Move protocol_version to core.release

IPython/core/release.py

@@ -1,148 +1,151 b''
 # -*- coding: utf-8 -*-
 """Release data for the IPython project."""
 
 #-----------------------------------------------------------------------------
 #  Copyright (c) 2008, IPython Development Team.
 #  Copyright (c) 2001, Fernando Perez <[e-mail]>
 #  Copyright (c) 2001, Janko Hauser <[e-mail]>
 #  Copyright (c) 2001, Nathaniel Gray <[e-mail]>
 #
 #  Distributed under the terms of the Modified BSD License.
 #
 #  The full license is in the file COPYING.txt, distributed with this software.
 #-----------------------------------------------------------------------------
 
 # Name of the package for release purposes.  This is the name which labels
 # the tarballs and RPMs made by distutils, so it's best to lowercase it.
 name = 'ipython'
 
 # IPython version information.  An empty _version_extra corresponds to a full
 # release.  'dev' as a _version_extra string means this is a development
 # version
 _version_major = 0
 _version_minor = 14
 _version_micro = 0  # use 0 for first of series, number for 1 and above
 _version_extra = 'dev'
 #_version_extra = 'rc1'
 # _version_extra = ''  # Uncomment this for full releases
 
 # Construct full version string from these.
 _ver = [_version_major, _version_minor]
 if _version_micro:
     _ver.append(_version_micro)
 if _version_extra:
     _ver.append(_version_extra)
 
 __version__ = '.'.join(map(str, _ver))
 
 version = __version__  # backwards compatibility name
 version_info = (_version_major, _version_minor, _version_micro, _version_extra)
 
+# Change this when incrementing the kernel protocol version
+kernel_protocol_version_info = (4, 0)
+
 description = "IPython: Productive Interactive Computing"
 
 long_description = \
 """
 IPython provides a rich toolkit to help you make the most out of using Python
 interactively.  Its main components are:
 
 * Powerful interactive Python shells (terminal- and Qt-based).
 * A web-based interactive notebook environment with all shell features plus
   support for embedded figures, animations and rich media.
 * Support for interactive data visualization and use of GUI toolkits.
 * Flexible, embeddable interpreters to load into your own projects.
 * A high-performance library for high level and interactive parallel computing
   that works in multicore systems, clusters, supercomputing and cloud scenarios.
 
 The enhanced interactive Python shells have the following main features:
 
 * Comprehensive object introspection.
 
 * Input history, persistent across sessions.
 
 * Caching of output results during a session with automatically generated
   references.
 
 * Extensible tab completion, with support by default for completion of python
   variables and keywords, filenames and function keywords.
 
 * Extensible system of 'magic' commands for controlling the environment and
   performing many tasks related either to IPython or the operating system.
 
 * A rich configuration system with easy switching between different setups
   (simpler than changing $PYTHONSTARTUP environment variables every time).
 
 * Session logging and reloading.
 
 * Extensible syntax processing for special purpose situations.
 
 * Access to the system shell with user-extensible alias system.
 
 * Easily embeddable in other Python programs and GUIs.
 
 * Integrated access to the pdb debugger and the Python profiler.
 
 The parallel computing architecture has the following main features:
 
 * Quickly parallelize Python code from an interactive Python/IPython session.
 
 * A flexible and dynamic process model that be deployed on anything from
   multicore workstations to supercomputers.
 
 * An architecture that supports many different styles of parallelism, from
   message passing to task farming.
 
 * Both blocking and fully asynchronous interfaces.
 
 * High level APIs that enable many things to be parallelized in a few lines
   of code.
 
 * Share live parallel jobs with other users securely.
 
 * Dynamically load balanced task farming system.
 
 * Robust error handling in parallel code.
 
 The latest development version is always available from IPython's `GitHub
 site <http://github.com/ipython>`_.
 """
 
 license = 'BSD'
 
 authors = {'Fernando' : ('Fernando Perez','[e-mail]'),
            'Janko'    : ('Janko Hauser','[e-mail]'),
            'Nathan'   : ('Nathaniel Gray','[e-mail]'),
            'Ville'    : ('Ville Vainio','[e-mail]'),
            'Brian'    : ('Brian E Granger', '[e-mail]'),
            'Min'      : ('Min Ragan-Kelley', '[e-mail]'),
            'Thomas'   : ('Thomas A. Kluyver', '[e-mail]'),
            'Jorgen'   : ('Jorgen Stenarson', '[e-mail]'),
            'Matthias' : ('Matthias Bussonnier', '[e-mail]'),
            }
 
 author = 'The IPython Development Team'
 
 author_email = '[e-mail]'
 
 url = 'http://ipython.org'
 
 download_url = 'https://github.com/ipython/ipython/downloads'
 
 platforms = ['Linux','Mac OSX','Windows XP/2000/NT/Vista/7']
 
 keywords = ['Interactive','Interpreter','Shell','Parallel','Distributed',
             'Web-based computing', 'Qt console', 'Embedding']
 
 classifiers = [
     'Intended Audience :: Developers',
     'Intended Audience :: Science/Research',
     'License :: OSI Approved :: BSD License',
     'Programming Language :: Python',
     'Programming Language :: Python :: 2',
     'Programming Language :: Python :: 2.6',
     'Programming Language :: Python :: 2.7',
     'Programming Language :: Python :: 3',
     'Programming Language :: Python :: 3.1',
     'Programming Language :: Python :: 3.2',
     'Topic :: System :: Distributed Computing',
     'Topic :: System :: Shells'
     ]

IPython/zmq/ipkernel.py

@@ -1,949 +1,950 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
 #-----------------------------------------------------------------------------
 from __future__ import print_function
 
 # Standard library imports
 import __builtin__
 import atexit
 import sys
 import time
 import traceback
 import logging
 import uuid
 
 from datetime import datetime
 from signal import (
         signal, getsignal, default_int_handler, SIGINT, SIG_IGN
 )
 
 # System library imports
 import zmq
 from zmq.eventloop import ioloop
 from zmq.eventloop.zmqstream import ZMQStream
 
 # Local imports
-import IPython
 from IPython.config.configurable import Configurable
 from IPython.config.application import boolean_flag, catch_config_error
 from IPython.core.application import ProfileDir
 from IPython.core.error import StdinNotImplementedError
+from IPython.core import release
 from IPython.core.shellapp import (
     InteractiveShellApp, shell_flags, shell_aliases
 )
 from IPython.utils import io
 from IPython.utils import py3compat
 from IPython.utils.frame import extract_module_locals
 from IPython.utils.jsonutil import json_clean
 from IPython.utils.traitlets import (
     Any, Instance, Float, Dict, CaselessStrEnum, List, Set, Integer, Unicode
 )
 
 from entry_point import base_launch_kernel
 from kernelapp import KernelApp, kernel_flags, kernel_aliases
 from serialize import serialize_object, unpack_apply_message
-from session import Session, Message, protocol_version
+from session import Session, Message
 from zmqshell import ZMQInteractiveShell
 
 
 #-----------------------------------------------------------------------------
 # Main kernel class
 #-----------------------------------------------------------------------------
 
-ipython_version = list(IPython.version_info)
+protocol_version = list(release.kernel_protocol_version_info)
+ipython_version = list(release.version_info)
 language_version = list(sys.version_info[:3])
 
 
 class Kernel(Configurable):
 
     #---------------------------------------------------------------------------
     # Kernel interface
     #---------------------------------------------------------------------------
 
     # attribute to override with a GUI
     eventloop = Any(None)
     def _eventloop_changed(self, name, old, new):
         """schedule call to eventloop from IOLoop"""
         loop = ioloop.IOLoop.instance()
         loop.add_timeout(time.time()+0.1, self.enter_eventloop)
 
     shell = Instance('IPython.core.interactiveshell.InteractiveShellABC')
     session = Instance(Session)
     profile_dir = Instance('IPython.core.profiledir.ProfileDir')
     shell_streams = List()
     control_stream = Instance(ZMQStream)
     iopub_socket = Instance(zmq.Socket)
     stdin_socket = Instance(zmq.Socket)
     log = Instance(logging.Logger)
     
     user_module = Any()
     def _user_module_changed(self, name, old, new):
         if self.shell is not None:
             self.shell.user_module = new
     
     user_ns = Dict(default_value=None)
     def _user_ns_changed(self, name, old, new):
         if self.shell is not None:
             self.shell.user_ns = new
             self.shell.init_user_ns()
 
     # identities:
     int_id = Integer(-1)
     ident = Unicode()
 
     def _ident_default(self):
         return unicode(uuid.uuid4())
 
 
     # Private interface
     
     # Time to sleep after flushing the stdout/err buffers in each execute
     # cycle.  While this introduces a hard limit on the minimal latency of the
     # execute cycle, it helps prevent output synchronization problems for
     # clients.
     # Units are in seconds.  The minimum zmq latency on local host is probably
     # ~150 microseconds, set this to 500us for now.  We may need to increase it
     # a little if it's not enough after more interactive testing.
     _execute_sleep = Float(0.0005, config=True)
 
     # Frequency of the kernel's event loop.
     # Units are in seconds, kernel subclasses for GUI toolkits may need to
     # adapt to milliseconds.
     _poll_interval = Float(0.05, config=True)
 
     # If the shutdown was requested over the network, we leave here the
     # necessary reply message so it can be sent by our registered atexit
     # handler.  This ensures that the reply is only sent to clients truly at
     # the end of our shutdown process (which happens after the underlying
     # IPython shell's own shutdown).
     _shutdown_message = None
 
     # 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 = Dict()
     
     # set of aborted msg_ids
     aborted = Set()
 
 
     def __init__(self, **kwargs):
         super(Kernel, self).__init__(**kwargs)
 
         # Initialize the InteractiveShell subclass
         self.shell = ZMQInteractiveShell.instance(config=self.config,
             profile_dir = self.profile_dir,
             user_module = self.user_module,
             user_ns     = self.user_ns,
         )
         self.shell.displayhook.session = self.session
         self.shell.displayhook.pub_socket = self.iopub_socket
         self.shell.displayhook.topic = self._topic('pyout')
         self.shell.display_pub.session = self.session
         self.shell.display_pub.pub_socket = self.iopub_socket
         self.shell.data_pub.session = self.session
         self.shell.data_pub.pub_socket = self.iopub_socket
 
         # TMP - hack while developing
         self.shell._reply_content = None
 
         # Build dict of handlers for message types
         msg_types = [ 'execute_request', 'complete_request',
                       'object_info_request', 'history_request',
                       'kernel_info_request',
                       'connect_request', 'shutdown_request',
                       'apply_request',
                     ]
         self.shell_handlers = {}
         for msg_type in msg_types:
             self.shell_handlers[msg_type] = getattr(self, msg_type)
         
         control_msg_types = msg_types + [ 'clear_request', 'abort_request' ]
         self.control_handlers = {}
         for msg_type in control_msg_types:
             self.control_handlers[msg_type] = getattr(self, msg_type)
 
     def dispatch_control(self, msg):
         """dispatch control requests"""
         idents,msg = self.session.feed_identities(msg, copy=False)
         try:
             msg = self.session.unserialize(msg, content=True, copy=False)
         except:
             self.log.error("Invalid Control Message", exc_info=True)
             return
 
         self.log.debug("Control received: %s", msg)
 
         header = msg['header']
         msg_id = header['msg_id']
         msg_type = header['msg_type']
 
         handler = self.control_handlers.get(msg_type, None)
         if handler is None:
             self.log.error("UNKNOWN CONTROL MESSAGE TYPE: %r", msg_type)
         else:
             try:
                 handler(self.control_stream, idents, msg)
             except Exception:
                 self.log.error("Exception in control handler:", exc_info=True)
     
     def dispatch_shell(self, stream, msg):
         """dispatch shell requests"""
         # flush control requests first
         if self.control_stream:
             self.control_stream.flush()
         
         idents,msg = self.session.feed_identities(msg, copy=False)
         try:
             msg = self.session.unserialize(msg, content=True, copy=False)
         except:
             self.log.error("Invalid Message", exc_info=True)
             return
 
         header = msg['header']
         msg_id = header['msg_id']
         msg_type = msg['header']['msg_type']
         
         # Print some info about this message and leave a '--->' marker, so it's
         # easier to trace visually the message chain when debugging.  Each
         # handler prints its message at the end.
         self.log.debug('\n*** MESSAGE TYPE:%s***', msg_type)
         self.log.debug('   Content: %s\n   --->\n   ', msg['content'])
 
         if msg_id in self.aborted:
             self.aborted.remove(msg_id)
             # is it safe to assume a msg_id will not be resubmitted?
             reply_type = msg_type.split('_')[0] + '_reply'
             status = {'status' : 'aborted'}
             md = {'engine' : self.ident}
             md.update(status)
             reply_msg = self.session.send(stream, reply_type, metadata=md,
                         content=status, parent=msg, ident=idents)
             return
         
         handler = self.shell_handlers.get(msg_type, None)
         if handler is None:
             self.log.error("UNKNOWN MESSAGE TYPE: %r", msg_type)
         else:
             # ensure default_int_handler during handler call
             sig = signal(SIGINT, default_int_handler)
             try:
                 handler(stream, idents, msg)
             except Exception:
                 self.log.error("Exception in message handler:", exc_info=True)
             finally:
                 signal(SIGINT, sig)
     
     def enter_eventloop(self):
         """enter eventloop"""
         self.log.info("entering eventloop")
         # restore default_int_handler
         signal(SIGINT, default_int_handler)
         while self.eventloop is not None:
             try:
                 self.eventloop(self)
             except KeyboardInterrupt:
                 # Ctrl-C shouldn't crash the kernel
                 self.log.error("KeyboardInterrupt caught in kernel")
                 continue
             else:
                 # eventloop exited cleanly, this means we should stop (right?)
                 self.eventloop = None
                 break
         self.log.info("exiting eventloop")
 
     def start(self):
         """register dispatchers for streams"""
         self.shell.exit_now = False
         if self.control_stream:
             self.control_stream.on_recv(self.dispatch_control, copy=False)
 
         def make_dispatcher(stream):
             def dispatcher(msg):
                 return self.dispatch_shell(stream, msg)
             return dispatcher
 
         for s in self.shell_streams:
             s.on_recv(make_dispatcher(s), copy=False)
     
     def do_one_iteration(self):
         """step eventloop just once"""
         if self.control_stream:
             self.control_stream.flush()
         for stream in self.shell_streams:
             # handle at most one request per iteration
             stream.flush(zmq.POLLIN, 1)
             stream.flush(zmq.POLLOUT)
 
 
     def record_ports(self, ports):
         """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 = ports
 
     #---------------------------------------------------------------------------
     # Kernel request handlers
     #---------------------------------------------------------------------------
     
     def _make_metadata(self, other=None):
         """init metadata dict, for execute/apply_reply"""
         new_md = {
             'dependencies_met' : True,
             'engine' : self.ident,
             'started': datetime.now(),
         }
         if other:
             new_md.update(other)
         return new_md
     
     def _publish_pyin(self, code, parent, execution_count):
         """Publish the code request on the pyin stream."""
 
         self.session.send(self.iopub_socket, u'pyin',
                             {u'code':code, u'execution_count': execution_count},
                             parent=parent, ident=self._topic('pyin')
         )
     
     def _publish_status(self, status, parent=None):
         """send status (busy/idle) on IOPub"""
         self.session.send(self.iopub_socket,
                           u'status',
                           {u'execution_state': status},
                           parent=parent,
                           ident=self._topic('status'),
                           )
         
 
     def execute_request(self, stream, ident, parent):
         """handle an execute_request"""
         
         self._publish_status(u'busy', parent)
         
         try:
             content = parent[u'content']
             code = content[u'code']
             silent = content[u'silent']
             store_history = content.get(u'store_history', not silent)
         except:
             self.log.error("Got bad msg: ")
             self.log.error("%s", parent)
             return
         
         md = self._make_metadata(parent['metadata'])
 
         shell = self.shell # we'll need this a lot here
 
         # Replace raw_input. Note that is not sufficient to replace
         # raw_input in the user namespace.
         if content.get('allow_stdin', False):
             raw_input = lambda prompt='': self._raw_input(prompt, ident, parent)
         else:
             raw_input = lambda prompt='' : self._no_raw_input()
 
         if py3compat.PY3:
             __builtin__.input = raw_input
         else:
             __builtin__.raw_input = raw_input
 
         # Set the parent message of the display hook and out streams.
         shell.displayhook.set_parent(parent)
         shell.display_pub.set_parent(parent)
         shell.data_pub.set_parent(parent)
         sys.stdout.set_parent(parent)
         sys.stderr.set_parent(parent)
 
         # Re-broadcast our input for the benefit of listening clients, and
         # start computing output
         if not silent:
             self._publish_pyin(code, parent, shell.execution_count)
 
         reply_content = {}
         try:
             # FIXME: the shell calls the exception handler itself.
             shell.run_cell(code, store_history=store_history, silent=silent)
         except:
             status = u'error'
             # FIXME: this code right now isn't being used yet by default,
             # because the run_cell() call above directly fires off exception
             # reporting.  This code, therefore, is only active in the scenario
             # where runlines itself has an unhandled exception.  We need to
             # uniformize this, for all exception construction to come from a
             # single location in the codbase.
             etype, evalue, tb = sys.exc_info()
             tb_list = traceback.format_exception(etype, evalue, tb)
             reply_content.update(shell._showtraceback(etype, evalue, tb_list))
         else:
             status = u'ok'
 
         reply_content[u'status'] = status
 
         # Return the execution counter so clients can display prompts
         reply_content['execution_count'] = shell.execution_count - 1
 
         # FIXME - fish exception info out of shell, possibly left there by
         # runlines.  We'll need to clean up this logic later.
         if shell._reply_content is not None:
             reply_content.update(shell._reply_content)
             e_info = dict(engine_uuid=self.ident, engine_id=self.int_id, method='execute')
             reply_content['engine_info'] = e_info
             # reset after use
             shell._reply_content = None
 
         # At this point, we can tell whether the main code execution succeeded
         # or not.  If it did, we proceed to evaluate user_variables/expressions
         if reply_content['status'] == 'ok':
             reply_content[u'user_variables'] = \
                          shell.user_variables(content.get(u'user_variables', []))
             reply_content[u'user_expressions'] = \
                          shell.user_expressions(content.get(u'user_expressions', {}))
         else:
             # If there was an error, don't even try to compute variables or
             # expressions
             reply_content[u'user_variables'] = {}
             reply_content[u'user_expressions'] = {}
 
         # Payloads should be retrieved regardless of outcome, so we can both
         # recover partial output (that could have been generated early in a
         # block, before an error) and clear the payload system always.
         reply_content[u'payload'] = shell.payload_manager.read_payload()
         # Be agressive about clearing the payload because we don't want
         # it to sit in memory until the next execute_request comes in.
         shell.payload_manager.clear_payload()
 
         # Flush output before sending the reply.
         sys.stdout.flush()
         sys.stderr.flush()
         # FIXME: on rare occasions, the flush doesn't seem to make it to the
         # clients... This seems to mitigate the problem, but we definitely need
         # to better understand what's going on.
         if self._execute_sleep:
             time.sleep(self._execute_sleep)
 
         # Send the reply.
         reply_content = json_clean(reply_content)
         
         md['status'] = reply_content['status']
         if reply_content['status'] == 'error' and \
                         reply_content['ename'] == 'UnmetDependency':
                 md['dependencies_met'] = False
 
         reply_msg = self.session.send(stream, u'execute_reply',
                                       reply_content, parent, metadata=md,
                                       ident=ident)
         
         self.log.debug("%s", reply_msg)
 
         if not silent and reply_msg['content']['status'] == u'error':
             self._abort_queues()
 
         self._publish_status(u'idle', parent)
 
     def complete_request(self, stream, ident, parent):
         txt, matches = self._complete(parent)
         matches = {'matches' : matches,
                    'matched_text' : txt,
                    'status' : 'ok'}
         matches = json_clean(matches)
         completion_msg = self.session.send(stream, 'complete_reply',
                                            matches, parent, ident)
         self.log.debug("%s", completion_msg)
 
     def object_info_request(self, stream, ident, parent):
         content = parent['content']
         object_info = self.shell.object_inspect(content['oname'],
                         detail_level = content.get('detail_level', 0)
         )
         # Before we send this object over, we scrub it for JSON usage
         oinfo = json_clean(object_info)
         msg = self.session.send(stream, 'object_info_reply',
                                 oinfo, parent, ident)
         self.log.debug("%s", msg)
 
     def history_request(self, stream, ident, parent):
         # We need to pull these out, as passing **kwargs doesn't work with
         # unicode keys before Python 2.6.5.
         hist_access_type = parent['content']['hist_access_type']
         raw = parent['content']['raw']
         output = parent['content']['output']
         if hist_access_type == 'tail':
             n = parent['content']['n']
             hist = self.shell.history_manager.get_tail(n, raw=raw, output=output,
                                                             include_latest=True)
 
         elif hist_access_type == 'range':
             session = parent['content']['session']
             start = parent['content']['start']
             stop = parent['content']['stop']
             hist = self.shell.history_manager.get_range(session, start, stop,
                                                         raw=raw, output=output)
 
         elif hist_access_type == 'search':
             n = parent['content'].get('n')
             pattern = parent['content']['pattern']
             hist = self.shell.history_manager.search(pattern, raw=raw,
                                                      output=output, n=n)
 
         else:
             hist = []
         hist = list(hist)
         content = {'history' : hist}
         content = json_clean(content)
         msg = self.session.send(stream, 'history_reply',
                                 content, parent, ident)
         self.log.debug("Sending history reply with %i entries", len(hist))
 
     def connect_request(self, stream, ident, parent):
         if self._recorded_ports is not None:
             content = self._recorded_ports.copy()
         else:
             content = {}
         msg = self.session.send(stream, 'connect_reply',
                                 content, parent, ident)
         self.log.debug("%s", msg)
 
     def kernel_info_request(self, stream, ident, parent):
         vinfo = {
             'protocol_version': protocol_version,
             'ipython_version': ipython_version,
             'language_version': language_version,
             'language': 'python',
         }
         msg = self.session.send(stream, 'kernel_info_reply',
                                 vinfo, parent, ident)
         self.log.debug("%s", msg)
 
     def shutdown_request(self, stream, ident, parent):
         self.shell.exit_now = True
         content = dict(status='ok')
         content.update(parent['content'])
         self.session.send(stream, u'shutdown_reply', content, parent, ident=ident)
         # same content, but different msg_id for broadcasting on IOPub
         self._shutdown_message = self.session.msg(u'shutdown_reply',
                                                   content, parent
         )
 
         self._at_shutdown()
         # call sys.exit after a short delay
         loop = ioloop.IOLoop.instance()
         loop.add_timeout(time.time()+0.1, loop.stop)
 
     #---------------------------------------------------------------------------
     # Engine methods
     #---------------------------------------------------------------------------
 
     def apply_request(self, stream, ident, parent):
         try:
             content = parent[u'content']
             bufs = parent[u'buffers']
             msg_id = parent['header']['msg_id']
         except:
             self.log.error("Got bad msg: %s", parent, exc_info=True)
             return
 
         self._publish_status(u'busy', parent)
         
         # Set the parent message of the display hook and out streams.
         shell = self.shell
         shell.displayhook.set_parent(parent)
         shell.display_pub.set_parent(parent)
         shell.data_pub.set_parent(parent)
         sys.stdout.set_parent(parent)
         sys.stderr.set_parent(parent)
 
         # pyin_msg = self.session.msg(u'pyin',{u'code':code}, parent=parent)
         # self.iopub_socket.send(pyin_msg)
         # self.session.send(self.iopub_socket, u'pyin', {u'code':code},parent=parent)
         md = self._make_metadata(parent['metadata'])
         try:
             working = shell.user_ns
 
             prefix = "_"+str(msg_id).replace("-","")+"_"
 
             f,args,kwargs = unpack_apply_message(bufs, working, copy=False)
 
             fname = getattr(f, '__name__', 'f')
 
             fname = prefix+"f"
             argname = prefix+"args"
             kwargname = prefix+"kwargs"
             resultname = prefix+"result"
 
             ns = { fname : f, argname : args, kwargname : kwargs , resultname : None }
             # print ns
             working.update(ns)
             code = "%s = %s(*%s,**%s)" % (resultname, fname, argname, kwargname)
             try:
                 exec code in shell.user_global_ns, shell.user_ns
                 result = working.get(resultname)
             finally:
                 for key in ns.iterkeys():
                     working.pop(key)
 
             result_buf = serialize_object(result,
                 buffer_threshold=self.session.buffer_threshold,
                 item_threshold=self.session.item_threshold,
             )
         
         except:
             # invoke IPython traceback formatting
             shell.showtraceback()
             # FIXME - fish exception info out of shell, possibly left there by
             # run_code.  We'll need to clean up this logic later.
             reply_content = {}
             if shell._reply_content is not None:
                 reply_content.update(shell._reply_content)
                 e_info = dict(engine_uuid=self.ident, engine_id=self.int_id, method='apply')
                 reply_content['engine_info'] = e_info
                 # reset after use
                 shell._reply_content = None
             
             self.session.send(self.iopub_socket, u'pyerr', reply_content, parent=parent,
                                 ident=self._topic('pyerr'))
             result_buf = []
 
             if reply_content['ename'] == 'UnmetDependency':
                 md['dependencies_met'] = False
         else:
             reply_content = {'status' : 'ok'}
 
         # put 'ok'/'error' status in header, for scheduler introspection:
         md['status'] = reply_content['status']
 
         # flush i/o
         sys.stdout.flush()
         sys.stderr.flush()
         
         reply_msg = self.session.send(stream, u'apply_reply', reply_content,
                     parent=parent, ident=ident,buffers=result_buf, metadata=md)
 
         self._publish_status(u'idle', parent)
 
     #---------------------------------------------------------------------------
     # Control messages
     #---------------------------------------------------------------------------
 
     def abort_request(self, stream, ident, parent):
         """abort a specifig msg by id"""
         msg_ids = parent['content'].get('msg_ids', None)
         if isinstance(msg_ids, basestring):
             msg_ids = [msg_ids]
         if not msg_ids:
             self.abort_queues()
         for mid in msg_ids:
             self.aborted.add(str(mid))
 
         content = dict(status='ok')
         reply_msg = self.session.send(stream, 'abort_reply', content=content,
                 parent=parent, ident=ident)
         self.log.debug("%s", reply_msg)
 
     def clear_request(self, stream, idents, parent):
         """Clear our namespace."""
         self.shell.reset(False)
         msg = self.session.send(stream, 'clear_reply', ident=idents, parent=parent,
                 content = dict(status='ok'))
 
 
     #---------------------------------------------------------------------------
     # Protected interface
     #---------------------------------------------------------------------------
 
 
     def _wrap_exception(self, method=None):
         # import here, because _wrap_exception is only used in parallel,
         # and parallel has higher min pyzmq version
         from IPython.parallel.error import wrap_exception
         e_info = dict(engine_uuid=self.ident, engine_id=self.int_id, method=method)
         content = wrap_exception(e_info)
         return content
 
     def _topic(self, topic):
         """prefixed topic for IOPub messages"""
         if self.int_id >= 0:
             base = "engine.%i" % self.int_id
         else:
             base = "kernel.%s" % self.ident
         
         return py3compat.cast_bytes("%s.%s" % (base, topic))
     
     def _abort_queues(self):
         for stream in self.shell_streams:
             if stream:
                 self._abort_queue(stream)
 
     def _abort_queue(self, stream):
         poller = zmq.Poller()
         poller.register(stream.socket, zmq.POLLIN)
         while True:
             idents,msg = self.session.recv(stream, zmq.NOBLOCK, content=True)
             if msg is None:
                 return
 
             self.log.info("Aborting:")
             self.log.info("%s", msg)
             msg_type = msg['header']['msg_type']
             reply_type = msg_type.split('_')[0] + '_reply'
 
             status = {'status' : 'aborted'}
             md = {'engine' : self.ident}
             md.update(status)
             reply_msg = self.session.send(stream, reply_type, metadata=md,
                         content=status, parent=msg, ident=idents)
             self.log.debug("%s", reply_msg)
             # We need to wait a bit for requests to come in. This can probably
             # be set shorter for true asynchronous clients.
             poller.poll(50)
 
 
     def _no_raw_input(self):
         """Raise StdinNotImplentedError if active frontend doesn't support
         stdin."""
         raise StdinNotImplementedError("raw_input was called, but this "
                                        "frontend does not support stdin.") 
         
     def _raw_input(self, prompt, ident, parent):
         # Flush output before making the request.
         sys.stderr.flush()
         sys.stdout.flush()
 
         # Send the input request.
         content = json_clean(dict(prompt=prompt))
         self.session.send(self.stdin_socket, u'input_request', content, parent,
                           ident=ident)
 
         # Await a response.
         while True:
             try:
                 ident, reply = self.session.recv(self.stdin_socket, 0)
             except Exception:
                 self.log.warn("Invalid Message:", exc_info=True)
             else:
                 break
         try:
             value = reply['content']['value']
         except:
             self.log.error("Got bad raw_input reply: ")
             self.log.error("%s", parent)
             value = ''
         if value == '\x04':
             # EOF
             raise EOFError
         return value
 
     def _complete(self, msg):
         c = msg['content']
         try:
             cpos = int(c['cursor_pos'])
         except:
             # If we don't get something that we can convert to an integer, at
             # least attempt the completion guessing the cursor is at the end of
             # the text, if there's any, and otherwise of the line
             cpos = len(c['text'])
             if cpos==0:
                 cpos = len(c['line'])
         return self.shell.complete(c['text'], c['line'], cpos)
 
     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 _at_shutdown(self):
         """Actions taken at shutdown by the kernel, called by python's atexit.
         """
         # io.rprint("Kernel at_shutdown") # dbg
         if self._shutdown_message is not None:
             self.session.send(self.iopub_socket, self._shutdown_message, ident=self._topic('shutdown'))
             self.log.debug("%s", self._shutdown_message)
         [ s.flush(zmq.POLLOUT) for s in self.shell_streams ]
 
 #-----------------------------------------------------------------------------
 # Aliases and Flags for the IPKernelApp
 #-----------------------------------------------------------------------------
 
 flags = dict(kernel_flags)
 flags.update(shell_flags)
 
 addflag = lambda *args: flags.update(boolean_flag(*args))
 
 flags['pylab'] = (
     {'IPKernelApp' : {'pylab' : 'auto'}},
     """Pre-load matplotlib and numpy for interactive use with
     the default matplotlib backend."""
 )
 
 aliases = dict(kernel_aliases)
 aliases.update(shell_aliases)
 
 #-----------------------------------------------------------------------------
 # The IPKernelApp class
 #-----------------------------------------------------------------------------
 
 class IPKernelApp(KernelApp, InteractiveShellApp):
     name = 'ipkernel'
 
     aliases = Dict(aliases)
     flags = Dict(flags)
     classes = [Kernel, ZMQInteractiveShell, ProfileDir, Session]
 
     @catch_config_error
     def initialize(self, argv=None):
         super(IPKernelApp, self).initialize(argv)
         self.init_path()
         self.init_shell()
         self.init_gui_pylab()
         self.init_extensions()
         self.init_code()
 
     def init_kernel(self):
         
         shell_stream = ZMQStream(self.shell_socket)
 
         kernel = Kernel(config=self.config, session=self.session,
                                 shell_streams=[shell_stream],
                                 iopub_socket=self.iopub_socket,
                                 stdin_socket=self.stdin_socket,
                                 log=self.log,
                                 profile_dir=self.profile_dir,
         )
         self.kernel = kernel
         kernel.record_ports(self.ports)
         shell = kernel.shell
 
     def init_gui_pylab(self):
         """Enable GUI event loop integration, taking pylab into account."""
 
         # Provide a wrapper for :meth:`InteractiveShellApp.init_gui_pylab`
         # to ensure that any exception is printed straight to stderr.
         # Normally _showtraceback associates the reply with an execution,
         # which means frontends will never draw it, as this exception
         # is not associated with any execute request.
 
         shell = self.shell
         _showtraceback = shell._showtraceback
         try:
             # replace pyerr-sending traceback with stderr
             def print_tb(etype, evalue, stb):
                 print ("GUI event loop or pylab initialization failed",
                        file=io.stderr)
                 print (shell.InteractiveTB.stb2text(stb), file=io.stderr)
             shell._showtraceback = print_tb
             InteractiveShellApp.init_gui_pylab(self)
         finally:
             shell._showtraceback = _showtraceback
 
     def init_shell(self):
         self.shell = self.kernel.shell
         self.shell.configurables.append(self)
 
 
 #-----------------------------------------------------------------------------
 # Kernel main and launch functions
 #-----------------------------------------------------------------------------
 
 def launch_kernel(*args, **kwargs):
     """Launches a localhost IPython kernel, binding to the specified ports.
 
     This function simply calls entry_point.base_launch_kernel with the right
     first command to start an ipkernel.  See base_launch_kernel for arguments.
 
     Returns
     -------
     A tuple of form:
         (kernel_process, shell_port, iopub_port, stdin_port, hb_port)
     where kernel_process is a Popen object and the ports are integers.
     """
     return base_launch_kernel('from IPython.zmq.ipkernel import main; main()',
                               *args, **kwargs)
 
 
 def embed_kernel(module=None, local_ns=None, **kwargs):
     """Embed and start an IPython kernel in a given scope.
     
     Parameters
     ----------
     module : ModuleType, optional
         The module to load into IPython globals (default: caller)
     local_ns : dict, optional
         The namespace to load into IPython user namespace (default: caller)
     
     kwargs : various, optional
         Further keyword args are relayed to the KernelApp constructor,
         allowing configuration of the Kernel.  Will only have an effect
         on the first embed_kernel call for a given process.
     
     """
     # get the app if it exists, or set it up if it doesn't
     if IPKernelApp.initialized():
         app = IPKernelApp.instance()
     else:
         app = IPKernelApp.instance(**kwargs)
         app.initialize([])
         # Undo unnecessary sys module mangling from init_sys_modules.
         # This would not be necessary if we could prevent it
         # in the first place by using a different InteractiveShell
         # subclass, as in the regular embed case.
         main = app.kernel.shell._orig_sys_modules_main_mod
         if main is not None:
             sys.modules[app.kernel.shell._orig_sys_modules_main_name] = main
 
     # load the calling scope if not given
     (caller_module, caller_locals) = extract_module_locals(1)
     if module is None:
         module = caller_module
     if local_ns is None:
         local_ns = caller_locals
     
     app.kernel.user_module = module
     app.kernel.user_ns = local_ns
     app.shell.set_completer_frame()
     app.start()
 
 def main():
     """Run an IPKernel as an application"""
     app = IPKernelApp.instance()
     app.initialize()
     app.start()
 
 
 if __name__ == '__main__':
     main()

IPython/zmq/session.py

@@ -1,769 +1,766 b''
 """Session object for building, serializing, sending, and receiving messages in
 IPython. The Session object supports serialization, HMAC signatures, and
 metadata on messages.
 
 Also defined here are utilities for working with Sessions:
 * A SessionFactory to be used as a base class for configurables that work with
 Sessions.
 * A Message object for convenience that allows attribute-access to the msg dict.
 
 Authors:
 
 * Min RK
 * Brian Granger
 * Fernando Perez
 """
 #-----------------------------------------------------------------------------
 #  Copyright (C) 2010-2011  The IPython Development Team
 #
 #  Distributed under the terms of the BSD License.  The full license is in
 #  the file COPYING, distributed as part of this software.
 #-----------------------------------------------------------------------------
 
 #-----------------------------------------------------------------------------
 # Imports
 #-----------------------------------------------------------------------------
 
 import hmac
 import logging
 import os
 import pprint
 import uuid
 from datetime import datetime
 
 try:
     import cPickle
     pickle = cPickle
 except:
     cPickle = None
     import pickle
 
 import zmq
 from zmq.utils import jsonapi
 from zmq.eventloop.ioloop import IOLoop
 from zmq.eventloop.zmqstream import ZMQStream
 
 from IPython.config.application import Application, boolean_flag
 from IPython.config.configurable import Configurable, LoggingConfigurable
 from IPython.utils.importstring import import_item
 from IPython.utils.jsonutil import extract_dates, squash_dates, date_default
 from IPython.utils.py3compat import str_to_bytes
 from IPython.utils.traitlets import (CBytes, Unicode, Bool, Any, Instance, Set,
                                         DottedObjectName, CUnicode, Dict, Integer)
 from IPython.zmq.serialize import MAX_ITEMS, MAX_BYTES
 
 #-----------------------------------------------------------------------------
 # utility functions
 #-----------------------------------------------------------------------------
 
 def squash_unicode(obj):
     """coerce unicode back to bytestrings."""
     if isinstance(obj,dict):
         for key in obj.keys():
             obj[key] = squash_unicode(obj[key])
             if isinstance(key, unicode):
                 obj[squash_unicode(key)] = obj.pop(key)
     elif isinstance(obj, list):
         for i,v in enumerate(obj):
             obj[i] = squash_unicode(v)
     elif isinstance(obj, unicode):
         obj = obj.encode('utf8')
     return obj
 
 #-----------------------------------------------------------------------------
 # globals and defaults
 #-----------------------------------------------------------------------------
 
-# Change this when incrementing the kernel protocol version
-protocol_version = [4, 0]
-
 # ISO8601-ify datetime objects
 json_packer = lambda obj: jsonapi.dumps(obj, default=date_default)
 json_unpacker = lambda s: extract_dates(jsonapi.loads(s))
 
 pickle_packer = lambda o: pickle.dumps(o,-1)
 pickle_unpacker = pickle.loads
 
 default_packer = json_packer
 default_unpacker = json_unpacker
 
 DELIM = b"<IDS|MSG>"
 # singleton dummy tracker, which will always report as done
 DONE = zmq.MessageTracker()
 
 #-----------------------------------------------------------------------------
 # Mixin tools for apps that use Sessions
 #-----------------------------------------------------------------------------
 
 session_aliases = dict(
     ident = 'Session.session',
     user = 'Session.username',
     keyfile = 'Session.keyfile',
 )
 
 session_flags  = {
     'secure' : ({'Session' : { 'key' : str_to_bytes(str(uuid.uuid4())),
                             'keyfile' : '' }},
         """Use HMAC digests for authentication of messages.
         Setting this flag will generate a new UUID to use as the HMAC key.
         """),
     'no-secure' : ({'Session' : { 'key' : b'', 'keyfile' : '' }},
         """Don't authenticate messages."""),
 }
 
 def default_secure(cfg):
     """Set the default behavior for a config environment to be secure.
     
     If Session.key/keyfile have not been set, set Session.key to
     a new random UUID.
     """
     
     if 'Session' in cfg:
         if 'key' in cfg.Session or 'keyfile' in cfg.Session:
             return
     # key/keyfile not specified, generate new UUID:
     cfg.Session.key = str_to_bytes(str(uuid.uuid4()))
 
 
 #-----------------------------------------------------------------------------
 # Classes
 #-----------------------------------------------------------------------------
 
 class SessionFactory(LoggingConfigurable):
     """The Base class for configurables that have a Session, Context, logger,
     and IOLoop.
     """
 
     logname = Unicode('')
     def _logname_changed(self, name, old, new):
         self.log = logging.getLogger(new)
 
     # not configurable:
     context = Instance('zmq.Context')
     def _context_default(self):
         return zmq.Context.instance()
 
     session = Instance('IPython.zmq.session.Session')
 
     loop = Instance('zmq.eventloop.ioloop.IOLoop', allow_none=False)
     def _loop_default(self):
         return IOLoop.instance()
 
     def __init__(self, **kwargs):
         super(SessionFactory, self).__init__(**kwargs)
 
         if self.session is None:
             # construct the session
             self.session = Session(**kwargs)
 
 
 class Message(object):
     """A simple message object that maps dict keys to attributes.
 
     A Message can be created from a dict and a dict from a Message instance
     simply by calling dict(msg_obj)."""
 
     def __init__(self, msg_dict):
         dct = self.__dict__
         for k, v in dict(msg_dict).iteritems():
             if isinstance(v, dict):
                 v = Message(v)
             dct[k] = v
 
     # Having this iterator lets dict(msg_obj) work out of the box.
     def __iter__(self):
         return iter(self.__dict__.iteritems())
 
     def __repr__(self):
         return repr(self.__dict__)
 
     def __str__(self):
         return pprint.pformat(self.__dict__)
 
     def __contains__(self, k):
         return k in self.__dict__
 
     def __getitem__(self, k):
         return self.__dict__[k]
 
 
 def msg_header(msg_id, msg_type, username, session):
     date = datetime.now()
     return locals()
 
 def extract_header(msg_or_header):
     """Given a message or header, return the header."""
     if not msg_or_header:
         return {}
     try:
         # See if msg_or_header is the entire message.
         h = msg_or_header['header']
     except KeyError:
         try:
             # See if msg_or_header is just the header
             h = msg_or_header['msg_id']
         except KeyError:
             raise
         else:
             h = msg_or_header
     if not isinstance(h, dict):
         h = dict(h)
     return h
 
 class Session(Configurable):
     """Object for handling serialization and sending of messages.
 
     The Session object handles building messages and sending them
     with ZMQ sockets or ZMQStream objects.  Objects can communicate with each
     other over the network via Session objects, and only need to work with the
     dict-based IPython message spec. The Session will handle
     serialization/deserialization, security, and metadata.
 
     Sessions support configurable serialiization via packer/unpacker traits,
     and signing with HMAC digests via the key/keyfile traits.
 
     Parameters
     ----------
 
     debug : bool
         whether to trigger extra debugging statements
     packer/unpacker : str : 'json', 'pickle' or import_string
         importstrings for methods to serialize message parts.  If just
         'json' or 'pickle', predefined JSON and pickle packers will be used.
         Otherwise, the entire importstring must be used.
 
         The functions must accept at least valid JSON input, and output *bytes*.
 
         For example, to use msgpack:
         packer = 'msgpack.packb', unpacker='msgpack.unpackb'
     pack/unpack : callables
         You can also set the pack/unpack callables for serialization directly.
     session : bytes
         the ID of this Session object.  The default is to generate a new UUID.
     username : unicode
         username added to message headers.  The default is to ask the OS.
     key : bytes
         The key used to initialize an HMAC signature.  If unset, messages
         will not be signed or checked.
     keyfile : filepath
         The file containing a key.  If this is set, `key` will be initialized
         to the contents of the file.
 
     """
 
     debug=Bool(False, config=True, help="""Debug output in the Session""")
 
     packer = DottedObjectName('json',config=True,
             help="""The name of the packer for serializing messages.
             Should be one of 'json', 'pickle', or an import name
             for a custom callable serializer.""")
     def _packer_changed(self, name, old, new):
         if new.lower() == 'json':
             self.pack = json_packer
             self.unpack = json_unpacker
             self.unpacker = new
         elif new.lower() == 'pickle':
             self.pack = pickle_packer
             self.unpack = pickle_unpacker
             self.unpacker = new
         else:
             self.pack = import_item(str(new))
 
     unpacker = DottedObjectName('json', config=True,
         help="""The name of the unpacker for unserializing messages.
         Only used with custom functions for `packer`.""")
     def _unpacker_changed(self, name, old, new):
         if new.lower() == 'json':
             self.pack = json_packer
             self.unpack = json_unpacker
             self.packer = new
         elif new.lower() == 'pickle':
             self.pack = pickle_packer
             self.unpack = pickle_unpacker
             self.packer = new
         else:
             self.unpack = import_item(str(new))
 
     session = CUnicode(u'', config=True,
         help="""The UUID identifying this session.""")
     def _session_default(self):
         u = unicode(uuid.uuid4())
         self.bsession = u.encode('ascii')
         return u
 
     def _session_changed(self, name, old, new):
         self.bsession = self.session.encode('ascii')
 
     # bsession is the session as bytes
     bsession = CBytes(b'')
 
     username = Unicode(os.environ.get('USER',u'username'), config=True,
         help="""Username for the Session. Default is your system username.""")
 
     metadata = Dict({}, config=True,
         help="""Metadata dictionary, which serves as the default top-level metadata dict for each message.""")
 
     # message signature related traits:
     
     key = CBytes(b'', config=True,
         help="""execution key, for extra authentication.""")
     def _key_changed(self, name, old, new):
         if new:
             self.auth = hmac.HMAC(new)
         else:
             self.auth = None
     auth = Instance(hmac.HMAC)
     digest_history = Set()
 
     keyfile = Unicode('', config=True,
         help="""path to file containing execution key.""")
     def _keyfile_changed(self, name, old, new):
         with open(new, 'rb') as f:
             self.key = f.read().strip()
 
     # serialization traits:
     
     pack = Any(default_packer) # the actual packer function
     def _pack_changed(self, name, old, new):
         if not callable(new):
             raise TypeError("packer must be callable, not %s"%type(new))
 
     unpack = Any(default_unpacker) # the actual packer function
     def _unpack_changed(self, name, old, new):
         # unpacker is not checked - it is assumed to be
         if not callable(new):
             raise TypeError("unpacker must be callable, not %s"%type(new))
     
     # thresholds:
     copy_threshold = Integer(2**16, config=True,
         help="Threshold (in bytes) beyond which a buffer should be sent without copying.")
     buffer_threshold = Integer(MAX_BYTES, config=True,
         help="Threshold (in bytes) beyond which an object's buffer should be extracted to avoid pickling.")
     item_threshold = Integer(MAX_ITEMS, config=True,
         help="""The maximum number of items for a container to be introspected for custom serialization.
         Containers larger than this are pickled outright.
         """
     )
     
     def __init__(self, **kwargs):
         """create a Session object
 
         Parameters
         ----------
 
         debug : bool
             whether to trigger extra debugging statements
         packer/unpacker : str : 'json', 'pickle' or import_string
             importstrings for methods to serialize message parts.  If just
             'json' or 'pickle', predefined JSON and pickle packers will be used.
             Otherwise, the entire importstring must be used.
 
             The functions must accept at least valid JSON input, and output
             *bytes*.
 
             For example, to use msgpack:
             packer = 'msgpack.packb', unpacker='msgpack.unpackb'
         pack/unpack : callables
             You can also set the pack/unpack callables for serialization
             directly.
         session : unicode (must be ascii)
             the ID of this Session object.  The default is to generate a new
             UUID.
         bsession : bytes
             The session as bytes
         username : unicode
             username added to message headers.  The default is to ask the OS.
         key : bytes
             The key used to initialize an HMAC signature.  If unset, messages
             will not be signed or checked.
         keyfile : filepath
             The file containing a key.  If this is set, `key` will be
             initialized to the contents of the file.
         """
         super(Session, self).__init__(**kwargs)
         self._check_packers()
         self.none = self.pack({})
         # ensure self._session_default() if necessary, so bsession is defined:
         self.session
 
     @property
     def msg_id(self):
         """always return new uuid"""
         return str(uuid.uuid4())
 
     def _check_packers(self):
         """check packers for binary data and datetime support."""
         pack = self.pack
         unpack = self.unpack
 
         # check simple serialization
         msg = dict(a=[1,'hi'])
         try:
             packed = pack(msg)
         except Exception:
             raise ValueError("packer could not serialize a simple message")
 
         # ensure packed message is bytes
         if not isinstance(packed, bytes):
             raise ValueError("message packed to %r, but bytes are required"%type(packed))
 
         # check that unpack is pack's inverse
         try:
             unpacked = unpack(packed)
         except Exception:
             raise ValueError("unpacker could not handle the packer's output")
 
         # check datetime support
         msg = dict(t=datetime.now())
         try:
             unpacked = unpack(pack(msg))
         except Exception:
             self.pack = lambda o: pack(squash_dates(o))
             self.unpack = lambda s: extract_dates(unpack(s))
 
     def msg_header(self, msg_type):
         return msg_header(self.msg_id, msg_type, self.username, self.session)
 
     def msg(self, msg_type, content=None, parent=None, header=None, metadata=None):
         """Return the nested message dict.
 
         This format is different from what is sent over the wire. The
         serialize/unserialize methods converts this nested message dict to the wire
         format, which is a list of message parts.
         """
         msg = {}
         header = self.msg_header(msg_type) if header is None else header
         msg['header'] = header
         msg['msg_id'] = header['msg_id']
         msg['msg_type'] = header['msg_type']
         msg['parent_header'] = {} if parent is None else extract_header(parent)
         msg['content'] = {} if content is None else content
         msg['metadata'] = self.metadata.copy()
         if metadata is not None:
             msg['metadata'].update(metadata)
         return msg
 
     def sign(self, msg_list):
         """Sign a message with HMAC digest. If no auth, return b''.
 
         Parameters
         ----------
         msg_list : list
             The [p_header,p_parent,p_content] part of the message list.
         """
         if self.auth is None:
             return b''
         h = self.auth.copy()
         for m in msg_list:
             h.update(m)
         return str_to_bytes(h.hexdigest())
 
     def serialize(self, msg, ident=None):
         """Serialize the message components to bytes.
 
         This is roughly the inverse of unserialize. The serialize/unserialize
         methods work with full message lists, whereas pack/unpack work with
         the individual message parts in the message list.
 
         Parameters
         ----------
         msg : dict or Message
             The nexted message dict as returned by the self.msg method.
 
         Returns
         -------
         msg_list : list
             The list of bytes objects to be sent with the format:
             [ident1,ident2,...,DELIM,HMAC,p_header,p_parent,p_metadata,p_content,
              buffer1,buffer2,...]. In this list, the p_* entities are
             the packed or serialized versions, so if JSON is used, these
             are utf8 encoded JSON strings.
         """
         content = msg.get('content', {})
         if content is None:
             content = self.none
         elif isinstance(content, dict):
             content = self.pack(content)
         elif isinstance(content, bytes):
             # content is already packed, as in a relayed message
             pass
         elif isinstance(content, unicode):
             # should be bytes, but JSON often spits out unicode
             content = content.encode('utf8')
         else:
             raise TypeError("Content incorrect type: %s"%type(content))
 
         real_message = [self.pack(msg['header']),
                         self.pack(msg['parent_header']),
                         self.pack(msg['metadata']),
                         content,
         ]
 
         to_send = []
 
         if isinstance(ident, list):
             # accept list of idents
             to_send.extend(ident)
         elif ident is not None:
             to_send.append(ident)
         to_send.append(DELIM)
 
         signature = self.sign(real_message)
         to_send.append(signature)
 
         to_send.extend(real_message)
 
         return to_send
 
     def send(self, stream, msg_or_type, content=None, parent=None, ident=None,
              buffers=None, track=False, header=None, metadata=None):
         """Build and send a message via stream or socket.
 
         The message format used by this function internally is as follows:
 
         [ident1,ident2,...,DELIM,HMAC,p_header,p_parent,p_content,
          buffer1,buffer2,...]
 
         The serialize/unserialize methods convert the nested message dict into this
         format.
 
         Parameters
         ----------
 
         stream : zmq.Socket or ZMQStream
             The socket-like object used to send the data.
         msg_or_type : str or Message/dict
             Normally, msg_or_type will be a msg_type unless a message is being
             sent more than once. If a header is supplied, this can be set to
             None and the msg_type will be pulled from the header.
 
         content : dict or None
             The content of the message (ignored if msg_or_type is a message).
         header : dict or None
             The header dict for the message (ignored if msg_to_type is a message).
         parent : Message or dict or None
             The parent or parent header describing the parent of this message
             (ignored if msg_or_type is a message).
         ident : bytes or list of bytes
             The zmq.IDENTITY routing path.
         metadata : dict or None
             The metadata describing the message
         buffers : list or None
             The already-serialized buffers to be appended to the message.
         track : bool
             Whether to track.  Only for use with Sockets, because ZMQStream
             objects cannot track messages.
             
 
         Returns
         -------
         msg : dict
             The constructed message.
         """
 
         if not isinstance(stream, (zmq.Socket, ZMQStream)):
             raise TypeError("stream must be Socket or ZMQStream, not %r"%type(stream))
         elif track and isinstance(stream, ZMQStream):
             raise TypeError("ZMQStream cannot track messages")
 
         if isinstance(msg_or_type, (Message, dict)):
             # We got a Message or message dict, not a msg_type so don't
             # build a new Message.
             msg = msg_or_type
         else:
             msg = self.msg(msg_or_type, content=content, parent=parent,
                            header=header, metadata=metadata)
 
         buffers = [] if buffers is None else buffers
         to_send = self.serialize(msg, ident)
         to_send.extend(buffers)
         longest = max([ len(s) for s in to_send ])
         copy = (longest < self.copy_threshold)
         
         if buffers and track and not copy:
             # only really track when we are doing zero-copy buffers
             tracker = stream.send_multipart(to_send, copy=False, track=True)
         else:
             # use dummy tracker, which will be done immediately
             tracker = DONE
             stream.send_multipart(to_send, copy=copy)
 
         if self.debug:
             pprint.pprint(msg)
             pprint.pprint(to_send)
             pprint.pprint(buffers)
 
         msg['tracker'] = tracker
 
         return msg
 
     def send_raw(self, stream, msg_list, flags=0, copy=True, ident=None):
         """Send a raw message via ident path.
 
         This method is used to send a already serialized message.
 
         Parameters
         ----------
         stream : ZMQStream or Socket
             The ZMQ stream or socket to use for sending the message.
         msg_list : list
             The serialized list of messages to send. This only includes the
             [p_header,p_parent,p_metadata,p_content,buffer1,buffer2,...] portion of
             the message.
         ident : ident or list
             A single ident or a list of idents to use in sending.
         """
         to_send = []
         if isinstance(ident, bytes):
             ident = [ident]
         if ident is not None:
             to_send.extend(ident)
 
         to_send.append(DELIM)
         to_send.append(self.sign(msg_list))
         to_send.extend(msg_list)
         stream.send_multipart(msg_list, flags, copy=copy)
 
     def recv(self, socket, mode=zmq.NOBLOCK, content=True, copy=True):
         """Receive and unpack a message.
 
         Parameters
         ----------
         socket : ZMQStream or Socket
             The socket or stream to use in receiving.
 
         Returns
         -------
         [idents], msg
             [idents] is a list of idents and msg is a nested message dict of
             same format as self.msg returns.
         """
         if isinstance(socket, ZMQStream):
             socket = socket.socket
         try:
             msg_list = socket.recv_multipart(mode, copy=copy)
         except zmq.ZMQError as e:
             if e.errno == zmq.EAGAIN:
                 # We can convert EAGAIN to None as we know in this case
                 # recv_multipart won't return None.
                 return None,None
             else:
                 raise
         # split multipart message into identity list and message dict
         # invalid large messages can cause very expensive string comparisons
         idents, msg_list = self.feed_identities(msg_list, copy)
         try:
             return idents, self.unserialize(msg_list, content=content, copy=copy)
         except Exception as e:
             # TODO: handle it
             raise e
 
     def feed_identities(self, msg_list, copy=True):
         """Split the identities from the rest of the message.
 
         Feed until DELIM is reached, then return the prefix as idents and
         remainder as msg_list. This is easily broken by setting an IDENT to DELIM,
         but that would be silly.
 
         Parameters
         ----------
         msg_list : a list of Message or bytes objects
             The message to be split.
         copy : bool
             flag determining whether the arguments are bytes or Messages
 
         Returns
         -------
         (idents, msg_list) : two lists
             idents will always be a list of bytes, each of which is a ZMQ
             identity. msg_list will be a list of bytes or zmq.Messages of the
             form [HMAC,p_header,p_parent,p_content,buffer1,buffer2,...] and
             should be unpackable/unserializable via self.unserialize at this
             point.
         """
         if copy:
             idx = msg_list.index(DELIM)
             return msg_list[:idx], msg_list[idx+1:]
         else:
             failed = True
             for idx,m in enumerate(msg_list):
                 if m.bytes == DELIM:
                     failed = False
                     break
             if failed:
                 raise ValueError("DELIM not in msg_list")
             idents, msg_list = msg_list[:idx], msg_list[idx+1:]
             return [m.bytes for m in idents], msg_list
 
     def unserialize(self, msg_list, content=True, copy=True):
         """Unserialize a msg_list to a nested message dict.
 
         This is roughly the inverse of serialize. The serialize/unserialize
         methods work with full message lists, whereas pack/unpack work with
         the individual message parts in the message list.
 
         Parameters:
         -----------
         msg_list : list of bytes or Message objects
             The list of message parts of the form [HMAC,p_header,p_parent,
             p_metadata,p_content,buffer1,buffer2,...].
         content : bool (True)
             Whether to unpack the content dict (True), or leave it packed
             (False).
         copy : bool (True)
             Whether to return the bytes (True), or the non-copying Message
             object in each place (False).
 
         Returns
         -------
         msg : dict
             The nested message dict with top-level keys [header, parent_header,
             content, buffers].
         """
         minlen = 5
         message = {}
         if not copy:
             for i in range(minlen):
                 msg_list[i] = msg_list[i].bytes
         if self.auth is not None:
             signature = msg_list[0]
             if not signature:
                 raise ValueError("Unsigned Message")
             if signature in self.digest_history:
                 raise ValueError("Duplicate Signature: %r"%signature)
             self.digest_history.add(signature)
             check = self.sign(msg_list[1:5])
             if not signature == check:
                 raise ValueError("Invalid Signature: %r" % signature)
         if not len(msg_list) >= minlen:
             raise TypeError("malformed message, must have at least %i elements"%minlen)
         header = self.unpack(msg_list[1])
         message['header'] = header
         message['msg_id'] = header['msg_id']
         message['msg_type'] = header['msg_type']
         message['parent_header'] = self.unpack(msg_list[2])
         message['metadata'] = self.unpack(msg_list[3])
         if content:
             message['content'] = self.unpack(msg_list[4])
         else:
             message['content'] = msg_list[4]
 
         message['buffers'] = msg_list[5:]
         return message
 
 def test_msg2obj():
     am = dict(x=1)
     ao = Message(am)
     assert ao.x == am['x']
 
     am['y'] = dict(z=1)
     ao = Message(am)
     assert ao.y.z == am['y']['z']
 
     k1, k2 = 'y', 'z'
     assert ao[k1][k2] == am[k1][k2]
 
     am2 = dict(ao)
     assert am['x'] == am2['x']
     assert am['y']['z'] == am2['y']['z']