Class: Roby::Query

Inherits:
TaskMatcher show all
Includes:
Enumerable
Defined in:
lib/roby/query.rb,
lib/roby/distributed/protocol.rb

Overview

A query is a predicate on both the task internal properties, and their plan-related properties as well.

Defined Under Namespace

Classes: DRoby

Constant Summary

Constants inherited from TaskMatcher

TaskMatcher::STATE_PREDICATES

Instance Attribute Summary collapse

Attributes inherited from TaskMatcher

#arguments, #improved_information, #model, #needed_information, #neg_predicates, #owners, #predicates

Class Method Summary collapse

Instance Method Summary collapse

Methods included from Enumerable

#empty?

Methods inherited from TaskMatcher

#&, declare_class_methods, #filter, match_predicates, #negate, #owned_by, #self_owned, #which_fullfills, #which_improves, #which_needs, #with_arguments, #with_model, #with_model_arguments, #|

Constructor Details

#initialize(plan) ⇒ Query

Create a query object on the given plan



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# File 'lib/roby/query.rb', line 222

def initialize(plan)
    @plan = plan
    super()
    @plan_predicates = Array.new
    @neg_plan_predicates = Array.new
end

Instance Attribute Details

#neg_plan_predicates ⇒ Object (readonly)

The set of predicates of Plan which must return false for #=== to return true.



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# File 'lib/roby/query.rb', line 248

def neg_plan_predicates
  @neg_plan_predicates
end

#plan ⇒ Object (readonly)

The plan this query acts on



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# File 'lib/roby/query.rb', line 219

def plan
  @plan
end

#plan_predicates ⇒ Object (readonly)

The set of predicates of Plan which must return true for #=== to return true



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# File 'lib/roby/query.rb', line 245

def plan_predicates
  @plan_predicates
end

Class Method Details

.match_plan_predicates(*names) ⇒ Object

For each name in names, define the #name and #not_name methods on Query objects. When one of these methods is called on a Query object, plan.name?(task) must return true (resp. false) for the task to match.



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# File 'lib/roby/query.rb', line 255

def match_plan_predicates(*names)
    names.each do |name|
 class_eval " def \#{name}\n      if neg_plan_predicates.include?(:\#{name}?)\n  raise ArgumentError, \"trying to match (\#{name}? & !\#{name}?)\"\n     end\n      plan_predicates << :\#{name}?\n      self\n end\n def not_\#{name}\n      if plan_predicates.include?(:\#{name}?)\n  raise ArgumentError, \"trying to match (\#{name}? & !\#{name}?)\"\n     end\n      neg_plan_predicates << :\#{name}?\n      self\n end\n EOD\n    end\nend\n"

Instance Method Details

#===(task) ⇒ Object

True if task matches the query. Call #result_set to have the set of tasks which match in the given plan.



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# File 'lib/roby/query.rb', line 287

def ===(task)
    return unless super

    for pred in plan_predicates
  return unless plan.send(pred, task)
    end
    for neg_pred in neg_plan_predicates
  return if plan.send(neg_pred, task)
    end
    true
end

#droby_dump(dest) ⇒ Object

Returns an intermediate representation of self suitable to be sent to the dest peer.



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# File 'lib/roby/distributed/protocol.rb', line 193

def droby_dump(dest)
    marshalled_matcher = super
    DRoby.new(plan_predicates, neg_plan_predicates, marshalled_matcher.args)
end

#each(&block) ⇒ Object

Iterates on all the tasks in the given plan which match the query



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# File 'lib/roby/query.rb', line 300

def each(&block)
    plan.query_each(result_set, &block)
    self
end

#reset ⇒ Object

#result_set is a cached value. Call this method to reinitialize, making sure the result set is recomputed next time #result_set is called.



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# File 'lib/roby/query.rb', line 238

def reset
    @result_set = nil
    self
end

#result_set ⇒ Object

The set of tasks which match in plan. This is a cached value, so use #reset to actually recompute this set.



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# File 'lib/roby/query.rb', line 231

def result_set
    @result_set ||= plan.query_result_set(self)
end

#roots(relation) ⇒ Object

Returns the set of tasks from the query for which no parent in relation can be found in the query itself



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# File 'lib/roby/query.rb', line 280

def roots(relation)
    @result_set = plan.query_roots(result_set, relation)
    self
end