mercurial-scm/hg: comparison mercurial/wireprotov2server.py

equal deleted inserted replaced

-:039bf1eddc2e
+:aa7e312375cf
 caps['rawrepoformats'] = sorted(repo.requirements &
 repo.supportedformats)
 return proto.addcapabilities(repo, caps)
-def builddeltarequests(store, nodes):
+def builddeltarequests(store, nodes, haveparents):
 """Build a series of revision delta requests against a backend store.
 Returns a list of revision numbers in the order they should be sent
 and a list of ``irevisiondeltarequest`` instances to be made against
 the backend store.
 # a list of nodes and delta preconditions over a figurative wall and
 # have the storage backend figure it out for us.
 revs = dagop.linearize({store.rev(n) for n in nodes}, store.parentrevs)
 requests = []
+seenrevs = set()
 for rev in revs:
 node = store.node(rev)
-parents = store.parents(node)
+parentnodes = store.parents(node)
-deltaparent = store.node(store.deltaparent(rev))
+parentrevs = [store.rev(n) for n in parentnodes]
+deltabaserev = store.deltaparent(rev)
-# There is a delta in storage. That means we can send the delta
+deltabasenode = store.node(deltabaserev)
-# efficiently.
+# The choice of whether to send a fulltext revision or a delta and
+# what delta to send is governed by a few factors.
 #
-# But, the delta may be against a revision the receiver doesn't
+# To send a delta, we need to ensure the receiver is capable of
-# have (e.g. shallow clone or when the delta isn't against a parent
+# decoding it. And that requires the receiver to have the base
-# revision). For now, we ignore the problem of shallow clone. As
+# revision the delta is against.
-# long as a delta exists against a parent, we send it.
-# TODO allow arguments to control this behavior, as the receiver
-# may not have the base revision in some scenarios.
-if deltaparent != nullid and deltaparent in parents:
-basenode = deltaparent
-# Else there is no delta parent in storage or the delta that is
-# # there isn't suitable. Let's use a delta against a parent
-# revision, if possible.
 #
-# There is room to check if the delta parent is in the ancestry of
+# We can only guarantee the receiver has the base revision if
-# this node. But there isn't an API on the manifest storage object
+# a) we've already sent the revision as part of this group
-# for that. So ignore this case for now.
+# b) the receiver has indicated they already have the revision.
+# And the mechanism for "b" is the client indicating they have
-elif parents[0] != nullid:
+# parent revisions. So this means we can only send the delta if
-basenode = parents[0]
+# it is sent before or it is against a delta and the receiver says
-elif parents[1] != nullid:
+# they have a parent.
-basenode = parents[1]
+# We can send storage delta if it is against a revision we've sent
-# No potential bases to delta against. Send a full revision.
+# in this group.
+if deltabaserev != nullrev and deltabaserev in seenrevs:
+basenode = deltabasenode
+# We can send storage delta if it is against a parent revision and
+# the receiver indicates they have the parents.
+elif (deltabaserev != nullrev and deltabaserev in parentrevs
+and haveparents):
+basenode = deltabasenode
+# Otherwise the storage delta isn't appropriate. Fall back to
+# using another delta, if possible.
+# Use p1 if we've emitted it or receiver says they have it.
+elif parentrevs[0] != nullrev and (
+parentrevs[0] in seenrevs or haveparents):
+basenode = parentnodes[0]
+# Use p2 if we've emitted it or receiver says they have it.
+elif parentrevs[1] != nullrev and (
+parentrevs[1] in seenrevs or haveparents):
+basenode = parentnodes[1]
+# Nothing appropriate to delta against. Send the full revision.
 else:
 basenode = nullid
 requests.append(changegroup.revisiondeltarequest(
 node=node,
-p1node=parents[0],
+p1node=parentnodes[0],
-p2node=parents[1],
+p2node=parentnodes[1],
 # Receiver deals with linknode resolution.
 linknode=nullid,
 basenode=basenode,
 ))
+seenrevs.add(rev)
 return revs, requests
 def wireprotocommand(name, args=None, permission='push'):
 """Decorator to declare a wire protocol command.
 return fl
 @wireprotocommand('filedata',
 args={
+'haveparents': True,
 'nodes': [b'0123456...'],
 'fields': [b'parents', b'revision'],
 'path': b'foo.txt',
 },
 permission='pull')
-def filedata(repo, proto, nodes=None, fields=None, path=None):
+def filedata(repo, proto, haveparents=False, nodes=None, fields=None,
+path=None):
 fields = fields or set()
 if nodes is None:
 raise error.WireprotoCommandError('nodes argument must be defined')
 store.rev(node)
 except error.LookupError:
 raise error.WireprotoCommandError('unknown file node: %s',
 (hex(node),))
-revs, requests = builddeltarequests(store, nodes)
+revs, requests = builddeltarequests(store, nodes, haveparents)
 yield {
 b'totalitems': len(revs),
 }
 yield node
 @wireprotocommand('manifestdata',
 args={
 'nodes': [b'0123456...'],
+'haveparents': True,
 'fields': [b'parents', b'revision'],
 'tree': b'',
 },
 permission='pull')
-def manifestdata(repo, proto, nodes=None, fields=None, tree=None):
+def manifestdata(repo, proto, haveparents=False, nodes=None, fields=None,
+tree=None):
 fields = fields or set()
 if nodes is None:
 raise error.WireprotoCommandError(
 'nodes argument must be defined')
 store.rev(node)
 except error.LookupError:
 raise error.WireprotoCommandError(
 'unknown node: %s', (node,))
-revs, requests = builddeltarequests(store, nodes)
+revs, requests = builddeltarequests(store, nodes, haveparents)
 yield {
 b'totalitems': len(revs),
 }

changeset 39641	aa7e312375cf
parent 39639	0e03e6a44dee
child 39810	0b61d21f05cc