Class: Zoidberg::Pool

Inherits:
Object
  • Object
show all
Includes:
Shell
Defined in:
lib/zoidberg/pool.rb

Overview

Populate a collection of instances and proxy requests to free instances within the pool

Instance Attribute Summary collapse

Instance Method Summary collapse

Methods included from Shell

included

Constructor Details

#initialize(*args, &block) ⇒ self

Create a new pool instance. Provide class + instance initialization arguments when creating the pool. These will be used to build all instances within the pool.



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# File 'lib/zoidberg/pool.rb', line 20

def initialize(*args, &block)
  _validate_worker_class!(args.first)
  @_signal = Signal.new
  @_worker_count = 1
  @_workers = []
  @builder = lambda do
    inst = args.first.new(
      *args.slice(1, args.size),
      &block
    )
    inst._zoidberg_signal = _signal
    inst
  end
  _zoidberg_balance
end

Dynamic Method Handling

This class handles dynamic methods through the method_missing method

#method_missing(*args, &block) ⇒ Object

Used to proxy request to worker



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# File 'lib/zoidberg/pool.rb', line 79

def method_missing(*args, &block)
  worker = _zoidberg_free_worker
  defer{ worker.send(*args, &block) }
end

Instance Attribute Details

#_signal ⇒ Signal (readonly) 



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# File 'lib/zoidberg/pool.rb', line 13

def _signal
  @_signal
end

#_workers ⇒ Array<Object> (readonly) 



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# File 'lib/zoidberg/pool.rb', line 11

def _workers
  @_workers
end

Instance Method Details

#_validate_worker_class!(klass) ⇒ Object

Validate worker class is properly supervised

Raises:

  • (TypeError) 


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# File 'lib/zoidberg/pool.rb', line 39

def _validate_worker_class!(klass)
  unless(klass.ancestors.include?(Zoidberg::Supervise))
    raise TypeError.new "Worker class `#{klass}` must include the `Zoidberg::Supervise` module!"
  end
end

#_worker_count(num = nil) ⇒ Integer

Set or get the number of workers within the pool



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# File 'lib/zoidberg/pool.rb', line 49

def _worker_count(num=nil)
  if(num)
    @_worker_count = num.to_i
    _zoidberg_balance
  end
  @_worker_count
end

#_zoidberg_balance ⇒ TrueClass

Balance the pool to ensure the correct number of workers are available



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# File 'lib/zoidberg/pool.rb', line 61

def _zoidberg_balance
  unless(_workers.size == _worker_count)
    if(_workers.size < _worker_count)
      (_worker_count - _workers.size).times do
        _workers << @builder.call
      end
    else
      (_workers.size - _worker_count).times do
        worker = _zoidberg_free_worker
        worker._zoidberg_destroy!
        _workers.delete(worker)
      end
    end
  end
  true
end

#_zoidberg_free_worker ⇒ Object

Find or wait for a free worker



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# File 'lib/zoidberg/pool.rb', line 87

def _zoidberg_free_worker
  until(worker = @_workers.detect(&:_zoidberg_available?))
    defer{ _signal.wait_for(:unlocked) }
  end
  worker
end

#terminate ⇒ Object

Force termination of all workers when terminated



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# File 'lib/zoidberg/pool.rb', line 95

def terminate
  @_workers.map(&:_zoidberg_destroy!)
end