Class: Procrastinator::Scheduler

Inherits:
Object
  • Object
show all
Defined in:
lib/procrastinator/scheduler.rb

Overview

A Scheduler object provides the API for client applications to manage scheduled tasks.

Use Scheduler#defer to schedule new tasks, Scheduler#reschedule to alter existing tasks, and Scheduler#cancel to remove unwanted tasks.

Author:

  • Robin Miller

Defined Under Namespace

Modules: DaemonWorking, SerialWorking, ThreadedWorking Classes: UpdateProxy, WorkProxy

Instance Method Summary collapse

Constructor Details

#initialize(config) ⇒ Scheduler 



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# File 'lib/procrastinator/scheduler.rb', line 13

def initialize(config)
   @config = config
end

Instance Method Details

#cancel(queue, identifier) ⇒ Object

Removes an existing task, as located by the given identifying information.

The identifier can include any data field stored in the task loader. Often this is the information in :data.

See Also:



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# File 'lib/procrastinator/scheduler.rb', line 61

def cancel(queue, identifier)
   queue = @config.queue(name: queue)

   tasks = queue.read(identifier.merge(queue: queue.name.to_s))

   raise "no task matches search: #{ identifier }" if tasks.empty?
   raise "multiple tasks match search: #{ identifier }" if tasks.size > 1

   queue.delete(tasks.first[:id])
end

#defer(queue_name = nil, data: nil, run_at: Time.now, expire_at: nil) ⇒ Object Also known as: delay

Records a new task to be executed at the given time.

Raises:

  • (ArgumentError) 


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# File 'lib/procrastinator/scheduler.rb', line 23

def defer(queue_name = nil, data: nil, run_at: Time.now, expire_at: nil)
   raise ArgumentError, "      must provide a queue name as the first argument. Received: \#{ queue_name }\n   ERR\n\n   queue = @config.queue(name: queue_name)\n\n   queue.create(run_at: run_at, expire_at: expire_at, data: data)\nend\n" unless queue_name.nil? || queue_name.is_a?(Symbol)

#reschedule(queue, identifier) ⇒ Object

Alters an existing task to run at a new time, expire at a new time, or both.

Call UpdateProxy#to on the result and pass in the new :run_at and/or :expire_at.

Example:

scheduler.reschedule(:alerts, data: {user_id: 5}).to(run_at: Time.now, expire_at: Time.now + 10)

The identifier can include any data field stored in the task loader. Often this is the information in :data.

See Also:



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# File 'lib/procrastinator/scheduler.rb', line 49

def reschedule(queue, identifier)
   UpdateProxy.new(@config.queue(name: queue), identifier: identifier)
end

#work(*queue_names) ⇒ Object

Spawns a new worker thread for each queue defined in the config



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# File 'lib/procrastinator/scheduler.rb', line 76

def work(*queue_names)
   queue_names = @config.queues if queue_names.empty?

   workers = queue_names.collect do |queue_name|
      QueueWorker.new(queue: queue_name, config: @config)
   end

   WorkProxy.new(workers, @config)
end