Txmsgpackrpc
txmsgpackrpc is a Twisted library to support msgpack-rpc / msgpack.org[Python/Twisted]
Install / Use
/learn @jakm/TxmsgpackrpcREADME
txmsgpackrpc
.. image:: https://travis-ci.org/jakm/txmsgpackrpc.svg?branch=master :target: https://travis-ci.org/jakm/txmsgpackrpc
For the latest source code, see http://github.com/jakm/txmsgpackrpc
txmsgpackrpc is a library for writing asynchronous
msgpack-rpc <https://github.com/msgpack-rpc/msgpack-rpc/blob/master/spec.md>__
servers and clients in Python, using Twisted framework <http://twistedmatrix.com>. Library is based on
txMsgpack <https://github.com/donalm/txMsgpack>, but some
improvements and fixes were made.
Features
- user friendly API
- modular object model
- working timeouts and reconnecting
- connection pool support
- TCP, SSL, UDP and UNIX sockets
Python 3 note
To use UNIX sockets with Python 3 please use Twisted framework 15.3.0 and above.
Dependencies
- msgpack-python https://pypi.python.org/pypi/msgpack-python/
- Twisted http://twistedmatrix.com/trac/
Installation
.. code:: sh
% pip install txmsgpackrpc
Debian packages are available on project's Releases page <https://github.com/jakm/txmsgpackrpc/releases/latest>__.
TCP example
Computation of PI using Chudnovsky algorithm in subprocess. For details, see http://www.craig-wood.com/nick/articles/pi-chudnovsky/.
Results
::
Computation of PI with 5 places finished in 0.022390 seconds
Computation of PI with 100 places finished in 0.037856 seconds
Computation of PI with 1000 places finished in 0.038070 seconds
Computation of PI with 10000 places finished in 0.073907 seconds
Computation of PI with 100000 places finished in 6.741683 seconds
Computation of PI with 5 places finished in 0.001142 seconds
Computation of PI with 100 places finished in 0.001182 seconds
Computation of PI with 1000 places finished in 0.001206 seconds
Computation of PI with 10000 places finished in 0.001230 seconds
Computation of PI with 100000 places finished in 0.001255 seconds
Computation of PI with 1000000 places finished in 432.574457 seconds
Computation of PI with 1000000 places finished in 402.551226 seconds
DONE
Server
~~~~~~
.. code:: python
from __future__ import print_function
from collections import defaultdict
from twisted.internet import defer, reactor, utils
from twisted.python import failure
from txmsgpackrpc.server import MsgpackRPCServer
pi_chudovsky_bs = '''
"""
Python3 program to calculate Pi using python long integers, binary
splitting and the Chudnovsky algorithm
See: http://www.craig-wood.com/nick/articles/pi-chudnovsky/ for more
info
Nick Craig-Wood <nick@craig-wood.com>
"""
import math
from time import time
def sqrt(n, one):
"""
Return the square root of n as a fixed point number with the one
passed in. It uses a second order Newton-Raphson convgence. This
doubles the number of significant figures on each iteration.
"""
# Use floating point arithmetic to make an initial guess
floating_point_precision = 10**16
n_float = float((n * floating_point_precision) // one) / floating_point_precision
x = (int(floating_point_precision * math.sqrt(n_float)) * one) // floating_point_precision
n_one = n * one
while 1:
x_old = x
x = (x + n_one // x) // 2
if x == x_old:
break
return x
def pi_chudnovsky_bs(digits):
"""
Compute int(pi * 10**digits)
This is done using Chudnovsky's series with binary splitting
"""
C = 640320
C3_OVER_24 = C**3 // 24
def bs(a, b):
"""
Computes the terms for binary splitting the Chudnovsky infinite series
a(a) = +/- (13591409 + 545140134*a)
p(a) = (6*a-5)*(2*a-1)*(6*a-1)
b(a) = 1
q(a) = a*a*a*C3_OVER_24
returns P(a,b), Q(a,b) and T(a,b)
"""
if b - a == 1:
# Directly compute P(a,a+1), Q(a,a+1) and T(a,a+1)
if a == 0:
Pab = Qab = 1
else:
Pab = (6*a-5)*(2*a-1)*(6*a-1)
Qab = a*a*a*C3_OVER_24
Tab = Pab * (13591409 + 545140134*a) # a(a) * p(a)
if a & 1:
Tab = -Tab
else:
# Recursively compute P(a,b), Q(a,b) and T(a,b)
# m is the midpoint of a and b
m = (a + b) // 2
# Recursively calculate P(a,m), Q(a,m) and T(a,m)
Pam, Qam, Tam = bs(a, m)
# Recursively calculate P(m,b), Q(m,b) and T(m,b)
Pmb, Qmb, Tmb = bs(m, b)
# Now combine
Pab = Pam * Pmb
Qab = Qam * Qmb
Tab = Qmb * Tam + Pam * Tmb
return Pab, Qab, Tab
# how many terms to compute
DIGITS_PER_TERM = math.log10(C3_OVER_24/6/2/6)
N = int(digits/DIGITS_PER_TERM + 1)
# Calclate P(0,N) and Q(0,N)
P, Q, T = bs(0, N)
one = 10**digits
sqrtC = sqrt(10005*one, one)
return (Q*426880*sqrtC) // T
if __name__ == "__main__":
import sys
digits = int(sys.argv[1])
pi = pi_chudnovsky_bs(digits)
print(pi)
'''
def set_timeout(deferred, timeout=30):
def callback(value):
if not watchdog.called:
watchdog.cancel()
return value
deferred.addBoth(callback)
watchdog = reactor.callLater(timeout, defer.timeout, deferred)
class ComputePI(MsgpackRPCServer):
def __init__(self):
self.waiting = defaultdict(list)
self.results = {}
def remote_PI(self, digits, timeout=None):
if digits in self.results:
return defer.succeed(self.results[digits])
d = defer.Deferred()
if digits not in self.waiting:
subprocessDeferred = self.computePI(digits, timeout)
def callWaiting(res):
waiting = self.waiting[digits]
del self.waiting[digits]
if isinstance(res, failure.Failure):
func = lambda d: d.errback(res)
else:
func = lambda d: d.callback(res)
for d in waiting:
func(d)
subprocessDeferred.addBoth(callWaiting)
self.waiting[digits].append(d)
return d
def computePI(self, digits, timeout):
d = utils.getProcessOutputAndValue('/usr/bin/python', args=('-c', pi_chudovsky_bs, str(digits)))
def callback((out, err, code)):
if code == 0:
pi = int(out)
self.results[digits] = pi
return pi
else:
return failure.Failure(RuntimeError('Computation failed: ' + err))
if timeout is not None:
set_timeout(d, timeout)
d.addCallback(callback)
return d
def main():
server = ComputePI()
reactor.listenTCP(8000, server.getStreamFactory())
if __name__ == '__main__':
reactor.callWhenRunning(main)
reactor.run()
Client
~~~~~~
.. code:: python
from __future__ import print_function
import sys
import time
from twisted.internet import defer, reactor, task
from twisted.python import failure
@defer.inlineCallbacks
def main():
try:
from txmsgpackrpc.client import connect
c = yield connect('localhost', 8000, waitTimeout=900)
def callback(res, digits, start_time):
if isinstance(res, failure.Failure):
print('Computation of PI with %d places failed: %s' %
(digits, res.getErrorMessage()), end='\n\n')
else:
print('Computation of PI with %d places finished in %f seconds' %
(digits, time.time() - start_time), end='\n\n')
sys.stdout.flush()
defers = []
for _ in range(2):
for digits in (5, 100, 1000, 10000, 100000, 1000000):
d = c.createRequest('PI', digits, 600)
d.addBoth(callback, digits, time.time())
defers.append(d)
# wait for 30 seconds
yield task.deferLater(reactor, 30, lambda: None)
yield defer.DeferredList(defers)
print('DONE')
except Exception:
import traceback
traceback.print_exc()
finally:
reactor.stop()
if __name__ == '__main__':
reactor.callWhenRunning(main)
reactor.run()
Multicast UDP example
---------------------
Example servers join to group 224.0.0.5 and listen on port 8000. Their only
method ``echo`` returns its parameter.
Client joins group to 224.0.0.5, sends multicast request to group on port 8000
and waits for 5 seconds for responses. If some responses are received,
protocol callbacks with tuple of results and individual parts are checked for
errors. If no responses are received, protocol errbacks with TimeoutError.
Because there is no common way to determine number of peers in group,
MsgpackMulticastDatagramProtocol always wait for responses until waitTimeout
expires.
.. code:: sh
$ # setup multicast routing
$ ip route add 224.0.0.0/4 dev eth0
$ echo 1 > /proc/sys/net/ipv4/ip_forward
$
$ # start servers listening on port 8000
$ python examples/tx_rpc_server_udp_multicast.py &
[1] 3584
$ python examples/tx_rpc_server_udp_multicast.py &
[2] 3585
$ python examples/tx_rpc_server_udp_multicast.py &
[3]
