A minimalistic and zero-dependency scheduling library for Go.
Inspired by the Quartz Java scheduler.
type Scheduler interface {
// Start starts the scheduler. The scheduler will run until
// the Stop method is called or the context is canceled. Use
// the Wait method to block until all running jobs have completed.
Start(context.Context)
// IsStarted determines whether the scheduler has been started.
IsStarted() bool
// ScheduleJob schedules a job using a specified trigger.
ScheduleJob(jobDetail *JobDetail, trigger Trigger) error
// GetJobKeys returns the keys of scheduled jobs.
// For a job key to be returned, the job must satisfy all of the
// matchers specified.
// Given no matchers, it returns the keys of all scheduled jobs.
GetJobKeys(...Matcher[ScheduledJob]) ([]*JobKey, error)
// GetScheduledJob returns the scheduled job with the specified key.
GetScheduledJob(jobKey *JobKey) (ScheduledJob, error)
// DeleteJob removes the job with the specified key from the
// scheduler's execution queue.
DeleteJob(jobKey *JobKey) error
// PauseJob suspends the job with the specified key from being
// executed by the scheduler.
PauseJob(jobKey *JobKey) error
// ResumeJob restarts the suspended job with the specified key.
ResumeJob(jobKey *JobKey) error
// Clear removes all of the scheduled jobs.
Clear() error
// Wait blocks until the scheduler stops running and all jobs
// have returned. Wait will return when the context passed to
// it has expired. Until the context passed to start is
// cancelled or Stop is called directly.
Wait(context.Context)
// Stop shutdowns the scheduler.
Stop()
}
Implemented Schedulers
- StdScheduler
type Trigger interface {
// NextFireTime returns the next time at which the Trigger is scheduled to fire.
NextFireTime(prev int64) (int64, error)
// Description returns the description of the Trigger.
Description() string
}
Implemented Triggers
- CronTrigger
- SimpleTrigger
- RunOnceTrigger
Any type that implements it can be scheduled.
type Job interface {
// Execute is called by a Scheduler when the Trigger associated with this job fires.
Execute(context.Context) error
// Description returns the description of the Job.
Description() string
}
Several common Job implementations can be found in the job package.
Field Name | Mandatory | Allowed Values | Allowed Special Characters |
---|---|---|---|
Seconds | YES | 0-59 | , - * / |
Minutes | YES | 0-59 | , - * / |
Hours | YES | 0-23 | , - * / |
Day of month | YES | 1-31 | , - * ? / |
Month | YES | 1-12 or JAN-DEC | , - * / |
Day of week | YES | 1-7 or SUN-SAT | , - * ? / |
Year | NO | empty, 1970- | , - * / |
The scheduler can use its own implementation of quartz.JobQueue
to allow state sharing.
An example implementation of the job queue using the file system as a persistence layer
can be found here.
To set a custom logger, use the logger.SetDefault
function.
The argument must implement the logger.Logger
interface.
The following example shows how to disable library logs.
import "github.com/reugn/go-quartz/logger"
logger.SetDefault(logger.NewSimpleLogger(nil, logger.LevelOff))
package main
import (
"context"
"net/http"
"time"
"github.com/reugn/go-quartz/job"
"github.com/reugn/go-quartz/quartz"
)
func main() {
ctx, cancel := context.WithCancel(context.Background())
defer cancel()
// create scheduler
sched := quartz.NewStdScheduler()
// async start scheduler
sched.Start(ctx)
// create jobs
cronTrigger, _ := quartz.NewCronTrigger("1/5 * * * * *")
shellJob := job.NewShellJob("ls -la")
request, _ := http.NewRequest(http.MethodGet, "https://worldtimeapi.org/api/timezone/utc", nil)
curlJob := job.NewCurlJob(request)
functionJob := job.NewFunctionJob(func(_ context.Context) (int, error) { return 42, nil })
// register jobs to scheduler
sched.ScheduleJob(quartz.NewJobDetail(shellJob, quartz.NewJobKey("shellJob")),
cronTrigger)
sched.ScheduleJob(quartz.NewJobDetail(curlJob, quartz.NewJobKey("curlJob")),
quartz.NewSimpleTrigger(time.Second*7))
sched.ScheduleJob(quartz.NewJobDetail(functionJob, quartz.NewJobKey("functionJob")),
quartz.NewSimpleTrigger(time.Second*5))
// stop scheduler
sched.Stop()
// wait for all workers to exit
sched.Wait(ctx)
}
More code samples can be found in the examples directory.
Licensed under the MIT License.