1 import logging 2 import time 3 4 # 64位ID的划分 5 WORKER_ID_BITS = 3 6 DATACENTER_ID_BITS = 5 7 SEQUENCE_BITS = 12 8 9 # 最大取值计算 10 MAX_WORKER_ID = -1 ^ (-1 << WORKER_ID_BITS) # 2**5-1 0b11111 11 MAX_DATACENTER_ID = -1 ^ (-1 << DATACENTER_ID_BITS) 12 13 # 移位偏移计算 14 WOKER_ID_SHIFT = SEQUENCE_BITS 15 DATACENTER_ID_SHIFT = SEQUENCE_BITS + WORKER_ID_BITS 16 TIMESTAMP_LEFT_SHIFT = SEQUENCE_BITS + WORKER_ID_BITS + DATACENTER_ID_BITS 17 18 # 序号循环掩码 19 SEQUENCE_MASK = -1 ^ (-1 << SEQUENCE_BITS) 20 21 # Twitter元年时间戳 22 TWEPOCH = 1288834974657 23 24 logger = logging.getLogger('view.logger') 25 26 27 class IdWorker(object): 28 """ 29 用于生成IDs 30 """ 31 32 def __init__(self, datacenter_id, worker_id, sequence=0): 33 """ 34 初始化 35 :param datacenter_id: 数据中心（机器区域）ID 36 :param worker_id: 机器ID 37 :param sequence: 其实序号 38 """ 39 # sanity check 40 if worker_id > MAX_WORKER_ID or worker_id < 0: 41 raise ValueError('worker_id值越界') 42 43 if datacenter_id > MAX_DATACENTER_ID or datacenter_id < 0: 44 raise ValueError('datacenter_id值越界') 45 46 self.worker_id = worker_id 47 self.datacenter_id = datacenter_id 48 self.sequence = sequence 49 50 self.last_timestamp = -1 # 上次计算的时间戳 51 52 def _gen_timestamp(self): 53 """ 54 生成整数时间戳 55 :return:int timestamp 56 """ 57 return int(time.time() * 1000) 58 59 def get_id(self): 60 """ 61 获取新ID 62 :return: 63 """ 64 timestamp = self._gen_timestamp() 65 66 # 时钟回拨 67 if timestamp < self.last_timestamp: 68 logger.error('clock is moving backwards. Rejecting requests until{}'.format(self.last_timestamp)) 69 raise Exception 70 71 if timestamp == self.last_timestamp: 72 self.sequence = (self.sequence + 1) & SEQUENCE_MASK 73 if self.sequence == 0: 74 timestamp = self._til_next_millis(self.last_timestamp) 75 else: 76 self.sequence = 0 77 78 self.last_timestamp = timestamp 79 80 new_id = ((timestamp - TWEPOCH) << TIMESTAMP_LEFT_SHIFT) | (self.datacenter_id << DATACENTER_ID_SHIFT) | ( 81 self.worker_id << WOKER_ID_SHIFT) | self.sequence 82 83 return new_id 84 85 def _til_next_millis(self, last_timestamp): 86 """ 87 等到下一毫秒 88 """ 89 timestamp = self._gen_timestamp() 90 while timestamp <= last_timestamp: 91 timestamp = self._gen_timestamp() 92 return timestamp 93 94 95 __worker = IdWorker(1, 1, 0) 96 97 98 def generate_id(): 99 return __worker.get_id() 100 101 102 if __name__ == '__main__': 103 from threading import Thread 104 105 106 def test(): 107 for i in range(10): 108 id = worker.get_id() 109 print(id) 110 111 112 worker = IdWorker(1, 1, 0) 113 114 l = list() 115 for i in range(2): 116 t = Thread(target=test) 117 t.start() 118 l.append(t) 119 for t in l: 120 t.join()
