#!/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 sys import time import traceback # System library imports. import zmq # Local imports. from IPython.utils.traitlets import HasTraits, Instance from completer import KernelCompleter from entry_point import base_launch_kernel, make_default_main from session import Session, Message #----------------------------------------------------------------------------- # Main kernel class #----------------------------------------------------------------------------- class Kernel(HasTraits): # Private interface # This is a dict of port number that the kernel is listening on. It is set # by record_ports and used by connect_request. _recorded_ports = None #--------------------------------------------------------------------------- # Kernel interface #--------------------------------------------------------------------------- session = Instance(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.user_ns = {} self.history = [] self.compiler = CommandCompiler() self.completer = KernelCompleter(self.user_ns) # Build dict of handlers for message types msg_types = [ 'execute_request', 'complete_request', 'object_info_request', 'shutdown_request' ] self.handlers = {} for msg_type in msg_types: self.handlers[msg_type] = getattr(self, msg_type) def start(self): """ Start the kernel main loop. """ while True: ident,msg = self.session.recv(self.reply_socket,0) assert ident is not None, "Missing message part." 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) def record_ports(self, xrep_port, pub_port, req_port, hb_port): """Record the ports that this kernel is using. The creator of the Kernel instance must call this methods if they want the :meth:`connect_request` method to return the port numbers. """ self._recorded_ports = { 'xrep_port' : xrep_port, 'pub_port' : pub_port, 'req_port' : req_port, 'hb_port' : hb_port } #--------------------------------------------------------------------------- # 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.send(self.pub_socket, u'pyin',{u'code':code}, parent=parent) try: comp_code = self.compiler(code, '') # 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 # Set the parent message of the display hook and out streams. sys.displayhook.set_parent(parent) sys.stdout.set_parent(parent) sys.stderr.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.send(self.pub_socket, u'pyerr', exc_content, parent) reply_content = exc_content else: reply_content = { 'status' : 'ok', 'payload' : {} } # Flush output before sending the reply. sys.stderr.flush() sys.stdout.flush() # Send the reply. reply_msg = self.session.send(self.reply_socket, u'execute_reply', reply_content, parent, ident=ident) print>>sys.__stdout__, Message(reply_msg) if reply_msg['content']['status'] == u'error': self._abort_queue() 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 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 shutdown_request(self, ident, parent): content = dict(parent['content']) msg = self.session.send(self.reply_socket, 'shutdown_reply', content, parent, ident) msg = self.session.send(self.pub_socket, 'shutdown_reply', content, parent, ident) print >> sys.__stdout__, msg time.sleep(0.1) sys.exit(0) #--------------------------------------------------------------------------- # Protected interface #--------------------------------------------------------------------------- def _abort_queue(self): while True: ident,msg = self.session.recv(self.reply_socket, zmq.NOBLOCK) if msg is None: break else: assert ident is not None, "Unexpected missing message part." 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.send(self.reply_socket, reply_type, {'status':'aborted'}, msg, ident=ident) print>>sys.__stdout__, Message(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.send(self.req_socket, u'input_request', content, parent) # Await a response. ident,reply = self.session.recv(self.req_socket, 0) try: value = reply['content']['value'] except: print>>sys.__stderr__, "Got bad raw_input reply: " print>>sys.__stderr__, Message(parent) value = '' return value def _complete(self, msg): return self.completer.complete(msg.content.line, msg.content.text) 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 launch_kernel(ip=None, xrep_port=0, pub_port=0, req_port=0, hb_port=0, stdin=None, stdout=None, stderr=None, executable=None, independent=False): """ Launches a localhost kernel, binding to the specified ports. Parameters ---------- ip : str, optional The ip address the kernel will bind to. 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. hb_port : int, optional The port to use for the hearbeat REP channel. stdin, stdout, stderr : optional (default None) Standards streams, as defined in subprocess.Popen. executable : str, optional (default sys.executable) The Python executable to use for the kernel process. 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. """ extra_arguments = [] if ip is not None: extra_arguments.append('--ip') if isinstance(ip, basestring): extra_arguments.append(ip) return base_launch_kernel('from IPython.zmq.pykernel import main; main()', xrep_port, pub_port, req_port, hb_port, stdin, stdout, stderr, executable, independent, extra_arguments) main = make_default_main(Kernel) if __name__ == '__main__': main()