cron

type Cron struct {
	// contains filtered or unexported fields
}

type Job struct {
	// The unique name of the job.
	Name string

	// The cron expression. See https://github.com/gorhill/cronexpr#implementation.
	//
	// Note that the execution interval of the job must be greater than LockTTL.
	Expr string

	// The handler of the job.
	Task func()
}

type Locker interface {
	// Lock obtains the lock to execute the job named job. If the lock is
	// successfully obtained, Lock will return true, otherwise it will return false.
	//
	// The implementation of Locker must release the obtained lock automatically
	// after ttl elapses.
	Lock(job string, ttl time.Duration) (bool, error)
}

type NilLocker struct{}

type Options struct {
	// The location name, which must be "Local", "UTC" or a location name corresponding
	// to a file in the IANA Time Zone database, such as "Asia/Shanghai".
	//
	// Defaults to "UTC".
	Timezone string

	// LockTTL is the time duration after which the successfully obtained lock
	// will be released. It is a time window used to protect a job from
	// being executed more than once per execution time of its schedule,
	// which may be caused by the clock error among different machines.
	//
	// Defaults to 1s.
	LockTTL time.Duration

	// The handler for errors.
	ErrHandler func(error)
}