hg

largefiles: optimize status when files are specified (issue3144)

This fixes a performance issue with 'hg status' when files are specified
on the command-line.  Previously, a large amount of largefiles code was
executed, even if files were specified on the command-line and those files
were not largefiles.  This patch fixes the problem by first checking if
non-largefiles were specified on the command-line and, just letting the
normal status function handle the case if they were.

On a brand new machine, the execution time for 'hg status filename' on
a repository with largefiles was:

real    0m0.636s
user    0m0.512s
sys     0m0.120s

versus the following (the same repository, with largefiles disabled):

real    0m0.215s
user    0m0.180s
sys     0m0.032s

After this patch, the performance of 'hg status filename' on the same
repository, with largefiles enabled is:

real    0m0.228s
user    0m0.189s
sys     0m0.036s

This performance boost is also true when patterns (rather than specific
files) are specified on the command-line.

In the case where patterns are specified in addition to a file list, we
just defer to the normal codepath in order to not spend extra time
expanding the patterns to just risk having to expand them again later.

#!/usr/bin/env python
#
# mercurial - scalable distributed SCM
#
# Copyright 2005-2007 Matt Mackall <[e-mail]>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.

import os
import sys

libdir = '@LIBDIR@'

if libdir != '@' 'LIBDIR' '@':
    if not os.path.isabs(libdir):
        libdir = os.path.join(os.path.dirname(os.path.realpath(__file__)),
                              libdir)
        libdir = os.path.abspath(libdir)
    sys.path.insert(0, libdir)

# enable importing on demand to reduce startup time
try:
    from mercurial import demandimport; demandimport.enable()
except ImportError:
    import sys
    sys.stderr.write("abort: couldn't find mercurial libraries in [%s]\n" %
                     ' '.join(sys.path))
    sys.stderr.write("(check your install and PYTHONPATH)\n")
    sys.exit(-1)

import mercurial.util
import mercurial.dispatch

for fp in (sys.stdin, sys.stdout, sys.stderr):
    mercurial.util.setbinary(fp)

mercurial.dispatch.run()