view tests/test-wireproto.py @ 36672:9e7b14caf67f

xdiff: remove patience and histogram diff algorithms

Patience diff is the normal diff algorithm, plus some greediness that
unconditionally matches common common unique lines.  That means it is easy to
construct cases to let it generate suboptimal result, like:

```
open('a', 'w').write('\n'.join(list('a' + 'x' * 300 + 'u' + 'x' * 700 + 'a\n')))
open('b', 'w').write('\n'.join(list('b' + 'x' * 700 + 'u' + 'x' * 300 + 'b\n')))
```

Patience diff has been advertised as being able to generate better results for
some C code changes. However, the more scientific way to do that is the
indention heuristic [1].

Since patience diff could generate suboptimal result more easily and its
"better" diff feature could be replaced by the new indention heuristic, let's
just remove it and its variant histogram diff to simplify the code.

[1]: https://github.com/git/git/commit/433860f3d0beb0c6f205290bd16cda413148f098

Test Plan:
`gcc -fPIC *.c --shared -o xdiff.so` still builds.

Differential Revision: https://phab.mercurial-scm.org/D2573

from __future__ import absolute_import, print_function

from mercurial import (
    error,
    pycompat,
    util,
    wireproto,
    wireprototypes,
)
stringio = util.stringio

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

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

    @property
    def ui(self):
        return self.serverrepo.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 = wireproto.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))

    @wireproto.batchable
    def greet(self, name):
        f = wireproto.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)))

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

srv = serverrepo()
clt = clientpeer(srv)

print(clt.greet(b"Foobar"))
b = clt.iterbatch()
list(map(b.greet, (b'Fo, =;:<o', b'Bar')))
b.submit()
print([r for r in b.results()])