view contrib/showstack.py @ 45450:47d10ade5bc4

histedit: cache description line

Navigating the curses-based histedit interface can be pretty slow
because it redraws everything whenever you make a change.

This patch simply replaces `@property` by `@util.propertycache` on the
`histeditrule.desc()` function so it's not re-calculated every time
the screen needs to be re-rendered. I timed it on an example of 30
simple commits, where I moved the top commit down 25 steps and then up
25 steps after. Before this patch, that (the whole `hg histedit`
invocation) took 11.6 s of CPU and after this patch it took 0.8 s).

Differential Revision: https://phab.mercurial-scm.org/D9016

# showstack.py - extension to dump a Python stack trace on signal
#
# binds to both SIGQUIT (Ctrl-\) and SIGINFO (Ctrl-T on BSDs)
r"""dump stack trace when receiving SIGQUIT (Ctrl-\) or SIGINFO (Ctrl-T on BSDs)
"""

from __future__ import absolute_import, print_function
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 sigexit(*args):
    sigshow(*args)
    print('alarm!')
    sys.exit(1)


def extsetup(ui):
    signal.signal(signal.SIGQUIT, sigshow)
    signal.signal(signal.SIGALRM, sigexit)
    try:
        signal.signal(signal.SIGINFO, sigshow)
    except AttributeError:
        pass