PYTHON-1003 Avoid checking out multiple sockets per thread.

Author: ajdavis

pymongo/collection.py

@@ -1418,19 +1418,20 @@ def options(self):
  cursor = self.__database._list_collections(sock_info,
  slave_ok,
  criteria)
- result = None
- for doc in cursor:
- result = doc
- break
 
- if not result:
- return {}
+ result = None
+ for doc in cursor:
+ result = doc
+ break
 
- options = result.get("options", {})
- if "create" in options:
- del options["create"]
+ if not result:
+ return {}
 
- return options
+ options = result.get("options", {})
+ if "create" in options:
+ del options["create"]
+
+ return options
 
  def aggregate(self, pipeline, **kwargs):
  """Perform an aggregation using the aggregation framework on this

pymongo/database.py

@@ -487,15 +487,20 @@ def collection_names(self, include_system_collections=True):
  will not include system collections (e.g ``system.indexes``)
  """
  with self.__client._socket_for_reads(
- ReadPreference.PRIMARY) as (sock_info, slave_okay):
+  ReadPreference.PRIMARY) as (sock_info, slave_okay):
 
+ wire_version = sock_info.max_wire_version
  results = self._list_collections(sock_info, slave_okay)
- names = [result["name"] for result in results]
- if sock_info.max_wire_version <= 2:
- # MongoDB 2.4 and older return index namespaces and collection
- # namespaces prefixed with the database name.
- names = [n[len(self.__name) + 1:] for n in names
- if n.startswith(self.__name + ".") and "$" not in n]
+
+ # Iterating the cursor to completion may require a socket for getmore.
+ # Ensure we do that outside the "with" block so we don't require more
+ # than one socket at a time.
+ names = [result["name"] for result in results]
+ if wire_version <= 2:
+ # MongoDB 2.4 and older return index namespaces and collection
+ # namespaces prefixed with the database name.
+ names = [n[len(self.__name) + 1:] for n in names
+ if n.startswith(self.__name + ".") and "$" not in n]
 
  if not include_system_collections:
  names = [name for name in names if not name.startswith("system.")]