mercurial/utils/hashutil.py

stream-clone: add a stream-v3 variant of test-persistent-nodemap.t

This will be useful to track and validate future changes to the stream-v3
protocol.

import hashlib

try:
    from ..thirdparty import sha1dc  # pytype: disable=import-error

    sha1 = sha1dc.sha1
except (ImportError, AttributeError):
    sha1 = hashlib.sha1