Add splitOutput option if have multiple outputs

emitter.go

@@ -18,15 +18,28 @@ func Start(stop chan int) {
 // Copy from 1 reader to multiple writers
 func CopyMulty(src io.Reader, writers ...io.Writer) (err error) {
 	buf := make([]byte, 32*1024)
+	wIndex := 0
 
 	for {
 		nr, er := src.Read(buf)
 		if nr > 0 {
 			Debug("Sending", src, ": ", string(buf[0:nr]))
 
-			for _, dst := range writers {
-				dst.Write(buf[0:nr])
+			if Settings.splitOutput {
+				// Simple round robin
+				writers[wIndex].Write(buf[0:nr])
+
+				wIndex++
+
+				if wIndex >= len(writers) {
+					wIndex = 0
+				}
+			} else {
+				for _, dst := range writers {
+					dst.Write(buf[0:nr])
+				}
 			}
+
 		}
 		if er == io.EOF {
 			break

emitter_test.go

@@ -3,6 +3,7 @@ package gor
 import (
 	"io"
 	"sync"
+	"sync/atomic"
 	"testing"
 )
 
@@ -29,3 +30,44 @@ func TestEmitter(t *testing.T) {
 
 	close(quit)
 }
+
+func TestEmitterRoundRobin(t *testing.T) {
+	wg := new(sync.WaitGroup)
+	quit := make(chan int)
+
+	input := NewTestInput()
+
+	var counter1, counter2 int32
+
+	output1 := NewTestOutput(func(data []byte) {
+		atomic.AddInt32(&counter1, 1)
+		wg.Done()
+	})
+
+	output2 := NewTestOutput(func(data []byte) {
+		atomic.AddInt32(&counter2, 1)
+		wg.Done()
+	})
+
+	Plugins.Inputs = []io.Reader{input}
+	Plugins.Outputs = []io.Writer{output1, output2}
+
+	Settings.splitOutput = true
+
+	go Start(quit)
+
+	for i := 0; i < 1000; i++ {
+		wg.Add(1)
+		input.EmitGET()
+	}
+
+	wg.Wait()
+
+	close(quit)
+
+	if counter1 == 0 || counter2 == 0 {
+		t.Errorf("Round robin should split traffic equally: %d vs %d", counter1, counter2)
+	}
+
+	Settings.splitOutput = false
+}

settings.go

@@ -8,6 +8,8 @@ import (
 type AppSettings struct {
 	verbose bool
 
+	splitOutput bool
+
 	inputDummy  MultiOption
 	outputDummy MultiOption
 
@@ -28,6 +30,8 @@ var Settings AppSettings = AppSettings{}
 func init() {
 	flag.BoolVar(&Settings.verbose, "verbose", false, "")
 
+	flag.BoolVar(&Settings.splitOutput, "split-output", false, "")
+
 	flag.Var(&Settings.inputDummy, "input-dummy", "")
 	flag.Var(&Settings.outputDummy, "output-dummy", "")