commandserver: add experimental option to use separate message channel
This is loosely based on the idea of the TortoiseHg's pipeui extension,
which attaches ui.label to message text so the command-server client can
capture prompt text, for example.
https://bitbucket.org/tortoisehg/thg/src/4.7.2/tortoisehg/util/pipeui.py
I was thinking that this functionality could be generalized to templating,
but changed mind as doing template stuff would be unnecessarily complex.
It's merely a status message, a simple serialization option should suffice.
Since this slightly changes the command-server protocol, it's gated by a
config knob. If the config is enabled, and if it's supported by the server,
"message-encoding: <name>" is advertised so the client can stop parsing
'o'/'e' channel data and read encoded messages from the 'm' channel. As we
might add new message encodings in future releases, client can specify a list
of encoding names in preferred order.
This patch includes 'cbor' encoding as example. Perhaps, 'json' should be
supported as well.
# 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