Class: PPipe::Message

Inherits:
Object show all
Defined in:
lib/parallelpipes.rb

Overview

Quick Links: PPipe, parallelpipes.rb, PPipe::Methods, PPipe::Controller, PPipe::Message

A Message object is designed to make the syntax of receiving messages as beautiful and Ruby-esque as possible. It stores the label, contents and options of the message. At all times it tries to ‘be’ its contents, except if you want specific information out of it, like the label, options, pipe it was sent from (fp) or thread it was sent from (ft).

NB: as well as defining the following methods (see below for their documentation):

tp, tps, tp=, pop_tps # tp means ‘to pipe(s)’

Message also dynamically defines 12 other methods, with very similar meanings.

ep, eps, ep=, pop_eps # ep means ‘exclude pipe(s)’ tt, tts, tt=, pop_tts # tt means ‘to thread(s)’ et, ets, et=, pop_ets # et means ‘exclude thread(s)’

Footnote:

tp, ep, tt and et make up the Message’s address. A message can be given an address before it can be sent. (Although if it has no address this is not an error, as it will be sent to every pipe and every process - see Methods#i_send). Messages that have been returned by t_recv, w_recv, i_recv, i.e. messages that have arrived at their destination, do not have an address.

Constant Summary collapse

SPLITTER =

Internal use only

"PPipe:::"

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(label, contents, options = {}) ⇒ Message

Create a new message. The arguments are identical to those for Methods#i_send



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# File 'lib/parallelpipes.rb', line 564

def initialize(label, contents, options={})
  ArgumentError.check([:label, label, [Symbol, String, Fixnum, NilClass]], [:options, options, [Hash, NilClass]])
  ArgumentError.check(['options[:tp]', options[:tp], [Integer, Fixnum, Array, NilClass]], ['options[:ep]', options[:ep], [Integer, Fixnum, Array, NilClass]], ['options[:tt]', options[:tt], [Integer, Fixnum, Array, NilClass]], ['options[:et]', options[:et], [Integer, Fixnum, Array, NilClass]]) if options
  @label = label
  @contents = contents
  @options = options
  check_ambiguities
end

Dynamic Method Handling

This class handles dynamic methods through the method_missing method

#method_missing(*args) ⇒ Object

Any other methods (except for object_id) are passed to the message’s contents…

message = PPipe::Message.new(:Winnie_the_Pooh, ‘I like honey’, {})

puts message # I like honey

puts message.inspect # “I like honey”

puts message + ‘ very much’ # I like honey very much

puts message.length # 12

puts message.sub(/honey/, ‘bees’) # I like bees

puts message.class # String

So how do you tell if something is a PPipe::Message? parallelpipes.rb adds a method to Object: Object#is_a_ppipe_message? This method will return false for every object except a Message:

puts message.is_a_ppipe_message? # true

puts message.contents.is_a_ppipe_message? # false



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# File 'lib/parallelpipes.rb', line 717

def method_missing(*args)
  @contents.send(*args)
end

Instance Attribute Details

#contents ⇒ Object (readonly)

see Methods#i_send



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# File 'lib/parallelpipes.rb', line 560

def contents
  @contents
end

#label ⇒ Object (readonly)

see Methods#i_send



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# File 'lib/parallelpipes.rb', line 560

def label
  @label
end

#options ⇒ Object (readonly)

see Methods#i_send



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# File 'lib/parallelpipes.rb', line 560

def options
  @options
end

Class Method Details

.from_transmission(line) ⇒ Object

:nodoc:



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# File 'lib/parallelpipes.rb', line 728

def self.from_transmission(line) # :nodoc: 
  packets = line.split(SPLITTER, -1) # in case two lines got stuck together.
  extra = packets.shift # something put into the pipe not by ppipe.
#       raise PPipeFatal.new("extra is #{extra.inspect}, line was #{line.inspect}") unless extra
  if extra == nil # line was "", a new line submitted by the user
    extra = ""
  elsif extra == "" # lines was "PPipe:::[etc]", a ppipe message
    extra = nil
  else # Line was "stuffPPipe:::[etc]", a ppipe message with some stuff in front of it, or "stuff", a line submitted by the user
  end
    
  if packets.size == 1
#         if line =~ /^PPipe:::(?<message>.+$)/ 
#         message = new(*eval($~[:message]))  
    message = new(*eval(packets[0]))
  elsif packets.size == 0
    message = nil
  else
    raise PPipeFatal.new("Corrupted message: stuck together: #{line.inspect}")
  end  
  return extra, message
end

.with_listening_thread(thread) ⇒ Object

:nodoc:



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# File 'lib/parallelpipes.rb', line 652

def self.with_listening_thread(thread) # :nodoc:
  new(nil, nil, nil).with_listening_thread(thread)
end

Instance Method Details

#arrived? ⇒ Boolean

Has the message arrived? (see Methods#i_recv)

Returns:

  • (Boolean) 


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# File 'lib/parallelpipes.rb', line 671

def arrived?
#       raise ("This message is not listening for anything: it was not created by i_recv") unless @thread 
  return true unless @thread
  return !@thread.alive?
end

#blocking ⇒ Object

Was the message sent by Methods#w_send ?



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# File 'lib/parallelpipes.rb', line 636

def blocking
  return @options[:blocking] 
end

#fp ⇒ Object

The number of the pipe the message came from



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# File 'lib/parallelpipes.rb', line 581

def fp
return @options[:fp]
end

#ft ⇒ Object

The id of the thread the message came from



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# File 'lib/parallelpipes.rb', line 587

def ft
  return @options[:ft]
end

#is_a_ppipe_message? ⇒ Boolean

parallelpipes.rb adds a method to Object: Object#is_a_ppipe_message? This method will return false for every object except a Message:

puts message.is_a_ppipe_message? # true

puts message.contents.is_a_ppipe_message? # false

See Message#method_missing for an explanation.

Returns:

  • (Boolean) 


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# File 'lib/parallelpipes.rb', line 648

def is_a_ppipe_message?
  true
end

#join ⇒ Object 



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# File 'lib/parallelpipes.rb', line 687

def join
  raise ("This message is not listening for anything: it was not created by i_recv") unless @thread 
#       return self unless @thread
  @thread.join
  self
end

#kill ⇒ Object

Stop checking to see if the message has arrived. (see Methods#i_recv)



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# File 'lib/parallelpipes.rb', line 679

def kill
  raise ("This message is not listening for anything: it was not created by i_recv") unless @thread 
  @thread.kill
end

#pop_tps ⇒ Object

Return a list of pipes the message is addressed to (see tps) and delete @options



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# File 'lib/parallelpipes.rb', line 611

def pop_tps
end

#to_transmission ⇒ Object

private :SPLITTER



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# File 'lib/parallelpipes.rb', line 725

def to_transmission
  return SPLITTER + [@label, @contents, @options].inspect + "\n"
end

#tp ⇒ Object

The pipe the message is addressed to (@options)



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# File 'lib/parallelpipes.rb', line 596

def tp
end

#tp=(value) ⇒ Object

Set the pipe the message is address to (value can be an Integer or and array of integers)



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# File 'lib/parallelpipes.rb', line 606

def tp=(value)
end

#tps ⇒ Object

A list of pipes the message is addressed to (returns @options if @options is an array, and [@options] if it is an integer)



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# File 'lib/parallelpipes.rb', line 601

def tps
end

#with_listening_thread(thread) ⇒ Object

Internal use only



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# File 'lib/parallelpipes.rb', line 658

def with_listening_thread(thread)
  @thread = Thread.ppipe_new do
    thread.join
    message = thread[:message]
    @contents = message.contents
    @label = message.label
    @options = message.options
  end
  return self
end