70 lines
2.3 KiB
Python
70 lines
2.3 KiB
Python
# -*- coding: utf-8 -*-
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# Copyright 2014 Objectif Libre
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#
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# Licensed under the Apache License, Version 2.0 (the "License"); you may
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# not use this file except in compliance with the License. You may obtain
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# 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, WITHOUT
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# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
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# License for the specific language governing permissions and limitations
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# under the License.
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#
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import abc
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import six
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from stevedore import extension
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TRANSFORMERS_NAMESPACE = 'cloudkitty.transformers'
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def get_transformers():
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transformers = {}
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transformer_exts = extension.ExtensionManager(
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TRANSFORMERS_NAMESPACE,
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invoke_on_load=True)
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for transformer in transformer_exts:
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t_name = transformer.name
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t_obj = transformer.obj
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transformers[t_name] = t_obj
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return transformers
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@six.add_metaclass(abc.ABCMeta)
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class BaseTransformer(object):
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metadata_item = ''
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def generic_strip(self, datatype, data):
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metadata = getattr(data, self.metadata_item, data)
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mappings = getattr(self, datatype + '_map', {})
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result = {}
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for key, transform in mappings.items():
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if isinstance(transform, list):
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for meta_key in transform:
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if key not in result or result[key] is None:
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try:
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data = getattr(metadata, meta_key)
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except AttributeError:
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data = metadata.get(meta_key)
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result[key] = data
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else:
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trans_data = transform(self, metadata)
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if trans_data:
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result[key] = trans_data
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return result
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def strip_resource_data(self, res_type, res_data):
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res_type = res_type.replace('.', '_')
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strip_func = getattr(self, '_strip_' + res_type, None)
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if strip_func:
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return strip_func(res_data)
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return self.generic_strip(res_type, res_data) or res_data
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def get_metadata(self, res_type):
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"""Return list of metadata available for given resource type."""
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return []
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