text: #!/usr/bin/env python3
  # Copyright (c) 2015-2016 The Bitcoin 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 API."""
  import configparser
  import os
  import struct
  
  from test_framework.test_framework import BitcoinTestFramework, SkipTest
  from test_framework.util import (assert_equal,
                                   bytes_to_hex_str,
                                   )
  
  class ZMQTest (BitcoinTestFramework):
  
      def __init__(self):
          super().__init__()
          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 bitcoin has been built with ZMQ enabled
          config = configparser.ConfigParser()
          if not self.options.configfile:
              self.options.configfile = os.path.dirname(__file__) + "/../config.ini"
          config.read_file(open(self.options.configfile))
  
          if not config["components"].getboolean("ENABLE_ZMQ"):
              raise SkipTest("kashcoind has not been built with zmq enabled.")
  
          self.zmqContext = zmq.Context()
          self.zmqSubSocket = self.zmqContext.socket(zmq.SUB)
          self.zmqSubSocket.set(zmq.RCVTIMEO, 60000)
          self.zmqSubSocket.setsockopt(zmq.SUBSCRIBE, b"hashblock")
          self.zmqSubSocket.setsockopt(zmq.SUBSCRIBE, b"hashtx")
          ip_address = "tcp://127.0.0.1:28332"
          self.zmqSubSocket.connect(ip_address)
          extra_args = [['-zmqpubhashtx=%s' % ip_address, '-zmqpubhashblock=%s' % ip_address], []]
          self.nodes = self.start_nodes(self.num_nodes, self.options.tmpdir, extra_args)
  
      def run_test(self):
          try:
              self._zmq_test()
          finally:
              # Destroy the zmq context
              self.log.debug("Destroying zmq context")
              self.zmqContext.destroy(linger=None)
  
      def _zmq_test(self):
          genhashes = self.nodes[0].generate(1)
          self.sync_all()
  
          self.log.info("Wait for tx")
          msg = self.zmqSubSocket.recv_multipart()
          topic = msg[0]
          assert_equal(topic, b"hashtx")
          body = msg[1]
          msgSequence = struct.unpack('<I', msg[-1])[-1]
          assert_equal(msgSequence, 0)  # must be sequence 0 on hashtx
  
          self.log.info("Wait for block")
          msg = self.zmqSubSocket.recv_multipart()
          topic = msg[0]
          body = msg[1]
          msgSequence = struct.unpack('<I', msg[-1])[-1]
          assert_equal(msgSequence, 0)  # must be sequence 0 on hashblock
          blkhash = bytes_to_hex_str(body)
  
          assert_equal(genhashes[0], blkhash)  # blockhash from generate must be equal to the hash received over zmq
  
          self.log.info("Generate 10 blocks (and 10 coinbase txes)")
          n = 10
          genhashes = self.nodes[1].generate(n)
          self.sync_all()
  
          zmqHashes = []
          blockcount = 0
          for x in range(n * 2):
              msg = self.zmqSubSocket.recv_multipart()
              topic = msg[0]
              body = msg[1]
              if topic == b"hashblock":
                  zmqHashes.append(bytes_to_hex_str(body))
                  msgSequence = struct.unpack('<I', msg[-1])[-1]
                  assert_equal(msgSequence, blockcount + 1)
                  blockcount += 1
  
          for x in range(n):
              assert_equal(genhashes[x], zmqHashes[x])  # blockhash from generate must be equal to the hash received over zmq
  
          self.log.info("Wait for tx from second node")
          # test tx from a second node
          hashRPC = self.nodes[1].sendtoaddress(self.nodes[0].getnewaddress(), 1.0)
          self.sync_all()
  
          # now we should receive a zmq msg because the tx was broadcast
          msg = self.zmqSubSocket.recv_multipart()
          topic = msg[0]
          body = msg[1]
          assert_equal(topic, b"hashtx")
          hashZMQ = bytes_to_hex_str(body)
          msgSequence = struct.unpack('<I', msg[-1])[-1]
          assert_equal(msgSequence, blockcount + 1)
  
          assert_equal(hashRPC, hashZMQ)  # txid from sendtoaddress must be equal to the hash received over zmq
  
  if __name__ == '__main__':
      ZMQTest().main()
  