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Diffstat (limited to 'contrib/zmq/zmq_sub3.4.py')
-rwxr-xr-x | contrib/zmq/zmq_sub3.4.py | 89 |
1 files changed, 89 insertions, 0 deletions
diff --git a/contrib/zmq/zmq_sub3.4.py b/contrib/zmq/zmq_sub3.4.py new file mode 100755 index 0000000000..1cb7eec0c0 --- /dev/null +++ b/contrib/zmq/zmq_sub3.4.py @@ -0,0 +1,89 @@ +#!/usr/bin/env python3 +# Copyright (c) 2014-2016 The Bitcoin Core developers +# Distributed under the MIT software license, see the accompanying +# file COPYING or http://www.opensource.org/licenses/mit-license.php. + +""" + ZMQ example using python3's asyncio + + Bitcoin should be started with the command line arguments: + bitcoind -testnet -daemon \ + -zmqpubhashblock=tcp://127.0.0.1:28332 \ + -zmqpubrawtx=tcp://127.0.0.1:28332 \ + -zmqpubhashtx=tcp://127.0.0.1:28332 \ + -zmqpubhashblock=tcp://127.0.0.1:28332 + + We use the asyncio library here. `self.handle()` installs itself as a + future at the end of the function. Since it never returns with the event + loop having an empty stack of futures, this creates an infinite loop. An + alternative is to wrap the contents of `handle` inside `while True`. + + The `@asyncio.coroutine` decorator and the `yield from` syntax found here + was introduced in python 3.4 and has been deprecated in favor of the `async` + and `await` keywords respectively. + + A blocking example using python 2.7 can be obtained from the git history: + https://github.com/bitcoin/bitcoin/blob/37a7fe9e440b83e2364d5498931253937abe9294/contrib/zmq/zmq_sub.py +""" + +import binascii +import asyncio +import zmq +import zmq.asyncio +import signal +import struct +import sys + +if not (sys.version_info.major >= 3 and sys.version_info.minor >= 4): + print("This example only works with Python 3.4 and greater") + exit(1) + +port = 28332 + +class ZMQHandler(): + def __init__(self): + self.loop = zmq.asyncio.install() + self.zmqContext = zmq.asyncio.Context() + + self.zmqSubSocket = self.zmqContext.socket(zmq.SUB) + self.zmqSubSocket.setsockopt_string(zmq.SUBSCRIBE, "hashblock") + self.zmqSubSocket.setsockopt_string(zmq.SUBSCRIBE, "hashtx") + self.zmqSubSocket.setsockopt_string(zmq.SUBSCRIBE, "rawblock") + self.zmqSubSocket.setsockopt_string(zmq.SUBSCRIBE, "rawtx") + self.zmqSubSocket.connect("tcp://127.0.0.1:%i" % port) + + @asyncio.coroutine + def handle(self) : + msg = yield from self.zmqSubSocket.recv_multipart() + topic = msg[0] + body = msg[1] + sequence = "Unknown" + if len(msg[-1]) == 4: + msgSequence = struct.unpack('<I', msg[-1])[-1] + sequence = str(msgSequence) + if topic == b"hashblock": + print('- HASH BLOCK ('+sequence+') -') + print(binascii.hexlify(body)) + elif topic == b"hashtx": + print('- HASH TX ('+sequence+') -') + print(binascii.hexlify(body)) + elif topic == b"rawblock": + print('- RAW BLOCK HEADER ('+sequence+') -') + print(binascii.hexlify(body[:80])) + elif topic == b"rawtx": + print('- RAW TX ('+sequence+') -') + print(binascii.hexlify(body)) + # schedule ourselves to receive the next message + asyncio.ensure_future(self.handle()) + + def start(self): + self.loop.add_signal_handler(signal.SIGINT, self.stop) + self.loop.create_task(self.handle()) + self.loop.run_forever() + + def stop(self): + self.loop.stop() + self.zmqContext.destroy() + +daemon = ZMQHandler() +daemon.start() |