contrib/debugcmdserver.py
author Gregory Szorc <gregory.szorc@gmail.com>
Sat, 06 Aug 2016 13:55:21 -0700
changeset 29746 62e2e048d068
parent 28353 cd03fbd5ab57
child 43076 2372284d9457
permissions -rwxr-xr-x
wireproto: unescape argument names in batch command (BC) Clients escape both argument names and values when using the batch command. Yet the server was only unescaping argument values. Fortunately we don't have any argument names that need escaped. But that isn't an excuse to lack symmetry in the code. Since the server wasn't properly unescaping argument names, this means we can never introduce an argument to a batchable command that needs escaped because an old server wouldn't properly decode its name. So we've introduced an assertion to detect the accidental introduction of this in the future. Of course, we could introduce a server capability that says the server knows how to decode argument names and allow special argument names to go through. But until there is a need for it (which I doubt there will be), we shouldn't bother with adding an unused capability.

#!/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()