67 lines
2.4 KiB
Python
67 lines
2.4 KiB
Python
import time
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import threading
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EPOCH_JAVA_COMMON = 1288834974657
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class Snowflake:
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def __init__(self, datacenter_id: int = 0, worker_id: int = 0, epoch: int = 1480166465631):
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# 机器和数据中心配置
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self.worker_id_bits = 5
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self.datacenter_id_bits = 5
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self.sequence_bits = 12
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self.max_worker_id = -1 ^ (-1 << self.worker_id_bits)
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self.max_datacenter_id = -1 ^ (-1 << self.datacenter_id_bits)
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if worker_id > self.max_worker_id or worker_id < 0:
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raise ValueError(f"worker_id 超出范围 (0 ~ {self.max_worker_id})")
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if datacenter_id > self.max_datacenter_id or datacenter_id < 0:
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raise ValueError(f"datacenter_id 超出范围 (0 ~ {self.max_datacenter_id})")
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self.worker_id = worker_id
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self.datacenter_id = datacenter_id
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self.epoch = epoch
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self.sequence = 0
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self.last_timestamp = -1
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self.worker_id_shift = self.sequence_bits
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self.datacenter_id_shift = self.sequence_bits + self.worker_id_bits
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self.timestamp_left_shift = self.sequence_bits + self.worker_id_bits + self.datacenter_id_bits
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self.sequence_mask = -1 ^ (-1 << self.sequence_bits)
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self.lock = threading.Lock()
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def _timestamp(self):
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return int(time.time() * 1000)
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def _til_next_millis(self, last_timestamp):
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timestamp = self._timestamp()
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while timestamp <= last_timestamp:
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timestamp = self._timestamp()
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return timestamp
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def next_id(self) -> int:
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with self.lock:
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timestamp = self._timestamp()
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if timestamp < self.last_timestamp:
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raise Exception("时钟回拨，拒绝生成ID")
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if timestamp == self.last_timestamp:
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self.sequence = (self.sequence + 1) & self.sequence_mask
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if self.sequence == 0:
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timestamp = self._til_next_millis(self.last_timestamp)
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else:
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self.sequence = 0
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self.last_timestamp = timestamp
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return ((timestamp - self.epoch) << self.timestamp_left_shift) | \
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(self.datacenter_id << self.datacenter_id_shift) | \
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(self.worker_id << self.worker_id_shift) | \
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self.sequence
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if __name__ == "__main__":
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snowflake = Snowflake(datacenter_id=0, worker_id=0, epoch=EPOCH_JAVA_COMMON)
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for _ in range(10):
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print(str(snowflake.next_id()))
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