add performance reporting

costs ~9% bomb performance;
can be toggled in Rán REPL via 'metrics'

pixelflut/net.go

@@ -1,13 +1,76 @@
 package pixelflut
 
 import (
+	"fmt"
 	"log"
 	"net"
 	"sync"
+	"time"
 )
 
-// @speed: add some performance reporting mechanism on these functions when
-//   called as goroutines
+// Performance contains pixelflut metrics
+type Performance struct {
+	Enabled     bool
+	Conns       int
+	BytesPerSec int
+	BytesTotal  int
+
+	connsReporter chan int
+	bytesReporter chan int
+	bytes         int
+}
+
+func (p Performance) String() string {
+	return fmt.Sprintf("%v conns\t%v\t%v/s",
+		p.Conns, fmtBytes(p.BytesTotal), fmtBytes(p.BytesPerSec))
+}
+
+// https://yourbasic.org/golang/byte-count.go
+func fmtBytes(b int) string {
+	const unit = 1024
+	if b < unit {
+		return fmt.Sprintf("%d B", b)
+	}
+	div, exp := int64(unit), 0
+	for n := b / unit; n >= unit; n /= unit {
+		div *= unit
+		exp++
+	}
+	return fmt.Sprintf("%.1f %ciB",
+		float64(b)/float64(div), "KMGTPE"[exp])
+}
+
+// PerformanceReporter provides pixelflut performance metrics, when Enabled is true.
+//   @speed: Note that enabling  costs ~9% bomb performance under high throughput.
+var PerformanceReporter = initPerfReporter()
+
+// should be called only once
+func initPerfReporter() *Performance {
+	r := new(Performance)
+	r.bytesReporter = make(chan int, 512)
+	r.connsReporter = make(chan int, 512)
+
+	go func() {
+		for {
+			select {
+			case b := <-r.bytesReporter:
+				r.bytes += b
+				r.BytesTotal += b
+			case c := <-r.connsReporter:
+				r.Conns += c
+			}
+		}
+	}()
+	go func() {
+		for {
+			time.Sleep(time.Second)
+			r.BytesPerSec = r.bytes
+			r.bytes = 0
+		}
+	}()
+
+	return r
+}
 
 // bombAddress writes the given message via plain TCP to the given address,
 // as fast as possible, until stop is closed.
@@ -22,15 +85,21 @@ func bombAddress(message []byte, address string, stop chan bool, wg *sync.WaitGr
 }
 
 func bombConn(message []byte, conn net.Conn, stop chan bool) {
+	PerformanceReporter.connsReporter <- 1
+	defer func() { PerformanceReporter.connsReporter <- -1 }()
+
 	for {
 		select {
 		case <-stop:
 			return
 		default:
-			_, err := conn.Write(message)
+			b, err := conn.Write(message)
 			if err != nil {
 				log.Fatal(err)
 			}
+			if PerformanceReporter.Enabled {
+				PerformanceReporter.bytesReporter <- b
+			}
 		}
 	}
 }

rpc/dottir.go

@@ -39,6 +39,12 @@ type FlutTask struct {
 
 type FlutAck struct{ Ok bool }
 
+type FlutStatus struct {
+	*pixelflut.Performance
+	Ok      bool
+	Fluting bool
+}
+
 func (h *Hevring) Flut(task FlutTask, reply *FlutAck) error {
 	if (h.task != FlutTask{}) {
 		// @incomplete: stop old task if new task is received
@@ -56,9 +62,11 @@ func (h *Hevring) Flut(task FlutTask, reply *FlutAck) error {
 	return nil
 }
 
-func (h *Hevring) Status(x int, reply *FlutAck) error {
-	// @incomplete: provide performance metrics
+func (h *Hevring) Status(metrics bool, reply *FlutStatus) error {
+	pixelflut.PerformanceReporter.Enabled = metrics
+	reply.Performance = pixelflut.PerformanceReporter
 	reply.Ok = true
+	reply.Fluting = h.taskQuit != nil
 	return nil
 }
 

rpc/ran.go

@@ -1,7 +1,6 @@
 package rpc
 
 import (
-	// "io"
 	"bufio"
 	"fmt"
 	"image"
@@ -12,11 +11,14 @@ import (
 	"strings"
 	"sync"
 	"time"
+
+	"github.com/SpeckiJ/Hochwasser/pixelflut"
 )
 
 type Rán struct {
 	clients []*rpc.Client
 	task    FlutTask
+	metrics pixelflut.Performance
 }
 
 // SummonRán sets up the RPC master, accepting connections at addres (":1234")
@@ -59,11 +61,19 @@ func SummonRán(address string, stopChan chan bool, wg *sync.WaitGroup) *Rán {
 			time.Sleep(100 * time.Millisecond)
 
 			var clients []*rpc.Client
+
+			r.metrics.Conns = 0
+			r.metrics.BytesPerSec = 0
+			r.metrics.BytesTotal = 0
+
 			for _, c := range r.clients {
-				status := FlutAck{}
-				err := c.Call("Hevring.Status", 0, &status)
+				status := FlutStatus{}
+				err := c.Call("Hevring.Status", r.metrics.Enabled, &status)
 				if err == nil && status.Ok {
 					clients = append(clients, c)
+					r.metrics.Conns += status.Conns
+					r.metrics.BytesPerSec += status.BytesPerSec
+					r.metrics.BytesTotal += status.BytesTotal
 				}
 			}
 			if len(r.clients) != len(clients) {
@@ -73,6 +83,16 @@ func SummonRán(address string, stopChan chan bool, wg *sync.WaitGroup) *Rán {
 		}
 	}()
 
+	// print performance
+	go func() {
+		for {
+			time.Sleep(5 * time.Second)
+			if r.metrics.Enabled {
+				fmt.Println(r.metrics)
+			}
+		}
+	}()
+
 	// REPL to change tasks without loosing clients
 	go func() {
 		scanner := bufio.NewScanner(os.Stdin)
@@ -86,6 +106,18 @@ func SummonRán(address string, stopChan chan bool, wg *sync.WaitGroup) *Rán {
 					c.Call("Hevring.Stop", 0, &ack) // @speed: async
 				}
 
+			} else if cmd == "start" {
+				if (r.task != FlutTask{}) {
+					for _, c := range r.clients {
+						ack := FlutAck{}
+						// @speed: should send tasks async
+						err := c.Call("Hevring.Flut", r.task, &ack)
+						if err != nil || !ack.Ok {
+							log.Printf("[rán] client didn't accept task")
+						}
+					}
+				}
+
 			} else if cmd == "img" && len(args) > 0 {
 				// // @incomplete
 				// path := args[0]
@@ -97,6 +129,10 @@ func SummonRán(address string, stopChan chan bool, wg *sync.WaitGroup) *Rán {
 				// 	offset = image.Pt(x, y)
 				// }
 				// task := FlutTask{}
+
+			} else if cmd == "metrics" {
+				r.metrics.Enabled = !r.metrics.Enabled
+
 			}
 		}
 	}()