112 lines
4.5 KiB
Python
112 lines
4.5 KiB
Python
from threading import local
|
|
|
|
from django.core.urlresolvers import resolve
|
|
from django.db import connection, transaction
|
|
from django.db.models.signals import pre_delete, post_save, m2m_changed
|
|
from django.dispatch import receiver
|
|
from django.http.response import HttpResponseServerError
|
|
|
|
from orchestra.utils.python import OrderedSet
|
|
|
|
from . import manager
|
|
from .helpers import message_user
|
|
from .models import BackendLog, BackendOperation as Operation
|
|
|
|
|
|
@receiver(post_save, dispatch_uid='orchestration.post_save_collector')
|
|
def post_save_collector(sender, *args, **kwargs):
|
|
if sender not in [BackendLog, Operation]:
|
|
OperationsMiddleware.collect(Operation.SAVE, **kwargs)
|
|
|
|
|
|
@receiver(pre_delete, dispatch_uid='orchestration.pre_delete_collector')
|
|
def pre_delete_collector(sender, *args, **kwargs):
|
|
if sender not in [BackendLog, Operation]:
|
|
OperationsMiddleware.collect(Operation.DELETE, **kwargs)
|
|
|
|
|
|
@receiver(m2m_changed, dispatch_uid='orchestration.m2m_collector')
|
|
def m2m_collector(sender, *args, **kwargs):
|
|
# m2m relations without intermediary models are shit. Model.post_save is not sent and
|
|
# by the time related.post_save is sent rel objects are not accessible via RelatedManager.all()
|
|
if kwargs.pop('action') == 'post_add' and kwargs['pk_set']:
|
|
OperationsMiddleware.collect(Operation.SAVE, **kwargs)
|
|
|
|
|
|
class OperationsMiddleware(object):
|
|
"""
|
|
Stores all the operations derived from save and delete signals and executes them
|
|
at the end of the request/response cycle
|
|
|
|
It also works as a transaction middleware, making requets to run within an atomic block.
|
|
"""
|
|
# Thread local is used because request object is not available on model signals
|
|
thread_locals = local()
|
|
|
|
@classmethod
|
|
def get_pending_operations(cls):
|
|
# Check if an error poped up before OperationsMiddleware.process_request()
|
|
if hasattr(cls.thread_locals, 'request'):
|
|
request = cls.thread_locals.request
|
|
if not hasattr(request, 'pending_operations'):
|
|
request.pending_operations = OrderedSet()
|
|
return request.pending_operations
|
|
return set()
|
|
|
|
@classmethod
|
|
def get_route_cache(cls):
|
|
""" chache the routes to save sql queries """
|
|
if hasattr(cls.thread_locals, 'request'):
|
|
request = cls.thread_locals.request
|
|
if not hasattr(request, 'route_cache'):
|
|
request.route_cache = {}
|
|
return request.route_cache
|
|
return {}
|
|
|
|
@classmethod
|
|
def collect(cls, action, **kwargs):
|
|
""" Collects all pending operations derived from model signals """
|
|
request = getattr(cls.thread_locals, 'request', None)
|
|
if request is None:
|
|
return
|
|
kwargs['operations'] = cls.get_pending_operations()
|
|
kwargs['route_cache'] = cls.get_route_cache()
|
|
instance = kwargs.pop('instance')
|
|
manager.collect(instance, action, **kwargs)
|
|
|
|
def enter_transaction_management(self):
|
|
type(self).thread_locals.transaction = transaction.atomic()
|
|
type(self).thread_locals.transaction.__enter__()
|
|
|
|
def leave_transaction_management(self, exception=None):
|
|
type(self).thread_locals.transaction.__exit__(exception, None, None)
|
|
|
|
def process_request(self, request):
|
|
""" Store request on a thread local variable """
|
|
type(self).thread_locals.request = request
|
|
self.enter_transaction_management()
|
|
|
|
def process_exception(self, request, exception):
|
|
"""Rolls back the database and leaves transaction management"""
|
|
self.leave_transaction_management(exception)
|
|
|
|
def process_response(self, request, response):
|
|
""" Processes pending backend operations """
|
|
if not isinstance(response, HttpResponseServerError):
|
|
operations = type(self).get_pending_operations()
|
|
if operations:
|
|
try:
|
|
scripts, block = manager.generate(operations)
|
|
except Exception as exception:
|
|
self.leave_transaction_management(exception)
|
|
raise
|
|
# We commit transaction just before executing operations
|
|
# because here is when IntegrityError show up
|
|
self.leave_transaction_management()
|
|
logs = manager.execute(scripts, block=block)
|
|
if logs and resolve(request.path).app_name == 'admin':
|
|
message_user(request, logs)
|
|
return response
|
|
self.leave_transaction_management()
|
|
return response
|