perf: add perfchangegroupchangelog command
This command can be used for testing the performance of producing the
changelog portion of a changegroup.
We could use additional perf* commands for testing other parts of
changegroup. Those can be written another time, when they are needed.
(And those may want to refactor the changegroup generation API so code
can be reused.) Speaking of code reuse, yes, this command does reinvent
a small wheel. I didn't want to scope bloat to change the changegroup
API because that will invite bikeshedding.
# showstack.py - extension to dump a Python stack trace on signal
#
# binds to both SIGQUIT (Ctrl-\) and SIGINFO (Ctrl-T on BSDs)
from __future__ import absolute_import
import signal
import sys
import traceback
def sigshow(*args):
sys.stderr.write("\n")
traceback.print_stack(args[1], limit=10, file=sys.stderr)
sys.stderr.write("----\n")
def extsetup(ui):
signal.signal(signal.SIGQUIT, sigshow)
try:
signal.signal(signal.SIGINFO, sigshow)
except AttributeError:
pass