copies: avoid unnecessary copying of copy dict
When storing copy information in the changesets, this patch speeds up
hg debugpathcopies FENNEC_58_0_2_BUILD1 FIREFOX_59_0b8_BUILD2
from 11s to 5.9s. That command takes 6.2s when storing copy
information in filelogs.
Differential Revision: https://phab.mercurial-scm.org/D6421
# Copyright 2016-present Facebook. All Rights Reserved.
#
# error: errors used in fastannotate
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.
from __future__ import absolute_import
class CorruptedFileError(Exception):
pass
class CannotReuseError(Exception):
"""cannot reuse or update the cache incrementally"""