contrib/debugcmdserver.py

dirstate: add a `set_tracked` method for "hg add"-like usage

This is a step further toward clarifying the semantic of various dirstate call.

Having a dedicated function comes with a couple of benefits:

1) we can move duplicated logic about how to handle the previous state within
the dirstate. Since we are sure this is always called in the same situation, we
can implement that logic once in the dirstate.

2) having a dedicated method for this case unlock also having a dedicated
method for the other case and recording more information at that time. All this
leading having more code within the dirstate and higher level API that are less
error prone.

Differential Revision: https://phab.mercurial-scm.org/D11013

#!/usr/bin/env python3
#
# 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()