view contrib/debugcmdserver.py @ 30763:a520aefb96f1

httppeer: advertise and support application/mercurial-0.2

Now that servers expose a capability indicating they support
application/mercurial-0.2 and compression, clients can key off
this to say they support responses that are compressed with
various compression formats.

After this commit, the HTTP wire protocol client now sends an
"X-HgProto-<N>" request header indicating its support for
"application/mercurial-0.2" media type and various compression
formats.

This commit also implements support for handling
"application/mercurial-0.2" responses. It simply reads the header
compression engine identifier then routes the remainder of the
response to the appropriate decompressor.

There were some test changes, but only to logging. That points to
an obvious gap in our test coverage. This will be addressed in a
subsequent commit once server support is in place (it is hard to
test without server support).

#!/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()