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 580

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 733

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 576

def contents
  @contents
end

#label ⇒ Object (readonly)

see Methods#i_send



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# File 'lib/parallelpipes.rb', line 576

def label
  @label
end

#options ⇒ Object (readonly)

see Methods#i_send



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# File 'lib/parallelpipes.rb', line 576

def options
  @options
end

Class Method Details

.from_transmission(line) ⇒ Object

:nodoc:



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# File 'lib/parallelpipes.rb', line 744

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 668

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 687

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 652

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 597

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 603

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 664

def is_a_ppipe_message?
	true
end

#join ⇒ Object 



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# File 'lib/parallelpipes.rb', line 703

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 695

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 627

def pop_tps
end

#to_transmission ⇒ Object

private :SPLITTER



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# File 'lib/parallelpipes.rb', line 741

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 612

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 622

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 617

def tps
end

#with_listening_thread(thread) ⇒ Object

Internal use only



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# File 'lib/parallelpipes.rb', line 674

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