Added delete option to database storage.

venv/Lib/site-packages/grpc/framework/foundation/callable_util.py

@@ -0,0 +1,96 @@
+# Copyright 2015 gRPC authors.
+#
+# 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
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+"""Utilities for working with callables."""
+
+import abc
+import collections
+import enum
+import functools
+import logging
+
+import six
+
+_LOGGER = logging.getLogger(__name__)
+
+
+class Outcome(six.with_metaclass(abc.ABCMeta)):
+    """A sum type describing the outcome of some call.
+
+  Attributes:
+    kind: One of Kind.RETURNED or Kind.RAISED respectively indicating that the
+      call returned a value or raised an exception.
+    return_value: The value returned by the call. Must be present if kind is
+      Kind.RETURNED.
+    exception: The exception raised by the call. Must be present if kind is
+      Kind.RAISED.
+  """
+
+    @enum.unique
+    class Kind(enum.Enum):
+        """Identifies the general kind of the outcome of some call."""
+
+        RETURNED = object()
+        RAISED = object()
+
+
+class _EasyOutcome(
+        collections.namedtuple('_EasyOutcome',
+                               ['kind', 'return_value', 'exception']), Outcome):
+    """A trivial implementation of Outcome."""
+
+
+def _call_logging_exceptions(behavior, message, *args, **kwargs):
+    try:
+        return _EasyOutcome(Outcome.Kind.RETURNED, behavior(*args, **kwargs),
+                            None)
+    except Exception as e:  # pylint: disable=broad-except
+        _LOGGER.exception(message)
+        return _EasyOutcome(Outcome.Kind.RAISED, None, e)
+
+
+def with_exceptions_logged(behavior, message):
+    """Wraps a callable in a try-except that logs any exceptions it raises.
+
+  Args:
+    behavior: Any callable.
+    message: A string to log if the behavior raises an exception.
+
+  Returns:
+    A callable that when executed invokes the given behavior. The returned
+      callable takes the same arguments as the given behavior but returns a
+      future.Outcome describing whether the given behavior returned a value or
+      raised an exception.
+  """
+
+    @functools.wraps(behavior)
+    def wrapped_behavior(*args, **kwargs):
+        return _call_logging_exceptions(behavior, message, *args, **kwargs)
+
+    return wrapped_behavior
+
+
+def call_logging_exceptions(behavior, message, *args, **kwargs):
+    """Calls a behavior in a try-except that logs any exceptions it raises.
+
+  Args:
+    behavior: Any callable.
+    message: A string to log if the behavior raises an exception.
+    *args: Positional arguments to pass to the given behavior.
+    **kwargs: Keyword arguments to pass to the given behavior.
+
+  Returns:
+    An Outcome describing whether the given behavior returned a value or raised
+      an exception.
+  """
+    return _call_logging_exceptions(behavior, message, *args, **kwargs)