debian-mirror-gitlab/lib/gitlab/sidekiq_middleware/duplicate_jobs/duplicate_job.rb
2020-04-22 19:07:51 +05:30

116 lines
3.1 KiB
Ruby

# frozen_string_literal: true
require 'digest'
module Gitlab
module SidekiqMiddleware
module DuplicateJobs
# This class defines an identifier of a job in a queue
# The identifier based on a job's class and arguments.
#
# As strategy decides when to keep track of the job in redis and when to
# remove it.
#
# Storing the deduplication key in redis can be done by calling `check!`
# check returns the `jid` of the job if it was scheduled, or the `jid` of
# the duplicate job if it was already scheduled
#
# When new jobs can be scheduled again, the strategy calls `#delete`.
class DuplicateJob
DUPLICATE_KEY_TTL = 6.hours
attr_reader :existing_jid
def initialize(job, queue_name, strategy: :until_executing)
@job = job
@queue_name = queue_name
@strategy = strategy
end
# This will continue the middleware chain if the job should be scheduled
# It will return false if the job needs to be cancelled
def schedule(&block)
Strategies.for(strategy).new(self).schedule(job, &block)
end
# This will continue the server middleware chain if the job should be
# executed.
# It will return false if the job should not be executed.
def perform(&block)
Strategies.for(strategy).new(self).perform(job, &block)
end
# This method will return the jid that was set in redis
def check!
read_jid = nil
Sidekiq.redis do |redis|
redis.multi do |multi|
redis.set(idempotency_key, jid, ex: DUPLICATE_KEY_TTL, nx: true)
read_jid = redis.get(idempotency_key)
end
end
self.existing_jid = read_jid.value
end
def delete!
Sidekiq.redis do |redis|
redis.del(idempotency_key)
end
end
def duplicate?
raise "Call `#check!` first to check for existing duplicates" unless existing_jid
jid != existing_jid
end
def droppable?
idempotent? && duplicate?
end
private
attr_reader :queue_name, :strategy, :job
attr_writer :existing_jid
def worker_class_name
job['class']
end
def arguments
job['args']
end
def jid
job['jid']
end
def idempotency_key
@idempotency_key ||= "#{namespace}:#{idempotency_hash}"
end
def idempotency_hash
Digest::SHA256.hexdigest(idempotency_string)
end
def namespace
"#{Gitlab::Redis::Queues::SIDEKIQ_NAMESPACE}:duplicate:#{queue_name}"
end
def idempotency_string
"#{worker_class_name}:#{arguments.join('-')}"
end
def idempotent?
worker_class = worker_class_name.to_s.safe_constantize
return false unless worker_class
return false unless worker_class.respond_to?(:idempotent?)
worker_class.idempotent?
end
end
end
end
end