text: #!/usr/bin/env python3
  # Copyright (c) 2015-2017 The Bitcash Core developers
  # Distributed under the MIT software license, see the accompanying
  # file COPYING or http://www.opensource.org/licenses/mit-license.php.
  """Test the ZMQ notification interface."""
  import configparser
  import struct
  
  from test_framework.test_framework import BitcashTestFramework, SkipTest
  from test_framework.mininode import CTransaction
  from test_framework.util import (assert_equal,
                                   bytes_to_hex_str,
                                   hash256,
                                  )
  from io import BytesIO
  
  class ZMQSubscriber:
      def __init__(self, socket, topic):
          self.sequence = 0
          self.socket = socket
          self.topic = topic
  
          import zmq
          self.socket.setsockopt(zmq.SUBSCRIBE, self.topic)
  
      def receive(self):
          topic, body, seq = self.socket.recv_multipart()
          # Topic should match the subscriber topic.
          assert_equal(topic, self.topic)
          # Sequence should be incremental.
          assert_equal(struct.unpack('<I', seq)[-1], self.sequence)
          self.sequence += 1
          return body
  
  
  class ZMQTest (BitcashTestFramework):
      def set_test_params(self):
          self.num_nodes = 2
  
      def setup_nodes(self):
          # Try to import python3-zmq. Skip this test if the import fails.
          try:
              import zmq
          except ImportError:
              raise SkipTest("python3-zmq module not available.")
  
          # Check that bitcash has been built with ZMQ enabled.
          config = configparser.ConfigParser()
          config.read_file(open(self.options.configfile))
  
          if not config["components"].getboolean("ENABLE_ZMQ"):
              raise SkipTest("bitcashd has not been built with zmq enabled.")
  
          # Initialize ZMQ context and socket.
          # All messages are received in the same socket which means
          # that this test fails if the publishing order changes.
          # Note that the publishing order is not defined in the documentation and
          # is subject to change.
          address = "tcp://127.0.0.1:25722"
          self.zmq_context = zmq.Context()
          socket = self.zmq_context.socket(zmq.SUB)
          socket.set(zmq.RCVTIMEO, 60000)
          socket.connect(address)
  
          # Subscribe to all available topics.
          self.hashblock = ZMQSubscriber(socket, b"hashblock")
          self.hashtx = ZMQSubscriber(socket, b"hashtx")
          self.rawblock = ZMQSubscriber(socket, b"rawblock")
          self.rawtx = ZMQSubscriber(socket, b"rawtx")
  
          self.extra_args = [["-zmqpub%s=%s" % (sub.topic.decode(), address) for sub in [self.hashblock, self.hashtx, self.rawblock, self.rawtx]], []]
          self.add_nodes(self.num_nodes, self.extra_args)
          self.start_nodes()
  
      def run_test(self):
          try:
              self._zmq_test()
          finally:
              # Destroy the ZMQ context.
              self.log.debug("Destroying ZMQ context")
              self.zmq_context.destroy(linger=None)
  
      def _zmq_test(self):
          num_blocks = 5
          self.log.info("Generate %(n)d blocks (and %(n)d coinbase txes)" % {"n": num_blocks})
          genhashes = self.nodes[0].generate(num_blocks)
          self.sync_all()
  
          for x in range(num_blocks):
              # Should receive the coinbase txid.
              txid = self.hashtx.receive()
  
              # Should receive the coinbase raw transaction.
              hex = self.rawtx.receive()
              tx = CTransaction()
              tx.deserialize(BytesIO(hex))
              tx.calc_sha256()
              assert_equal(tx.hash, bytes_to_hex_str(txid))
  
              # Should receive the generated block hash.
              hash = bytes_to_hex_str(self.hashblock.receive())
              assert_equal(genhashes[x], hash)
              # The block should only have the coinbase txid.
              assert_equal([bytes_to_hex_str(txid)], self.nodes[1].getblock(hash)["tx"])
  
              # Should receive the generated raw block.
              block = self.rawblock.receive()
              assert_equal(genhashes[x], bytes_to_hex_str(hash256(block[:80])))
  
          self.log.info("Wait for tx from second node")
          payment_txid = self.nodes[1].sendtoaddress(self.nodes[0].getnewaddress(), 1.0)
          self.sync_all()
  
          # Should receive the broadcasted txid.
          txid = self.hashtx.receive()
          assert_equal(payment_txid, bytes_to_hex_str(txid))
  
          # Should receive the broadcasted raw transaction.
          hex = self.rawtx.receive()
          assert_equal(payment_txid, bytes_to_hex_str(hash256(hex)))
  
  if __name__ == '__main__':
      ZMQTest().main()
  