Module: Resque::Plugins::Lock
- Defined in:
- lib/resque/plugins/lock.rb
Overview
If you want only one instance of your job queued at a time, extend it with this module.
For example:
require ‘resque/plugins/lock’
class UpdateNetworkGraph
extend Resque::Plugins::Lock
def self.perform(repo_id)
heavy_lifting
end
end
No other UpdateNetworkGraph jobs will be placed on the queue, the QueueLock class will check Redis to see if any others are queued with the same arguments before queueing. If another is queued the enqueue will be aborted.
If you want to define the key yourself you can override the ‘lock` class method in your subclass, e.g.
class UpdateNetworkGraph
extend Resque::Plugins::Lock
# Run only one at a time, regardless of repo_id.
def self.lock(repo_id)
"network-graph"
end
def self.perform(repo_id)
heavy_lifting
end
end
The above modification will ensure only one job of class UpdateNetworkGraph is running at a time, regardless of the repo_id. Normally a job is locked using a combination of its class name and arguments.
Instance Method Summary collapse
- #around_perform_lock(*args) ⇒ Object
- #before_enqueue_lock(*args) ⇒ Object
-
#lock(*args) ⇒ Object
Override in your job to control the lock key.
Instance Method Details
#around_perform_lock(*args) ⇒ Object
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# File 'lib/resque/plugins/lock.rb', line 55 def around_perform_lock(*args) begin yield ensure # Always clear the lock when we're done, even if there is an # error. Resque.redis.del(lock(*args)) end end |
#before_enqueue_lock(*args) ⇒ Object
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# File 'lib/resque/plugins/lock.rb', line 51 def before_enqueue_lock(*args) Resque.redis.setnx(lock(*args), true) end |
#lock(*args) ⇒ Object
Override in your job to control the lock key. It is passed the same arguments as ‘perform`, that is, your job’s payload.
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# File 'lib/resque/plugins/lock.rb', line 47 def lock(*args) "lock:#{name}-#{args.to_s}" end |