Source code for pymodm.connection

# Copyright 2016 MongoDB, Inc.
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# See the License for the specific language governing permissions and
# limitations under the License.

"""Tools for managing connections in MongoModels."""
import sys

from collections import namedtuple

from pymongo import uri_parser, MongoClient

from pymodm.compat import reraise

__all__ = ['connect']

"""Information stored with each connection alias."""
ConnectionInfo = namedtuple(
    'ConnectionInfo', ('parsed_uri', 'conn_string', 'database'))



[docs]def connect(mongodb_uri, alias=DEFAULT_CONNECTION_ALIAS, **kwargs): """Register a connection to MongoDB, optionally providing a name for it. Note: :func:`connect` must be called with before any :class:`~pymodm.MongoModel` is used with the given `alias`. :parameters: - `mongodb_uri`: A MongoDB connection string. Any options may be passed within the string that are supported by PyMongo. `mongodb_uri` must specify a database, which will be used by any :class:`~pymodm.MongoModel` that uses this connection. - `alias`: An optional name for this connection, backed by a :class:`~pymongo.mongo_client.MongoClient` instance that is cached under this name. You can specify what connection a MongoModel uses by specifying the connection's alias via the `connection_alias` attribute inside their `Meta` class. Switching connections is also possible using the :class:`~pymodm.context_managers.switch_connection` context manager. Note that calling `connect()` multiple times with the same alias will replace any previous connections. - `kwargs`: Additional keyword arguments to pass to the underlying :class:`~pymongo.mongo_client.MongoClient`. """ # Make sure the database is provided. parsed_uri = uri_parser.parse_uri(mongodb_uri) if not parsed_uri.get('database'): raise ValueError('Connection must specify a database.') _CONNECTIONS[alias] = ConnectionInfo( parsed_uri=parsed_uri, conn_string=mongodb_uri, database=MongoClient(mongodb_uri, **kwargs)[parsed_uri['database']])
def _get_connection(alias=DEFAULT_CONNECTION_ALIAS): """Return a `ConnectionInfo` by connection alias.""" try: return _CONNECTIONS[alias] except KeyError: _, _, tb = sys.exc_info() reraise(ValueError, "No such alias '%s'. Did you forget to call connect()?" % alias, tb) def _get_db(alias=DEFAULT_CONNECTION_ALIAS): """Return the `pymongo.database.Database` instance for the given alias.""" return _get_connection(alias).database