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engineservice.py
876 lines | 28.2 KiB | text/x-python | PythonLexer
# encoding: utf-8
# -*- test-case-name: IPython.kernel.tests.test_engineservice -*-
"""A Twisted Service Representation of the IPython core.
The IPython Core exposed to the network is called the Engine. Its
representation in Twisted in the EngineService. Interfaces and adapters
are used to abstract out the details of the actual network protocol used.
The EngineService is an Engine that knows nothing about the actual protocol
used.
The EngineService is exposed with various network protocols in modules like:
enginepb.py
enginevanilla.py
As of 12/12/06 the classes in this module have been simplified greatly. It was
felt that we had over-engineered things. To improve the maintainability of the
code we have taken out the ICompleteEngine interface and the completeEngine
method that automatically added methods to engines.
"""
__docformat__ = "restructuredtext en"
#-------------------------------------------------------------------------------
# Copyright (C) 2008 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 os, sys, copy
import cPickle as pickle
from new import instancemethod
from twisted.application import service
from twisted.internet import defer, reactor
from twisted.python import log, failure, components
import zope.interface as zi
from IPython.kernel.core.interpreter import Interpreter
from IPython.kernel import newserialized, error, util
from IPython.kernel.util import printer
from IPython.kernel.twistedutil import gatherBoth, DeferredList
from IPython.kernel import codeutil
#-------------------------------------------------------------------------------
# Interface specification for the Engine
#-------------------------------------------------------------------------------
class IEngineCore(zi.Interface):
"""The minimal required interface for the IPython Engine.
This interface provides a formal specification of the IPython core.
All these methods should return deferreds regardless of what side of a
network connection they are on.
In general, this class simply wraps a shell class and wraps its return
values as Deferred objects. If the underlying shell class method raises
an exception, this class should convert it to a twisted.failure.Failure
that will be propagated along the Deferred's errback chain.
In addition, Failures are aggressive. By this, we mean that if a method
is performing multiple actions (like pulling multiple object) if any
single one fails, the entire method will fail with that Failure. It is
all or nothing.
"""
id = zi.interface.Attribute("the id of the Engine object")
properties = zi.interface.Attribute("A dict of properties of the Engine")
def execute(lines):
"""Execute lines of Python code.
Returns a dictionary with keys (id, number, stdin, stdout, stderr)
upon success.
Returns a failure object if the execution of lines raises an exception.
"""
def push(namespace):
"""Push dict namespace into the user's namespace.
Returns a deferred to None or a failure.
"""
def pull(keys):
"""Pulls values out of the user's namespace by keys.
Returns a deferred to a tuple objects or a single object.
Raises NameError if any one of objects doess not exist.
"""
def push_function(namespace):
"""Push a dict of key, function pairs into the user's namespace.
Returns a deferred to None or a failure."""
def pull_function(keys):
"""Pulls functions out of the user's namespace by keys.
Returns a deferred to a tuple of functions or a single function.
Raises NameError if any one of the functions does not exist.
"""
def get_result(i=None):
"""Get the stdin/stdout/stderr of command i.
Returns a deferred to a dict with keys
(id, number, stdin, stdout, stderr).
Raises IndexError if command i does not exist.
Raises TypeError if i in not an int.
"""
def reset():
"""Reset the shell.
This clears the users namespace. Won't cause modules to be
reloaded. Should also re-initialize certain variables like id.
"""
def kill():
"""Kill the engine by stopping the reactor."""
def keys():
"""Return the top level variables in the users namspace.
Returns a deferred to a dict."""
class IEngineSerialized(zi.Interface):
"""Push/Pull methods that take Serialized objects.
All methods should return deferreds.
"""
def push_serialized(namespace):
"""Push a dict of keys and Serialized objects into the user's namespace."""
def pull_serialized(keys):
"""Pull objects by key from the user's namespace as Serialized.
Returns a list of or one Serialized.
Raises NameError is any one of the objects does not exist.
"""
class IEngineProperties(zi.Interface):
"""Methods for access to the properties object of an Engine"""
properties = zi.Attribute("A StrictDict object, containing the properties")
def set_properties(properties):
"""set properties by key and value"""
def get_properties(keys=None):
"""get a list of properties by `keys`, if no keys specified, get all"""
def del_properties(keys):
"""delete properties by `keys`"""
def has_properties(keys):
"""get a list of bool values for whether `properties` has `keys`"""
def clear_properties():
"""clear the properties dict"""
class IEngineBase(IEngineCore, IEngineSerialized, IEngineProperties):
"""The basic engine interface that EngineService will implement.
This exists so it is easy to specify adapters that adapt to and from the
API that the basic EngineService implements.
"""
pass
class IEngineQueued(IEngineBase):
"""Interface for adding a queue to an IEngineBase.
This interface extends the IEngineBase interface to add methods for managing
the engine's queue. The implicit details of this interface are that the
execution of all methods declared in IEngineBase should appropriately be
put through a queue before execution.
All methods should return deferreds.
"""
def clear_queue():
"""Clear the queue."""
def queue_status():
"""Get the queued and pending commands in the queue."""
def register_failure_observer(obs):
"""Register an observer of pending Failures.
The observer must implement IFailureObserver.
"""
def unregister_failure_observer(obs):
"""Unregister an observer of pending Failures."""
class IEngineThreaded(zi.Interface):
"""A place holder for threaded commands.
All methods should return deferreds.
"""
pass
#-------------------------------------------------------------------------------
# Functions and classes to implement the EngineService
#-------------------------------------------------------------------------------
class StrictDict(dict):
"""This is a strict copying dictionary for use as the interface to the
properties of an Engine.
:IMPORTANT:
This object copies the values you set to it, and returns copies to you
when you request them. The only way to change properties os explicitly
through the setitem and getitem of the dictionary interface.
Example:
>>> e = kernel.get_engine(id)
>>> L = someList
>>> e.properties['L'] = L
>>> L == e.properties['L']
... True
>>> L.append(something Else)
>>> L == e.properties['L']
... False
getitem copies, so calls to methods of objects do not affect the
properties, as in the following example:
>>> e.properties[1] = range(2)
>>> print e.properties[1]
... [0, 1]
>>> e.properties[1].append(2)
>>> print e.properties[1]
... [0, 1]
"""
def __init__(self, *args, **kwargs):
dict.__init__(self, *args, **kwargs)
self.modified = True
def __getitem__(self, key):
return copy.deepcopy(dict.__getitem__(self, key))
def __setitem__(self, key, value):
# check if this entry is valid for transport around the network
# and copying
try:
pickle.dumps(key, 2)
pickle.dumps(value, 2)
newvalue = copy.deepcopy(value)
except:
raise error.InvalidProperty(value)
dict.__setitem__(self, key, newvalue)
self.modified = True
def __delitem__(self, key):
dict.__delitem__(self, key)
self.modified = True
def update(self, dikt):
for k,v in dikt.iteritems():
self[k] = v
def pop(self, key):
self.modified = True
return dict.pop(self, key)
def popitem(self):
self.modified = True
return dict.popitem(self)
def clear(self):
self.modified = True
dict.clear(self)
def subDict(self, *keys):
d = {}
for key in keys:
d[key] = self[key]
return d
class EngineAPI(object):
"""This is the object through which the user can edit the `properties`
attribute of an Engine.
The Engine Properties object copies all object in and out of itself.
See the EngineProperties object for details.
"""
_fix=False
def __init__(self, id):
self.id = id
self.properties = StrictDict()
self._fix=True
def __setattr__(self, k,v):
if self._fix:
raise error.KernelError("I am protected!")
else:
object.__setattr__(self, k, v)
def __delattr__(self, key):
raise error.KernelError("I am protected!")
_apiDict = {}
def get_engine(id):
"""Get the Engine API object, whcih currently just provides the properties
object, by ID"""
global _apiDict
if not _apiDict.get(id):
_apiDict[id] = EngineAPI(id)
return _apiDict[id]
def drop_engine(id):
"""remove an engine"""
global _apiDict
if _apiDict.has_key(id):
del _apiDict[id]
class EngineService(object, service.Service):
"""Adapt a IPython shell into a IEngine implementing Twisted Service."""
zi.implements(IEngineBase)
name = 'EngineService'
def __init__(self, shellClass=Interpreter, mpi=None):
"""Create an EngineService.
shellClass: something that implements IInterpreter or core1
mpi: an mpi module that has rank and size attributes
"""
self.shellClass = shellClass
self.shell = self.shellClass()
self.mpi = mpi
self.id = None
self.properties = get_engine(self.id).properties
if self.mpi is not None:
log.msg("MPI started with rank = %i and size = %i" %
(self.mpi.rank, self.mpi.size))
self.id = self.mpi.rank
self._seedNamespace()
# Make id a property so that the shell can get the updated id
def _setID(self, id):
self._id = id
self.properties = get_engine(id).properties
self.shell.push({'id': id})
def _getID(self):
return self._id
id = property(_getID, _setID)
def _seedNamespace(self):
self.shell.push({'mpi': self.mpi, 'id' : self.id})
def executeAndRaise(self, msg, callable, *args, **kwargs):
"""Call a method of self.shell and wrap any exception."""
d = defer.Deferred()
try:
result = callable(*args, **kwargs)
except:
# This gives the following:
# et=exception class
# ev=exception class instance
# tb=traceback object
et,ev,tb = sys.exc_info()
# This call adds attributes to the exception value
et,ev,tb = self.shell.formatTraceback(et,ev,tb,msg)
# Add another attribute
ev._ipython_engine_info = msg
f = failure.Failure(ev,et,None)
d.errback(f)
else:
d.callback(result)
return d
# The IEngine methods. See the interface for documentation.
def execute(self, lines):
msg = {'engineid':self.id,
'method':'execute',
'args':[lines]}
d = self.executeAndRaise(msg, self.shell.execute, lines)
d.addCallback(self.addIDToResult)
return d
def addIDToResult(self, result):
result['id'] = self.id
return result
def push(self, namespace):
msg = {'engineid':self.id,
'method':'push',
'args':[repr(namespace.keys())]}
d = self.executeAndRaise(msg, self.shell.push, namespace)
return d
def pull(self, keys):
msg = {'engineid':self.id,
'method':'pull',
'args':[repr(keys)]}
d = self.executeAndRaise(msg, self.shell.pull, keys)
return d
def push_function(self, namespace):
msg = {'engineid':self.id,
'method':'push_function',
'args':[repr(namespace.keys())]}
d = self.executeAndRaise(msg, self.shell.push_function, namespace)
return d
def pull_function(self, keys):
msg = {'engineid':self.id,
'method':'pull_function',
'args':[repr(keys)]}
d = self.executeAndRaise(msg, self.shell.pull_function, keys)
return d
def get_result(self, i=None):
msg = {'engineid':self.id,
'method':'get_result',
'args':[repr(i)]}
d = self.executeAndRaise(msg, self.shell.getCommand, i)
d.addCallback(self.addIDToResult)
return d
def reset(self):
msg = {'engineid':self.id,
'method':'reset',
'args':[]}
del self.shell
self.shell = self.shellClass()
self.properties.clear()
d = self.executeAndRaise(msg, self._seedNamespace)
return d
def kill(self):
drop_engine(self.id)
try:
reactor.stop()
except RuntimeError:
log.msg('The reactor was not running apparently.')
return defer.fail()
else:
return defer.succeed(None)
def keys(self):
"""Return a list of variables names in the users top level namespace.
This used to return a dict of all the keys/repr(values) in the
user's namespace. This was too much info for the ControllerService
to handle so it is now just a list of keys.
"""
remotes = []
for k in self.shell.user_ns.iterkeys():
if k not in ['__name__', '_ih', '_oh', '__builtins__',
'In', 'Out', '_', '__', '___', '__IP', 'input', 'raw_input']:
remotes.append(k)
return defer.succeed(remotes)
def set_properties(self, properties):
msg = {'engineid':self.id,
'method':'set_properties',
'args':[repr(properties.keys())]}
return self.executeAndRaise(msg, self.properties.update, properties)
def get_properties(self, keys=None):
msg = {'engineid':self.id,
'method':'get_properties',
'args':[repr(keys)]}
if keys is None:
keys = self.properties.keys()
return self.executeAndRaise(msg, self.properties.subDict, *keys)
def _doDel(self, keys):
for key in keys:
del self.properties[key]
def del_properties(self, keys):
msg = {'engineid':self.id,
'method':'del_properties',
'args':[repr(keys)]}
return self.executeAndRaise(msg, self._doDel, keys)
def _doHas(self, keys):
return [self.properties.has_key(key) for key in keys]
def has_properties(self, keys):
msg = {'engineid':self.id,
'method':'has_properties',
'args':[repr(keys)]}
return self.executeAndRaise(msg, self._doHas, keys)
def clear_properties(self):
msg = {'engineid':self.id,
'method':'clear_properties',
'args':[]}
return self.executeAndRaise(msg, self.properties.clear)
def push_serialized(self, sNamespace):
msg = {'engineid':self.id,
'method':'push_serialized',
'args':[repr(sNamespace.keys())]}
ns = {}
for k,v in sNamespace.iteritems():
try:
unserialized = newserialized.IUnSerialized(v)
ns[k] = unserialized.getObject()
except:
return defer.fail()
return self.executeAndRaise(msg, self.shell.push, ns)
def pull_serialized(self, keys):
msg = {'engineid':self.id,
'method':'pull_serialized',
'args':[repr(keys)]}
if isinstance(keys, str):
keys = [keys]
if len(keys)==1:
d = self.executeAndRaise(msg, self.shell.pull, keys)
d.addCallback(newserialized.serialize)
return d
elif len(keys)>1:
d = self.executeAndRaise(msg, self.shell.pull, keys)
@d.addCallback
def packThemUp(values):
serials = []
for v in values:
try:
serials.append(newserialized.serialize(v))
except:
return defer.fail(failure.Failure())
return serials
return packThemUp
def queue(methodToQueue):
def queuedMethod(this, *args, **kwargs):
name = methodToQueue.__name__
return this.submitCommand(Command(name, *args, **kwargs))
return queuedMethod
class QueuedEngine(object):
"""Adapt an IEngineBase to an IEngineQueued by wrapping it.
The resulting object will implement IEngineQueued which extends
IEngineCore which extends (IEngineBase, IEngineSerialized).
This seems like the best way of handling it, but I am not sure. The
other option is to have the various base interfaces be used like
mix-in intefaces. The problem I have with this is adpatation is
more difficult and complicated because there can be can multiple
original and final Interfaces.
"""
zi.implements(IEngineQueued)
def __init__(self, engine):
"""Create a QueuedEngine object from an engine
engine: An implementor of IEngineCore and IEngineSerialized
keepUpToDate: whether to update the remote status when the
queue is empty. Defaults to False.
"""
# This is the right way to do these tests rather than
# IEngineCore in list(zi.providedBy(engine)) which will only
# picks of the interfaces that are directly declared by engine.
assert IEngineBase.providedBy(engine), \
"engine passed to QueuedEngine doesn't provide IEngineBase"
self.engine = engine
self.id = engine.id
self.queued = []
self.history = {}
self.engineStatus = {}
self.currentCommand = None
self.failureObservers = []
def _get_properties(self):
return self.engine.properties
properties = property(_get_properties, lambda self, _: None)
# Queue management methods. You should not call these directly
def submitCommand(self, cmd):
"""Submit command to queue."""
d = defer.Deferred()
cmd.setDeferred(d)
if self.currentCommand is not None:
if self.currentCommand.finished:
# log.msg("Running command immediately: %r" % cmd)
self.currentCommand = cmd
self.runCurrentCommand()
else: # command is still running
# log.msg("Command is running: %r" % self.currentCommand)
# log.msg("Queueing: %r" % cmd)
self.queued.append(cmd)
else:
# log.msg("No current commands, running: %r" % cmd)
self.currentCommand = cmd
self.runCurrentCommand()
return d
def runCurrentCommand(self):
"""Run current command."""
cmd = self.currentCommand
f = getattr(self.engine, cmd.remoteMethod, None)
if f:
d = f(*cmd.args, **cmd.kwargs)
if cmd.remoteMethod is 'execute':
d.addCallback(self.saveResult)
d.addCallback(self.finishCommand)
d.addErrback(self.abortCommand)
else:
return defer.fail(AttributeError(cmd.remoteMethod))
def _flushQueue(self):
"""Pop next command in queue and run it."""
if len(self.queued) > 0:
self.currentCommand = self.queued.pop(0)
self.runCurrentCommand()
def saveResult(self, result):
"""Put the result in the history."""
self.history[result['number']] = result
return result
def finishCommand(self, result):
"""Finish currrent command."""
# The order of these commands is absolutely critical.
self.currentCommand.handleResult(result)
self.currentCommand.finished = True
self._flushQueue()
return result
def abortCommand(self, reason):
"""Abort current command.
This eats the Failure but first passes it onto the Deferred that the
user has.
It also clear out the queue so subsequence commands don't run.
"""
# The order of these 3 commands is absolutely critical. The currentCommand
# must first be marked as finished BEFORE the queue is cleared and before
# the current command is sent the failure.
# Also, the queue must be cleared BEFORE the current command is sent the Failure
# otherwise the errback chain could trigger new commands to be added to the
# queue before we clear it. We should clear ONLY the commands that were in
# the queue when the error occured.
self.currentCommand.finished = True
s = "%r %r %r" % (self.currentCommand.remoteMethod, self.currentCommand.args, self.currentCommand.kwargs)
self.clear_queue(msg=s)
self.currentCommand.handleError(reason)
return None
#---------------------------------------------------------------------------
# IEngineCore methods
#---------------------------------------------------------------------------
@queue
def execute(self, lines):
pass
@queue
def push(self, namespace):
pass
@queue
def pull(self, keys):
pass
@queue
def push_function(self, namespace):
pass
@queue
def pull_function(self, keys):
pass
def get_result(self, i=None):
if i is None:
i = max(self.history.keys()+[None])
cmd = self.history.get(i, None)
# Uncomment this line to disable chaching of results
#cmd = None
if cmd is None:
return self.submitCommand(Command('get_result', i))
else:
return defer.succeed(cmd)
def reset(self):
self.clear_queue()
self.history = {} # reset the cache - I am not sure we should do this
return self.submitCommand(Command('reset'))
def kill(self):
self.clear_queue()
return self.submitCommand(Command('kill'))
@queue
def keys(self):
pass
#---------------------------------------------------------------------------
# IEngineSerialized methods
#---------------------------------------------------------------------------
@queue
def push_serialized(self, namespace):
pass
@queue
def pull_serialized(self, keys):
pass
#---------------------------------------------------------------------------
# IEngineProperties methods
#---------------------------------------------------------------------------
@queue
def set_properties(self, namespace):
pass
@queue
def get_properties(self, keys=None):
pass
@queue
def del_properties(self, keys):
pass
@queue
def has_properties(self, keys):
pass
@queue
def clear_properties(self):
pass
#---------------------------------------------------------------------------
# IQueuedEngine methods
#---------------------------------------------------------------------------
def clear_queue(self, msg=''):
"""Clear the queue, but doesn't cancel the currently running commmand."""
for cmd in self.queued:
cmd.deferred.errback(failure.Failure(error.QueueCleared(msg)))
self.queued = []
return defer.succeed(None)
def queue_status(self):
if self.currentCommand is not None:
if self.currentCommand.finished:
pending = repr(None)
else:
pending = repr(self.currentCommand)
else:
pending = repr(None)
dikt = {'queue':map(repr,self.queued), 'pending':pending}
return defer.succeed(dikt)
def register_failure_observer(self, obs):
self.failureObservers.append(obs)
def unregister_failure_observer(self, obs):
self.failureObservers.remove(obs)
# Now register QueuedEngine as an adpater class that makes an IEngineBase into a
# IEngineQueued.
components.registerAdapter(QueuedEngine, IEngineBase, IEngineQueued)
class Command(object):
"""A command object that encapslates queued commands.
This class basically keeps track of a command that has been queued
in a QueuedEngine. It manages the deferreds and hold the method to be called
and the arguments to that method.
"""
def __init__(self, remoteMethod, *args, **kwargs):
"""Build a new Command object."""
self.remoteMethod = remoteMethod
self.args = args
self.kwargs = kwargs
self.finished = False
def setDeferred(self, d):
"""Sets the deferred attribute of the Command."""
self.deferred = d
def __repr__(self):
if not self.args:
args = ''
else:
args = str(self.args)[1:-2] #cut off (...,)
for k,v in self.kwargs.iteritems():
if args:
args += ', '
args += '%s=%r' %(k,v)
return "%s(%s)" %(self.remoteMethod, args)
def handleResult(self, result):
"""When the result is ready, relay it to self.deferred."""
self.deferred.callback(result)
def handleError(self, reason):
"""When an error has occured, relay it to self.deferred."""
self.deferred.errback(reason)
class ThreadedEngineService(EngineService):
"""An EngineService subclass that defers execute commands to a separate
thread.
ThreadedEngineService uses twisted.internet.threads.deferToThread to
defer execute requests to a separate thread. GUI frontends may want to
use ThreadedEngineService as the engine in an
IPython.frontend.frontendbase.FrontEndBase subclass to prevent
block execution from blocking the GUI thread.
"""
zi.implements(IEngineBase)
def __init__(self, shellClass=Interpreter, mpi=None):
EngineService.__init__(self, shellClass, mpi)
def execute(self, lines):
# Only import this if we are going to use this class
from twisted.internet import threads
msg = {'engineid':self.id,
'method':'execute',
'args':[lines]}
d = threads.deferToThread(self.shell.execute, lines)
d.addCallback(self.addIDToResult)
return d