Python

Source code for gcloud.storage._implicit_environ

# Copyright 2015 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.

"""Module to provide implicit behavior based on enviroment.

Allows the storage package to infer the default bucket and connection
from the enviroment.
"""


from gcloud._helpers import _lazy_property_deco
from gcloud.storage.connection import Connection


class _DefaultsContainer(object):
    """Container for defaults.

    :type bucket: :class:`gcloud.storage.bucket.Bucket`
    :param bucket: Persistent implied default bucket from environment.

    :type connection: :class:`gcloud.storage.connection.Connection`
    :param connection: Persistent implied connection from environment.
    """

    @_lazy_property_deco
    @staticmethod
    def connection():
        """Return the implicit default connection.."""
        return get_connection()

    def __init__(self, bucket=None, connection=None, implicit=False):
        self.bucket = bucket
        if connection is not None or not implicit:
            self.connection = connection


[docs]def get_default_bucket():
    """Get default bucket.

    :rtype: :class:`gcloud.storage.bucket.Bucket` or ``NoneType``
    :returns: The default bucket if one has been set.
    """
    return _DEFAULTS.bucket


[docs]def get_default_connection():
    """Get default connection.

    :rtype: :class:`gcloud.storage.connection.Connection` or ``NoneType``
    :returns: The default connection if one has been set.
    """
    return _DEFAULTS.connection


[docs]def get_connection():
    """Shortcut method to establish a connection to Cloud Storage.

    Use this if you are going to access several buckets with the same
    set of credentials:

    >>> from gcloud import storage
    >>> connection = storage.get_connection()
    >>> bucket1 = storage.get_bucket('bucket1', connection=connection)
    >>> bucket2 = storage.get_bucket('bucket2', connection=connection)

    :rtype: :class:`gcloud.storage.connection.Connection`
    :returns: A connection defined with the proper credentials.
    """
    return Connection.from_environment()


[docs]def set_default_connection(connection=None):
    """Set default connection either explicitly or implicitly as fall-back.

    :type connection: :class:`gcloud.storage.connection.Connection`
    :param connection: A connection provided to be the default.
    """
    connection = connection or get_connection()
    _DEFAULTS.connection = connection


_DEFAULTS = _DefaultsContainer(implicit=True)