Class: OMF::Rete::Planner::PlanBuilder

Inherits:
Object
  • Object
show all
Defined in:
lib/omf_rete/planner/plan_builder.rb

Overview

This class builds all the possible plans for a given query

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(query, store, opts = {}) ⇒ PlanBuilder

query – query consists of an array of tuple paterns with binding declarations store – store to attach source sets to



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# File 'lib/omf_rete/planner/plan_builder.rb', line 36

def initialize(query, store, opts = {})
  @store = store
  @opts = opts

  _parse_query(query)

  @complete_plans = []
  if (@source_cnt == 1)
    # only one source means a trivial plan, the source itself
    @complete_plans = @sources.to_a
  end

end

Instance Attribute Details

#plan ⇒ Object (readonly)

Returns the value of attribute plan.



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# File 'lib/omf_rete/planner/plan_builder.rb', line 31

def plan
  @plan
end

#store ⇒ Object (readonly)

Returns the value of attribute store.



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# File 'lib/omf_rete/planner/plan_builder.rb', line 31

def store
  @store
end

Instance Method Details

#best_plan ⇒ Object

Return plan with lowest cost



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# File 'lib/omf_rete/planner/plan_builder.rb', line 69

def best_plan()
  # best_plan = nil
  # lowest_cost = 9999999999
#
  # each_plan do |plan|
    # cost = plan.cost
    # if (cost < lowest_cost)
      # lowest_cost = cost
      # best_plan = plan
    # end
  # end
  best_plan = @complete_plans.min do |p1, p2|
    p1.cost <=> p2.cost
  end
  best_plan
end

#build ⇒ Object 



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# File 'lib/omf_rete/planner/plan_builder.rb', line 50

def build()
  level = 0
  maxLevels = @source_cnt + 10 # pull the emergency breaks sometimes
  while (@complete_plans.empty? && level < maxLevels) do
    _iterate()
    level += 1
  end
  if (@complete_plans.empty?)
    raise PlannerException.new("Can't create plan")
  end
  @complete_plans
end

#describe(out = STDOUT, offset = 0, incr = 2, sep = "\n") ⇒ Object 



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# File 'lib/omf_rete/planner/plan_builder.rb', line 121

def describe(out = STDOUT, offset = 0, incr = 2, sep = "\n")
  out << "\n=========\n"
  @complete_plans.each do |p|
    out << "------\n"
    p.describe(out, offset, incr, sep)
  end
end

#each_plan ⇒ Object 



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# File 'lib/omf_rete/planner/plan_builder.rb', line 63

def each_plan()
  @complete_plans.each do |p| yield(p) end
end

#materialize(projectPattern = nil, plan = nil, opts = nil, &block) ⇒ Object

Materialize the plan. Create all the relevant operations and tuple sets to realize a configuration for the respective query. Returns the result set.



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# File 'lib/omf_rete/planner/plan_builder.rb', line 91

def materialize(projectPattern = nil, plan = nil, opts = nil, &block)
  unless block
    raise PlannerException.new("Missing block to process result tuples with")
  end
  unless plan
    plan = best_plan()
  end
  unless plan
    raise PlannerException.new("No plan to materialize");
  end
  if (plan.is_a?(SourcePlan))
    # This is really just a simple pattern on the store
    #plan = SimpleSourcePlan.new(plan)
    #plan.materialize(projectPattern, opts, &block)
    endS = _materialize_simple_plan(projectPattern, plan, opts, &block)
  else
    # this is the root of the plan
    if projectPattern
      description = projectPattern
    else
      description = plan.result_set.to_a.sort
    end
    frontS, endS = _materialize_result_stream(plan, projectPattern, opts, &block)
    plan.materialize(nil, frontS, opts, &block)
    #endS
  end
  FinalPlan.new(endS)
end