tests/test-wireproto.py

sparse-revlog: new requirement enabled with format.sparse-revlog

The meaning of the new 'sparse-revlog' requirement is that the revlogs are
allowed to contain wider delta chains with larger holes between the interesting
chunks. These sparse delta chains should be read in several chunks to avoid a
potential explosion of memory usage.

Former version won't know how to read a delta chain in several chunks. They
would keep reading them in a single read, and therefore would be subject to the
potential memory explosion. Hence this new requirement: only versions having
support of sparse-revlog reading should be allowed to read such a revlog.

Implementation of this new algorithm and tools to enable or disable the
requirement will follow in the next changesets.

from __future__ import absolute_import, print_function

import sys

from mercurial import (
    error,
    pycompat,
    ui as uimod,
    util,
    wireprototypes,
    wireprotov1peer,
    wireprotov1server,
)
from mercurial.utils import (
    stringutil,
)
stringio = util.stringio

class proto(object):
    def __init__(self, args):
        self.args = args
        self.name = 'dummyproto'

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

    def checkperm(self, perm):
        pass

wireprototypes.TRANSPORTS['dummyproto'] = {
    'transport': 'dummy',
    'version': 1,
}

class clientpeer(wireprotov1peer.wirepeer):
    def __init__(self, serverrepo, ui):
        self.serverrepo = serverrepo
        self.ui = ui

    def url(self):
        return b'test'

    def local(self):
        return None

    def peer(self):
        return self

    def canpush(self):
        return True

    def close(self):
        pass

    def capabilities(self):
        return [b'batch']

    def _call(self, cmd, **args):
        args = pycompat.byteskwargs(args)
        res = wireprotov1server.dispatch(self.serverrepo, proto(args), cmd)
        if isinstance(res, wireprototypes.bytesresponse):
            return res.data
        elif isinstance(res, bytes):
            return res
        else:
            raise error.Abort('dummy client does not support response type')

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

    @wireprotov1peer.batchable
    def greet(self, name):
        f = wireprotov1peer.future()
        yield {b'name': mangle(name)}, f
        yield unmangle(f.value)

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

    def filtered(self, name):
        return self

def mangle(s):
    return b''.join(pycompat.bytechr(ord(c) + 1) for c in pycompat.bytestr(s))
def unmangle(s):
    return b''.join(pycompat.bytechr(ord(c) - 1) for c in pycompat.bytestr(s))

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

wireprotov1server.commands[b'greet'] = (greet, b'name')

srv = serverrepo()
clt = clientpeer(srv, uimod.ui())

def printb(data, end=b'\n'):
    out = getattr(sys.stdout, 'buffer', sys.stdout)
    out.write(data + end)
    out.flush()

printb(clt.greet(b"Foobar"))

with clt.commandexecutor() as e:
    fgreet1 = e.callcommand(b'greet', {b'name': b'Fo, =;:<o'})
    fgreet2 = e.callcommand(b'greet', {b'name': b'Bar'})

printb(stringutil.pprint([f.result() for f in (fgreet1, fgreet2)],
                         bprefix=True))