mirror of
https://github.com/crazybber/go-pattern-examples.git
synced 2024-11-22 03:46:03 +03:00
update code content for fan-out pattern
This commit is contained in:
Edward
parent
5e5c367660
commit
fe3617814c
@ -1,131 +1,132 @@
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package fanout
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import (
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"context"
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"sync"
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"sync/atomic"
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// Split 重复分发数据为多份
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// Split a channel into n channels that receive messages in a round-robin fashion.
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func Split(ch <-chan int, n int) []chan int {
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"go.uber.org/zap"
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)
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//get a queue of chan
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cs := make([]chan int, n)
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var (
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log, _ = zap.NewDevelopment()
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)
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const (
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MaxWorkers = 16
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MaxQueueSize = 512
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MasterQueueSize = MaxQueueSize * MaxWorkers
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)
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type Pipeline struct {
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workers map[int]*worker
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chain chan interface{}
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}
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func (p *Pipeline) Start(ctx context.Context) {
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go func(pipe *Pipeline) {
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for {
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expectationWorkers := len(pipe.chain) % MaxWorkers
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if expectationWorkers >= MaxWorkers {
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expectationWorkers = 0
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// Distributes the work in a round robin fashion among the stated number
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// of channels until the main channel has been closed. In that case, close
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// all channels and return.
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distributeToChannels := func(ch <-chan int, cs []chan int) {
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// Close every channel when the execution ends.
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defer func(cs []chan int) {
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for _, c := range cs {
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close(c)
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}
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}(cs)
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//this version will block
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for {
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//get a target from ch
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select {
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case <-ctx.Done():
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return
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case val, ok := <-pipe.chain:
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case val, ok := <-ch:
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if !ok {
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return
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}
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go pipe.workers[expectationWorkers].stream(val)
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//send value to all channels
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for _, c := range cs {
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c <- val
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}
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}
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}
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}(p)
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}
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func (p *Pipeline) Dispatch(msg interface{}) {
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p.chain <- msg
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}
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type DispatcherBuilder func() Dispatcher
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func NewPipeline(d DispatcherBuilder, idle uint32, debug bool) *Pipeline {
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ch := make(chan interface{}, MasterQueueSize)
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wk := make(map[int]*worker)
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for i := 0; i < MaxWorkers; i++ {
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wk[i] = &worker{
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index: uint32(i + 1),
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chain: make(chan interface{}, MaxQueueSize),
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mutex: new(sync.Mutex),
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debug: debug,
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idle: idle,
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Dispatcher: d(),
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}
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}
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return &Pipeline{workers: wk, chain: ch}
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// a worker to distribute message
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go distributeToChannels(ch, cs)
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return cs
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}
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type Dispatcher interface {
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Before(context.Context) error
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After() error
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Process(interface{}) error
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}
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// Split2 多工作者重复分发
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// Split2 a channel into n channels that receive messages in a round-robin fashion.
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func Split2(ch <-chan int, n int) []<-chan int {
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type worker struct {
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index uint32
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mutex *sync.Mutex
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running bool
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chain chan interface{}
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debug bool
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idle uint32
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Dispatcher
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}
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cs := make([]chan int, n)
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func (c *worker) stream(val interface{}) {
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c.chain <- val
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if !c.running {
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c.mutex.Lock()
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c.running = true
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ctx, cancel := context.WithCancel(context.Background())
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defer func(w *worker, cancel context.CancelFunc) {
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if w.debug {
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log.Info("Worker leaving", zap.Any("index", w.index), zap.Any("idle", w.idle))
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//this version will block
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for {
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//get a target from ch
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select {
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case val, ok := <-ch:
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if !ok {
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return cs
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}
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err := c.After()
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if err != nil {
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log.Error("can not finish track issue", zap.Error(err))
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}
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cancel()
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w.mutex.Unlock()
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w.running = false
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}(c, cancel)
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err := c.Before(ctx)
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//send value to all channels
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for _, c := range cs {
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go func(tmpV int) {
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c <- tmpV
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}(val)
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if err != nil {
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log.Error("can not start worker", zap.Error(err))
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}
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}
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var idle uint32 = 0
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}
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return cs
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}
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//Split3 随机分发到不同的目的地
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//Split3 a channel into n channels that receive messages in a round-robin fashion.
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func Split3(ch <-chan int, n int) []<-chan int {
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cs := make([]chan int, n)
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// Distributes the work in a round robin fashion among the stated number
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// of channels until the main channel has been closed. In that case, close
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// all channels and return.
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distributeToChannels := func(ch <-chan int, cs []chan<- int) {
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// Close every channel when the execution ends.
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defer func(cs []chan<- int) {
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for _, c := range cs {
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close(c)
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}
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}(cs)
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for {
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select {
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case msg := <-c.chain:
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atomic.StoreUint32(&idle, 0)
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if msg != nil {
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err := c.Process(msg)
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if err != nil {
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log.Error("can not process message",
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zap.Any("msg", &msg),
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zap.Error(err),
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)
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}
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}
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default:
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atomic.AddUint32(&idle, 1)
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if i := atomic.LoadUint32(&idle); i > 0 {
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if i > c.idle {
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for _, c := range cs {
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select {
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case val, ok := <-ch:
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if !ok {
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return
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}
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c <- val
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}
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}
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}
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}
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go distributeToChannels(ch, cs)
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return cs
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}
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//The first stage, gen, is a function that converts a list of integers to a channel that emits the integers in the list.
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// The gen function starts a goroutine that sends the integers on the channel and closes the channel when all
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// the values have been sent:
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func gen(nums ...int) <-chan int {
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out := make(chan int)
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go func() {
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defer close(out)
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for _, n := range nums {
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out <- n
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}
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}()
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return out
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}
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//The second stage, sq, receives integers from a channel and returns a channel that emits the square of
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// each received integer. After the inbound channel is closed and this stage has sent all the values downstream,
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// it closes the outbound channel:
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func sq(in <-chan int) <-chan int {
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out := make(chan int)
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go func() {
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for n := range in {
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out <- n * n
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}
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close(out)
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}()
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return out
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}
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@ -1,140 +0,0 @@
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package fanout
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import (
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"context"
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"fmt"
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"log"
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"sync"
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"testing"
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"time"
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)
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func TestFanInOut(T *testing.T) {
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ctx, cancelFunc := context.WithCancel(context.Background())
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defer cancelFunc()
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var errList []chan error
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nChan, err, err := generateNumbers(ctx)
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if err != nil {
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log.Fatal(err)
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}
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errList = append(errList, err)
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fChannel, errList, err := fanout(ctx, nChan, squareNumbers)
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errList = append(errList, errList...)
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res, errRes, err := fanin(fChannel, errList)
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go func() {
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for {
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select {
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case r := <-res:
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v, ok := r.(int)
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if !ok {
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// TODO
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_ = ok
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}
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fmt.Println(v)
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case e := <-errRes:
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fmt.Println(e)
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}
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}
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}()
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fmt.Println("finished")
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time.Sleep(10 * time.Duration(time.Second))
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}
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type Op func(context.Context, chan interface{}) (chan interface{}, chan error, error)
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func generateNumbers(ctx context.Context) (chan interface{}, chan error, error) {
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fmt.Println("generateNumbers called")
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out := make(chan interface{}, 100)
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err := make(chan error, 100)
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go func() {
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defer close(out)
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defer close(err)
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for i := 0; i < 10; i++ {
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fmt.Println("gen: ", i)
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out <- i
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}
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}()
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return out, err, nil
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}
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func fanout(ctx context.Context, in chan interface{}, fct Op) ([]chan interface{}, []chan error, error) {
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fmt.Println("fanout called")
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var out []chan interface{}
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var errList []chan error
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for i := 0; i < 5; i++ {
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res, err, err := fct(ctx, in)
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// Todo: manage error
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_ = err
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out = append(out, res)
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errList = append(errList, err)
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}
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return out, errList, nil
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}
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func squareNumbers(ctx context.Context, in chan interface{}) (chan interface{}, chan error, error) {
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fmt.Println("squareNumbers called")
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out := make(chan interface{}, 100)
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err := make(chan error, 100)
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go func() {
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for v := range in {
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num, _ := v.(int)
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squared := num * num
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select {
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case out <- squared:
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case <-ctx.Done():
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fmt.Println("ctx done")
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return
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}
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}
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close(out)
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}()
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return out, err, nil
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}
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func fanin(ins []chan interface{}, errList []chan error) (chan interface{}, chan error, error) {
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fmt.Println("fanin called")
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out := make(chan interface{}, 100)
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errout := make(chan error, 100)
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var waitgroup sync.WaitGroup
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length := len(ins) + len(errList)
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waitgroup.Add(length)
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for _, v := range ins {
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go func(w chan interface{}) {
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for val := range w {
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out <- val
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}
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waitgroup.Done()
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}(v)
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}
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for _, e := range errList {
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go func(err chan error) {
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for v := range err {
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errout <- v
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}
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waitgroup.Done()
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}(e)
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}
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go func() {
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waitgroup.Wait()
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close(out)
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close(errout)
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}()
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return out, errout, nil
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}
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@ -1 +1,64 @@
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package fanout
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import (
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"fmt"
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"sync"
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"testing"
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)
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func TestMultiFanOutNumbersSeq(T *testing.T) {
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//一路输入源
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dataStreams := []int{13, 44, 56, 99, 9, 45, 67, 90, 78, 23}
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//generator integer stream
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inputChan := gen(dataStreams...)
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// transfer to
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ch := sq(inputChan)
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// split it to 3 channel
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// 重复分发
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outArray := Split(ch, 3)
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var wg sync.WaitGroup
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wg.Add(len(outArray))
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for i := 0; i < len(outArray); i++ {
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go func(in <-chan int, index int) {
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sum := 0
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for item := range in {
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sum += item
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}
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fmt.Println("worker:", index, sum)
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wg.Done()
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}(outArray[i], i)
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}
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wg.Wait()
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}
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func TestManualFanOutNumbersSeq(T *testing.T) {
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//一路输入源
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dataStreams := []int{13, 44, 56, 99, 9, 45, 67, 90, 78, 23}
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// generate the common channel with inputs
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inputChan1 := gen(dataStreams...)
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inputChan2 := gen(dataStreams...)
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//Manual Fan-out to 2 Go-routine
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c1 := sq(inputChan1)
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c2 := sq(inputChan2)
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fmt.Print("c1 queue: ")
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for n := range c1 {
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fmt.Print(n, " ")
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}
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fmt.Println()
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fmt.Print("c2 queue: ")
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for n := range c2 {
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fmt.Print(n, " ")
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}
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fmt.Println()
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}
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@ -1,206 +0,0 @@
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# Implementation
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We can activate worker base on traffic of parent channel
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```go
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package concurrency
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import (
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"context"
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"io"
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"sync"
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"sync/atomic"
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"bitbucket.org/sakariai/sakari/log"
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"bitbucket.org/sakariai/sakari/log/field"
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)
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const (
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MaxWorkers = 32
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MaxQueueSize = 128
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)
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var (
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running uint32 = 0
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)
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type Pipeline struct {
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workers []*worker
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chain chan interface{}
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}
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func (p *Pipeline) Start() {
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distributeToChannels := func(ch chan interface{}, cs []*worker) {
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writer := cs[0] //first worker must stream as default
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for {
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for _, c := range cs {
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expectationWorkers := uint32(len(ch)/(MaxQueueSize/MaxWorkers)) + 1
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select {
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case val := <-ch:
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runningWorker := atomic.LoadUint32(&running)
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if c.index <= runningWorker || c.index <= expectationWorkers {
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writer = c
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}
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if c.debug {
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log.Info("Worker receiving", field.Any("index", writer.index), field.Any("running", runningWorker), field.Any("no# workers", expectationWorkers))
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}
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go writer.stream(val)
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}
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}
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}
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}
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go distributeToChannels(p.chain, p.workers)
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}
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func (p *Pipeline) Dispatch(msg interface{}) {
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p.chain <- msg
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}
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type DispatcherBuilder func() Dispatcher
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func NewPipeline(d DispatcherBuilder, ch chan interface{}, idle uint32, debug bool) *Pipeline {
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wk := make([]*worker, 0, MaxWorkers)
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for i := 0; i < MaxWorkers; i++ {
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wk = append(wk,
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&worker{
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index: uint32(i + 1),
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chain: make(chan interface{}, MaxQueueSize),
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mutex: new(sync.Mutex),
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debug: debug,
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idle: idle,
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Dispatcher: d(),
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})
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}
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return &Pipeline{workers: wk, chain: ch}
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}
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|
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type Dispatcher interface {
|
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Before(context.Context) error
|
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After() error
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Process(interface{}) error
|
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}
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|
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type worker struct {
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index uint32
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mutex *sync.Mutex
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running bool
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chain chan interface{}
|
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debug bool
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idle uint32
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Dispatcher
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}
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|
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func (c *worker) stream(val interface{}) {
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c.chain <- val
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if !c.running {
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c.mutex.Lock()
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c.running = true
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atomic.AddUint32(&running, 1)
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defer atomic.AddUint32(&running, ^uint32(1-1))
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ctx, cancel := context.WithCancel(context.Background())
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err := c.Before(ctx)
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|
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if err != nil {
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log.Error("can not start worker", field.Error(err))
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}
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defer func(w *worker, cancel context.CancelFunc) {
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if w.debug {
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log.Info("Worker leaving", field.Any("index", w.index), field.Any("idle", w.idle))
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}
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err := c.After()
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if err != nil {
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log.Error("can not finish track issue", field.Error(err))
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}
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cancel()
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w.mutex.Unlock()
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w.running = false
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}(c, cancel)
|
||||
var idle uint32 = 0
|
||||
for {
|
||||
select {
|
||||
case msg := <-c.chain:
|
||||
atomic.StoreUint32(&idle, 0)
|
||||
if msg != nil {
|
||||
err := c.Process(msg)
|
||||
if err != nil {
|
||||
log.Error("can not process message",
|
||||
field.Any("msg", &msg),
|
||||
field.Error(err),
|
||||
)
|
||||
}
|
||||
if err == io.EOF {
|
||||
return
|
||||
}
|
||||
}
|
||||
default:
|
||||
atomic.AddUint32(&idle, 1)
|
||||
if i := atomic.LoadUint32(&idle); i > 0 {
|
||||
if i > c.idle {
|
||||
return
|
||||
}
|
||||
if c.debug {
|
||||
log.Info("Idle", field.Any("worker index", c.index), field.Any("idle", idle))
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
```
|
||||
|
||||
## Usage
|
||||
|
||||
```go
|
||||
import concurrency
|
||||
|
||||
type taggingDispatcher struct {
|
||||
Address string
|
||||
stream proto.Havilah_StreamMetricClient
|
||||
conn *grpc.ClientConn
|
||||
}
|
||||
|
||||
func (d *taggingDispatcher) Before(ctx context.Context) error {
|
||||
conn, err := grpc.Dial(d.Address, grpc.WithInsecure())
|
||||
if err != nil {
|
||||
return err
|
||||
}
|
||||
d.conn = conn
|
||||
client := proto.NewHavilahClient(conn)
|
||||
|
||||
stream, err := client.StreamMetric(ctx)
|
||||
if err != nil {
|
||||
return err
|
||||
}
|
||||
d.stream = stream
|
||||
return nil
|
||||
}
|
||||
|
||||
func (d *taggingDispatcher) After() error {
|
||||
_, err := d.stream.CloseAndRecv()
|
||||
|
||||
e := d.conn.Close()
|
||||
if e != nil {
|
||||
log.Error("close havilah connection error", field.Error(e))
|
||||
}
|
||||
return err
|
||||
}
|
||||
|
||||
func (d *taggingDispatcher) Process(msg interface{}) error {
|
||||
return d.stream.Send(msg.(*proto.Tagging))
|
||||
}
|
||||
|
||||
|
||||
tagging := &Tagging{
|
||||
topic: topic,
|
||||
pipeline: concurrency.NewPipeline(func() concurrency.Dispatcher {
|
||||
return &taggingDispatcher{Address: address}
|
||||
}, ch, idle, debug),
|
||||
}
|
||||
tagging.pipeline.Start()
|
||||
|
||||
func main(){
|
||||
tagging.pipeline.Dispatch(youStruct{})
|
||||
}
|
||||
```
|
||||
Loading…
Reference in New Issue
Block a user