Mercurial > hg
view mercurial/pushkey.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 | 7b200566e474 |
children | 57875cf423c9 |
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# pushkey.py - dispatching for pushing and pulling keys # # Copyright 2010 Matt Mackall <mpm@selenic.com> # # This software may be used and distributed according to the terms of the # GNU General Public License version 2 or any later version. from __future__ import absolute_import from . import ( bookmarks, encoding, obsolete, phases, ) def _nslist(repo): n = {} for k in _namespaces: n[k] = "" if not obsolete.isenabled(repo, obsolete.exchangeopt): n.pop('obsolete') return n _namespaces = {"namespaces": (lambda *x: False, _nslist), "bookmarks": (bookmarks.pushbookmark, bookmarks.listbookmarks), "phases": (phases.pushphase, phases.listphases), "obsolete": (obsolete.pushmarker, obsolete.listmarkers), } def register(namespace, pushkey, listkeys): _namespaces[namespace] = (pushkey, listkeys) def _get(namespace): return _namespaces.get(namespace, (lambda *x: False, lambda *x: {})) def push(repo, namespace, key, old, new): '''should succeed iff value was old''' pk = _get(namespace)[0] return pk(repo, key, old, new) def list(repo, namespace): '''return a dict''' lk = _get(namespace)[1] return lk(repo) encode = encoding.fromlocal decode = encoding.tolocal def encodekeys(keys): """encode the content of a pushkey namespace for exchange over the wire""" return '\n'.join(['%s\t%s' % (encode(k), encode(v)) for k, v in keys]) def decodekeys(data): """decode the content of a pushkey namespace from exchange over the wire""" result = {} for l in data.splitlines(): k, v = l.split('\t') result[decode(k)] = decode(v) return result