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from __future__ import absolute_import
import random
from .hashed import murmur2
class DefaultPartitioner(object):
"""Default partitioner.
Hashes key to partition using murmur2 hashing (from java client)
If key is None, selects partition randomly from available,
or from all partitions if none are currently available
"""
@classmethod
def __call__(cls, key, all_partitions, available):
if key is None:
if available:
return random.choice(available)
return random.choice(all_partitions)
idx = murmur2(key)
idx &= 0x7fffffff
idx %= len(all_partitions)
return all_partitions[idx]
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