Added delete option to database storage.

venv/Lib/site-packages/google/resumable_media/common.py

@@ -0,0 +1,148 @@
+# Copyright 2017 Google 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
+#
+#     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.
+
+"""Common utilities for Google Media Downloads and Resumable Uploads.
+
+Includes custom exception types, useful constants and shared helpers.
+"""
+
+
+_SLEEP_RETRY_ERROR_MSG = (
+    u"At most one of `max_cumulative_retry` and `max_retries` " u"can be specified."
+)
+
+UPLOAD_CHUNK_SIZE = 262144  # 256 * 1024
+"""int: Chunks in a resumable upload must come in multiples of 256 KB."""
+PERMANENT_REDIRECT = 308
+"""int: Permanent redirect status code.
+
+It is used by Google services to indicate some (but not all) of
+a resumable upload has been completed.
+
+``http.client.PERMANENT_REDIRECT`` was added in Python 3.5, so
+can't be used in a "general" code base.
+
+For more information, see `RFC 7238`_.
+
+.. _RFC 7238: https://tools.ietf.org/html/rfc7238
+"""
+TOO_MANY_REQUESTS = 429
+"""int: Status code indicating rate-limiting.
+
+``http.client.TOO_MANY_REQUESTS`` was added in Python 3.3, so
+can't be used in a "general" code base.
+
+For more information, see `RFC 6585`_.
+
+.. _RFC 6585: https://tools.ietf.org/html/rfc6585#section-4
+"""
+MAX_SLEEP = 64.0
+"""float: Maximum amount of time allowed between requests.
+
+Used during the retry process for sleep after a failed request.
+Chosen since it is the power of two nearest to one minute.
+"""
+MAX_CUMULATIVE_RETRY = 600.0
+"""float: Maximum total sleep time allowed during retry process.
+
+This is provided (10 minutes) as a default. When the cumulative sleep
+exceeds this limit, no more retries will occur.
+"""
+
+
+class InvalidResponse(Exception):
+    """Error class for responses which are not in the correct state.
+
+    Args:
+        response (object): The HTTP response which caused the failure.
+        args (tuple): The positional arguments typically passed to an
+            exception class.
+    """
+
+    def __init__(self, response, *args):
+        super(InvalidResponse, self).__init__(*args)
+        self.response = response
+        """object: The HTTP response object that caused the failure."""
+
+
+class DataCorruption(Exception):
+    """Error class for corrupt media transfers.
+
+    Args:
+        response (object): The HTTP response which caused the failure.
+        args (tuple): The positional arguments typically passed to an
+            exception class.
+    """
+
+    def __init__(self, response, *args):
+        super(DataCorruption, self).__init__(*args)
+        self.response = response
+        """object: The HTTP response object that caused the failure."""
+
+
+class RetryStrategy(object):
+    """Configuration class for retrying failed requests.
+
+    At most one of ``max_cumulative_retry`` and ``max_retries`` can be
+    specified (they are both caps on the total number of retries). If
+    neither are specified, then ``max_cumulative_retry`` is set as
+    :data:`MAX_CUMULATIVE_RETRY`.
+
+    Args:
+        max_sleep (Optional[float]): The maximum amount of time to sleep after
+            a failed request. Default is :attr:`MAX_SLEEP`.
+        max_cumulative_retry (Optional[float]): The maximum **total** amount of
+            time to sleep during retry process.
+        max_retries (Optional[int]): The number of retries to attempt.
+
+    Attributes:
+        max_sleep (float): Maximum amount of time allowed between requests.
+        max_cumulative_retry (Optional[float]): Maximum total sleep time
+            allowed during retry process.
+        max_retries (Optional[int]): The number retries to attempt.
+
+    Raises:
+        ValueError: If both of ``max_cumulative_retry`` and ``max_retries``
+            are passed.
+    """
+
+    def __init__(
+        self, max_sleep=MAX_SLEEP, max_cumulative_retry=None, max_retries=None
+    ):
+        if max_cumulative_retry is not None and max_retries is not None:
+            raise ValueError(_SLEEP_RETRY_ERROR_MSG)
+        if max_cumulative_retry is None and max_retries is None:
+            max_cumulative_retry = MAX_CUMULATIVE_RETRY
+
+        self.max_sleep = max_sleep
+        self.max_cumulative_retry = max_cumulative_retry
+        self.max_retries = max_retries
+
+    def retry_allowed(self, total_sleep, num_retries):
+        """Check if another retry is allowed.
+
+        Args:
+            total_sleep (float): The amount of sleep accumulated by the caller.
+            num_retries (int): The number of retries already attempted by
+                the caller.
+
+        Returns:
+            bool: Indicating if another retry is allowed (depending on either
+            the cumulative sleep allowed or the maximum number of retries
+            allowed.
+        """
+        if self.max_cumulative_retry is None:
+            return num_retries <= self.max_retries
+        else:
+            return total_sleep <= self.max_cumulative_retry