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2# Licensed to the Apache Software Foundation (ASF) under one
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7# "License"); you may not use this file except in compliance
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10# http://www.apache.org/licenses/LICENSE-2.0
11#
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17# under the License.
18from __future__ import annotations
19
20from enum import Enum
21
22import methodtools
23
24
25class WeightRule(str, Enum):
26 """Weight rules."""
27
28 DOWNSTREAM = "downstream"
29 UPSTREAM = "upstream"
30 ABSOLUTE = "absolute"
31
32 @classmethod
33 def is_valid(cls, weight_rule: str) -> bool:
34 """Check if weight rule is valid."""
35 return weight_rule in cls.all_weight_rules()
36
37 @methodtools.lru_cache(maxsize=None)
38 @classmethod
39 def all_weight_rules(cls) -> set[str]:
40 """Return all weight rules."""
41 return set(cls.__members__.values())
42
43 def __str__(self) -> str:
44 return self.value