Mercurial > hg
view mercurial/utils/interfaceutil.py @ 39814:d059cb669632
wireprotov2: allow multiple fields to follow revision maps
The *data wire protocol commands emit a series of CBOR values.
Because revision/delta data may be large, their data is emitted
outside the map as a top-level bytestring value.
Before this commit, we'd emit a single optional bytestring
value after the revision descriptor map. This got the job done.
But it was limiting in that we could only send a single field.
And, it required the consumer to know that the presence of a
key in the map implied the existence of a following bytestring
value.
This commit changes the encoding strategy so top-level bytestring
values in the stream are explicitly denoted in a "fieldsfollowing"
key. This key contains an array defining what fields that follow
and the expected size of each field.
By defining things this way, we can easily send N bytestring
values without any ambiguity about their order. In addition,
clients only need to know how to parse ``fieldsfollowing`` to
know if extra values are present.
Because this breaks backwards compatibility, we've bumped the version
number of the wire protocol version 2 API endpoint.
Differential Revision: https://phab.mercurial-scm.org/D4620
author | Gregory Szorc <gregory.szorc@gmail.com> |
---|---|
date | Thu, 20 Sep 2018 12:57:23 -0700 |
parents | 856f381ad74b |
children |
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# interfaceutil.py - Utilities for declaring interfaces. # # Copyright 2018 Gregory Szorc <gregory.szorc@gmail.com> # # This software may be used and distributed according to the terms of the # GNU General Public License version 2 or any later version. # zope.interface imposes a run-time cost due to module import overhead and # bookkeeping for declaring interfaces. So, we use stubs for various # zope.interface primitives unless instructed otherwise. from __future__ import absolute_import from .. import ( encoding, ) if encoding.environ.get('HGREALINTERFACES'): from ..thirdparty.zope import ( interface as zi, ) Attribute = zi.Attribute Interface = zi.Interface implementer = zi.implementer else: class Attribute(object): def __init__(self, __name__, __doc__=''): pass class Interface(object): def __init__(self, name, bases=(), attrs=None, __doc__=None, __module__=None): pass def implementer(*ifaces): def wrapper(cls): return cls return wrapper