Source code for google.appengine.api.blobstore.blob_storage
#!/usr/bin/env python
#
# Copyright 2007 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
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# 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
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"""Definition of BlobStorage base class."""
[docs]class BlobStorage(object):
"""Base class for defining how blobs are stored.
This base class merely defines an interface that all stub blob-storage
mechanisms must implement.
"""
[docs] def StoreBlob(self, blob_key, blob_stream):
"""Store blob stream.
Implement this method to persist blob data.
Args:
blob_key: Blob key of blob to store.
blob_stream: Stream or stream-like object that will generate blob content.
"""
raise NotImplementedError('Storage class must override StoreBlob method.')
[docs] def OpenBlob(self, blob_key):
"""Open blob for streaming.
Args:
blob_key: Blob-key of existing blob to open for reading.
Returns:
Open file stream for reading blob. Caller is responsible for closing file.
"""
raise NotImplementedError('Storage class must override OpenBlob method.')
[docs] def DeleteBlob(self, blob_key):
"""Delete blob data from storage.
Args:
blob_key: Blob-key of existing blob to delete.
"""
raise NotImplementedError('Storage class must override DeleteBlob method.')