tags: avoid expensive access to repo.changelog in a loop
repo.changelog needs some cache invalidation when run on filtered repository.
Accessing it in that loop can be expensive when there is many heads (e.g.
mozilla try and it 25 000 heads).
Note that the loop itself seems useless, but after this patch it no longer take
about ⅛ of the time we spend computing cache for mozilla try.
before :
! wall 0.350994 comb 0.350000 user 0.330000 sys 0.020000 (median of 28)
after :
! wall 0.319520 comb 0.310000 user 0.290000 sys 0.020000 (median of 30)
# memory.py - track memory usage
#
# Copyright 2009 Olivia Mackall <olivia@selenic.com> and others
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.
'''helper extension to measure memory usage
Reads current and peak memory usage from ``/proc/self/status`` and
prints it to ``stderr`` on exit.
'''
def memusage(ui):
"""Report memory usage of the current process."""
result = {'peak': 0, 'rss': 0}
with open('/proc/self/status', 'r') as status:
# This will only work on systems with a /proc file system
# (like Linux).
for line in status:
parts = line.split()
key = parts[0][2:-1].lower()
if key in result:
result[key] = int(parts[1])
ui.write_err(
", ".join(
["%s: %.1f MiB" % (k, v / 1024.0) for k, v in result.iteritems()]
)
+ "\n"
)
def extsetup(ui):
ui.atexit(memusage, ui)