永不阻塞, 无限缓存的 Channel

A never-blocking, infinitely buffered channel. forked from smallnest/chanx

Ref: 实现无限缓存的channel | 鸟窝 https://colobu.com/2021/05/11/unbounded-channel-in-go/

变动

• 增加初始化可选参数 maxBufferSize
  • 用于限定最大缓存数量, 将无限缓存变为永不阻塞的有限缓存队列, 超过限制丢弃数据
• 增加数据丢弃时回调方法: c.SetOnDiscards(func(T))
  • 用于数据达到限定的最大缓存数量并丢弃时, 将数据传给回调方法处理(无限缓存无效)
• 增加动态调整最大缓存数量方法: c.SetMaxBufferSize(0)
  • 值为 0 时恢复无限缓存, 返回值为 0 或当前最大缓存限制数(含初始容量)
• 增加一些计数方法: c.BufCapacity() c.MaxBufferSize() c.Discards()

使用

• Go 1.17.x or below: unbounded_chan_test.go
• Go generic: unbounded_chanof_test.go

安装

go get github.com/fufuok/chanx

永不阻塞, 无限缓存的 Channel

Never Block, Infinitely Cached Channel

package main

import (
	"context"
	"fmt"

	"github.com/fufuok/chanx"
)

func main() {
	ctx, cancel := context.WithCancel(context.Background())
	defer cancel()

	ch := chanx.NewUnboundedChanOf[int](ctx, 10)
	// or
	// ch := chanx.NewUnboundedChanSizeOf[int](ctx, 10, 200, 1000)

	go func() {
		for i := 0; i < 100; i++ {
			ch.In <- i // send values
		}
		close(ch.In) // close In channel
	}()

	for v := range ch.Out { // read values
		fmt.Println(v + 1)
	}
}

永不阻塞, 带缓存上限的 Channel

Never block, Channel with buffer size limit

package main

import (
	"context"
	"fmt"

	"github.com/fufuok/chanx"
)

func main() {
	ctx, cancel := context.WithCancel(context.Background())
	defer cancel()

	// 可选参数, 缓冲上限
	const maxBufCapacity = 10
	ch := chanx.NewUnboundedChanOf[int](ctx, 10, maxBufCapacity)
	// or
	// ch := chanx.NewUnboundedChanSizeOf[int](ctx, 10, 10, 10, maxBufCapacity)

	// 有缓冲上限时, 可选设置数据丢弃时回调
	ch.SetOnDiscards(func(v int) {
		fmt.Println("discard: ", v)
	})

	go func() {
		for i := 0; i < 100; i++ {
			ch.In <- i // send values
		}
		close(ch.In) // close In channel
	}()

	for v := range ch.Out { // read values
		fmt.Println(v + 1)
	}
}

chanx

Unbounded chan with ringbuffer.

Refer to the below articles and issues:

1. golang/go#20352
2. https://stackoverflow.com/questions/41906146/why-go-channels-limit-the-buffer-size
3. https://medium.com/capital-one-tech/building-an-unbounded-channel-in-go-789e175cd2cd
4. https://erikwinter.nl/articles/2020/channel-with-infinite-buffer-in-golang/