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..a2ff64b29b
--- /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()