Task Schedule

This chapter contains schedule usage examples.

Introduction

Schedule components are roughly divided into two categories. One type is executed according to time intervals. This type of tasks is implemented using the native time.Ticker. The other type is executed using Linux Crontab expressions. This type of bottom layer encapsulates robfig/cron Class library. Scheduled tasks provide developers with easy-to-use syntax sugar.

Usage

Interval

main.go

import (
    "github.com/keepchen/go-sail/v3/schedule"
)

func main() {
    ch := make(chan, struct{})
    task := func() {
        fmt.Println("taskName...")
    }
    schedule.NewJob("taskName", task).EverySecond()
    ch <- struct{}{} //waiting...
}

Linux Crontab Style

main.go

import (
    "github.com/keepchen/go-sail/v3/schedule"
)

func main() {
    ch := make(chan, struct{})
    task := func() {
        fmt.Println("taskName...")
    }
    schedule.NewJob("taskName", task).RunAt("* * * * *")
    ch <- struct{}{} //waiting...
}

Delay (One-time)

main.go

import (
    "time"
    "github.com/keepchen/go-sail/v3/schedule"
)

func main() {
    ch := make(chan, struct{})
    task := func() {
        fmt.Println("taskName...")
    }
    schedule.NewJob("taskName", task).RunAfter(5*time.Second)
    ch <- struct{}{} //waiting...
}

Without Overlapping

The function of the WithoutOverlapping() method is to prevent tasks from running repeatedly at the same time. It is useful when your service runs multiple copies and you want to ensure the uniqueness of the task.

warning

This feature requires initializing the redis connection instance in advance, both in standalone mode and cluster mode.
Otherwise it will panic.

main.go

import (
    "github.com/keepchen/go-sail/v3/schedule"
)

func main() {
    ch := make(chan, struct{})
    task := func() {
        fmt.Println("taskName...")
    }
    schedule.NewJob("taskName", task).WithoutOverlapping().EverySecond()
    ch <- struct{}{} //waiting...
}

note

It should be noted that your task should not be entirely a goroutine, otherwise unexpected situations will occur and WithoutOverlapping() will also fail.

Here is an example of an error:

main.go

import (
    "github.com/keepchen/go-sail/v3/schedule"
)

func main() {
    ch := make(chan, struct{})
    task := func() {
        go func() {
            ...
            fmt.Println("taskName...")
            ...
        }
    }
    schedule.NewJob("taskName", task).WithoutOverlapping().EverySecond()
    ch <- struct{}{} //waiting...
}

Cancel

Tasks that have not been started or are not running will be canceled directly. A running task will wait for its run to complete and then not start again.

main.go

import (
    "time"
    "github.com/keepchen/go-sail/v3/schedule"
)

func main() {
    ch := make(chan, struct{})
    task := func() {
        fmt.Println("taskName...")
    }
    cancel := schedule.NewJob("taskName", task).WithoutOverlapping().EverySecond()
    time.Sleep(5*time.Second)
    cancel()
    ch <- struct{}{} //waiting...
}

Crontab Expressions

github.com/keepchen/go-sail/schedule/crontabexpr.go

EveryMinute                           = "* * * * *"             //每分钟的开始第0秒
EveryFiveMinute                       = "*/5 * * * *"           //每5分钟的开始第0秒
EveryTenMinute                        = "*/10 * * * *"          //每10分钟的开始第0秒
EveryFifteenMinute                    = "*/15 * * * *"          //每15分钟的开始第0秒
EveryTwentyMinute                     = "*/20 * * * *"          //每20分钟的开始第0秒
EveryThirtyMinute                     = "*/30 * * * *"          //每30分钟的开始第0秒
EveryFortyFiveMinute                  = "*/45 * * * *"          //每45分钟的开始第0秒
FirstDayOfMonth                       = "0 0 1 * *"             //每月的第一天的0点0分
LastDayOfMonth                        = "0 0 L * *"             //每月的最后一天的0点0分
FirstDayOfWeek                        = "0 0 * * 1"             //每周的第一天（周一）的0点0分
LastDayOfWeek                         = "0 0 * * 7"             //每周的最后一天（周天）的0点0分
TenClockAtWeekday                     = "0 10 * * MON-FRI"      //每个工作日（周一~周五）的上午10点0分
TenClockAtWeekend                     = "0 10 * * SAT,SUN"      //每个周末（周六和周日）的上午10点0分
HourlyBetween9And17ClockAtWeekday     = "0 9-17 * * MON-FRI"    //每个工作日（周一~周五）的上午9点0分到下午5点0分每小时一次
HalfHourlyBetween9And17ClockAtWeekday = "*/30 9-17 * * MON-FRI" //每个工作日（周一~周五）的上午9点0分到下午5点0分每半时一次

usage

main.go

import (
    "github.com/keepchen/go-sail/v3/schedule"
)

func main() {
    ch := make(chan, struct{})
    task := func() {
        fmt.Println("taskName...")
    }
    schedule.NewJob("taskName", task).WithoutOverlapping().RunAt(schedule.EveryFiveMinute)
    ch <- struct{}{} //waiting...
}