File size: 799 Bytes
d766458 | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 | import jax
# adopted from https://github.com/deepmind/alphafold/blob/main/alphafold/model/prng.py
class SafeKey:
"""Safety wrapper for PRNG keys."""
def __init__(self, key):
self._key = key
self._used = False
def _assert_not_used(self):
if self._used:
raise RuntimeError('Random key has been used previously.')
def get(self):
self._assert_not_used()
self._used = True
return self._key
def split(self, num_keys=2):
self._assert_not_used()
self._used = True
new_keys = jax.random.split(self._key, num_keys)
return jax.tree_util.tree_map(SafeKey, tuple(new_keys))
def duplicate(self, num_keys=2):
self._assert_not_used()
self._used = True
return tuple(SafeKey(self._key) for _ in range(num_keys))
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