27 lines
816 B
Python
27 lines
816 B
Python
NOT_PROVIDED = object()
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class FieldCacheMixin:
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"""Provide an API for working with the model's fields value cache."""
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def get_cache_name(self):
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raise NotImplementedError
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def get_cached_value(self, instance, default=NOT_PROVIDED):
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cache_name = self.get_cache_name()
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try:
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return instance._state.fields_cache[cache_name]
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except KeyError:
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if default is NOT_PROVIDED:
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raise
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return default
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def is_cached(self, instance):
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return self.get_cache_name() in instance._state.fields_cache
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def set_cached_value(self, instance, value):
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instance._state.fields_cache[self.get_cache_name()] = value
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def delete_cached_value(self, instance):
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del instance._state.fields_cache[self.get_cache_name()]
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