mirror of
https://github.com/QingdaoU/OnlineJudge.git
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91 lines
2.8 KiB
Python
91 lines
2.8 KiB
Python
from __future__ import print_function
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import time
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class TokenBucket:
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def __init__(self, fill_rate, capacity, last_capacity, last_timestamp):
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self.capacity = float(capacity)
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self._left_tokens = last_capacity
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self.fill_rate = float(fill_rate)
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self.timestamp = last_timestamp
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def consume(self, tokens=1):
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if tokens <= self.tokens:
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self._left_tokens -= tokens
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return True
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return False
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def expected_time(self, tokens=1):
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_tokens = self.tokens
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tokens = max(tokens, _tokens)
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return (tokens - _tokens) / self.fill_rate * 60
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@property
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def tokens(self):
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if self._left_tokens < self.capacity:
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now = time.time()
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delta = self.fill_rate * ((now - self.timestamp) / 60)
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self._left_tokens = min(self.capacity, self._left_tokens + delta)
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self.timestamp = now
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return self._left_tokens
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class BucketController:
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def __init__(self, factor, redis_conn, default_capacity):
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self.default_capacity = default_capacity
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self.redis = redis_conn
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self.key = "bucket_" + str(factor)
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@property
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def last_capacity(self):
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value = self.redis.hget(self.key, "last_capacity")
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if value is None:
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self.last_capacity = self.default_capacity
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return self.default_capacity
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return int(value)
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@last_capacity.setter
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def last_capacity(self, value):
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self.redis.hset(self.key, "last_capacity", value)
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@property
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def last_timestamp(self):
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value = self.redis.hget(self.key, "last_timestamp")
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if value is None:
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timestamp = int(time.time())
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self.last_timestamp = timestamp
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return timestamp
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return int(value)
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@last_timestamp.setter
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def last_timestamp(self, value):
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self.redis.hset(self.key, "last_timestamp", value)
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"""
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# # Token bucket, to limit submission rate
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# # Demo
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success = failure = 0
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current_user_id = 1
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token_bucket_default_capacity = 50
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token_bucket_fill_rate = 10
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for i in range(5000):
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controller = BucketController(user_id=current_user_id,
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redis_conn=redis.Redis(),
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default_capacity=token_bucket_default_capacity)
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bucket = TokenBucket(fill_rate=token_bucket_fill_rate,
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capacity=token_bucket_default_capacity,
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last_capacity=controller.last_capacity,
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last_timestamp=controller.last_timestamp)
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time.sleep(0.05)
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if bucket.consume():
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success += 1
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print(i, ": Accepted")
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controller.last_capacity -= 1
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else:
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failure += 1
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print(i, "Dropped, time left ", bucket.expected_time())
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print(success, failure)
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"""
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