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@nailor
Created November 11, 2010 09:52
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SequentialID and MonotonicID to use for CouchDBs not-so-random-IDs
import random
from datetime import datetime
import struct
import binascii
class SequentialID(object):
def __init__(self):
self.rng = random.Random()
self.reinit()
def reinit(self):
prefix_bytes = [self.rng.randint(0, 255) for x in xrange(13)]
self.prefix = binascii.hexlify(struct.pack('13B', *prefix_bytes))
self.seq = 0
def __call__(self):
if self.seq >= 0xfff000:
self.reinit()
self.seq += self.rng.randint(1, 4095)
return self.prefix + '%06x' % self.seq
class MonotonicID(object):
def __init__(self):
self.rng = random.Random()
self.seq = 0
def __call__(self):
if self.seq >= 9590:
self.seq = 0
now = datetime.utcnow()
self.seq += self.rng.randint(1, 409)
return '%04d%02d%02d%02d%02d%02d%06d%04d' % (
now.year,
now.month,
now.day,
now.hour,
now.minute,
now.second,
now.microsecond,
self.seq
)
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