view tests/test-issue5979.t @ 43961:b69d5f3a41d0

rust-index: add a struct wrapping the C index

Implementing the full index logic in one go is journey larger than we would
like.

To achieve a smoother transition, we start with a simple Rust wrapper that delegates
allwork to the current C implementation. Once we will have a fully working index
object in Rust, we can easily start using more and more Rust Code with it.

The object in this patch is functional and tested. However, multiple of the
currently existing rust (in the `hg-cpython` crate) requires a `Graph`. Right
now we build this `Graph` (as cindex::Index) using the C index passed as
a PyObject. They will have to be updated to be made compatible.

Differential Revision: https://phab.mercurial-scm.org/D7655

  $ 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