19,7 @@ import "github.com/lunixbochs/struc"
 import "bytes"
 
 // Reference imports to suppress errors if they are not otherwise used.
+var _ = api.RegisterMessage
 var _ = struc.Pack
 var _ = bytes.NewBuffer
 
diff --git a/examples/bin_api/ip/ip.ba.go b/examples/bin_api/ip/ip.ba.go
index c980b6a..9dc3d56 100644
--- a/examples/bin_api/ip/ip.ba.go
+++ b/examples/bin_api/ip/ip.ba.go
@@ -21,6 +21,7 @@ import "github.com/lunixbochs/struc"
 import "bytes"
 
 // Reference imports to suppress errors if they are not otherwise used.
+var _ = api.RegisterMessage
 var _ = struc.Pack
 var _ = bytes.NewBuffer
 
diff --git a/examples/bin_api/memif/memif.ba.go b/examples/bin_api/memif/memif.ba.go
index 3650355..ceb615f 100644
--- a/examples/bin_api/memif/memif.ba.go
+++ b/examples/bin_api/memif/memif.ba.go
@@ -18,6 +18,7 @@ import "github.com/lunixbochs/struc"
 import "bytes"
 
 // Reference imports to suppress errors if they are not otherwise used.
+var _ = api.RegisterMessage
 var _ = struc.Pack
 var _ = bytes.NewBuffer
 
diff --git a/examples/bin_api/stats/stats.ba.go b/examples/bin_api/stats/stats.ba.go
index eb2dd8f..b66a077 100644
--- a/examples/bin_api/stats/stats.ba.go
+++ b/examples/bin_api/stats/stats.ba.go
@@ -19,6 +19,7 @@ import "github.com/lunixbochs/struc"
 import "bytes"
 
 // Reference imports to suppress errors if they are not otherwise used.
+var _ = api.RegisterMessage
 var _ = struc.Pack
 var _ = bytes.NewBuffer
 
diff --git a/examples/bin_api/tap/tap.ba.go b/examples/bin_api/tap/tap.ba.go
index 36f5549..d2878ea 100644
--- a/examples/bin_api/tap/tap.ba.go
+++ b/examples/bin_api/tap/tap.ba.go
@@ -18,6 +18,7 @@ import "github.com/lunixbochs/struc"
 import "bytes"
 
 // Reference imports to suppress errors if they are not otherwise used.
+var _ = api.RegisterMessage
 var _ = struc.Pack
 var _ = bytes.NewBuffer
 
diff --git a/examples/bin_api/vpe/vpe.ba.go b/examples/bin_api/vpe/vpe.ba.go
index f91a164..50476c3 100644
--- a/examples/bin_api/vpe/vpe.ba.go
+++ b/examples/bin_api/vpe/vpe.ba.go
@@ -18,6 +18,7 @@ import "github.com/lunixbochs/struc"
 import "bytes"
 
 // Reference imports to suppress errors if they are not otherwise used.
+var _ = api.RegisterMessage
 var _ = struc.Pack
 var _ = bytes.NewBuffer
 
diff --git a/examples/cmd/perf-bench/perf-bench.go b/examples/cmd/perf-bench/perf-bench.go
index 5b4b17d..664f046 100644
--- a/examples/cmd/perf-bench/perf-bench.go
+++ b/examples/cmd/perf-bench/perf-bench.go
@@ -20,7 +20,6 @@ import (
 	"flag"
 	"fmt"
 	"log"
-	"os"
 	"time"
 
 	"github.com/pkg/profile"
@@ -65,16 +64,14 @@ func main() {
 	// connect to VPP
 	conn, err := govpp.Connect("")
 	if err != nil {
-		log.Println("Error:", err)
-		os.Exit(1)
+		log.Fatalln("Error:", err)
 	}
 	defer conn.Disconnect()
 
 	// create an API channel
 	ch, err := conn.NewAPIChannelBuffered(cnt, cnt)
 	if err != nil {
-		log.Println("Error:", err)
-		os.Exit(1)
+		log.Fatalln("Error:", err)
 	}
 	defer ch.Close()
 
@@ -101,10 +98,8 @@ func syncTest(ch api.Channel, cnt int) {
 		req := &vpe.ControlPing{}
 		reply := &vpe.ControlPingReply{}
 
-		err := ch.SendRequest(req).ReceiveReply(reply)
-		if err != nil {
-			log.Println("Error in reply:", err)
-			os.Exit(1)
+		if err := ch.SendRequest(req).ReceiveReply(reply); err != nil {
+			log.Fatalln("Error in reply:", err)
 		}
 	}
 }
@@ -125,8 +120,7 @@ func asyncTest(ch api.Channel, cnt int) {
 	for ctx := range ctxChan {
 		reply := &vpe.ControlPingReply{}
 		if err := ctx.ReceiveReply(reply); err != nil {
-			log.Println("Error in reply:", err)
-			os.Exit(1)
+			log.Fatalln("Error in reply:", err)
 		}
 	}
 }
diff --git a/examples/cmd/simple-client/simple_client.go b/examples/cmd/simple-client/simple_client.go
index b9e8052..08d4da6 100644
--- a/examples/cmd/simple-client/simple_client.go
+++ b/examples/cmd/simple-client/simple_client.go
@@ -18,6 +18,7 @@ package main
 
 import (
 	"fmt"
+	"log"
 	"net"
 	"os"
 	"strings"
@@ -35,16 +36,14 @@ func main() {
 	// connect to VPP
 	conn, err := govpp.Connect("")
 	if err != nil {
-		fmt.Println("Error:", err)
-		os.Exit(1)
+		log.Fatalln("ERROR:", err)
 	}
 	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)
+		log.Fatalln("ERROR:", err)
 	}
 	defer ch.Close()
 
@@ -64,20 +63,22 @@ func main() {
 
 // aclVersion is the simplest API example - one empty request message and one reply message.
 func aclVersion(ch api.Channel) {
+	fmt.Println("ACL getting version")
+
 	req := &acl.ACLPluginGetVersion{}
 	reply := &acl.ACLPluginGetVersionReply{}
 
-	err := ch.SendRequest(req).ReceiveReply(reply)
-
-	if err != nil {
-		fmt.Println("Error:", err)
+	if err := ch.SendRequest(req).ReceiveReply(reply); err != nil {
+		fmt.Println("ERROR:", err)
 	} else {
-		fmt.Printf("%+v\n", reply)
+		fmt.Printf("ACL version reply: %+v\n", reply)
 	}
 }
 
 // aclConfig is another simple API example - in this case, the request contains structured data.
 func aclConfig(ch api.Channel) {
+	fmt.Println("ACL adding replace")
+
 	req := &acl.ACLAddReplace{
 		ACLIndex: ^uint32(0),
 		Tag:      []byte("access list 1"),
@@ -102,10 +103,8 @@ func aclConfig(ch api.Channel) {
 	}
 	reply := &acl.ACLAddReplaceReply{}
 
-	err := ch.SendRequest(req).ReceiveReply(reply)
-
-	if err != nil {
-		fmt.Println("Error:", err)
+	if err := ch.SendRequest(req).ReceiveReply(reply); err != nil {
+		fmt.Println("ERROR:", err)
 		return
 	}
 	if reply.Retval != 0 {
@@ -113,19 +112,23 @@ func aclConfig(ch api.Channel) {
 		return
 	}
 
-	fmt.Printf("%+v\n", reply)
+	fmt.Printf("ACL add replace reply: %+v\n", reply)
 
 }
 
 // aclDump shows an example where SendRequest and ReceiveReply are not chained together.
 func aclDump(ch api.Channel) {
+	fmt.Println("Dumping ACL")
+
 	req := &acl.ACLDump{}
 	reply := &acl.ACLDetails{}
 
-	if err := ch.SendRequest(req).ReceiveReply(reply); err != nil {
-		fmt.Println("Error:", err)
+	reqCtx := ch.SendRequest(req)
+
+	if err := reqCtx.ReceiveReply(reply); err != nil {
+		fmt.Println("ERROR:", err)
 	} else {
-		fmt.Printf("%+v\n", reply)
+		fmt.Printf("ACL details: %+v\n", reply)
 	}
 }
 
@@ -133,14 +136,13 @@ func aclDump(ch api.Channel) {
 func interfaceDump(ch api.Channel) {
 	fmt.Println("Dumping interfaces")
 
-	req := &interfaces.SwInterfaceDump{}
-	reqCtx := ch.SendMultiRequest(req)
+	reqCtx := ch.SendMultiRequest(&interfaces.SwInterfaceDump{})
 
 	for {
 		msg := &interfaces.SwInterfaceDetails{}
 		stop, err := reqCtx.ReceiveReply(msg)
 		if stop {
-			break // break out of the loop
+			break
 		}
 		if err != nil {
 			fmt.Println("ERROR:", err)
@@ -148,7 +150,7 @@ func interfaceDump(ch api.Channel) {
 		ifaceName := strings.TrimFunc(string(msg.InterfaceName), func(r rune) bool {
 			return r == 0x00
 		})
-		fmt.Printf("Interface: %q %+v\n", ifaceName, msg)
+		fmt.Printf("Interface %q: %+v\n", ifaceName, msg)
 	}
 }
 
@@ -164,12 +166,12 @@ func ipAddressDump(ch api.Channel) {
 		msg := &ip.IPAddressDetails{}
 		stop, err := reqCtx.ReceiveReply(msg)
 		if stop {
-			break // break out of the loop
+			break
 		}
 		if err != nil {
 			fmt.Println("ERROR:", err)
 		}
-		fmt.Printf("ip address: %d %+v\n", msg.SwIfIndex, msg)
+		fmt.Printf("ip address details: %d %+v\n", msg.SwIfIndex, msg)
 	}
 }
 
@@ -183,7 +185,7 @@ func setIpUnnumbered(ch api.Channel) {
 	reply := &interfaces.SwInterfaceSetUnnumberedReply{}
 
 	if err := ch.SendRequest(req).ReceiveReply(reply); err != nil {
-		fmt.Println("Error:", err)
+		fmt.Println("ERROR:", err)
 	} else {
 		fmt.Printf("%+v\n", reply)
 	}
@@ -192,21 +194,20 @@ func setIpUnnumbered(ch api.Channel) {
 func ipUnnumberedDump(ch api.Channel) {
 	fmt.Println("Dumping IP unnumbered")
 
-	req := &ip.IPUnnumberedDump{
+	reqCtx := ch.SendMultiRequest(&ip.IPUnnumberedDump{
 		SwIfIndex: ^uint32(0),
-	}
-	reqCtx := ch.SendMultiRequest(req)
+	})
 
 	for {
 		msg := &ip.IPUnnumberedDetails{}
 		stop, err := reqCtx.ReceiveReply(msg)
 		if stop {
-			break // break out of the loop
+			break
 		}
 		if err != nil {
 			fmt.Println("ERROR:", err)
 		}
-		fmt.Printf("ip unnumbered: %+v\n", msg)
+		fmt.Printf("IP unnumbered details: %+v\n", msg)
 	}
 }
 
@@ -214,9 +215,12 @@ func ipUnnumberedDump(ch api.Channel) {
 // you are supposed to create your own Go channel with your preferred buffer size. If the channel's
 // buffer is full, the notifications will not be delivered into it.
 func interfaceNotifications(ch api.Channel) {
-	// subscribe for specific notification message
+	fmt.Println("Subscribing to notificaiton events")
+
 	notifChan := make(chan api.Message, 100)
-	subs, err := ch.SubscribeNotification(notifChan, interfaces.NewSwInterfaceEvent)
+
+	// subscribe for specific notification message
+	sub, err := ch.SubscribeNotification(notifChan, &interfaces.SwInterfaceEvent{})
 	if err != nil {
 		panic(err)
 	}
@@ -248,7 +252,7 @@ func interfaceNotifications(ch api.Channel) {
 
 	// receive one notification
 	notif := (<-notifChan).(*interfaces.SwInterfaceEvent)
-	fmt.Printf("NOTIF: %+v\n", notif)
+	fmt.Printf("incoming event: %+v\n", notif)
 
 	// disable interface events in VPP
 	err = ch.SendRequest(&interfaces.WantInterfaceEvents{
@@ -260,7 +264,7 @@ func interfaceNotifications(ch api.Channel) {
 	}
 
 	// unsubscribe from delivery of the notifications
-	err = ch.UnsubscribeNotification(subs)
+	err = sub.Unsubscribe()
 	if err != nil {
 		panic(err)
 	}
diff --git a/examples/cmd/stats-client/stats_client.go b/examples/cmd/stats-client/stats_client.go
index 4ea4659..f61f975 100644
--- a/examples/cmd/stats-client/stats_client.go
+++ b/examples/cmd/stats-client/stats_client.go
@@ -18,6 +18,7 @@ package main
 
 import (
 	"fmt"
+	"log"
 	"os"
 	"os/signal"
 
@@ -28,45 +29,41 @@ import (
 )
 
 func main() {
-	fmt.Println("Starting stats VPP client...")
+	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)
+		log.Fatalln("Error:", err)
 	}
 	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)
+		log.Fatalln("Error:", err)
 	}
-	defer fmt.Println("calling close")
 	defer ch.Close()
 
 	// create channel for Interrupt signal
 	sigChan := make(chan os.Signal, 1)
 	signal.Notify(sigChan, os.Interrupt)
 
-	var simpleCountersSubs *api.NotifSubscription
-	var combinedCountersSubs *api.NotifSubscription
 	var notifChan chan api.Message
+	var simpleSub api.SubscriptionCtx
+	var combinedSub api.SubscriptionCtx
 
 	// 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 simpleCountersSubs == nil {
-					simpleCountersSubs, combinedCountersSubs, notifChan = subscribeNotifications(ch)
+				if notifChan == nil {
+					simpleSub, combinedSub, notifChan = subscribeNotifications(ch)
 				}
 				requestStatistics(ch)
 
@@ -93,24 +90,24 @@ loop:
 		}
 	}
 
-	ch.UnsubscribeNotification(simpleCountersSubs)
-	ch.UnsubscribeNotification(combinedCountersSubs)
+	simpleSub.Unsubscribe()
+	combinedSub.Unsubscribe()
 }
 
 // subscribeNotifications subscribes for interface counters notifications.
-func subscribeNotifications(ch api.Channel) (*api.NotifSubscription, *api.NotifSubscription, chan api.Message) {
+func subscribeNotifications(ch api.Channel) (api.SubscriptionCtx, api.SubscriptionCtx, chan api.Message) {
 	notifChan := make(chan api.Message, 100)
 
-	simpleCountersSubs, err := ch.SubscribeNotification(notifChan, stats.NewVnetInterfaceSimpleCounters)
+	simpleSub, err := ch.SubscribeNotification(notifChan, &stats.VnetInterfaceSimpleCounters{})
 	if err != nil {
 		panic(err)
 	}
-	combinedCountersSubs, err := ch.SubscribeNotification(notifChan, stats.NewVnetInterfaceCombinedCounters)
+	combinedSub, err := ch.SubscribeNotification(notifChan, &stats.VnetInterfaceCombinedCounters{})
 	if err != nil {
 		panic(err)
 	}
 
-	return simpleCountersSubs, combinedCountersSubs, notifChan
+	return simpleSub, combinedSub, notifChan
 }
 
 // requestStatistics requests interface counters notifications from VPP.