83 lines
2.2 KiB
Python
83 lines
2.2 KiB
Python
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import random
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from django.db import models
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LOWER_BOUND = -2147483648
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UPPER_BOUND = 2147483647
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SHIFT = 92147483647
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class ConvertedValue(str):
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def __new__(cls, value):
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value = int(value)
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if UPPER_BOUND < value:
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display_value = value
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db_value = value - SHIFT
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else:
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db_value = value
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display_value = value + SHIFT
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self = super().__new__(cls, display_value)
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self.db_value = db_value
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return self
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def __repr__(self):
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return f"<{self.__class__.__name__}: {self.db_value}>"
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def __eq__(self, other):
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if isinstance(other, self.__class__):
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return self.db_value == other.db_value
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return self.db_value == other
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def __hash__(self):
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return hash(self.db_value)
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class ConvertedValueField(models.IntegerField):
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"""
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Roughly copied from https://github.com/django/django/blob/d6eaf7c0183cd04b78f2a55e1d60bb7e59598310/tests/custom_pk/fields.py
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"""
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def pre_save(self, instance, add):
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value = getattr(instance, self.attname, None)
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if not value:
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value = ConvertedValue(random.randint(LOWER_BOUND, UPPER_BOUND))
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setattr(instance, self.attname, value)
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return value
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def to_python(self, value):
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if not value:
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return
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if not isinstance(value, ConvertedValue):
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value = ConvertedValue(value)
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return value
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def get_prep_value(self, value):
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if value is None:
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return None
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if not isinstance(value, ConvertedValue):
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value = ConvertedValue(value)
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return super().get_prep_value(value.db_value)
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def from_db_value(self, value, expression, connection):
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if not value:
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return
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return ConvertedValue(value)
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def get_db_prep_save(self, value, connection):
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if not value:
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return
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return ConvertedValue(value).db_value
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def get_db_prep_value(self, value, connection, prepared=False):
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if not value:
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return
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return ConvertedValue(value).db_value
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def get_searchable_content(self, value):
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if not value:
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return
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return ConvertedValue(value).db_value
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