view contrib/debugcmdserver.py @ 43104:74802979dd9d

py3: define and use pycompat.itervalues()

.itervalues() only exists on Python 2. Python 3's equivalent is
.values(). But we don't want to blindly use .values() everywhere
because on Python 2, it will create a list, which will have performance
implications.

This commit introduces pycompat.itervalues() which will call the appropriate
method on the passed object. We update all callers of obj.itervalues()
to pycompat.itervalues(obj) instead.

With this commit, the only source tranforming remaining is for
iteritems(). Victory is near...

Differential Revision: https://phab.mercurial-scm.org/D7013

#!/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()