Updated DB_Helper by adding firebase methods.

venv/Lib/site-packages/gcloud/storage/_helpers.py

@@ -0,0 +1,173 @@
+# Copyright 2014 Google Inc. All rights reserved.
+#
+# 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.
+
+"""Helper functions for Cloud Storage utility classes.
+
+These are *not* part of the API.
+"""
+
+import base64
+from hashlib import md5
+
+
+class _PropertyMixin(object):
+    """Abstract mixin for cloud storage classes with associated propertties.
+
+    Non-abstract subclasses should implement:
+      - client
+      - path
+
+    :type name: string
+    :param name: The name of the object.
+    """
+
+    def __init__(self, name=None):
+        self.name = name
+        self._properties = {}
+        self._changes = set()
+
+    @property
+    def path(self):
+        """Abstract getter for the object path."""
+        raise NotImplementedError
+
+    @property
+    def client(self):
+        """Abstract getter for the object client."""
+        raise NotImplementedError
+
+    def _require_client(self, client):
+        """Check client or verify over-ride.
+
+        :type client: :class:`gcloud.storage.client.Client` or ``NoneType``
+        :param client: the client to use.  If not passed, falls back to the
+                       ``client`` stored on the current object.
+
+        :rtype: :class:`gcloud.storage.client.Client`
+        :returns: The client passed in or the currently bound client.
+        """
+        if client is None:
+            client = self.client
+        return client
+
+    def reload(self, client=None):
+        """Reload properties from Cloud Storage.
+
+        :type client: :class:`gcloud.storage.client.Client` or ``NoneType``
+        :param client: the client to use.  If not passed, falls back to the
+                       ``client`` stored on the current object.
+        """
+        client = self._require_client(client)
+        # Pass only '?projection=noAcl' here because 'acl' and related
+        # are handled via custom endpoints.
+        query_params = {'projection': 'noAcl'}
+        api_response = client.connection.api_request(
+            method='GET', path=self.path, query_params=query_params,
+            _target_object=self)
+        self._set_properties(api_response)
+
+    def _patch_property(self, name, value):
+        """Update field of this object's properties.
+
+        This method will only update the field provided and will not
+        touch the other fields.
+
+        It **will not** reload the properties from the server. The behavior is
+        local only and syncing occurs via :meth:`patch`.
+
+        :type name: string
+        :param name: The field name to update.
+
+        :type value: object
+        :param value: The value being updated.
+        """
+        self._changes.add(name)
+        self._properties[name] = value
+
+    def _set_properties(self, value):
+        """Set the properties for the current object.
+
+        :type value: dict or :class:`gcloud.storage.batch._FutureDict`
+        :param value: The properties to be set.
+        """
+        self._properties = value
+        # If the values are reset, the changes must as well.
+        self._changes = set()
+
+    def patch(self, client=None):
+        """Sends all changed properties in a PATCH request.
+
+        Updates the ``_properties`` with the response from the backend.
+
+        :type client: :class:`gcloud.storage.client.Client` or ``NoneType``
+        :param client: the client to use.  If not passed, falls back to the
+                       ``client`` stored on the current object.
+        """
+        client = self._require_client(client)
+        # Pass '?projection=full' here because 'PATCH' documented not
+        # to work properly w/ 'noAcl'.
+        update_properties = dict((key, self._properties[key])
+                                 for key in self._changes)
+        api_response = client.connection.api_request(
+            method='PATCH', path=self.path, data=update_properties,
+            query_params={'projection': 'full'}, _target_object=self)
+        self._set_properties(api_response)
+
+
+def _scalar_property(fieldname):
+    """Create a property descriptor around the :class:`_PropertyMixin` helpers.
+    """
+    def _getter(self):
+        """Scalar property getter."""
+        return self._properties.get(fieldname)
+
+    def _setter(self, value):
+        """Scalar property setter."""
+        self._patch_property(fieldname, value)
+
+    return property(_getter, _setter)
+
+
+def _write_buffer_to_hash(buffer_object, hash_obj, digest_block_size=8192):
+    """Read blocks from a buffer and update a hash with them.
+
+    :type buffer_object: bytes buffer
+    :param buffer_object: Buffer containing bytes used to update a hash object.
+
+    :type hash_obj: object that implements update
+    :param hash_obj: A hash object (MD5 or CRC32-C).
+
+    :type digest_block_size: integer
+    :param digest_block_size: The block size to write to the hash.
+                              Defaults to 8192.
+    """
+    block = buffer_object.read(digest_block_size)
+
+    while len(block) > 0:
+        hash_obj.update(block)
+        # Update the block for the next iteration.
+        block = buffer_object.read(digest_block_size)
+
+
+def _base64_md5hash(buffer_object):
+    """Get MD5 hash of bytes (as base64).
+
+    :type buffer_object: bytes buffer
+    :param buffer_object: Buffer containing bytes used to compute an MD5
+                          hash (as base64).
+    """
+    hash_obj = md5()
+    _write_buffer_to_hash(buffer_object, hash_obj)
+    digest_bytes = hash_obj.digest()
+    return base64.b64encode(digest_bytes)