basic finish fanout pattern

gomore/04_fan_in/fan_in_out_test.go

@@ -5,7 +5,7 @@ import (
 	"testing"
 )
 
-func TestFanInOutNumbersSeq(T *testing.T) {
+func TestFanInOutNumbersSeq(t *testing.T) {
 
 	//一路输入源
 	dataStreams := []int{13, 44, 56, 99, 9, 45, 67, 90, 78, 23}

gomore/04_fan_in/fan_in_test.go

@@ -5,7 +5,7 @@ import (
 	"testing"
 )
 
-func TestFanInNumbersSeq(T *testing.T) {
+func TestFanInNumbersSeq(t *testing.T) {
 
 	//第一路输入源
 	dataStreams1 := []int{13, 44, 56, 99, 9, 45, 67, 90, 78, 23}

gomore/05_fan_out/fan_out.go

@@ -1,22 +1,28 @@
 package fanout
 
+import "sync"
+
 // Split 重复分发数据为多份
 // Split a channel into n channels that receive messages in a round-robin fashion.
 func Split(ch <-chan int, n int) []chan int {
 
 	//get a queue of chan
-	cs := make([]chan int, n)
+	//cs := make([]chan int, n) //创建了个chan 数组但是空的
 
-	// Distributes the work in a round robin fashion among the stated number
+	cs := []chan int{}
-	// of channels until the main channel has been closed. In that case, close
+	for i := 0; i < n; i++ {
-	// all channels and return.
+		cs = append(cs, make(chan int))
+	}
+
+	//Distributes the work in a round robin fashion among the stated number of channels
+	//until the main channel has been closed. In that case, close all channels and return.
 	distributeToChannels := func(ch <-chan int, cs []chan int) {
 		// Close every channel when the execution ends.
-		defer func(cs []chan int) {
+		defer func() {
 			for _, c := range cs {
 				close(c)
 			}
-		}(cs)
+		}()
 
 		//this version will block
 		for {
@@ -24,7 +30,7 @@ func Split(ch <-chan int, n int) []chan int {
 			select {
 			case val, ok := <-ch:
 				if !ok {
-					return
+					return // channel closed
 				}
 				//send value to all channels
 				for _, c := range cs {
@@ -42,47 +48,68 @@ func Split(ch <-chan int, n int) []chan int {
 
 // Split2  多工作者重复分发
 // Split2 a channel into n channels that receive messages in a round-robin fashion.
-func Split2(ch <-chan int, n int) []<-chan int {
+func Split2(ch <-chan int, n int) []chan int {
 
-	cs := make([]chan int, n)
+	cs := make([]chan int, 0)
+	for i := 0; i < n; i++ {
+		cs = append(cs, make(chan int))
+	}
 
-	//this version will block
+	distributeToChannels := func(ch <-chan int, cs []chan int) {
+		// Close every channel when the execution ends.
+		defer func() {
+			for _, c := range cs {
+				close(c)
+			}
+		}()
+		var wg sync.WaitGroup
 		for {
 			//get a target from ch
 			select {
 			case val, ok := <-ch:
 				if !ok {
-				return cs
+					return
 				}
+				wg.Add(1)
+				go func(v int) {
+					defer wg.Done()
 					//send value to all channels
 					for _, c := range cs {
-				go func(tmpV int) {
+						c <- val
-					c <- tmpV
+					}
+
 				}(val)
 
 			}
 		}
+
+		wg.Wait()
 	}
 
+	go distributeToChannels(ch, cs)
+
 	return cs
 }
 
 //Split3  随机分发到不同的目的地
 //Split3 a channel into n channels that receive messages in a round-robin fashion.
-func Split3(ch <-chan int, n int) []<-chan int {
+func Split3(ch <-chan int, n int) []chan int {
 
-	cs := make([]chan int, n)
+	cs := make([]chan int, 0)
+	for i := 0; i < n; i++ {
+		cs = append(cs, make(chan int))
+	}
 
 	// Distributes the work in a round robin fashion among the stated number
 	// of channels until the main channel has been closed. In that case, close
 	// all channels and return.
-	distributeToChannels := func(ch <-chan int, cs []chan<- int) {
+	distributeToChannels := func(ch <-chan int, cs []chan int) {
 		// Close every channel when the execution ends.
-		defer func(cs []chan<- int) {
+		defer func() {
 			for _, c := range cs {
 				close(c)
 			}
-		}(cs)
+		}()
 
 		for {
 			for _, c := range cs {
@@ -91,7 +118,6 @@ func Split3(ch <-chan int, n int) []<-chan int {
 					if !ok {
 						return
 					}
-
 					c <- val
 				}
 			}

gomore/05_fan_out/fan_out_test.go

@@ -6,7 +6,8 @@ import (
 	"testing"
 )
 
-func TestMultiFanOutNumbersSeq(T *testing.T) {
+//重复分发
+func TestFanOutDuplicate(t *testing.T) {
 
 	//一路输入源
 	dataStreams := []int{13, 44, 56, 99, 9, 45, 67, 90, 78, 23}
@@ -20,9 +21,11 @@ func TestMultiFanOutNumbersSeq(T *testing.T) {
 	// 重复分发
 	outArray := Split(ch, 3)
 
+	length := len(outArray)
+	t.Log("length of out channel:", length)
 	var wg sync.WaitGroup
-	wg.Add(len(outArray))
+	wg.Add(length)
-	for i := 0; i < len(outArray); i++ {
+	for i := 0; i < length; i++ {
 
 		go func(in <-chan int, index int) {
 			sum := 0
@@ -37,6 +40,76 @@ func TestMultiFanOutNumbersSeq(T *testing.T) {
 	wg.Wait()
 }
 
+//随机分发
+// worker: 2 11245
+// worker: 0 14988
+// worker: 1 10117
+func TestFanOutRandom(t *testing.T) {
+
+	//一路输入源
+	dataStreams := []int{13, 44, 56, 99, 9, 45, 67, 90, 78, 23}
+	//generator integer stream
+	inputChan := gen(dataStreams...)
+
+	// transfer to
+	ch := sq(inputChan)
+
+	//	split it to 3 channel
+	// 重复分发
+	outArray := Split3(ch, 3)
+
+	length := len(outArray)
+	t.Log("length of out channel:", length)
+	var wg sync.WaitGroup
+	wg.Add(length)
+	for i := 0; i < length; i++ {
+
+		go func(in <-chan int, index int) {
+			sum := 0
+			for item := range in {
+				sum += item
+			}
+			fmt.Println("worker:", index, sum)
+
+			wg.Done()
+		}(outArray[i], i)
+	}
+	wg.Wait()
+}
+
+//多工作者,重复分发
+func TestFanOutDuplicateMultiWorkers(t *testing.T) {
+
+	//一路输入源
+	dataStreams := []int{13, 44, 56, 99, 9, 45, 67, 90, 78, 23}
+	//generator integer stream
+	inputChan := gen(dataStreams...)
+
+	// transfer to
+	ch := sq(inputChan)
+
+	//	split it to 3 channel
+	// 重复分发
+	outArray := Split2(ch, 3)
+
+	length := len(outArray)
+	t.Log("length of out channel:", length)
+	var wg sync.WaitGroup
+	wg.Add(length)
+	for i := 0; i < length; i++ {
+
+		go func(in <-chan int, index int) {
+			sum := 0
+			for item := range in {
+				sum += item
+			}
+			fmt.Println("worker:", index, sum)
+
+			wg.Done()
+		}(outArray[i], i)
+	}
+	wg.Wait()
+}
 func TestManualFanOutNumbersSeq(T *testing.T) {
 
 	//一路输入源