contrib/debugcmdserver.py

bundle: allow bundlerepo to support alternative manifest implementations

With our treemanifest logic, the manifests are no longer transported as part of
the changegroup and are no longer stored in a revlog. This means the
self.manifestlog line in bundlerepo.filestart no longer calls
_constructmanifest, and therefore does not consume the manifest portion of the
changegroup, which means filestart is not populated and we result in an infinite
loop.

The fix is to make filestart aware that self.manifestlog might not consume the
changegroup part, and consume it manually if necessary.

There's currently no way to test this in core, but our treemanifest extension
has tests to cover this.

Differential Revision: https://phab.mercurial-scm.org/D1329

#!/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()