Replace custom blob gRPC API with ByteStream

client/third_party/google/auth/_helpers.py

+# Copyright 2015 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.
+
+"""Helper functions for commonly used utilities."""
+
+import base64
+import calendar
+import datetime
+
+import six
+from six.moves import urllib
+
+
+CLOCK_SKEW_SECS = 300  # 5 minutes in seconds
+CLOCK_SKEW = datetime.timedelta(seconds=CLOCK_SKEW_SECS)
+
+
+def copy_docstring(source_class):
+    """Decorator that copies a method's docstring from another class.
+
+    Args:
+        source_class (type): The class that has the documented method.
+
+    Returns:
+        Callable: A decorator that will copy the docstring of the same
+            named method in the source class to the decorated method.
+    """
+    def decorator(method):
+        """Decorator implementation.
+
+        Args:
+            method (Callable): The method to copy the docstring to.
+
+        Returns:
+            Callable: the same method passed in with an updated docstring.
+
+        Raises:
+            ValueError: if the method already has a docstring.
+        """
+        if method.__doc__:
+            raise ValueError('Method already has a docstring.')
+
+        source_method = getattr(source_class, method.__name__)
+        method.__doc__ = source_method.__doc__
+
+        return method
+    return decorator
+
+
+def utcnow():
+    """Returns the current UTC datetime.
+
+    Returns:
+        datetime: The current time in UTC.
+    """
+    return datetime.datetime.utcnow()
+
+
+def datetime_to_secs(value):
+    """Convert a datetime object to the number of seconds since the UNIX epoch.
+
+    Args:
+        value (datetime): The datetime to convert.
+
+    Returns:
+        int: The number of seconds since the UNIX epoch.
+    """
+    return calendar.timegm(value.utctimetuple())
+
+
+def to_bytes(value, encoding='utf-8'):
+    """Converts a string value to bytes, if necessary.
+
+    Unfortunately, ``six.b`` is insufficient for this task since in
+    Python 2 because it does not modify ``unicode`` objects.
+
+    Args:
+        value (Union[str, bytes]): The value to be converted.
+        encoding (str): The encoding to use to convert unicode to bytes.
+            Defaults to "utf-8".
+
+    Returns:
+        bytes: The original value converted to bytes (if unicode) or as
+            passed in if it started out as bytes.
+
+    Raises:
+        ValueError: If the value could not be converted to bytes.
+    """
+    result = (value.encode(encoding)
+              if isinstance(value, six.text_type) else value)
+    if isinstance(result, six.binary_type):
+        return result
+    else:
+        raise ValueError('{0!r} could not be converted to bytes'.format(value))
+
+
+def from_bytes(value):
+    """Converts bytes to a string value, if necessary.
+
+    Args:
+        value (Union[str, bytes]): The value to be converted.
+
+    Returns:
+        str: The original value converted to unicode (if bytes) or as passed in
+            if it started out as unicode.
+
+    Raises:
+        ValueError: If the value could not be converted to unicode.
+    """
+    result = (value.decode('utf-8')
+              if isinstance(value, six.binary_type) else value)
+    if isinstance(result, six.text_type):
+        return result
+    else:
+        raise ValueError(
+            '{0!r} could not be converted to unicode'.format(value))
+
+
+def update_query(url, params, remove=None):
+    """Updates a URL's query parameters.
+
+    Replaces any current values if they are already present in the URL.
+
+    Args:
+        url (str): The URL to update.
+        params (Mapping[str, str]): A mapping of query parameter
+            keys to values.
+        remove (Sequence[str]): Parameters to remove from the query string.
+
+    Returns:
+        str: The URL with updated query parameters.
+
+    Examples:
+
+        >>> url = 'http://example.com?a=1'
+        >>> update_query(url, {'a': '2'})
+        http://example.com?a=2
+        >>> update_query(url, {'b': '3'})
+        http://example.com?a=1&b=3
+        >> update_query(url, {'b': '3'}, remove=['a'])
+        http://example.com?b=3
+
+    """
+    if remove is None:
+        remove = []
+
+    # Split the URL into parts.
+    parts = urllib.parse.urlparse(url)
+    # Parse the query string.
+    query_params = urllib.parse.parse_qs(parts.query)
+    # Update the query parameters with the new parameters.
+    query_params.update(params)
+    # Remove any values specified in remove.
+    query_params = {
+        key: value for key, value
+        in six.iteritems(query_params)
+        if key not in remove}
+    # Re-encoded the query string.
+    new_query = urllib.parse.urlencode(query_params, doseq=True)
+    # Unsplit the url.
+    new_parts = parts._replace(query=new_query)
+    return urllib.parse.urlunparse(new_parts)
+
+
+def scopes_to_string(scopes):
+    """Converts scope value to a string suitable for sending to OAuth 2.0
+    authorization servers.
+
+    Args:
+        scopes (Sequence[str]): The sequence of scopes to convert.
+
+    Returns:
+        str: The scopes formatted as a single string.
+    """
+    return ' '.join(scopes)
+
+
+def string_to_scopes(scopes):
+    """Converts stringifed scopes value to a list.
+
+    Args:
+        scopes (Union[Sequence, str]): The string of space-separated scopes
+            to convert.
+    Returns:
+        Sequence(str): The separated scopes.
+    """
+    if not scopes:
+        return []
+
+    return scopes.split(' ')
+
+
+def padded_urlsafe_b64decode(value):
+    """Decodes base64 strings lacking padding characters.
+
+    Google infrastructure tends to omit the base64 padding characters.
+
+    Args:
+        value (Union[str, bytes]): The encoded value.
+
+    Returns:
+        bytes: The decoded value
+    """
+    b64string = to_bytes(value)
+    padded = b64string + b'=' * (-len(b64string) % 4)
+    return base64.urlsafe_b64decode(padded)