view contrib/showstack.py @ 40391:abbd077965c0

wireprotov2: support exposing linknode of file revisions

When supporting shallow file storage, clients may fetch file revisions
by changeset. But they may not readily know which changeset introduced a
specific file revision. The "linknode" is used to record which changeset
introduces which file revision.

This commit teaches the "filedata" and "filesdata" wire protocol commands
to expose the linknode for file revisions. The implementation is likely
wrong when hidden changesets are in play, since the linknode may refer to
a hidden changeset. We can deal with this problem later.

Differential Revision: https://phab.mercurial-scm.org/D5167

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