view tests/test-issue5979.t @ 44180:58c74a517a00 stable

rust-dirstatemap: cache non normal and other parent set

Performance of `hg update` was significantly worse since the introduction of
the Rust `dirstatemap`. This regression was noticed by Valentin Gatien-Baron
when working on a large repository, as it goes unnoticed for smaller
repositories like Mercurial itself.

This fix introduces the same getter/setter mechanism at `hg-core` level as
for `set/get_dirs`.

While this technique is, as previously discussed, quite suboptimal, it fixes an
important enough problem. Refactoring `hg-core` to use the typestate
pattern could be a good approach to improving code quality in a future patch.

This is a graft of stable of 83b2b829c94e

Differential Revision: https://phab.mercurial-scm.org/D8110

  $ hg init r1
  $ cd r1
  $ hg ci --config ui.allowemptycommit=true -m c0
  $ hg ci --config ui.allowemptycommit=true -m c1
  $ hg ci --config ui.allowemptycommit=true -m c2
  $ hg co -q 0
  $ hg ci --config ui.allowemptycommit=true -m c3
  created new head
  $ hg co -q 3
  $ hg merge --quiet
  $ hg ci --config ui.allowemptycommit=true -m c4

  $ hg log -G -T'{desc}'
  @    c4
  |\
  | o  c3
  | |
  o |  c2
  | |
  o |  c1
  |/
  o  c0
  

  >>> from mercurial import hg
  >>> from mercurial import ui as uimod
  >>> repo = hg.repository(uimod.ui())
  >>> for anc in repo.changelog.ancestors([4], inclusive=True):
  ...   print(anc)
  4
  3
  2
  1
  0