PYTHON-785 Don't use requests in GridFS.

gridfs/__init__.py

@@ -118,19 +118,16 @@ class GridFS(object):
         :Parameters:
           - `data`: data to be written as a file.
           - `**kwargs` (optional): keyword arguments for file creation
+
+        .. versionchanged:: 3.0
+           w=0 writes to GridFS are now prohibited.
         """
         grid_file = GridIn(self.__collection, **kwargs)
-
-        # Start a request - necessary if w=0, harmless otherwise
-        request = self.__collection.database.connection.start_request()
         try:
-            try:
-                grid_file.write(data)
-            finally:
-                grid_file.close()
+            grid_file.write(data)
         finally:
-            # Ensure request is ended even if close() throws error
-            request.end()
+            grid_file.close()
+
         return grid_file._id
 
     def get(self, file_id):

gridfs/grid_file.py

@@ -27,7 +27,7 @@ from gridfs.errors import (CorruptGridFile,
 from pymongo import ASCENDING
 from pymongo.collection import Collection
 from pymongo.cursor import Cursor
-from pymongo.errors import DuplicateKeyError
+from pymongo.errors import DuplicateKeyError, InvalidOperation
 from pymongo.read_preferences import ReadPreference
 
 try:
@@ -130,29 +130,12 @@ class GridIn(object):
             that is written to the file will be converted to
             :class:`bytes`.
 
-        If you turn off write-acknowledgment for performance reasons, it is
-        critical to wrap calls to :meth:`write` and :meth:`close` within a
-        single request:
-
-           >>> from pymongo import MongoClient
-           >>> from gridfs import GridFS
-           >>> client = MongoClient(w=0) # turn off write acknowledgment
-           >>> fs = GridFS(client.database)
-           >>> gridin = fs.new_file()
-           >>> request = client.start_request()
-           >>> try:
-           ...     for i in range(10):
-           ...         gridin.write('foo')
-           ...     gridin.close()
-           ... finally:
-           ...     request.end()
-
-        In Python 2.5 and later this code can be simplified with a
-        with-statement, see :doc:`/examples/requests` for more information.
-
         :Parameters:
           - `root_collection`: root collection to write to
           - `**kwargs` (optional): file level options (see above)
+
+        .. versionchanged:: 3.0
+           w=0 writes to GridFS are now prohibited.
         """
         if not isinstance(root_collection, Collection):
             raise TypeError("root_collection must be an "
@@ -321,6 +304,10 @@ class GridIn(object):
         if self._closed:
             raise ValueError("cannot write to a closed file")
 
+        # With w=0, 'filemd5' might run before the final chunks are written.
+        if 0 == self._coll.database.connection.write_concern.get('w'):
+            raise InvalidOperation('Cannot write file to GridFS with w=0')
+
         try:
             # file-like
             read = data.read

test/test_grid_file.py

@@ -32,13 +32,14 @@ from gridfs.grid_file import (DEFAULT_CHUNK_SIZE,
                               GridOutCursor)
 from gridfs.errors import NoFile
 from pymongo import MongoClient
-from pymongo.errors import ConnectionFailure
+from pymongo.errors import ConnectionFailure, InvalidOperation
 from test import (client_knobs,
                   IntegrationTest,
                   host,
                   port,
                   unittest,
                   qcheck)
+from test.utils import rs_or_single_client
 
 
 class TestGridFileNoConnect(unittest.TestCase):
@@ -609,6 +610,13 @@ Bye"""))
             self.assertRaises(ConnectionFailure, infile.write, b'data')
             self.assertRaises(ConnectionFailure, infile.close)
 
+    def test_unacknowledged(self):
+        # w=0 is prohibited.
+        infile = GridIn(rs_or_single_client(w=0).pymongo_test.fs)
+
+        with self.assertRaises(InvalidOperation):
+            infile.write(b'data')
+
 
 if __name__ == "__main__":
     unittest.main()

test/test_gridfs.py

@@ -26,7 +26,7 @@ import gridfs
 
 from bson.py3compat import u, StringIO, string_type
 from pymongo.mongo_client import MongoClient
-from pymongo.errors import ConnectionFailure
+from pymongo.errors import ConnectionFailure, InvalidOperation
 from pymongo.read_preferences import ReadPreference
 from gridfs.errors import (FileExists,
                            NoFile)
@@ -37,7 +37,11 @@ from test import (client_context,
                   host,
                   port,
                   IntegrationTest)
-from test.utils import joinall, single_client, one, rs_client
+from test.utils import (joinall,
+                        single_client,
+                        one,
+                        rs_client,
+                        rs_or_single_client)
 
 
 class JustWrite(threading.Thread):
@@ -426,6 +430,13 @@ class TestGridfs(IntegrationTest):
 
         self.assertEqual(data, self.fs.get_version('f').read())
 
+    def test_unacknowledged(self):
+        # w=0 is prohibited.
+        fs = gridfs.GridFS(rs_or_single_client(w=0).pymongo_test)
+
+        with self.assertRaises(InvalidOperation):
+            fs.put(b'data')
+
 
 class TestGridfsReplicaSet(TestReplicaSetClientBase):