view contrib/debugcmdserver.py @ 29497:ee2027195847

perf: define command annotation locally for Mercurial earlier than 3.1

Before this patch, using cmdutil.command() for "@command" annotation
prevents perf.py from being loaded by Mercurial earlier than 1.9 (or
2daa5179e73f), because cmdutil.command() isn't available in such
Mercurial, even though there are some code paths for Mercurial earlier
than 1.9.

For example, setting "_prereadsize" attribute in perfindex() and
perfnodelookup() is effective only with hg earlier than 1.8 (or
61c9bc3da402).

In addition to it, "norepo" option of command annotation has been
available since 3.1 (or 75a96326cecb), and this is another blocker for
loading perf.py with earlier Mercurial.

  ============ ============ ======
               command of
  hg version   cmdutil      norepo
  ============ ============ ======
  3.1 or later      o         o
  1.9 or later      o         x
  earlier           x         x
  ============ ============ ======

This patch defines "command()" for annotation locally as below:

  - define wrapper of existing cmdutil.command(), if cmdutil.command()
    doesn't support "norepo"
    (for Mercurial earlier than 3.1)

  - define full command() locally with minimum function, if
    cmdutil.command() isn't available at runtime
    (for Mercurial earlier than 1.9)

This patch also defines parsealiases() locally without examining
whether it is available or not, because it is small enough to define
locally.

#!/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()