upstream/ipython Files · docs/examples/parallel/demo/noncopying.py

exclude buffers from default db_query...

exclude buffers from default db_query as described in Client.db_query docstring, buffers should be excluded by default, but this wasn't actually the case.

Fernando Perez - - Load All Authors

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        MinRK
    
added py4science demos as examples + NetworkX DAG dependencies

              r3564
            
      """non-copying sends"""

      import zmq

      import numpy

      n = 10

      iface = 'inproc://pub'

      ctx = zmq.Context()

      p = ctx.socket(zmq.PUB)

      p.bind(iface)

      # connect 2 subs

      s1 = ctx.socket(zmq.SUB)

      s1.connect(iface)

      s1.setsockopt(zmq.SUBSCRIBE, '')

      s2 = ctx.socket(zmq.SUB)

      s2.connect(iface)

      s2.setsockopt(zmq.SUBSCRIBE, '')

      A = numpy.random.random((1024,1024))

      # send

      p.send(A, copy=False)

      # recv on 1 non-copy

      msg1 = s1.recv(copy=False)

      B1 = numpy.frombuffer(msg1.buffer, dtype=A.dtype).reshape(A.shape)

      # recv on 2 copy

      msg2 = s2.recv(copy=False)

      B2 = numpy.frombuffer(buffer(msg2.bytes), dtype=A.dtype).reshape(A.shape)

      print (B1==B2).all()

      print (B1==A).all()

      A[0][0] += 10

      print "~"

      # after changing A in-place, B1 changes too, proving non-copying sends

      print (B1==A).all()

      # but B2 is fixed, since it called the msg.bytes attr, which copies

      print (B1==B2).all()

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MinRK added py4science demos as examples + NetworkX DAG dependencies	r3564	"""non-copying sends"""
		import zmq
		import numpy

		n = 10
		iface = 'inproc://pub'

		ctx = zmq.Context()

		p = ctx.socket(zmq.PUB)
		p.bind(iface)

		# connect 2 subs
		s1 = ctx.socket(zmq.SUB)
		s1.connect(iface)
		s1.setsockopt(zmq.SUBSCRIBE, '')

		s2 = ctx.socket(zmq.SUB)
		s2.connect(iface)
		s2.setsockopt(zmq.SUBSCRIBE, '')

		A = numpy.random.random((1024,1024))

		# send
		p.send(A, copy=False)
		# recv on 1 non-copy
		msg1 = s1.recv(copy=False)
		B1 = numpy.frombuffer(msg1.buffer, dtype=A.dtype).reshape(A.shape)
		# recv on 2 copy
		msg2 = s2.recv(copy=False)
		B2 = numpy.frombuffer(buffer(msg2.bytes), dtype=A.dtype).reshape(A.shape)

		print (B1==B2).all()
		print (B1==A).all()
		A[0][0] += 10
		print "~"
		# after changing A in-place, B1 changes too, proving non-copying sends
		print (B1==A).all()
		# but B2 is fixed, since it called the msg.bytes attr, which copies
		print (B1==B2).all()