view tests/test-wireproto.py @ 29859:a1092e2d70a3

help: internals topic for wire protocol

The Mercurial wire protocol is under-documented. This includes a lack
of source docstrings and comments as well as pages on the official
wiki.

This patch adds the beginnings of "internals" documentation on the
wire protocol.

The documentation should have nearly complete coverage on the
lower-level parts of the protocol, such as the different transport
mechanims, how commands and arguments are sent, capabilities, and,
of course, the commands themselves.

As part of writing this documentation, I discovered a number of
deficiencies in the protocol and bugs in the implementation. I've
started sending patches for some of the issues. I hope to send a lot
more.

This patch starts with the scaffolding for a new internals page.

from __future__ import absolute_import, print_function

from mercurial import (
    util,
    wireproto,
)
stringio = util.stringio

class proto(object):
    def __init__(self, args):
        self.args = args
    def getargs(self, spec):
        args = self.args
        args.setdefault('*', {})
        names = spec.split()
        return [args[n] for n in names]

class clientpeer(wireproto.wirepeer):
    def __init__(self, serverrepo):
        self.serverrepo = serverrepo

    def _capabilities(self):
        return ['batch']

    def _call(self, cmd, **args):
        return wireproto.dispatch(self.serverrepo, proto(args), cmd)

    def _callstream(self, cmd, **args):
        return stringio(self._call(cmd, **args))

    @wireproto.batchable
    def greet(self, name):
        f = wireproto.future()
        yield {'name': mangle(name)}, f
        yield unmangle(f.value)

class serverrepo(object):
    def greet(self, name):
        return "Hello, " + name

    def filtered(self, name):
        return self

def mangle(s):
    return ''.join(chr(ord(c) + 1) for c in s)
def unmangle(s):
    return ''.join(chr(ord(c) - 1) for c in s)

def greet(repo, proto, name):
    return mangle(repo.greet(unmangle(name)))

wireproto.commands['greet'] = (greet, 'name',)

srv = serverrepo()
clt = clientpeer(srv)

print(clt.greet("Foobar"))
b = clt.batch()
fs = [b.greet(s) for s in ["Fo, =;:<o", "Bar"]]
b.submit()
print([f.value for f in fs])