Class: Zhong::Scheduler

Inherits:
Object
  • Object
show all
Extended by:
Forwardable
Defined in:
lib/zhong/scheduler.rb

Constant Summary collapse

DEFAULT_CONFIG = 
{
  timeout: 0.5,
  grace: 15.minutes,
  long_running_timeout: 5.minutes
}.freeze

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(config = {}) ⇒ Scheduler

Returns a new instance of Scheduler.



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# File 'lib/zhong/scheduler.rb', line 14

def initialize(config = {})
  @jobs = {}
  @callbacks = {}
  @config = DEFAULT_CONFIG.merge(config)

  @category = nil
  @error_handler = nil
  @running = false
end

Instance Attribute Details

#jobs ⇒ Object (readonly)

Returns the value of attribute jobs.



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# File 'lib/zhong/scheduler.rb', line 6

def jobs
  @jobs
end

Instance Method Details

#category(name) {|_self| ... } ⇒ Object

Yields:

  • (_self)

Yield Parameters:



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# File 'lib/zhong/scheduler.rb', line 32

def category(name)
  raise "cannot nest categories: #{name} would be nested in #{@category} (#{caller.first})" if @category

  @category = name.to_s

  yield(self)

  @category = nil
end

#clear ⇒ Object 



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# File 'lib/zhong/scheduler.rb', line 24

def clear
  raise "unable to clear while running; run Zhong.stop first" if @running

  @jobs = {}
  @callbacks = {}
  @category = nil
end

#error_handler(&block) ⇒ Object 



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# File 'lib/zhong/scheduler.rb', line 52

def error_handler(&block)
  @error_handler = block if block_given?
  @error_handler
end

#every(period, name, opts = {}, &block) ⇒ Object 



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# File 'lib/zhong/scheduler.rb', line 42

def every(period, name, opts = {}, &block)
  raise "must specify a period for #{name} (#{caller.first})" unless period

  job = Job.new(name, opts.merge(@config).merge(every: period, category: @category), @callbacks, &block)

  raise "duplicate job #{job}" if jobs.key?(job.id)

  @jobs[job.id] = job
end

#find_by_name(job_name) ⇒ Object 



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# File 'lib/zhong/scheduler.rb', line 111

def find_by_name(job_name)
  @jobs[Digest::SHA256.hexdigest(job_name)]
end

#on(event, &block) ⇒ Object 



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# File 'lib/zhong/scheduler.rb', line 57

def on(event, &block)
  unless [:before_tick, :after_tick, :before_run, :after_run, :before_disable,
          :after_disable, :before_enable, :after_enable].include?(event.to_sym)
    raise "unknown callback #{event}"
  end
  (@callbacks[event.to_sym] ||= []) << block
end

#redis_time ⇒ Object 



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# File 'lib/zhong/scheduler.rb', line 115

def redis_time
  s, ms = redis.time # returns [seconds since epoch, microseconds]
  now = Time.at(s + ms / (10**6))
  tz ? now.in_time_zone(tz) : now
end

#start ⇒ Object 



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# File 'lib/zhong/scheduler.rb', line 65

def start
  logger.info "starting at #{redis_time}"

  @stop = false

  trap_signals

  raise "already running" if @running

  loop do
    @running = true

    if fire_callbacks(:before_tick)
      now = redis_time

      jobs_to_run(now).each do |_, job|
        break if @stop
        run_job(job, now)
      end

      break if @stop

      fire_callbacks(:after_tick)

      heartbeat(now)

      break if @stop
    else
      logger.info "skipping tick due to a `:before_tick` callback"
    end

    sleep_until_next_second

    break if @stop
  end

  @running = false

  Thread.new { logger.info "stopped" }.join
end

#stop ⇒ Object 



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# File 'lib/zhong/scheduler.rb', line 106

def stop
  Thread.new { logger.error "stopping" } if @running # thread necessary due to trap context
  @stop = true
end