class JoobQ::Scheduler

• JoobQ::Scheduler
• Reference
• Object

Overview

The Scheduler class is responsible for managing job scheduling. It supports scheduling jobs to run at specific intervals, delaying jobs, and running jobs based on cron patterns. The Scheduler ensures that jobs are executed at the right time and provides mechanisms for recurring and delayed job execution.

Properties

• jobs : Hash(String, RecurringJobs | CronParser) - A hash that stores scheduled jobs and their intervals or cron patterns.
• store : Store - The store instance used for job storage and retrieval.

Usage

Delaying a Job

To delay a job for a specific timespan, use the #delay method:

scheduler = JoobQ.scheduler
job = ExampleJob.new(x: 1)
scheduler.delay(job, for: 2.minutes)

Scheduling a Recurring Job

To schedule a job to run at a specific interval, use the #every method:

scheduler = JoobQ.scheduler
scheduler.every(5.minutes, ExampleJob, x: 1)

Scheduling a Cron Job

To schedule a job based on a cron pattern, use the #cron method:

scheduler = JoobQ.scheduler
scheduler.cron("*/5 * * * *") do
  ExampleJob.new(x: 1).perform
end

Scheduler Workflow

1. Initialization:

• The Scheduler class is initialized as a singleton instance using the .instance method.
• The #jobs hash is used to store scheduled jobs and their intervals or cron patterns.

2. Delaying Jobs:

• The #delay method schedules a job to be executed after a specified timespan.
• The job is added to the store with a delay in milliseconds.

3. Scheduling Recurring Jobs:

• The #every method schedules a job to run at a specified interval.
• A new job instance is created and stored in the #jobs hash.
• A loop is spawned to execute the job at the specified interval.

4. Scheduling Cron Jobs:

• The #cron method schedules a job based on a cron pattern.
• A CronParser instance is created and stored in the #jobs hash.
• A loop is spawned to execute the job based on the cron pattern.

5. Job Execution:

• For recurring jobs, the job is executed at the specified interval.
• For cron jobs, the job is executed based on the cron pattern.
• The perform method of the job is called to execute the job logic.

Example

Here is a complete example demonstrating how to use the Scheduler class:

require "joobq"

# Define a job
struct ExampleJob
  include JoobQ::Job
  property x : Int32

  def initialize(@x : Int32)
  end

  def perform
    puts "Performing job with x = #{x}"
  end
end

# Get the scheduler instance
scheduler = JoobQ.scheduler

# Delay a job
job = ExampleJob.new(x: 1)
scheduler.delay(job, for: 2.minutes)

# Schedule a recurring job
scheduler.every(5.minutes, ExampleJob, x: 1)

# Schedule a cron job
scheduler.cron("*/5 * * * *") do
  ExampleJob.new(x: 1).perform
end

This example sets up a scheduler, delays a job, schedules a recurring job, and schedules a cron job.

Defined in:

joobq/scheduler.cr

Class Method Summary

• .instance

Instance Method Summary

• #clear
• #cron(pattern, &block : -> )
• #delay(job : Job, for till : Time::Span)
• #enqueue(current_time = Time.local)
• #every(interval : Time::Span, job : Job.class, **args)
• #jobs : Hash(String, CronParser | JoobQ::Scheduler::RecurringJobs)
• #run

Class Method Detail

Instance Method Detail