SafeEyes/safeeyes/Plugins.py

144 lines
5.6 KiB
Python

# Safe Eyes is a utility to remind you to take break frequently
# to protect your eyes from eye strain.
# Copyright (C) 2017 Gobinath
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
# This program 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 General Public License for more details.
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
import logging, importlib, os, sys, inspect, copy
from multiprocessing.pool import ThreadPool
from safeeyes import Utility
plugins_directory = os.path.join(Utility.config_directory, 'plugins')
sys.path.append(os.path.abspath(plugins_directory))
class Plugins:
"""
Imports the Safe Eyes plugins and calls the methods defined in those plugins.
"""
def __init__(self, config):
logging.info('Load all the plugins')
self.__plugins = []
for plugin in config['plugins']:
if plugin['location'].lower() in ['left', 'right']:
if os.path.isfile(os.path.join(plugins_directory, plugin['name'] + '.py')):
module = importlib.import_module(plugin['name'])
if self.__has_method(module, 'start') and self.__has_method(module, 'pre_notification') and self.__has_method(module, 'pre_break') and self.__has_method(module, 'post_break') and self.__has_method(module, 'exit'):
self.__plugins.append({'name': plugin['name'], 'module': module, 'location': plugin['location'].lower()})
else:
logging.warning('Ignoring the plugin ' + str(plugin['name']) + ' due to invalid method signature')
else:
logging.warning('Plugin file ' + str(plugin['name']) + '.py not found')
else:
logging.warning('Ignoring the plugin ' + str(plugin['name']) + ' due to invalid location value: ' + plugin['location'])
if self.__plugins:
self.__thread_pool = ThreadPool(min([4, len(self.__plugins)]))
def start(self, context):
"""
Call the start function of all the plugins in separate thread.
"""
if self.__plugins:
context = copy.deepcopy(context) # If plugins change the context, it should not affect Safe Eyes
for plugin in self.__plugins:
try:
self.__thread_pool.apply_async(plugin['module'].start, (context,))
except Exception as e:
pass
def pre_notification(self, context):
"""
Call the pre_notification function of all the plugins in separate thread.
"""
if self.__plugins:
context = copy.deepcopy(context) # If plugins change the context, it should not affect Safe Eyes
for plugin in self.__plugins:
try:
self.__thread_pool.apply_async(plugin['module'].pre_notification, (context,))
except Exception as e:
pass
def pre_break(self, context):
"""
Call the pre_break function of all the plugins and provide maximum 1 second to return the result.
If they return the reault within 1 sec, append it to the output.
Returns: {'left': 'Markup of plugins to be aligned on left', 'right': 'Markup of plugins to be aligned on right' }
"""
output = {'left': ' \n', 'right': ' \n'}
if self.__plugins:
context = copy.deepcopy(context) # If plugins change the context, it should not affect Safe Eyes
multiple_results = [self.__thread_pool.apply_async(plugin['module'].pre_break, (context,)) for plugin in self.__plugins]
for i in range(len(multiple_results)):
try:
result = multiple_results[i].get(timeout=1)
if result:
# Limit the line length to 50 characters
large_lines = list(filter(lambda x: len(x) > 50, Utility.html_to_text(result).splitlines()))
if large_lines:
logging.warning('Ignoring lengthy result from the plugin ' + self.__plugins[i]['name'])
continue
output[self.__plugins[i]['location']] += (result + '\n\n')
except Exception:
# Something went wrong in the plugin
logging.warning('Error when executing the plugin ' + self.__plugins[i]['name'])
return output
def post_break(self, context):
"""
Call the post_break function of all the plugins in separate thread.
"""
if self.__plugins:
context = copy.deepcopy(context) # If plugins change the context, it should not affect Safe Eyes
for plugin in self.__plugins:
try:
self.__thread_pool.apply_async(plugin['module'].post_break, (context,))
except Exception as e:
pass
def exit(self, context):
"""
Call the exit function of all the plugins in separate thread.
"""
if self.__plugins:
context = copy.deepcopy(context) # If plugins change the context, it should not affect Safe Eyes
# Give maximum 1 sec for all plugins before terminating the thread pool
multiple_results = [self.__thread_pool.apply_async(plugin['module'].exit, (context,)) for plugin in self.__plugins]
for i in range(len(multiple_results)):
try:
multiple_results[i].get(timeout=1)
except Exception:
# Something went wrong in the plugin
pass
try:
self.__thread_pool.terminate() # Shutdown the pool
except Exception as e:
pass
def __has_method(self, module, method_name, no_of_args=1):
"""
Check whether the given function is defined in the module or not.
"""
if hasattr(module, method_name):
if len(inspect.getargspec(getattr(module, method_name)).args) == no_of_args:
return True
return False