old_contents: from niapi.dbi.mongoapi import get_connection
  import multiprocessing
  import threading
  
  __all__ = ['ConnectionError', 'connect']
  
  
  _connection_defaults = {
      'host': 'localhost',
      'port': 27017,
  }
  _connection = {}
  _connection_settings = _connection_defaults.copy()
  
  _db_name = None
  _db_username = None
  _db_password = None
  _db = {}
  
  
  class ConnectionError(Exception):
      pass
  
  
  def _get_connection(reconnect=False):
      """Handles the connection to the database
      """
      global _connection
      identity = get_identity()
      # Connect to the database if not already connected
      if _connection.get(identity) is None or reconnect:
          try:
              _connection[identity] = get_connection(preference='primary')
          except Exception, e:
              raise ConnectionError("Cannot connect to the database:\n%s" % e)
      return _connection[identity]
  
  def _get_db(reconnect=False):
      """Handles database connections and authentication based on the current
      identity
      """
      global _db, _connection
      identity = get_identity()
      # Connect if not already connected
      if _connection.get(identity) is None or reconnect:
          _connection[identity] = _get_connection(reconnect=reconnect)
  
      if _db.get(identity) is None or reconnect:
          # _db_name will be None if the user hasn't called connect()
          if _db_name is None:
              raise ConnectionError('Not connected to the database')
  
          # Get DB from current connection and authenticate if necessary
          _db[identity] = _connection[identity][_db_name]
          if _db_username and _db_password:
              _db[identity].authenticate(_db_username, _db_password)
  
      return _db[identity]
  
  def get_identity():
      """Creates an identity key based on the current process and thread
      identity.
      """
      identity = multiprocessing.current_process()._identity
      identity = 0 if not identity else identity[0]
  
      identity = (identity, threading.current_thread().ident)
      return identity
  
  def connect(db, username=None, password=None, **kwargs):
      """Connect to the database specified by the 'db' argument. Connection
      settings may be provided here as well if the database is not running on
      the default port on localhost. If authentication is needed, provide
      username and password arguments as well.
      """
      global _connection_settings, _db_name, _db_username, _db_password, _db
      _connection_settings = dict(_connection_defaults, **kwargs)
      _db_name = db
      _db_username = username
      _db_password = password
      return _get_db(reconnect=True)
  
  
new_contents: from pymongo import Connection
  import multiprocessing
  import threading
  
  __all__ = ['ConnectionError', 'connect']
  
  
  _connection_defaults = {
      'host': 'localhost',
      'port': 27017,
  }
  _connection = {}
  _connection_settings = _connection_defaults.copy()
  
  _db_name = None
  _db_username = None
  _db_password = None
  _db = {}
  
  
  class ConnectionError(Exception):
      pass
  
  
  def _get_connection(reconnect=False):
      """Handles the connection to the database
      """
      global _connection
      identity = get_identity()
      # Connect to the database if not already connected
      if _connection.get(identity) is None or reconnect:
          try:
              _connection[identity] = Connection(**_connection_settings)
          except Exception, e:
              raise ConnectionError("Cannot connect to the database:\n%s" % e)
      return _connection[identity]
  
  def _get_db(reconnect=False):
      """Handles database connections and authentication based on the current
      identity
      """
      global _db, _connection
      identity = get_identity()
      # Connect if not already connected
      if _connection.get(identity) is None or reconnect:
          _connection[identity] = _get_connection(reconnect=reconnect)
  
      if _db.get(identity) is None or reconnect:
          # _db_name will be None if the user hasn't called connect()
          if _db_name is None:
              raise ConnectionError('Not connected to the database')
  
          # Get DB from current connection and authenticate if necessary
          _db[identity] = _connection[identity][_db_name]
          if _db_username and _db_password:
              _db[identity].authenticate(_db_username, _db_password)
  
      return _db[identity]
  
  def get_identity():
      """Creates an identity key based on the current process and thread
      identity.
      """
      identity = multiprocessing.current_process()._identity
      identity = 0 if not identity else identity[0]
  
      identity = (identity, threading.current_thread().ident)
      return identity
  
  def connect(db, username=None, password=None, **kwargs):
      """Connect to the database specified by the 'db' argument. Connection
      settings may be provided here as well if the database is not running on
      the default port on localhost. If authentication is needed, provide
      username and password arguments as well.
      """
      global _connection_settings, _db_name, _db_username, _db_password, _db
      _connection_settings = dict(_connection_defaults, **kwargs)
      _db_name = db
      _db_username = username
      _db_password = password
      return _get_db(reconnect=True)
  
  
subject: Revert back to use Connection class instead of ReplicaSet