remotephase: avoid full changelog iteration (
issue5964)
Changeset
88efb7d6bcb6 introduced a performance regression by triggering a
full ancestors walk.
This changeset reworks this logic so that we no longer walk down the full
changelog. The motivation for
88efb7d6bcb6,
issue5939, is still fixed.
mercurial compared to a draft repository
----------------------------------------
8eeed92475d5: 0.012637 seconds
88efb7d6bcb6: 0.202699 seconds (x16)
46da52f4b820: 0.215551 seconds (+6%)
this code: 0.008397 seconds (-33% from base)
The payload size reduction we see in `test-bookmarks-pushpull.t` comes from a
more aggressive filter of nullid and is harmless.
nodes: expand/comment the magic nodes so they are more easily searchable
We just encountered `
000000000000modified`, and it was quite annoying to search
for these, even though I knew they existed. For those that don't know that they
exist, this is essentially impossible to search for :)
(Technically we encountered it in its hex form,
3030303030303030303030306d6f646966696564, so I'm adding comments with those
forms in case that's helpful to people in the future).
Differential Revision: https://phab.mercurial-scm.org/D4331