190 lines
6.2 KiB
Python
190 lines
6.2 KiB
Python
# -*- coding: utf-8 -*-
|
|
|
|
"""
|
|
Copyright(C) 2010 Romain Bignon
|
|
|
|
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, version 3 of the License.
|
|
|
|
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, write to the Free Software
|
|
Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
|
|
|
|
"""
|
|
|
|
from __future__ import with_statement
|
|
|
|
from logging import debug
|
|
from copy import copy
|
|
from threading import Thread, Event, RLock, Timer
|
|
from .tools.misc import get_backtrace
|
|
|
|
__all__ = ['BackendsCall', 'CallErrors']
|
|
|
|
class CallErrors(Exception):
|
|
def __init__(self, errors):
|
|
Exception.__init__(self, u"Several errors have been raised:\n%s" % (u'\n'.join((u'%s: %s' % (b, e)) for b, e in errors)))
|
|
self.errors = copy(errors)
|
|
|
|
def __iter__(self):
|
|
return self.errors.__iter__()
|
|
|
|
class Result(object):
|
|
def __init__(self, backend, result):
|
|
self.backend = backend
|
|
self.result = result
|
|
|
|
def __iter__(self):
|
|
"""
|
|
To allow unpack.
|
|
|
|
For example:
|
|
>>> for backend, result in self.weboob.do(blabla)
|
|
"""
|
|
yield self.backend
|
|
yield self.result
|
|
|
|
class BackendsCall(object):
|
|
def __init__(self, backends, function, *args, **kwargs):
|
|
"""
|
|
@param backends list of backends to call
|
|
@param function backends' method name, or callable object
|
|
@param args, kwargs arguments given to called functions
|
|
"""
|
|
# Store if a backend is finished
|
|
self.backends = {}
|
|
for backend in backends:
|
|
self.backends[backend.name] = False
|
|
# Global mutex on object
|
|
self.mutex = RLock()
|
|
# Event set when every backends have give their data
|
|
self.finish_event = Event()
|
|
# Event set when there are new responses
|
|
self.response_event = Event()
|
|
# Waiting responses
|
|
self.responses = []
|
|
# Errors
|
|
self.errors = []
|
|
# Threads
|
|
self.threads = []
|
|
|
|
# Create jobs for each backend
|
|
with self.mutex:
|
|
for b in backends:
|
|
debug('New timer for %s' % b)
|
|
self.threads.append(Timer(0, self._caller, (b, function, args, kwargs)).start())
|
|
if not backends:
|
|
self.finish_event.set()
|
|
|
|
def _store_error(self, b, e):
|
|
with self.mutex:
|
|
# TODO save backtrace and/or print it here (with debug)
|
|
self.errors.append((b, e))
|
|
debug(get_backtrace(e))
|
|
|
|
def _store_result(self, b, r):
|
|
with self.mutex:
|
|
self.responses.append((b,r))
|
|
self.response_event.set()
|
|
|
|
def _caller(self, b, function, args, kwargs):
|
|
debug('Hello from timer %s' % b)
|
|
with b:
|
|
try:
|
|
# Call method on backend
|
|
try:
|
|
if callable(function):
|
|
r = function(b, *args, **kwargs)
|
|
else:
|
|
r = getattr(b, function)(*args, **kwargs)
|
|
except Exception, e:
|
|
self._store_error(b, e)
|
|
else:
|
|
debug('%s: Got answer! %s' % (b, r))
|
|
|
|
if hasattr(r, '__iter__'):
|
|
# Loop on iterator
|
|
try:
|
|
for e in r:
|
|
# Lock mutex only in loop in case the iterator is slow
|
|
# (for example if backend do some parsing operations)
|
|
self._store_result(b, e)
|
|
except Exception, e:
|
|
self._store_error(b, e)
|
|
else:
|
|
self._store_result(b, r)
|
|
finally:
|
|
with self.mutex:
|
|
# This backend is now finished
|
|
self.backends[b.name] = True
|
|
for finished in self.backends.itervalues():
|
|
if not finished:
|
|
return
|
|
self.finish_event.set()
|
|
self.response_event.set()
|
|
|
|
def _callback_thread_run(self, callback, errback):
|
|
responses = []
|
|
while not self.finish_event.isSet() or self.response_event.isSet():
|
|
self.response_event.wait()
|
|
with self.mutex:
|
|
responses = self.responses
|
|
self.responses = []
|
|
|
|
# Reset event
|
|
self.response_event.clear()
|
|
|
|
# Consume responses
|
|
while responses:
|
|
callback(*responses.pop(0))
|
|
|
|
if errback:
|
|
with self.mutex:
|
|
while self.errors:
|
|
errback(*self.errors.pop(0))
|
|
|
|
callback(None, None)
|
|
|
|
def callback_thread(self, callback, errback=None):
|
|
"""
|
|
Call this method to create a thread which will callback a
|
|
specified function everytimes a new result comes.
|
|
|
|
When the process is over, the function will be called with
|
|
both arguments set to None.
|
|
|
|
The functions prototypes:
|
|
def callback(backend, result)
|
|
def errback(backend, error)
|
|
|
|
"""
|
|
thread = Thread(target=self._callback_thread_run, args=(callback, errback))
|
|
thread.start()
|
|
return thread
|
|
|
|
def __iter__(self):
|
|
# Don't know how to factorize with _callback_thread_run
|
|
responses = []
|
|
while not self.finish_event.isSet() or self.response_event.isSet():
|
|
self.response_event.wait()
|
|
with self.mutex:
|
|
responses = self.responses
|
|
self.responses = []
|
|
|
|
# Reset event
|
|
self.response_event.clear()
|
|
|
|
# Consume responses
|
|
while responses:
|
|
yield Result(*responses.pop(0))
|
|
|
|
# Raise errors
|
|
with self.mutex:
|
|
if self.errors:
|
|
raise CallErrors(self.errors)
|