Class: CompTree::Node

Inherits:
Object
  • Object
show all
Defined in:
lib/comp_tree/node.rb

Overview

Base class for nodes in the computation tree.

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(name) ⇒ Node

Create a node



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# File 'lib/comp_tree/node.rb', line 20

def initialize(name)
  @name = name
  @parents = []
  @children = []
  @function = nil
  reset_self
end

Instance Attribute Details

#children ⇒ Object

Returns the value of attribute children.



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# File 'lib/comp_tree/node.rb', line 9

def children
  @children
end

#computed ⇒ Object

Returns the value of attribute computed.



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# File 'lib/comp_tree/node.rb', line 9

def computed
  @computed
end

#function ⇒ Object

Returns the value of attribute function.



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# File 'lib/comp_tree/node.rb', line 9

def function
  @function
end

#name ⇒ Object (readonly)

Returns the value of attribute name.



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# File 'lib/comp_tree/node.rb', line 7

def name
  @name
end

#parents ⇒ Object

Returns the value of attribute parents.



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# File 'lib/comp_tree/node.rb', line 9

def parents
  @parents
end

#result ⇒ Object

Returns the value of attribute result.



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# File 'lib/comp_tree/node.rb', line 9

def result
  @result
end

Instance Method Details

#children_results ⇒ Object

If all children have been computed, return their results; otherwise return nil.



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# File 'lib/comp_tree/node.rb', line 71

def children_results
  @children_results ||= @children.map { |child|
    unless child.computed
      return nil
    end
    child.result
  }
end

#compute ⇒ Object

Compute this node; children must be computed and lock must be already acquired.



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# File 'lib/comp_tree/node.rb', line 84

def compute
  begin
    unless @function
      raise NoFunctionError.new(@name)
    end
    @result = @function.call(*@children_results)
    @computed = true
  rescue Exception => exception
    @computed = exception
  end
  @result
end

#compute_now ⇒ Object

Force all children and self to be computed; no locking required. Intended to be used outside of parallel computations.



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# File 'lib/comp_tree/node.rb', line 52

def compute_now
  unless @computed
    unless @children_results
      @children_results = @children.map { |child|
        child.compute_now
      }
    end
    compute
    if @computed.is_a? Exception
      raise @computed
    end
  end
  @result
end

#free? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/comp_tree/node.rb', line 97

def free?
  @lock_level.zero?
end

#lock ⇒ Object 



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# File 'lib/comp_tree/node.rb', line 101

def lock
  @lock_level = @lock_level.succ
  @parents.each { |parent|
    parent.lock
  }
end

#reset ⇒ Object

Reset the computation for this node and all children.



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# File 'lib/comp_tree/node.rb', line 41

def reset
  reset_self
  @children.each { |child|
    child.reset
  }
end

#reset_self ⇒ Object

Reset the computation for this node.



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# File 'lib/comp_tree/node.rb', line 31

def reset_self
  @result = nil
  @computed = nil
  @lock_level = 0
  @children_results = nil
end

#unlock ⇒ Object 



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# File 'lib/comp_tree/node.rb', line 108

def unlock
  @lock_level -= 1  # Fixnum#pred not in 1.8.6
  @parents.each { |parent|
    parent.unlock
  }
end