-# Copyright
+# Copyright (C) 2010-2012 W. Trevor King <wking@tremily.us>
+#
+# This file is part of Hooke.
+#
+# Hooke is free software: you can redistribute it and/or modify it under the
+# terms of the GNU Lesser General Public License as published by the Free
+# Software Foundation, either version 3 of the License, or (at your option) any
+# later version.
+#
+# Hooke is distributed in the hope that it will be useful, but WITHOUT ANY
+# WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
+# A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
+# details.
+#
+# You should have received a copy of the GNU Lesser General Public License
+# along with Hooke. If not, see <http://www.gnu.org/licenses/>.
"""The `engine` module provides :class:`CommandEngine` for executing
:class:`hooke.command.Command`\s.
"""
-from .ui import CloseEngine, CommandMessage
+import logging
+from Queue import Queue, Empty
+
+from .command import NullQueue
+
+
+class QueueMessage (object):
+ def __str__(self):
+ return self.__class__.__name__
+
+
+class CloseEngine (QueueMessage):
+ pass
+
+
+class CommandMessage (QueueMessage):
+ """A message storing a command to run, `command` should be the
+ name of a :class:`hooke.command.Command` instance, and `arguments`
+ should be a :class:`dict` with `argname` keys and `value` values
+ to be passed to the command.
+ """
+ def __init__(self, command, arguments=None):
+ self.command = command
+ if arguments == None:
+ arguments = {}
+ self.arguments = arguments
+ self.explicit_user_call = True
+ """Message is explicitly user-executed. This is useful for
+ distinguishing auto-generated calls (for which
+ `explicit_user_call` should be `False` such as the GUIs
+ current status requests.
+ """
+
+ def __str__(self):
+ return str(self.__unicode__())
+
+ def __unicode__(self):
+ """Return a unicode representation of the `CommandMessage`.
+
+ Examples
+ --------
+ >>> from .compat.odict import odict
+ >>> cm = CommandMessage('command A')
+ >>> print(unicode(cm))
+ <CommandMessage command A>
+ >>> cm.arguments = odict([('param a','value a'), ('param b', 'value b')])
+ >>> print(unicode(cm))
+ <CommandMessage command A {param a: value a, param b: value b}>
+
+ The parameters are sorted by name, so you won't be surprised
+ in any doctests, etc.
+
+ >>> cm.arguments = odict([('param b','value b'), ('param a', 'value a')])
+ >>> print(unicode(cm))
+ <CommandMessage command A {param a: value a, param b: value b}>
+ """
+ if len(self.arguments) > 0:
+ return u'<%s %s {%s}>' % (
+ self.__class__.__name__, self.command,
+ ', '.join(['%s: %s' % (key, value)
+ for key,value in sorted(self.arguments.items())]))
+ return u'<%s %s>' % (self.__class__.__name__, self.command)
+
+ def __repr__(self):
+ return self.__str__()
+
class CommandEngine (object):
def run(self, hooke, ui_to_command_queue, command_to_ui_queue):
- """Get a :class:`hooke.ui.QueueMessage` from the incoming
+ """Get a :class:`QueueMessage` from the incoming
`ui_to_command_queue` and act accordingly.
- If the message is a :class:`hooke.ui.CommandMessage` instance,
- the command run may read subsequent input from
+ If the message is a :class:`CommandMessage` instance, the
+ command run may read subsequent input from
`ui_to_command_queue` (if it is an interactive command). The
command may also put assorted data into `command_to_ui_queue`.
When the command completes, it will put a
:class:`hooke.command.CommandExit` instance into
`command_to_ui_queue`, at which point the `CommandEngine` will
- be ready to receive the next :class:`hooke.ui.QueueMessage`.
+ be ready to receive the next :class:`QueueMessage`.
"""
+ log = logging.getLogger('hooke')
+ log.debug('engine starting')
+ for playlist in hooke.playlists: # Curve._hooke is not pickled.
+ for curve in playlist:
+ curve.set_hooke(hooke)
while True:
+ log.debug('engine waiting for command')
msg = ui_to_command_queue.get()
if isinstance(msg, CloseEngine):
+ command_to_ui_queue.put(hooke)
+ log.debug(
+ 'engine closing, placed hooke instance in return queue')
break
assert isinstance(msg, CommandMessage), type(msg)
- msg.command.run(hooke, ui_to_command_queue, command_to_ui_queue,
- **msg.arguments)
+ log.debug('engine running %s' % msg)
+ cmd = hooke.command_by_name[msg.command]
+ cmd.run(hooke, ui_to_command_queue, command_to_ui_queue,
+ **msg.arguments)
+
+ def run_command(self, hooke, command, arguments):
+ """Run the command named `command` with `arguments` using
+ :meth:`~hooke.engine.CommandEngine.run_command`.
+
+ This allows commands to execute sub commands and enables
+ :class:`~hooke.command_stack.CommandStack` execution.
+
+ Note that these commands *do not* have access to the usual UI
+ communication queues, so make sure they will not need user
+ interaction.
+ """
+ log = logging.getLogger('hooke')
+ log.debug('engine running internal %s'
+ % CommandMessage(command, arguments))
+ outqueue = Queue()
+ cmd = hooke.command_by_name[command]
+ cmd.run(hooke, NullQueue(), outqueue, **arguments)
+ while True:
+ try:
+ msg = outqueue.get(block=False)
+ except Empty:
+ break
+ log.debug('engine message from %s (%s): %s' % (command, type(msg), msg))
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