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Merge branch 'newkernel' of git://github.com/ellisonbg/ipython into qtfrontend...
Merge branch 'newkernel' of git://github.com/ellisonbg/ipython into qtfrontend Conflicts: IPython/zmq/pykernel.py

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pykernel.py
472 lines | 16.9 KiB | text/x-python | PythonLexer
#!/usr/bin/env python
"""A simple interactive kernel that talks to a frontend over 0MQ.
Things to do:
* Implement `set_parent` logic. Right before doing exec, the Kernel should
call set_parent on all the PUB objects with the message about to be executed.
* Implement random port and security key logic.
* Implement control messages.
* Implement event loop and poll version.
"""
#-----------------------------------------------------------------------------
# Imports
#-----------------------------------------------------------------------------
# Standard library imports.
import __builtin__
from code import CommandCompiler
import os
import sys
import time
import traceback
# System library imports.
import zmq
# Local imports.
from IPython.external.argparse import ArgumentParser
from session import Session, Message
from completer import KernelCompleter
from iostream import OutStream
from displayhook import DisplayHook
from exitpoller import ExitPollerUnix, ExitPollerWindows
#-----------------------------------------------------------------------------
# Main kernel class
#-----------------------------------------------------------------------------
class Kernel(object):
# The global kernel instance.
_kernel = None
# Maps user-friendly backend names to matplotlib backend identifiers.
_pylab_map = { 'tk': 'TkAgg',
'gtk': 'GTKAgg',
'wx': 'WXAgg',
'qt': 'Qt4Agg', # qt3 not supported
'qt4': 'Qt4Agg',
'payload-svg' : \
'module://IPython.zmq.pylab.backend_payload_svg' }
#---------------------------------------------------------------------------
# Kernel interface
#---------------------------------------------------------------------------
def __init__(self, session, reply_socket, pub_socket, req_socket):
self.session = session
self.reply_socket = reply_socket
self.pub_socket = pub_socket
self.req_socket = req_socket
self.user_ns = {}
self.history = []
self.compiler = CommandCompiler()
self.completer = KernelCompleter(self.user_ns)
# Protected variables.
self._exec_payload = {}
# Build dict of handlers for message types
msg_types = [ 'execute_request', 'complete_request',
'object_info_request' ]
self.handlers = {}
for msg_type in msg_types:
self.handlers[msg_type] = getattr(self, msg_type)
def add_exec_payload(self, key, value):
""" Adds a key/value pair to the execute payload.
"""
self._exec_payload[key] = value
def activate_pylab(self, backend=None, import_all=True):
""" Activates pylab in this kernel's namespace.
Parameters:
-----------
backend : str, optional
A valid backend name.
import_all : bool, optional
If true, an 'import *' is done from numpy and pylab.
"""
# FIXME: This is adapted from IPython.lib.pylabtools.pylab_activate.
# Common funtionality should be refactored.
# We must set the desired backend before importing pylab.
import matplotlib
if backend:
backend_id = self._pylab_map[backend]
if backend_id.startswith('module://'):
# Work around bug in matplotlib: matplotlib.use converts the
# backend_id to lowercase even if a module name is specified!
matplotlib.rcParams['backend'] = backend_id
else:
matplotlib.use(backend_id)
# Import numpy as np/pyplot as plt are conventions we're trying to
# somewhat standardize on. Making them available to users by default
# will greatly help this.
exec ("import numpy\n"
"import matplotlib\n"
"from matplotlib import pylab, mlab, pyplot\n"
"np = numpy\n"
"plt = pyplot\n"
) in self.user_ns
if import_all:
exec("from matplotlib.pylab import *\n"
"from numpy import *\n") in self.user_ns
matplotlib.interactive(True)
@classmethod
def get_kernel(cls):
""" Return the global kernel instance or raise a RuntimeError if it does
not exist.
"""
if cls._kernel is None:
raise RuntimeError("Kernel not started!")
else:
return cls._kernel
def start(self):
""" Start the kernel main loop.
"""
# Set the global kernel instance.
Kernel._kernel = self
while True:
ident = self.reply_socket.recv()
assert self.reply_socket.rcvmore(), "Missing message part."
msg = self.reply_socket.recv_json()
omsg = Message(msg)
print>>sys.__stdout__
print>>sys.__stdout__, omsg
handler = self.handlers.get(omsg.msg_type, None)
if handler is None:
print >> sys.__stderr__, "UNKNOWN MESSAGE TYPE:", omsg
else:
handler(ident, omsg)
#---------------------------------------------------------------------------
# Kernel request handlers
#---------------------------------------------------------------------------
def execute_request(self, ident, parent):
try:
code = parent[u'content'][u'code']
except:
print>>sys.__stderr__, "Got bad msg: "
print>>sys.__stderr__, Message(parent)
return
pyin_msg = self.session.msg(u'pyin',{u'code':code}, parent=parent)
self.pub_socket.send_json(pyin_msg)
# Clear the execute payload from the last request.
self._exec_payload = {}
try:
comp_code = self.compiler(code, '<zmq-kernel>')
# Replace raw_input. Note that is not sufficient to replace
# raw_input in the user namespace.
raw_input = lambda prompt='': self._raw_input(prompt, ident, parent)
__builtin__.raw_input = raw_input
# Configure the display hook.
sys.displayhook.set_parent(parent)
exec comp_code in self.user_ns, self.user_ns
except:
etype, evalue, tb = sys.exc_info()
tb = traceback.format_exception(etype, evalue, tb)
exc_content = {
u'status' : u'error',
u'traceback' : tb,
u'ename' : unicode(etype.__name__),
u'evalue' : unicode(evalue)
}
exc_msg = self.session.msg(u'pyerr', exc_content, parent)
self.pub_socket.send_json(exc_msg)
reply_content = exc_content
else:
reply_content = { 'status' : 'ok', 'payload' : self._exec_payload }
# Flush output before sending the reply.
sys.stderr.flush()
sys.stdout.flush()
# Send the reply.
reply_msg = self.session.msg(u'execute_reply', reply_content, parent)
print>>sys.__stdout__, Message(reply_msg)
self.reply_socket.send(ident, zmq.SNDMORE)
self.reply_socket.send_json(reply_msg)
if reply_msg['content']['status'] == u'error':
self._abort_queue()
def complete_request(self, ident, parent):
comp = self.completer.complete(parent.content.line, parent.content.text)
matches = {'matches' : comp, 'status' : 'ok'}
completion_msg = self.session.send(self.reply_socket, 'complete_reply',
matches, parent, ident)
print >> sys.__stdout__, completion_msg
def object_info_request(self, ident, parent):
context = parent['content']['oname'].split('.')
object_info = self._object_info(context)
msg = self.session.send(self.reply_socket, 'object_info_reply',
object_info, parent, ident)
print >> sys.__stdout__, msg
#---------------------------------------------------------------------------
# Protected interface
#---------------------------------------------------------------------------
def _abort_queue(self):
while True:
try:
ident = self.reply_socket.recv(zmq.NOBLOCK)
except zmq.ZMQError, e:
if e.errno == zmq.EAGAIN:
break
else:
assert self.reply_socket.rcvmore(), "Missing message part."
msg = self.reply_socket.recv_json()
print>>sys.__stdout__, "Aborting:"
print>>sys.__stdout__, Message(msg)
msg_type = msg['msg_type']
reply_type = msg_type.split('_')[0] + '_reply'
reply_msg = self.session.msg(reply_type, {'status':'aborted'}, msg)
print>>sys.__stdout__, Message(reply_msg)
self.reply_socket.send(ident,zmq.SNDMORE)
self.reply_socket.send_json(reply_msg)
# We need to wait a bit for requests to come in. This can probably
# be set shorter for true asynchronous clients.
time.sleep(0.1)
def _raw_input(self, prompt, ident, parent):
# Flush output before making the request.
sys.stderr.flush()
sys.stdout.flush()
# Send the input request.
content = dict(prompt=prompt)
msg = self.session.msg(u'input_request', content, parent)
self.req_socket.send_json(msg)
# Await a response.
reply = self.req_socket.recv_json()
try:
value = reply['content']['value']
except:
print>>sys.__stderr__, "Got bad raw_input reply: "
print>>sys.__stderr__, Message(parent)
value = ''
return value
def _object_info(self, context):
symbol, leftover = self._symbol_from_context(context)
if symbol is not None and not leftover:
doc = getattr(symbol, '__doc__', '')
else:
doc = ''
object_info = dict(docstring = doc)
return object_info
def _symbol_from_context(self, context):
if not context:
return None, context
base_symbol_string = context[0]
symbol = self.user_ns.get(base_symbol_string, None)
if symbol is None:
symbol = __builtin__.__dict__.get(base_symbol_string, None)
if symbol is None:
return None, context
context = context[1:]
for i, name in enumerate(context):
new_symbol = getattr(symbol, name, None)
if new_symbol is None:
return symbol, context[i:]
else:
symbol = new_symbol
return symbol, []
#-----------------------------------------------------------------------------
# Kernel main and launch functions
#-----------------------------------------------------------------------------
def bind_port(socket, ip, port):
""" Binds the specified ZMQ socket. If the port is zero, a random port is
chosen. Returns the port that was bound.
"""
connection = 'tcp://%s' % ip
if port <= 0:
port = socket.bind_to_random_port(connection)
else:
connection += ':%i' % port
socket.bind(connection)
return port
def main():
""" Main entry point for launching a kernel.
"""
# Parse command line arguments.
parser = ArgumentParser()
parser.add_argument('--ip', type=str, default='127.0.0.1',
help='set the kernel\'s IP address [default: local]')
parser.add_argument('--xrep', type=int, metavar='PORT', default=0,
help='set the XREP channel port [default: random]')
parser.add_argument('--pub', type=int, metavar='PORT', default=0,
help='set the PUB channel port [default: random]')
parser.add_argument('--req', type=int, metavar='PORT', default=0,
help='set the REQ channel port [default: random]')
if sys.platform == 'win32':
parser.add_argument('--parent', type=int, metavar='HANDLE',
default=0, help='kill this process if the process '
'with HANDLE dies')
else:
parser.add_argument('--parent', action='store_true',
help='kill this process if its parent dies')
parser.add_argument('--pylab', type=str, metavar='GUI', nargs='?',
const='auto', help = \
"Pre-load matplotlib and numpy for interactive use. If GUI is not \
given, the GUI backend is matplotlib's, otherwise use one of: \
['tk', 'gtk', 'qt', 'wx', 'payload-svg'].")
namespace = parser.parse_args()
# Create a context, a session, and the kernel sockets.
print >>sys.__stdout__, "Starting the kernel..."
context = zmq.Context()
session = Session(username=u'kernel')
reply_socket = context.socket(zmq.XREP)
xrep_port = bind_port(reply_socket, namespace.ip, namespace.xrep)
print >>sys.__stdout__, "XREP Channel on port", xrep_port
pub_socket = context.socket(zmq.PUB)
pub_port = bind_port(pub_socket, namespace.ip, namespace.pub)
print >>sys.__stdout__, "PUB Channel on port", pub_port
req_socket = context.socket(zmq.XREQ)
req_port = bind_port(req_socket, namespace.ip, namespace.req)
print >>sys.__stdout__, "REQ Channel on port", req_port
# Create the kernel.
kernel = Kernel(session, reply_socket, pub_socket, req_socket)
# Set up pylab, if necessary.
if namespace.pylab:
if namespace.pylab == 'auto':
kernel.activate_pylab()
else:
kernel.activate_pylab(namespace.pylab)
# Redirect input streams and set a display hook.
sys.stdout = OutStream(session, pub_socket, u'stdout')
sys.stderr = OutStream(session, pub_socket, u'stderr')
sys.displayhook = DisplayHook(session, pub_socket)
# Configure this kernel/process to die on parent termination, if necessary.
if namespace.parent:
if sys.platform == 'win32':
poller = ExitPollerWindows(namespace.parent)
else:
poller = ExitPollerUnix()
poller.start()
# Start the kernel mainloop.
kernel.start()
def launch_kernel(xrep_port=0, pub_port=0, req_port=0,
pylab=False, independent=False):
""" Launches a localhost kernel, binding to the specified ports.
Parameters
----------
xrep_port : int, optional
The port to use for XREP channel.
pub_port : int, optional
The port to use for the SUB channel.
req_port : int, optional
The port to use for the REQ (raw input) channel.
pylab : bool or string, optional (default False)
If not False, the kernel will be launched with pylab enabled. If a
string is passed, matplotlib will use the specified backend. Otherwise,
matplotlib's default backend will be used.
independent : bool, optional (default False)
If set, the kernel process is guaranteed to survive if this process
dies. If not set, an effort is made to ensure that the kernel is killed
when this process dies. Note that in this case it is still good practice
to kill kernels manually before exiting.
Returns
-------
A tuple of form:
(kernel_process, xrep_port, pub_port, req_port)
where kernel_process is a Popen object and the ports are integers.
"""
import socket
from subprocess import Popen
# Find open ports as necessary.
ports = []
ports_needed = int(xrep_port <= 0) + int(pub_port <= 0) + int(req_port <= 0)
for i in xrange(ports_needed):
sock = socket.socket()
sock.bind(('', 0))
ports.append(sock)
for i, sock in enumerate(ports):
port = sock.getsockname()[1]
sock.close()
ports[i] = port
if xrep_port <= 0:
xrep_port = ports.pop(0)
if pub_port <= 0:
pub_port = ports.pop(0)
if req_port <= 0:
req_port = ports.pop(0)
# Build the kernel launch command.
command = 'from IPython.zmq.pykernel import main; main()'
arguments = [ sys.executable, '-c', command, '--xrep', str(xrep_port),
'--pub', str(pub_port), '--req', str(req_port) ]
if pylab:
arguments.append('--pylab')
if isinstance(pylab, basestring):
arguments.append(pylab)
# Spawn a kernel.
if independent:
if sys.platform == 'win32':
proc = Popen(['start', '/b'] + arguments, shell=True)
else:
proc = Popen(arguments, preexec_fn=lambda: os.setsid())
else:
if sys.platform == 'win32':
from _subprocess import DuplicateHandle, GetCurrentProcess, \
DUPLICATE_SAME_ACCESS
pid = GetCurrentProcess()
handle = DuplicateHandle(pid, pid, pid, 0,
True, # Inheritable by new processes.
DUPLICATE_SAME_ACCESS)
proc = Popen(arguments + ['--parent', str(int(handle))])
else:
proc = Popen(arguments + ['--parent'])
return proc, xrep_port, pub_port, req_port
if __name__ == '__main__':
main()