Question

我使用rufus调度程序同时启动了许多预定作业。我想在该代码中有一个变量，该变量只有在一段时间后再次运行时才可用于该预定作业。

如何为每个预定作业维护变量？

Answer 1

有多种方法可以做到这一点。我将详细介绍其中一些，从丑陋到某种优雅。

使用rufus-scheduler 2.0.23（https://rubygems.org/gems/rufus-scheduler）在Debian GNU / Linux 7上针对Ruby 1.9.3p392测试了解决方案。

您可以使用全局变量：

require 'rufus-scheduler'

scheduler = Rufus::Scheduler.start_new

scheduler.every '1s' do
  $counter0 ||= 0
  $counter0 += 1
  p [ :c0, $counter0 ]
end
scheduler.every '1s' do
  $counter1 ||= 0
  $counter1 += 1
  p [ :c0, $counter1 ]
end

scheduler.join

或者您可以将作业变量集中在一个全局变量中（注意：这不是线程安全的）：

require 'rufus-scheduler'

scheduler = Rufus::Scheduler.start_new

$job_vars = {}

scheduler.every '1s' do |job|
  ($job_vars[job.object_id] ||= {})['counter'] ||= 0
  $job_vars[job.object_id]['counter'] += 1
  p [ job.job_id, job.object_id, $job_vars[job.object_id]['counter'] ]
end
scheduler.every '1.5s' do |job|
  ($job_vars[job.object_id] ||= {})['counter'] ||= 0
  $job_vars[job.object_id]['counter'] += 1
  p [ job.job_id, job.object_id, $job_vars[job.object_id]['counter'] ]
end

scheduler.join

更进一步，只是为了好玩（但仍然不是线程安全的）：

require 'rufus-scheduler'

scheduler = Rufus::Scheduler.start_new

$job_vars = {}
job = lambda { |job|
  ($job_vars[job.object_id] ||= {})['counter'] ||= 0
  $job_vars[job.object_id]['counter'] += 1
  p [ job.job_id, job.object_id, $job_vars[job.object_id]['counter'] ]
}

scheduler.every '1s', &job
scheduler.every '1.5s', &job

scheduler.join

最后，您可以在Job类中添加#vars：

require 'rufus-scheduler'

class Rufus::Scheduler::Job
  def vars
    @vars ||= {}
  end
end

scheduler = Rufus::Scheduler.start_new

scheduler.every '1s' do |job|
  job.vars['counter'] = (job.vars['counter'] || 0) + 1
  p [ job.job_id, job.object_id, job.vars['counter'] ]
end
scheduler.every '1.5s' do |job|
  job.vars['counter'] = (job.vars['counter'] || 0) + 1
  p [ job.job_id, job.object_id, job.vars['counter'] ]
end

scheduler.join

这是我更喜欢的解决方案。我打算在rufus-scheduler 3.0（https://github.com/jmettraux/rufus-scheduler）中为Job添加一个类似的变量包。

您也可以将变量放在其他位置并使用job_id / job.object_id作为检索它的键（如第一段代码所做的那样）。

我希望这会有所帮助。

如何在一段时间后再次运行特定计划任务时可以使用的变量？

1 个答案: