perf: import newer modules separately for earlier Mercurial
demandimport of early Mercurial loads an imported module immediately,
if a module is imported absolutely by "from a import b" style. Recent
perf.py satisfies this condition, because it does:
- have "from __future__ import absolute_import" line
- use "from a import b" style for modules in "mercurial" package
Before this patch, importing modules below prevents perf.py from being
loaded by earlier Mercurial, because these aren't available in such
Mercurial, even though there are some code paths for Mercurial earlier
than 1.9.
- branchmap 2.5 (or bcee63733aad)
- repoview 2.5 (or 3a6ddacb7198)
- obsolete 2.3 (or ad0d6c2b3279)
- scmutil 1.9 (or 8b252e826c68)
For example, setting "_prereadsize" attribute in perfindex() and
perfnodelookup() is effective only with Mercurial earlier than 1.8 (or
61c9bc3da402).
After this patch, "mercurial.error" is the only blocker in "from
mercurial import" statement for loading perf.py with Mercurial earlier
than 1.2. This patch ignores it, because just importing it separately
isn't enough.
#!/usr/bin/env python
#
# An example hgweb CGI script, edit as necessary
# See also https://mercurial-scm.org/wiki/PublishingRepositories
# Path to repo or hgweb config to serve (see 'hg help hgweb')
config = "/path/to/repo/or/config"
# Uncomment and adjust if Mercurial is not installed system-wide
# (consult "installed modules" path from 'hg debuginstall'):
#import sys; sys.path.insert(0, "/path/to/python/lib")
# Uncomment to send python tracebacks to the browser if an error occurs:
#import cgitb; cgitb.enable()
from mercurial import demandimport; demandimport.enable()
from mercurial.hgweb import hgweb, wsgicgi
application = hgweb(config)
wsgicgi.launch(application)