Mercurial > hg
view mercurial/node.py @ 27223:a40c84defd76
mercurial: be more strict about loading dual implemented modules
With this change in place, we should have slightly stronger guarantees
about how modules with both Python and C implementations are loaded.
Before, our module loader's default policy looked under both mercurial/*
and mercurial/pure/* and imported whatever it found, C or pure. The fact
it looked in both locations by default was a temporary regression from
the beginning of this series.
This patch does 2 things:
1) Changes the default module load policy to only load C modules
2) Verifies that files loaded from mercurial/* are actually C modules
This 2nd behavior change makes our new module loading mechanism
stricter than from before this series. Before, it was possible to load
a .py-based module from mercurial/*. This could happen if an old
installation orphaned a file and then somehow didn't install the C
version for the new install. We now detect this odd configuration
and fall back to loading the pure Python module, assuming it is
allowed. In the case of a busted installation, we fail fast. While
we could fall back, we explicitly decide not to do this because
we don't want people accidentally not running the C modules and having
slow performance as a result.
author | Gregory Szorc <gregory.szorc@gmail.com> |
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date | Tue, 24 Nov 2015 22:50:04 -0800 |
parents | 18f50b8cbf1e |
children | a3f3fdac8433 |
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# node.py - basic nodeid manipulation for mercurial # # Copyright 2005, 2006 Matt Mackall <mpm@selenic.com> # # 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 import binascii # This ugly style has a noticeable effect in manifest parsing hex = binascii.hexlify bin = binascii.unhexlify nullrev = -1 nullid = "\0" * 20 nullhex = hex(nullid) # pseudo identifiers for working directory # (they are experimental, so don't add too many dependencies on them) wdirrev = 0x7fffffff wdirid = "\xff" * 20 def short(node): return hex(node[:6])