[IPython-dev] ipython embedded in twisted, no threads
Jörgen Stenarson
jorgen.stenarson at bostream.nu
Wed Apr 18 14:37:07 EDT 2007
Hi Stefan,
I have done some more experimenting. And now I think I have something
resembling what you were after. If you replace the emacs.py file in
pyreadline/modes/emacs.py with the attached version. Then running the
async_test.py should give you a prompt where you can type away and at
the same time the window title has a counter that is increased every
second. Make sure you have a recent update from svn before replacing
emacs.py.
If you have any suggestions for improving this interface I'm open for
suggestions. I'm not sure on the best way to handle Ctrl-D and ctrl-C,
especially ctrl-c is problematic since it can be caught by other parts
of the program as well.
/Jörgen
Stefan Rank skrev:
> Hi Jörgen,
>
> on 16.04.2007 20:16 Jörgen Stenarson said the following:
>> Hi Stefan,
>>
>> I'm not sure exactly what you are after (I don't use twisted myself).
>
> I am not an expert either, I am afraid.
>
>> But in pyreadline it is now fairly straightforward to add a new
>> console class (there are currently two: the standard win32 and one for
>> .NET/IronPython) which should implement the lowlevel keyboard and
>> screen output routines. If this is what is needed I would be happy to
>> accept patches and answer questions to help make it happen. We would
>> probably also have to work out a more sofisticated method of choosing
>> low-level console backend than what is used now.
>
> I think what is needed for readline support in twisted is not a new
> backend but an additional frontend/API.
> The 'problem' (read advantage ;-) with twisted is that it needs a
> callback interface that does not block, as it wants to do the polling
> for input events itself.
>
> GNU readline has a callback interface that should be usable for that:
> http://cnswww.cns.cwru.edu/php/chet/readline/readline.html#SEC41
> (for triggering single character reading)
> Would this be possible with pyreadline?
>
> cheers,
> stefan
>
>> Stefan Rank skrev:
>>> Hi,
>>> [apologies if this arrives twice, posting via gmane didn't work - yet.]
>>>
>>> attached is an ugly first attempt at embedding IPython in a twisted
>>> application without using threads.
>>>
>>> twisted.internet.stdio and a LineReceiver implementation are responsible
>>> for getting input events.
>>> I had to subclass the IPython shell and rearrange code to
>>> create a non-blocking callback interface (splitting on the main,
>>> blocking, raw_input call).
>>>
>>> It's far from perfect: readline functionality is missing (no commandline
>>> navigation, history navigation, completion), and sometimes continuation
>>> lines eat the input counter (In[2] ... In[4]).
>>>
>>> Would IPython developers be interested in patches that allow a less ugly
>>> version of such a callback-friendly subclass? ;-)
>>> The basic idea: refactor the main loop (InteractiveShell.interact) to::
>>>
>>> setup()
>>> while ...:
>>> promptforline()
>>> raw_input
>>> handleline()
>>> teardown()
>>>
>>> (I think it might also be interesting for the frontend to the IPython
>>> parallel computing effort, which uses twisted.)
>>>
>>> cheers,
>>> stefan
>>>
>>>
>>> ------------------------------------------------------------------------
>>>
>>> '''Testing a way to embed IPython in a twisted app without using
>>> threads.
>>> (seems to work on Py25/WinXP, twisted2.5 patched with #2157,
>>> IPython0.8.0)
>>>
>>> twisted.internet.stdio is responsible for getting user input.
>>> An implementation of the LineReceiver protocol passes received lines
>>> to a custom subclass of the IPython shell (main raw_input call removed).
>>>
>>> No readline behaviour is available.
>>> (But IPython still sets up readline and uses it for colour printing.)
>>>
>>> TODO:
>>> integrate readline functionality: two possibilities
>>>
>>> 1) Change pyreadline so that it can be called back by t.i.stdio for
>>> all things except waiting for input (i.e. completion, key
>>> bindings, ...)
>>> This would mean no further changes to IPython, which would still
>>> be using pyreadline directly.
>>> (or use a GNU readline callback interface: a t.i.stdio-alike
>>> would be
>>> polling/selecting for input, but then call readline to
>>> actually consume it.)
>>> 2) Build a readline compatible interface for t.i.stdio
>>> (only the parts for setting up completeres, key bindings, ...)
>>> and make the IPython subclass use that instead of pyreadline
>>>
>>> As there is a lot of pasted IPython code including comments, I added
>>> ##### multi-hash comments and
>>> docstrings explaining the rearrangements.
>>>
>>> :author: strank
>>> '''
>>>
>>> __docformat__ = "restructuredtext en"
>>>
>>> import sys
>>> import __builtin__
>>>
>>> from twisted.internet import reactor, stdio
>>> from twisted.protocols import basic
>>> from IPython.Shell import IPShellEmbed
>>> from IPython.iplib import InteractiveShell, ultraTB
>>> from IPython.ipmaker import make_IPython
>>>
>>>
>>> def main():
>>> ###### this is what we want:
>>> reactor.callWhenRunning(startTwistedStdioShell)
>>> ###### because this blocks the reactor while IPython is active:
>>> #reactor.callWhenRunning(startIPShell)
>>> reactor.run()
>>>
>>>
>>> def startIPShell(args=None):
>>> '''The non-twisted-friendly way of embedding IPython.'''
>>> if args is None:
>>> args = []
>>> some_recognisable_local = 'WAGAWAGA' # gets exposed in Shell
>>> ipshell = IPShellEmbed(args,
>>> banner='Standard IPython called from
>>> twisted (blocking)',
>>> exit_msg='Leaving Interpreter, back to
>>> program.')
>>> ipshell('***Called from top level. '
>>> 'Hit Ctrl-D to exit interpreter and continue program.')
>>> reactor.stop()
>>>
>>>
>>> def startTwistedStdioShell(args=None, local_ns=None):
>>> '''On Windows, this only works with a patched twisted,
>>> because twisted.internet.stdio in twisted2.5 is unix only,
>>> see ticket #2157.
>>> '''
>>> if args is None:
>>> args = []
>>> ipshell = TwistedIPShellEmbed([],
>>> banner='IPython embedded in a
>>> Twisted application',
>>> exit_msg='Leaving Interpreter, back
>>> to program.')
>>> sp = ShellProtocol(ipshell, '***Called from top level. ',
>>> local_ns=local_ns)
>>> #sp.setRawMode()
>>> stdio.StandardIO(sp)
>>>
>>>
>>> class TwistedIPShellEmbed(IPShellEmbed):
>>> '''Same as superclass, BUT:
>>> __init__ is duplicated, with a single difference:
>>> The actual IP shell_class is set to our own subclass.
>>> __call__ is split into two methods for setup / teardown.
>>> '''
>>>
>>> def
>>> __init__(self,argv=None,banner='',exit_msg=None,rc_override=None,
>>> user_ns=None):
>>> """Note that argv here is a string, NOT a list."""
>>> self.set_banner(banner)
>>> self.set_exit_msg(exit_msg)
>>> self.set_dummy_mode(0)
>>> # sys.displayhook is a global, we need to save the user's
>>> original
>>> # Don't rely on __displayhook__, as the user may have changed
>>> that.
>>> self.sys_displayhook_ori = sys.displayhook
>>> # save readline completer status
>>> try:
>>> #print 'Save completer',sys.ipcompleter # dbg
>>> self.sys_ipcompleter_ori = sys.ipcompleter
>>> except:
>>> pass # not nested with IPython
>>> self.IP = make_IPython(argv,rc_override=rc_override,
>>> embedded=True,
>>> user_ns=user_ns,
>>> ###### HERE IS THE DIFFERENCE --
>>> StefanRank
>>> shell_class=TwistedInteractiveShell)
>>> # copy our own displayhook also
>>> self.sys_displayhook_embed = sys.displayhook
>>> # and leave the system's display hook clean
>>> sys.displayhook = self.sys_displayhook_ori
>>> # don't use the ipython crash handler so that user exceptions
>>> aren't
>>> # trapped
>>> sys.excepthook = ultraTB.FormattedTB(color_scheme =
>>> self.IP.rc.colors,
>>> mode = self.IP.rc.xmode,
>>> call_pdb = self.IP.rc.pdb)
>>> self.restore_system_completer()
>>>
>>> def
>>> __call__(self,header='',local_ns=None,global_ns=None,dummy=None):
>>> # Set global subsystems (display,completions) to our values
>>> sys.displayhook = self.sys_displayhook_embed
>>> if self.IP.has_readline:
>>> self.IP.set_completer()
>>> if self.banner and header:
>>> format = '%s\n%s\n'
>>> else:
>>> format = '%s%s\n'
>>> banner = format % (self.banner,header)
>>> # Call the embedding code with a stack depth of 1 so it can
>>> skip over
>>> # our call and get the original caller's namespaces.
>>> ###### STOP HERE, THIS embed_mainloop DOESN'T BLOCK, RETURN
>>> THE SHELL --StefanRank
>>> return
>>> self.IP.embed_mainloop(banner,local_ns,global_ns,stack_depth=1)
>>>
>>> def teardown(self):
>>> ###### call the code that would have been called at the end
>>> of IP.embed_mainloop:
>>> self.IP.teardown()
>>> ###### This is the code formerly known as: the end of __call__:
>>> if self.exit_msg:
>>> print self.exit_msg
>>> # Restore global systems (display, completion)
>>> sys.displayhook = self.sys_displayhook_ori
>>> self.restore_system_completer()
>>>
>>>
>>> class TwistedInteractiveShell(InteractiveShell):
>>> '''Subclassing to remove raw_input call and provide a callback
>>> interface.
>>> Copy-pasted and split up code of embed_mainloop, interact,
>>> raw_input.
>>> '''
>>>
>>> def
>>> embed_mainloop(self,header='',local_ns=None,global_ns=None,stack_depth=0):
>>>
>>> # Get locals and globals from caller
>>> if local_ns is None or global_ns is None:
>>> call_frame = sys._getframe(stack_depth).f_back
>>> if local_ns is None:
>>> local_ns = call_frame.f_locals
>>> if global_ns is None:
>>> global_ns = call_frame.f_globals
>>> self.user_global_ns = global_ns
>>> local_varnames = local_ns.keys()
>>> self.user_ns.update(local_ns)
>>> if local_ns is None and global_ns is None:
>>> self.user_global_ns.update(__main__.__dict__)
>>> self.set_completer_frame()
>>> self.add_builtins()
>>> self.interact(header)
>>> return self ###### needed for later calls, interact is now
>>> non-blocking
>>>
>>> def teardown(self):
>>> '''This is the code formerly known as: the end of interact
>>> and embed_mainloop.'''
>>> ##### from interact:
>>> # We are off again...
>>> __builtin__.__dict__['__IPYTHON__active'] -= 1
>>> ##### from embed_mainloop:
>>> # now, purge out the user namespace from anything we might
>>> have added
>>> # from the caller's local namespace
>>> ###### local_varnames not accessible any more,
>>> ###### should probably be saved... (TODO)
>>> ###delvar = self.user_ns.pop
>>> ###for var in local_varnames:
>>> ### delvar(var,None)
>>> # and clean builtins we may have overridden
>>> self.clean_builtins()
>>>
>>> def interact(self, banner=None):
>>> ###### HERE IT GETS HAIRY: code copied from
>>> self.interact(header)
>>> if self.exit_now:
>>> # batch run -> do not interact
>>> return ###### This does not make any sense now, since we
>>> are non-blocking
>>> cprt = 'Type "copyright", "credits" or "license" for more
>>> information.'
>>> if banner is None:
>>> self.write("Python %s on %s\n%s\n(%s)\n" %
>>> (sys.version, sys.platform, cprt,
>>> self.__class__.__name__))
>>> else:
>>> self.write(banner)
>>> more = 0
>>> # Mark activity in the builtins
>>> __builtin__.__dict__['__IPYTHON__active'] += 1
>>> self.promptForLine(more)
>>> return self
>>>
>>> def promptForLine(self, more):
>>> '''New method. To be called before waiting for the next line.'''
>>> prompt = ''
>>> ###### THIS NEEDED TO BE UNTANGLED: originally a while loop
>>> in self.interact
>>> # exit_now is set by a call to %Exit or %Quit
>>> if not self.exit_now:
>>> if more:
>>> prompt = self.hooks.generate_prompt(True)
>>> if self.autoindent:
>>> self.readline_startup_hook(self.pre_readline)
>>> else:
>>> prompt = self.hooks.generate_prompt(False)
>>> ####### code from self.raw_input:
>>> self.set_completer()
>>> ####### write the prompt here, writing it in the
>>> LineReceiver
>>> ####### with sendLine messes up the colouring
>>> self.write(prompt)
>>> ####### raw_input BEGONE!!!
>>> ####### unfortunately all the exception handling in
>>> self.interact is also gone.
>>> ####### return and wait for a call to useLine
>>>
>>> def useLine(self, line, continue_prompt=False):
>>> '''New method. To be called with a new received line.'''
>>> ####### code from self.raw_input:
>>> if line.strip():
>>> if continue_prompt:
>>> self.input_hist_raw[-1] += '%s\n' % line
>>> if self.has_readline: # and some config option is set?
>>> try:
>>> histlen =
>>> self.readline.get_current_history_length()
>>> newhist = self.input_hist_raw[-1].rstrip()
>>> self.readline.remove_history_item(histlen-1)
>>>
>>> self.readline.replace_history_item(histlen-2,newhist)
>>> except AttributeError:
>>> pass # re{move,place}_history_item are new in
>>> 2.4.
>>> else:
>>> self.input_hist_raw.append('%s\n' % line)
>>> try:
>>> lineout = self.prefilter(line,continue_prompt)
>>> except:
>>> # blanket except, in case a user-defined prefilter
>>> crashes, so it
>>> # can't take all of ipython with it.
>>> self.showtraceback()
>>> lineout = ''
>>> ###### CODE FROM INTERACT AGAIN:
>>> more = self.push(lineout)
>>> if (self.SyntaxTB.last_syntax_error and
>>> self.rc.autoedit_syntax):
>>> self.edit_syntax_error()
>>> self.promptForLine(more)
>>> ###### indicate if we want to quit
>>> return not self.exit_now
>>>
>>>
>>> class ShellProtocol(basic.LineReceiver):
>>> delimiter = '\n' # does not work with '\r\n' on Windows...
>>> # this might be an issue with the #2157 patches?
>>>
>>> def __init__(self, ipshell, banner, **kwargs):
>>> self.ipshell = ipshell
>>> self.banner = banner
>>> self.kwargs = kwargs
>>>
>>> def connectionMade(self):
>>> #self.sendLine("Yay, type something!")
>>> # locals here are available in the shell:
>>> # (but in practice the locals of the ShellProtocol() call site
>>> # would be more interesting.)
>>> another_strange_local = 'hubabuba'
>>> from twisted.internet import reactor
>>> self.sheller = self.ipshell(self.banner
>>> + '\n quit.....quits via LineReceiver,'
>>> + '\n exit()...quits via IPython,'
>>> + '\n pause....test pausing the LineReceiver',
>>> **self.kwargs)
>>>
>>> def lineReceived(self, line):
>>> if line == 'quit':
>>> self.sendLine('OK quitting')
>>> self.transport.loseConnection()
>>> return
>>> if line == 'pause':
>>> self.sendLine('OK pausing for 2 seconds')
>>> self.pauseProducing()
>>> self.clearLineBuffer()
>>> # still receives keys typed during the pause,
>>> # no matter how many clearLineBuffer()s, I use.
>>> # might be a feature of Windows cmd... ?
>>> def restart():
>>> self.clearLineBuffer()
>>> self.resumeProducing()
>>> self.clearLineBuffer()
>>> reactor.callLater(2, restart)
>>> return
>>> #self.sendLine("Echo: " + line)
>>> if not self.sheller.useLine(line): # processes line, prints
>>> output and next prompt
>>> self.sendLine("IPython wants to quit")
>>> self.transport.loseConnection()
>>> #self.transport.write("Yay, type more!")
>>>
>>> #def rawDataReceived(self, data):
>>> # self.sendLine('RawEcho: ' + str(data))
>>> # self.transport.write("Yay, type more!")
>>>
>>> def connectionLost(self, reason):
>>> try:
>>> self.ipshell.teardown()
>>> except IOError:
>>> pass # is raised by IPython code when you type quit
>>> # stop the reactor, only because this is meant to be run in
>>> Stdio.
>>> reactor.stop()
>>>
>>>
>>> if __name__ == '__main__':
>>> main()
>>>
>>>
>>> ------------------------------------------------------------------------
>>>
>>> _______________________________________________
>>> IPython-dev mailing list
>>> IPython-dev at scipy.org
>>> http://lists.ipython.scipy.org/mailman/listinfo/ipython-dev
>>
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