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view tests/md5sum.py @ 31209:dd2364f5180a
localrepo: handle rename with hardlinks properly
In "aftertrans", we rename "journal.*" to "undo.*". We expect "journal.*"
files to disappear after renaming.
However, if "journal.foo" and "undo.foo" refer to a same file (hardlink),
rename may be a no-op, leaving both files on disk, according to Linux
manpage [1]:
If oldpath and newpath are existing hard links referring to the same
file, then rename() does nothing, and returns a suc‐ cess status.
The POSIX specification [2] is not very clear about what to do.
To be safe, remove "undo.*" before the rename so "journal.*" cannot be left
on disk.
[1]: http://man7.org/linux/man-pages/man2/rename.2.html
[2]: http://pubs.opengroup.org/onlinepubs/9699919799/
author | Jun Wu <quark@fb.com> |
---|---|
date | Thu, 02 Mar 2017 21:49:30 -0800 |
parents | 8d1cdee372e6 |
children | 3a64ac39b893 |
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#!/usr/bin/env python # # Based on python's Tools/scripts/md5sum.py # # This software may be used and distributed according to the terms # of the PYTHON SOFTWARE FOUNDATION LICENSE VERSION 2, which is # GPL-compatible. from __future__ import absolute_import import os import sys try: import hashlib md5 = hashlib.md5 except ImportError: import md5 md5 = md5.md5 try: import msvcrt msvcrt.setmode(sys.stdout.fileno(), os.O_BINARY) msvcrt.setmode(sys.stderr.fileno(), os.O_BINARY) except ImportError: pass for filename in sys.argv[1:]: try: fp = open(filename, 'rb') except IOError as msg: sys.stderr.write('%s: Can\'t open: %s\n' % (filename, msg)) sys.exit(1) m = md5() try: for data in iter(lambda: fp.read(8192), ''): m.update(data) except IOError as msg: sys.stderr.write('%s: I/O error: %s\n' % (filename, msg)) sys.exit(1) sys.stdout.write('%s %s\n' % (m.hexdigest(), filename)) sys.exit(0)