class BdrbJobQueue

Model for storing jobs/tasks persisted to the database

Public Class Methods

find_next(worker_name,worker_key = nil) click to toggle source

find next task from the table

# File lib/backgroundrb/bdrb_job_queue.rb, line 6
def self.find_next(worker_name,worker_key = nil)
  returned_job = nil
  ActiveRecord::Base.verify_active_connections!
  transaction do
    unless worker_key
      #use ruby time stamps for time calculations as db might have different times than what is calculated by ruby/rails
      t_job = find(:first,:conditions => [" worker_name = ? AND taken = ? AND scheduled_at <= ? ", worker_name, 0, Time.now.utc ],:lock => true, :order => 'priority desc')
    else
      t_job = find(:first,:conditions => [" worker_name = ? AND taken = ? AND worker_key = ? AND scheduled_at <= ? ", worker_name, 0, worker_key, Time.now.utc ],:lock => true)
    end
    if t_job
      t_job.taken = 1
      t_job.started_at = Time.now.utc
      t_job.save
      returned_job = t_job
    end
  end
  returned_job
end
insert_job(options = { }) click to toggle source

insert a new job for processing. jobs added will be automatically picked by the appropriate worker

# File lib/backgroundrb/bdrb_job_queue.rb, line 47
def self.insert_job(options = { })
  ActiveRecord::Base.verify_active_connections!
  transaction do
    options.merge!(:submitted_at => Time.now.utc,:finished => 0,:taken => 0)
    t_job = new(options)
    t_job.save
  end
end
remove_job(options = { }) click to toggle source

remove a job from table

# File lib/backgroundrb/bdrb_job_queue.rb, line 57
def self.remove_job(options = { })
  ActiveRecord::Base.verify_active_connections!
  transaction do
    t_job_id = find(:first, :conditions => options.merge(:finished => 0,:taken => 0),:lock => true)
    delete(t_job_id)
  end
end

Public Instance Methods

args() click to toggle source
# File lib/backgroundrb/bdrb_job_queue.rb, line 31
def args
  Base64.decode64(read_attribute(:args))
end
args=(args) click to toggle source

these accessors get around any possible character encoding issues with the database

# File lib/backgroundrb/bdrb_job_queue.rb, line 27
def args=(args)
  write_attribute(:args, Base64.encode64(args))
end
finish!() click to toggle source

Mark a job as finished

# File lib/backgroundrb/bdrb_job_queue.rb, line 66
def finish!
  ActiveRecord::Base.verify_active_connections!
  self.class.transaction do
    self.finished = 1
    self.finished_at = Time.now.utc
    self.job_key = "finished_#{Time.now.utc.to_i}_#{job_key}"
    self.save
  end
  Thread.current[:persistent_job_id] = nil
  Thread.current[:job_key] = nil
  nil
end
release_job() click to toggle source

release a job and mark it to be unfinished and free. useful, if inside a worker, processing of this job failed and you want it to process later

# File lib/backgroundrb/bdrb_job_queue.rb, line 37
def release_job
  ActiveRecord::Base.verify_active_connections!
  self.class.transaction do
    self.taken = 0
    self.started_at = nil
    self.save
  end
end