def start_request(self):
"""Ensure the current thread or greenlet always uses the same socket
until it calls :meth:`end_request`. This ensures consistent reads,
even if you read after an unacknowledged write.
In Python 2.6 and above, or in Python 2.5 with
"from __future__ import with_statement", :meth:`start_request` can be
used as a context manager:
>>> connection = pymongo.MongoClient(auto_start_request=False)
>>> db = connection.test
>>> _id = db.test_collection.insert({})
>>> with connection.start_request():
... for i in range(100):
... db.test_collection.update({'_id': _id}, {'$set': {'i':i}})
...
... # Definitely read the document after the final update completes
... print db.test_collection.find({'_id': _id})
If a thread or greenlet calls start_request multiple times, an equal
number of calls to :meth:`end_request` is required to end the request.
.. versionchanged:: 2.4
Now counts the number of calls to start_request and doesn't end
request until an equal number of calls to end_request.
.. versionadded:: 2.2
The :class:`~pymongo.pool.Request` return value.
:meth:`start_request` previously returned None
"""
self.__pool.start_request()
return pool.Request(self)
def start_request(self):
"""Ensure the current thread or greenlet always uses the same socket
until it calls :meth:`end_request`. For
:class:`~pymongo.ReadPreference` PRIMARY, auto_start_request=True
ensures consistent reads, even if you read after an unsafe write. For
read preferences other than PRIMARY, there are no consistency
guarantees.
In Python 2.6 and above, or in Python 2.5 with
"from __future__ import with_statement", :meth:`start_request` can be
used as a context manager:
>>> connection = pymongo.ReplicaSetConnection(auto_start_request=False)
>>> db = connection.test
>>> _id = db.test_collection.insert({}, safe=True)
>>> with connection.start_request():
... for i in range(100):
... db.test_collection.update({'_id': _id}, {'$set': {'i':i}})
...
... # Definitely read the document after the final update completes
... print db.test_collection.find({'_id': _id})
.. versionadded:: 2.2
The :class:`~pymongo.pool.Request` return value.
:meth:`start_request` previously returned None
"""
for mongo in self.__pools.values():
if 'pool' in mongo:
mongo['pool'].start_request()
self.__in_request = True
return pool.Request(self)