Class: LogStash::Config::AST::Branch

Inherits:

Node

• Object
• Treetop::Runtime::SyntaxNode
• Node
• LogStash::Config::AST::Branch

Defined in:

lib/logstash/config/config_ast.rb

Instance Method Summary

• #compile ⇒ Object

Methods inherited from Node

#text_value_for_comments

Instance Method Details

#compile ⇒ Object

# File 'lib/logstash/config/config_ast.rb', line 418

def compile

  # this construct is non obvious. we need to loop through each event and apply the conditional.
  # each branch of a conditional will contain a construct (a filter for example) that also loops through
  # the events variable so we have to initialize it to [event] for the branch code.
  # at the end, events is returned to handle the case where no branch match and no branch code is executed
  # so we must make sure to return the current event.

  type = recursive_select_parent(PluginSection).first.plugin_type.text_value

  if type == "filter"
    i = LogStash::Config::AST.deferred_conditionals_index += 1
    source = <<-CODE
      @generated_objects[:cond_func_#{i}] = lambda do |input_events|
        result = []
        input_events.each do |event|
          events = [event]
          #{super}
          end
          result += events
        end
        result
      end
    CODE
    LogStash::Config::AST.deferred_conditionals << source

    <<-CODE
      events = @generated_objects[:cond_func_#{i}].call(events)
    CODE
  else # Output
    <<-CODE
      #{super}
      end
    CODE
  end
end