view contrib/debugcmdserver.py @ 44202:a7f8160cc4e4

setup: don't skip the search for global hg.exe if there is no local instance

The point of trying not to blindly execute `hg` on Windows is that the local
hg.exe would be given precedence, and if py3 isn't on PATH, it errors out with a
modal dialog.  But that's not a problem if there is no local executable that
could be run.

The problem that I recently ran into was I upgraded the repo format to use zstd.
But doing a `make clean` deletes all of the supporting libraries, causing the
next run to abort with a message about not understanding the
`revlog-compression-zstd` requirement.  By getting rid of the local executable
in the previous commit when cleaning, we avoid leaving a broken executable
around, and avoid the py3 PATH problem too.  There is still a small hole in that
`hg.exe` needs to be deleted before switching between py2/py3/PyOxidizer builds,
because the zstd module won't load.  But that seems like good hygiene anyway.

Differential Revision: https://phab.mercurial-scm.org/D8038

#!/usr/bin/env python
#
# Dumps output generated by Mercurial's command server in a formatted style to a
# given file or stderr if '-' is specified. Output is also written in its raw
# format to stdout.
#
# $ ./hg serve --cmds pipe | ./contrib/debugcmdserver.py -
# o, 52   -> 'capabilities: getencoding runcommand\nencoding: UTF-8'

from __future__ import absolute_import, print_function
import struct
import sys

if len(sys.argv) != 2:
    print('usage: debugcmdserver.py FILE')
    sys.exit(1)

outputfmt = '>cI'
outputfmtsize = struct.calcsize(outputfmt)

if sys.argv[1] == '-':
    log = sys.stderr
else:
    log = open(sys.argv[1], 'a')


def read(size):
    data = sys.stdin.read(size)
    if not data:
        raise EOFError
    sys.stdout.write(data)
    sys.stdout.flush()
    return data


try:
    while True:
        header = read(outputfmtsize)
        channel, length = struct.unpack(outputfmt, header)
        log.write('%s, %-4d' % (channel, length))
        if channel in 'IL':
            log.write(' -> waiting for input\n')
        else:
            data = read(length)
            log.write(' -> %r\n' % data)
        log.flush()
except EOFError:
    pass
finally:
    if log != sys.stderr:
        log.close()