D4214: changegroup: refactor delta parent code

[indygreg (Gregory Szorc)]

indygreg added a comment.


  It is a hard problem because the server can't make any assumptions about what nodes the receiver has! So you either need the client to transmit the set of nodes it has. Without that, the best the server can do is encode a delta against a revision in the same delta group. And that would strictly be better than what's implemented (which is to always send a full revision!). It should be easy enough to change the logic though. Although we'd need to pass more information down to the code doing the delta generation.

REPOSITORY
  rHG Mercurial

REVISION DETAIL
  https://phab.mercurial-scm.org/D4214

To: indygreg, #hg-reviewers
Cc: durin42, mercurial-devel