Mercurial > public > mercurial-scm > hg-stable
diff mercurial/wireprotov2server.py @ 39819: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 | c30faea8d02d |
| children | d3d333ab167a |
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--- a/mercurial/wireprotov2server.py Mon Sep 17 11:54:00 2018 -0700 +++ b/mercurial/wireprotov2server.py Thu Sep 20 12:57:23 2018 -0700 @@ -752,19 +752,24 @@ d[b'bookmarks'] = sorted(nodebookmarks[node]) del nodebookmarks[node] - revisiondata = None + followingmeta = [] + followingdata = [] if b'revision' in fields: revisiondata = cl.revision(node, raw=True) - d[b'revisionsize'] = len(revisiondata) + followingmeta.append((b'revision', len(revisiondata))) + followingdata.append(revisiondata) # TODO make it possible for extensions to wrap a function or register # a handler to service custom fields. + if followingmeta: + d[b'fieldsfollowing'] = followingmeta + yield d - if revisiondata is not None: - yield revisiondata + for extra in followingdata: + yield extra # If requested, send bookmarks from nodes that didn't have revision # data sent so receiver is aware of any bookmark updates. @@ -865,25 +870,29 @@ if b'parents' in fields: d[b'parents'] = store.parents(node) + followingmeta = [] + followingdata = [] + if b'revision' in fields: assert delta is not None assert delta.flags == 0 assert d[b'node'] == delta.node if delta.revision is not None: - revisiondata = delta.revision - d[b'revisionsize'] = len(revisiondata) + followingmeta.append((b'revision', len(delta.revision))) + followingdata.append(delta.revision) else: d[b'deltabasenode'] = delta.basenode - revisiondata = delta.delta - d[b'deltasize'] = len(revisiondata) - else: - revisiondata = None + followingmeta.append((b'delta', len(delta.delta))) + followingdata.append(delta.delta) + + if followingmeta: + d[b'fieldsfollowing'] = followingmeta yield d - if revisiondata is not None: - yield revisiondata + for extra in followingdata: + yield extra if deltas is not None: try: @@ -1020,25 +1029,29 @@ if b'parents' in fields: d[b'parents'] = store.parents(node) + followingmeta = [] + followingdata = [] + if b'revision' in fields: assert delta is not None assert delta.flags == 0 assert d[b'node'] == delta.node if delta.revision is not None: - revisiondata = delta.revision - d[b'revisionsize'] = len(revisiondata) + followingmeta.append((b'revision', len(delta.revision))) + followingdata.append(delta.revision) else: d[b'deltabasenode'] = delta.basenode - revisiondata = delta.delta - d[b'deltasize'] = len(revisiondata) - else: - revisiondata = None + followingmeta.append((b'delta', len(delta.delta))) + followingdata.append(delta.delta) + + if followingmeta: + d[b'fieldsfollowing'] = followingmeta yield d - if revisiondata is not None: - yield revisiondata + for extra in followingdata: + yield extra if deltas is not None: try: