Reenabling output trapping in the kernel.

IPython/zmq/ipkernel.py

@@ -1,364 +1,364 b''
 #!/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.config.configurable import Configurable
 from IPython.core.interactiveshell import InteractiveShell, InteractiveShellABC
 from IPython.external.argparse import ArgumentParser
 from IPython.utils.traitlets import Instance
 from IPython.zmq.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(Configurable):
 
     shell = Instance('IPython.core.interactiveshell.InteractiveShellABC')
     session = Instance('IPython.zmq.session.Session')
     reply_socket = Instance('zmq.Socket')
     pub_socket = Instance('zmq.Socket')
     req_socket = Instance('zmq.Socket')
 
     def __init__(self, **kwargs):
         super(Kernel, self).__init__(**kwargs)
         self.shell = InteractiveShell.instance()
         
         # 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 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(), "Unexpected 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 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)
 
         try:
             # 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)
 
             self.shell.runlines(code)
             # 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'}
             
         # 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 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 complete_request(self, ident, parent):
         matches = {'matches' : self.complete(parent),
                    'status' : 'ok'}
         completion_msg = self.session.send(self.reply_socket, 'complete_reply',
                                            matches, parent, ident)
         print >> sys.__stdout__, completion_msg
 
     def complete(self, msg):
         return self.shell.complete(msg.content.line)
 
     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
 
     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.shell.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, []
 
     def start(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 main and launch functions
 #-----------------------------------------------------------------------------
 
 def bind_port(socket, ip, port):
     """ Binds the specified ZMQ socket. If the port is less than 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')
     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
 
     # 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.stdout = OutStream(session, pub_socket, u'stdout')
+    sys.stderr = OutStream(session, pub_socket, u'stderr')
     sys.displayhook = DisplayHook(session, pub_socket)
 
     # Create the kernel.
     kernel = Kernel(
         session=session, reply_socket=reply_socket,
         pub_socket=pub_socket, req_socket=req_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, 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.
 
     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)
         
     # Spawn a kernel.
     command = 'from IPython.zmq.ipkernel import main; main()'
     arguments = [ sys.executable, '-c', command, '--xrep', str(xrep_port), 
                   '--pub', str(pub_port), '--req', str(req_port) ]
     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()