Project: Revactor

Revision: 129

Author: tarcieri

Date: 15 May 2008 15:12:27

• /trunk/examples/http_fetcher.rb

  ......	@@ -0,0 +1,95 @@
  	1	require 'zlib'
  	2	require 'stringio'
  	3
  	4	require 'rubygems'
  	5	require 'revactor'
  	6
  	7	# A concurrent HTTP fetcher, implemented using a central dispatcher which
  	8	# scatters requests to a worker pool.
  	9	#
  	10	# The HttpFetcher class is callback-driven and intended for subclassing.
  	11	# When a request completes successfully, the on_success callback is called.
  	12	# An on_failure callback represents non-200 HTTP responses, and on_error
  	13	# delivers any exceptions which occured during the fetch.
  	14	class HttpFetcher
  	15	def initialize(nworkers = 8)
  	16	@_nworkers = nworkers
  	17	@_workers, @_queue = [], []
  	18	nworkers.times { @_workers << Worker.spawn(Actor.current) }
  	19	end
  	20
  	21	def get(url, *args)
  	22	if @_workers.empty?
  	23	@_queue << T[url, args]
  	24	else
  	25	@_workers.shift << T[:fetch, url, args]
  	26	end
  	27	end
  	28
  	29	def run
  	30	while true
  	31	Actor.receive do |filter|
  	32	filter.when(T[:ready]) do |_, worker|
  	33	if @_queue.empty?
  	34	@_workers << worker
  	35	on_empty if @_workers.size == @_nworkers
  	36	else
  	37	worker << T[:fetch, *@_queue.shift]
  	38	end
  	39	end
  	40
  	41	filter.when(T[:fetched]) { |_, url, document, args| on_success url, document, *args }
  	42	filter.when(T[:failed]) { |_, url, status, args| on_failure url, status, *args }
  	43	filter.when(T[:error]) { |_, url, ex, args| on_error url, ex, *args }
  	44	end
  	45	end
  	46	end
  	47
  	48	def on_success(url, document, *args); end
  	49	def on_failure(url, status, *args); end
  	50	def on_error(url, ex, *args); end
  	51	def on_empty; exit; end
  	52
  	53	class Worker
  	54	extend Actorize
  	55
  	56	def initialize(fetcher)
  	57	@fetcher = fetcher
  	58	loop { wait_for_request }
  	59	end
  	60
  	61	def wait_for_request
  	62	Actor.receive do |filter|
  	63	filter.when(T[:fetch]) do |_, url, args|
  	64	begin
  	65	fetch url, args
  	66	rescue => ex
  	67	@fetcher << T[:error, url, ex, args]
  	68	end
  	69
  	70	# FIXME this should be unnecessary, but the HTTP client "leaks" messages
  	71	Actor.current.mailbox.clear
  	72	@fetcher << T[:ready, Actor.current]
  	73	end
  	74	end
  	75	end
  	76
  	77	def fetch(url, args)
  	78	Actor::HttpClient.get(url, :head => {'Accept-Encoding' => 'gzip'}) do |response|
  	79	if response.status == 200
  	80	@fetcher << T[:fetched, url, decode_body(response), args]
  	81	else
  	82	@fetcher << T[:failed, url, response.status, args]
  	83	end
  	84	end
  	85	end
  	86
  	87	def decode_body(response)
  	88	if response.content_encoding == 'gzip'
  	89	Zlib::GzipReader.new(StringIO.new(response.body)).read
  	90	else
  	91	response.body
  	92	end
  	93	end
  	94	end
  	95	end
  0	96	\ No newline at end of file

• /trunk/examples/ring.rb

  ......	@@ -1,3 +1,10 @@
  	1	# An Actor ring example
  	2	#
  	3	# Here we construct a ring of interconnected Actors which each know the
  	4	# next Actor to send messages to. Any message sent from the parent Actor
  	5	# is delivered around the ring and back to the parent.
  	6
  	7	require 'rubygems'
  1	8	require 'revactor'
  2	9
  3	10	NCHILDREN = 5

• /trunk/examples/trap_exit.rb

  ......	@@ -1,3 +1,13 @@
  	1	# An example of trapping exit messages
  	2	#
  	3	# Here we create a new Actor which raises an unhandled exception
  	4	# whenever it receives the :die message.
  	5	#
  	6	# The parent Actor is linked to this one, and is set to trap exits
  	7	# When the child raises the unhandled exception, the exit message
  	8	# is delivered back to the parent.
  	9
  	10	require 'rubygems'
  1	11	require 'revactor'
  2	12
  3	13	actor = Actor.spawn_link do