lancet/docs/api/packages/retry.md

Retry

retry 重试执行函数直到函数运行成功或被 context cancel。

源码:

• https://github.com/duke-git/lancet/blob/main/retry/retry.go

用法:

import (
    "github.com/duke-git/lancet/v2/retry"
)

目录

• Context
• Retry
• RetryFunc
• RetryDuration
• RetryTimes

文档

Context

设置重试context参数

函数签名:

func Context(ctx context.Context)

示例:运行

import (
    "context"
    "errors"
    "fmt"
    "lancet-demo/retry"
    "time"
)

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

    number := 0
    increaseNumber := func() error {
        number++
        if number > 3 {
            cancel()
        }
        return errors.New("error occurs")
    }

    duration := retry.RetryDuration(time.Microsecond*50)

    retry.Retry(increaseNumber,
        duration,
        retry.Context(ctx),
    )

    fmt.Println(number)

    // Output:
    // 4
}

RetryFunc

被重试执行的函数

函数签名:

type RetryFunc func() error

示例:运行

package main

import (
    "fmt"
    "errors"
    "log"
    "github.com/duke-git/lancet/v2/retry"
)

func main() {
    number := 0
    var increaseNumber retry.RetryFunc = func() error {
        number++
        if number == 3 {
            return nil
        }
        return errors.New("error occurs")
    }

    duration := retry.RetryDuration(time.Microsecond*50)

    err := retry.Retry(increaseNumber, duration)
    if err != nil {
        return
    }

    fmt.Println(number)

    // Output:
    // 3
}

RetryTimes

设置重试次数，默认5

函数签名:

func RetryTimes(n uint)

示例:运行

package main

import (
    "fmt"
    "errors"
    "log"
    "github.com/duke-git/lancet/v2/retry"
)

func main() {
    number := 0

    increaseNumber := func() error {
        number++
        if number == 3 {
            return nil
        }
        return errors.New("error occurs")
    }

    err := retry.Retry(increaseNumber, retry.RetryTimes(2))
    if err != nil {
        fmt.Println(err)
    }

    // Output:
    // function main.main.func1 run failed after 2 times retry
}

RetryDuration

设置重试间隔时间，默认3秒

函数签名:

func RetryDuration(d time.Duration)

示例:运行

package main

import (
    "fmt"
    "errors"
    "log"
    "github.com/duke-git/lancet/v2/retry"
)

func main() {
    number := 0
    increaseNumber := func() error {
        number++
        if number == 3 {
            return nil
        }
        return errors.New("error occurs")
    }

    duration := retry.RetryDuration(time.Microsecond*50)

    err := retry.Retry(increaseNumber, duration)
    if err != nil {
        return
    }

    fmt.Println(number)

    // Output:
    // 3
}

Retry

重试执行函数retryFunc，直到函数运行成功，或被context停止

函数签名:

func Retry(retryFunc RetryFunc, opts ...Option) error

示例:运行

package main

import (
    "fmt"
    "errors"
    "log"
    "github.com/duke-git/lancet/v2/retry"
)

func main() {
    number := 0
    increaseNumber := func() error {
        number++
        if number == 3 {
            return nil
        }
        return errors.New("error occurs")
    }

    duration := retry.RetryDuration(time.Microsecond*50)

    err := retry.Retry(increaseNumber, duration)
    if err != nil {
        return
    }

    fmt.Println(number)

    // Output:
    // 3
}