Introduce higer-level API for retrieving statistics

- see stats-api example

Change-Id: I11d29d32b60d25238e75cb6b86ee34842348ab38
Signed-off-by: Ondrej Fabry <ofabry@cisco.com>

2 files changed, 136 insertions, 12 deletions

diff --git a/examples/stats-api/README.md b/examples/stats-api/README.md
index 0f26197..77afad8 100644
--- a/examples/stats-api/README.md
+++ b/examples/stats-api/README.md
@@ -12,18 +12,96 @@ The following requirements are required to run this example:
   ```sh
   statseg {
   	default
+  	per-node-counters on
   }
-  ``` 
+  ```
   > The [default socket](https://wiki.fd.io/view/VPP/Command-line_Arguments#.22statseg.22_parameters) is located at `/run/vpp/stats.sock`.
-- run the VPP, ideally with some traffic
+- run the VPP (ideally with some traffic)
 
 ## Running example
 
-First build the example: `go build git.fd.io/govpp.git/examples/stats-api`. 
+First build the example: `go build git.fd.io/govpp.git/examples/stats-api`.
 
-Use commands `ls` and `dump` to list and dump statistics. Optionally, patterns can be used to filter the results.
+### Higher-level access to stats
 
-### List stats matching patterns `/sys/` and `/if/`
+Use commands following commands to retrieve stats that are aggregated and
+processed into logical structures from [api package](../../api).
+
+- `system` to retrieve system statistics
+- `nodes` to retrieve per node statistics
+- `interfaces` to retrieve per interface statistics
+- `errors` to retrieve error statistics (you can use patterns to filter the errors)
+
+#### System stats
+
+Following command will retrieve system stats.
+```
+$ ./stats-api system
+System stats: &{VectorRate:0 InputRate:0 LastUpdate:32560 LastStatsClear:0 Heartbeat:3255}
+```
+
+#### Node stats
+
+Following command will retrieve per node stats.
+```
+$ ./stats-api nodes
+Listing node stats..
+...
+ - {NodeIndex:554 Clocks:0 Vectors:0 Calls:0 Suspends:0}
+ - {NodeIndex:555 Clocks:189609 Vectors:15 Calls:15 Suspends:0}
+ - {NodeIndex:556 Clocks:2281847 Vectors:0 Calls:0 Suspends:21}
+ - {NodeIndex:557 Clocks:0 Vectors:0 Calls:0 Suspends:0}
+ - {NodeIndex:558 Clocks:0 Vectors:0 Calls:0 Suspends:0}
+ - {NodeIndex:559 Clocks:7094 Vectors:0 Calls:1 Suspends:1}
+ - {NodeIndex:560 Clocks:88159323916601 Vectors:0 Calls:14066116 Suspends:0}
+ - {NodeIndex:561 Clocks:0 Vectors:0 Calls:0 Suspends:0}
+ - {NodeIndex:562 Clocks:0 Vectors:0 Calls:0 Suspends:0}
+ - {NodeIndex:563 Clocks:0 Vectors:0 Calls:0 Suspends:0}
+ - {NodeIndex:564 Clocks:447894125 Vectors:0 Calls:0 Suspends:32395}
+ - {NodeIndex:565 Clocks:1099655497824612 Vectors:0 Calls:40 Suspends:117}
+ - {NodeIndex:566 Clocks:0 Vectors:0 Calls:0 Suspends:0}
+ - {NodeIndex:567 Clocks:0 Vectors:0 Calls:0 Suspends:0}
+ - {NodeIndex:568 Clocks:0 Vectors:0 Calls:0 Suspends:0}
+ - {NodeIndex:569 Clocks:0 Vectors:0 Calls:0 Suspends:0}
+ - {NodeIndex:570 Clocks:0 Vectors:0 Calls:0 Suspends:0}
+ - {NodeIndex:571 Clocks:0 Vectors:0 Calls:0 Suspends:0}
+ - {NodeIndex:572 Clocks:0 Vectors:0 Calls:0 Suspends:0}
+Listed 573 node counters
+```
+
+#### Interface stats
+
+Following command will retrieve per interface stats.
+```
+$ ./stats-api interfaces
+Listing interface stats..
+ - {InterfaceIndex:0 RxPackets:0 RxBytes:0 RxErrors:0 TxPackets:0 TxBytes:0 TxErrors:0 RxUnicast:[0 0] RxMulticast:[0 0] RxBroadcast:[0 0] TxUnicastMiss:[0 0] TxMulticast:[0 0] TxBroadcast:[0 0] Drops:0 Punts:0 IP4:0 IP6:0 RxNoBuf:0 RxMiss:0}
+ - {InterfaceIndex:1 RxPackets:0 RxBytes:0 RxErrors:0 TxPackets:0 TxBytes:0 TxErrors:0 RxUnicast:[0 0] RxMulticast:[0 0] RxBroadcast:[0 0] TxUnicastMiss:[0 0] TxMulticast:[0 0] TxBroadcast:[0 0] Drops:5 Punts:0 IP4:0 IP6:0 RxNoBuf:0 RxMiss:0}
+ - {InterfaceIndex:2 RxPackets:0 RxBytes:0 RxErrors:0 TxPackets:0 TxBytes:0 TxErrors:0 RxUnicast:[0 0] RxMulticast:[0 0] RxBroadcast:[0 0] TxUnicastMiss:[0 0] TxMulticast:[0 0] TxBroadcast:[0 0] Drops:0 Punts:0 IP4:0 IP6:0 RxNoBuf:0 RxMiss:0}
+ - {InterfaceIndex:3 RxPackets:0 RxBytes:0 RxErrors:0 TxPackets:0 TxBytes:0 TxErrors:0 RxUnicast:[0 0] RxMulticast:[0 0] RxBroadcast:[0 0] TxUnicastMiss:[0 0] TxMulticast:[0 0] TxBroadcast:[0 0] Drops:0 Punts:0 IP4:0 IP6:0 RxNoBuf:0 RxMiss:0}
+Listed 4 interface counters
+```
+
+#### Error stats
+
+Following command will retrieve error stats.
+Use flag `-all` to include stats with zero values.
+```
+$ ./stats-api errors ip
+Listing error stats.. ip
+ - {ip4-input/ip4 spoofed local-address packet drops 15}
+Listed 1 (825) error counters
+```
+
+### Low-level access to stats
+
+Use commands `ls` and `dump` to list and dump statistics in their raw format
+from [adapter package](../../adapter).
+Optionally, patterns can be used to filter the results.
+
+#### List stats
+
+Following command will list stats matching patterns `/sys/` and `/if/`.
 ```
 $ ./stats-api ls /sys/ /if/
 Listing stats.. /sys/ /if/
@@ -55,7 +133,10 @@ Listing stats.. /sys/ /if/
 Listed 25 stats
 ```
 
-### Dump all stats with their types and values
+#### Dump stats
+
+Following command will dump stats with their types and actual values.
+Use flag `-all` to include stats with zero values.
 ```
 $ ./stats-api dump
 Dumping stats..
diff --git a/examples/stats-api/stats_api.go b/examples/stats-api/stats_api.go
index 6fd46d2..b905f60 100644
--- a/examples/stats-api/stats_api.go
+++ b/examples/stats-api/stats_api.go
@@ -23,6 +23,7 @@ import (
 
 	"git.fd.io/govpp.git/adapter"
 	"git.fd.io/govpp.git/adapter/vppapiclient"
+	"git.fd.io/govpp.git/core"
 )
 
 // ------------------------------------------------------------------
@@ -39,7 +40,7 @@ var (
 
 func init() {
 	flag.Usage = func() {
-		fmt.Fprintf(os.Stderr, "%s: usage [ls|dump] <patterns>...\n", os.Args[0])
+		fmt.Fprintf(os.Stderr, "%s: usage [ls|dump|errors|interfaces|nodes|system] <patterns>...\n", os.Args[0])
 		flag.PrintDefaults()
 		os.Exit(1)
 	}
@@ -47,11 +48,11 @@ func init() {
 
 func main() {
 	flag.Parse()
+	skipZeros := !*dumpAll
 
 	cmd := flag.Arg(0)
-
 	switch cmd {
-	case "", "ls", "dump":
+	case "", "ls", "dump", "errors", "interfaces", "nodes", "system":
 	default:
 		flag.Usage()
 	}
@@ -65,14 +66,56 @@ func main() {
 
 	fmt.Printf("Connecting to stats socket: %s\n", *statsSocket)
 
-	if err := client.Connect(); err != nil {
+	c, err := core.ConnectStats(client)
+	if err != nil {
 		log.Fatalln("Connecting failed:", err)
 	}
-	defer client.Disconnect()
+	defer c.Disconnect()
 
 	switch cmd {
+	case "system":
+		stats, err := c.GetSystemStats()
+		if err != nil {
+			log.Fatalln("getting system stats failed:", err)
+		}
+		fmt.Printf("System stats: %+v\n", stats)
+	case "nodes":
+		fmt.Println("Listing node stats..")
+		stats, err := c.GetNodeStats()
+		if err != nil {
+			log.Fatalln("getting node stats failed:", err)
+		}
+		for _, iface := range stats.Nodes {
+			fmt.Printf(" - %+v\n", iface)
+		}
+		fmt.Printf("Listed %d node counters\n", len(stats.Nodes))
+	case "interfaces":
+		fmt.Println("Listing interface stats..")
+		stats, err := c.GetInterfaceStats()
+		if err != nil {
+			log.Fatalln("getting interface stats failed:", err)
+		}
+		for _, iface := range stats.Interfaces {
+			fmt.Printf(" - %+v\n", iface)
+		}
+		fmt.Printf("Listed %d interface counters\n", len(stats.Interfaces))
+	case "errors":
+		fmt.Printf("Listing error stats.. %s\n", strings.Join(patterns, " "))
+		stats, err := c.GetErrorStats(patterns...)
+		if err != nil {
+			log.Fatalln("getting error stats failed:", err)
+		}
+		n := 0
+		for _, counter := range stats.Errors {
+			if counter.Value == 0 && skipZeros {
+				continue
+			}
+			fmt.Printf(" - %v\n", counter)
+			n++
+		}
+		fmt.Printf("Listed %d (%d) error counters\n", n, len(stats.Errors))
 	case "dump":
-		dumpStats(client, patterns, !*dumpAll)
+		dumpStats(client, patterns, skipZeros)
 	default:
 		listStats(client, patterns)
 	}