47 lines
1.5 KiB
Python
47 lines
1.5 KiB
Python
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# Copyright 2020 The TensorFlow Authors. All Rights Reserved.
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#
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# Licensed under the Apache License, Version 2.0 (the "License");
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# you may not use this file except in compliance with the License.
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# You may obtain a copy of the License at
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#
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# http://www.apache.org/licenses/LICENSE-2.0
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#
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# Unless required by applicable law or agreed to in writing, software
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# distributed under the License is distributed on an "AS IS" BASIS,
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# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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# See the License for the specific language governing permissions and
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# limitations under the License.
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# ==============================================================================
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"""Abstraction for data ingestion logic."""
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import abc
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class DataIngester(metaclass=abc.ABCMeta):
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"""Link between a data source and a data provider.
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A data ingester starts a reload operation in the background and
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provides a data provider as a view.
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"""
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@property
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@abc.abstractmethod
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def data_provider(self):
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"""Returns a `DataProvider`.
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It may be an error to dereference this before `start` is called.
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"""
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pass
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@abc.abstractmethod
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def start(self):
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"""Starts ingesting data.
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This may start a background thread or process, and will return
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once communication with that task is established. It won't block
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forever as data is reloaded.
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Must only be called once.
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"""
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pass
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