gajim-plural/src/command_system/dispatcher.py

117 lines
3.6 KiB
Python

# Copyright (c) 2010, Alexander Cherniuk (ts33kr@gmail.com)
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
#
# * Redistributions of source code must retain the above copyright
# notice, this list of conditions and the following disclaimer.
#
# * Redistributions in binary form must reproduce the above copyright
# notice, this list of conditions and the following disclaimer in the
# documentation and/or other materials provided with the distribution.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
# HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
"""
Backbone of the command system. Provides smart and controllable
dispatching mechanism with an auto-discovery functionality. In addition
to automatic discovery and dispatching, also features manual control
over the process.
"""
from types import NoneType
from tools import remove
COMMANDS = {}
CONTAINERS = {}
def add_host(host):
CONTAINERS[host] = []
def remove_host(host):
remove(CONTAINERS, host)
def add_container(container):
for host in container.HOSTS:
CONTAINERS[host].append(container)
def remove_container(container):
for host in container.HOSTS:
remove(CONTAINERS[host], container)
def add_commands(container):
commands = COMMANDS.setdefault(container, {})
for command in traverse_commands(container):
for name in command.names:
commands[name] = command
def remove_commands(container):
remove(COMMANDS, container)
def traverse_commands(container):
for name in dir(container):
attribute = getattr(container, name)
if is_command(attribute):
yield attribute
def is_command(attribute):
from framework import Command
return isinstance(attribute, Command)
def is_root(namespace):
metaclass = namespace.get("__metaclass__", NoneType)
return issubclass(metaclass, Dispatchable)
def get_command(host, name):
for container in CONTAINERS[host]:
command = COMMANDS[container].get(name)
if command:
return command
def list_commands(host):
for container in CONTAINERS[host]:
commands = COMMANDS[container]
for name, command in commands.iteritems():
yield name, command
class Dispatchable(type):
def __init__(self, name, bases, namespace):
parents = super(Dispatchable, self)
parents.__init__(name, bases, namespace)
if not is_root(namespace):
self.dispatch()
def dispatch(self):
if self.AUTOMATIC:
self.enable()
class Host(Dispatchable):
def enable(self):
add_host(self)
def disable(self):
remove_host(self)
class Container(Dispatchable):
def enable(self):
add_container(self)
add_commands(self)
def disable(self):
remove_commands(self)
remove_container(self)