Class: RuleEngine::Base

Inherits:
Object
  • Object
show all
Defined in:
lib/cirrocumulus/rules/engine.rb

Overview

Core class for Cirrocumulus Rule Engine. All the magic about asserting/retracting facts and pattern-matching is performed here.

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize ⇒ Base

Returns a new instance of Base.



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# File 'lib/cirrocumulus/rules/engine.rb', line 56

def initialize
  @queue = RunQueue.new(self)
  @facts = []
  @fact_times = {}
  @mutex = Mutex.new
end

Class Method Details

.rule(name, facts, options = {}, &block) ⇒ Object

DSL-method for defining rules.



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# File 'lib/cirrocumulus/rules/engine.rb', line 52

def self.rule(name, facts, options = {}, &block)
  current_ruleset << RuleDescription.new(name, facts, options, block)
end

Instance Method Details

#assert(fact, options = {}, silent = false) ⇒ Object

Asserts new fact. If ‘silent’ is set to true, does not perform any associated rules

  • Returns :

    • nothing



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# File 'lib/cirrocumulus/rules/engine.rb', line 90

def assert(fact, options = {}, silent = false)
  silent = options unless options.is_a?(Hash)
  options = {} unless options.is_a?(Hash)

  @mutex.synchronize do
    assert_nonblocking(fact, options, silent)
  end
end

#dump_kb ⇒ Object 



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# File 'lib/cirrocumulus/rules/engine.rb', line 63

def dump_kb()
  log "Dumping current knowledge base:\n"

  @facts.each_with_index do |fact,i|
    log "%d) %s (at %s)" % [i, fact.inspect, @fact_times[fact]]
  end

  log "Empty" if @facts.empty?
end

#dump_ruleset ⇒ Object 



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# File 'lib/cirrocumulus/rules/engine.rb', line 73

def dump_ruleset()
  log "Dumping current ruleset:\n"
  self.class.current_ruleset.each_with_index do |rule,i|
    log "%d) %s" % [i, rule[:name]]
  end

  log "Empty ruleset" if self.class.current_ruleset.empty?
end

#execute ⇒ Object

Executes all associated with current KB rules. Normally, this shouldn’t be called by the programmer.



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# File 'lib/cirrocumulus/rules/engine.rb', line 195

def execute()
  process()
end

#match(pattern) ⇒ Object 



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# File 'lib/cirrocumulus/rules/engine.rb', line 159

def match(pattern)
  res = []
  find_matches_for_condition(pattern).each do |fact|
    res << bind_parameters(pattern, fact.data, {})
  end

  res
end

#query(fact) ⇒ Object 



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# File 'lib/cirrocumulus/rules/engine.rb', line 155

def query(fact)
  find_matches_for_condition(fact).map {|data| data.data}
end

#replace(pattern, values, options = {}) ⇒ Object

Replaces fact value. If fact was not found - asserts it

  • Returns :

    • nothing



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# File 'lib/cirrocumulus/rules/engine.rb', line 113

def replace(pattern, values, options = {})
  @mutex.synchronize do
    data = match(pattern)

    if data.empty?
      new_fact = pattern.clone

      pattern.each_with_index do |item,i|
        if item.is_a?(Symbol) && item.to_s.upcase == item.to_s
          new_fact[i] = values.is_a?(Hash) ? values[item] : values
        end
      end

      assert_nonblocking(new_fact, options, false)
    else
      data.each do |match_data|
        old_fact = pattern.clone
        new_fact = pattern.clone
        pattern.each_with_index do |item,i|
          if match_data.include? item
            old_fact[i] = match_data[item]
            new_fact[i] = values.is_a?(Hash) ? values[item] : values
          end
        end

        facts_are_same = true
        old_fact.each_with_index do |item, idx|
          new_item = new_fact[idx]
          facts_are_same = false if new_item != item
        end

        unless facts_are_same
          debug "replace #{pattern.inspect} for #{values.inspect}"

          retract_nonblocking(old_fact, true)
          assert_nonblocking(new_fact, {}, false)
        end
      end
    end
  end
end

#retract(fact, silent = false) ⇒ Object

Retracts an existing fact. If ‘silent’ is set to true, does not perform any associated rules

  • Returns :

    • nothing



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# File 'lib/cirrocumulus/rules/engine.rb', line 103

def retract(fact, silent = false)
  @mutex.synchronize do
    retract_nonblocking(fact, silent)
  end
end

#start ⇒ Object

Starts this rule engine instance.



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# File 'lib/cirrocumulus/rules/engine.rb', line 169

def start()
  @worker_thread = Thread.new do
    engine = nil
    while true do
      engine = Thread.current[:engine] if engine.nil?
      engine.tick() if engine
      @queue.run_queued_rules()
      sleep 0.1
    end
  end

  @worker_thread[:engine] = self
end

#tick ⇒ Object 



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# File 'lib/cirrocumulus/rules/engine.rb', line 183

def tick()
  @mutex.synchronize do
    to_retract = []
    @facts.each {|fact| to_retract << fact if fact.timed_out? }
    to_retract.each {|fact| retract_nonblocking(fact.data, true) }
    process() unless to_retract.empty?
  end
rescue Exception => ex
  p ex
end

#transaction ⇒ Object 



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# File 'lib/cirrocumulus/rules/engine.rb', line 82

def transaction

end