view tests/test-push-checkheads-multibranches-E2.t @ 49672:e92de86cf4f8

emitrevision: consider ancestors revision to emit as available base

This should make more delta base valid. This notably affects:

* case where we skipped some parent with empty delta to directly delta against
  an ancestors
* case where an intermediate snapshots is stored.

This change means we could sent largish intermediate snapshots over the wire.
However this is actually a sub goal here. Sending snapshots over the wire means
the client have a high odd of simply storing the pre-computed delta instead of
doing a lengthy process that will… end up doing the same intermediate snapshot.

In addition the overall size of snapshot (or any level) is "only" some or the
overall delta size. (0.17% for my mercurial clone, 20% for my clone of Mozilla
try). So Sending them other the wire is unlikely to change large impact on the
bandwidth used.

If we decide that minimising the bandwidth is an explicit goal, we should
introduce new logic to filter-out snapshot as delta. The current code has no
notion explicite of snapshot so far, they just tended to fall into the wobbly
filtering options.

In some cases, this patch can yield large improvement to the bundling time:

    ### data-env-vars.name      = mozilla-try-2019-02-18-zstd-sparse-revlog
      # benchmark.name          = perf-bundle
      # benchmark.variants.revs = last-100000
    before: 68.787066 seconds
    after:  47.552677 seconds (-30.87%)

That translate to large improvement to the pull time :

    ### data-env-vars.name           = mozilla-try-2019-02-18-zstd-sparse-revlog
      # benchmark.name               = pull
      # benchmark.variants.issue6528 = disabled
      # benchmark.variants.revs      = last-100000
    before: 142.186625 seconds
    after:   75.897745 seconds  (-46.62%)

No significant negative impact have been observed.

====================================
Testing head checking code: Case E-2
====================================

Mercurial checks for the introduction of new heads on push. Evolution comes
into play to detect if existing branches on the server are being replaced by
some of the new one we push.

This case is part of a series of tests checking this behavior.

Category E: case involving changeset on multiple branch
TestCase 8: moving interleaved branch away from each other

.. old-state:
..
.. * 2-changeset on branch default
.. * 1-changeset on branch Z (between the two other)
..
.. new-state:
..
.. * 2-changeset on branch default, aligned
.. * 1-changeset on branch Z (at the same location)
..
.. expected-result:
..
.. * push allowed
..
.. graph-summary:
..
..   C ø⇠◔ C'
..     | |
..   B ◔ |
..     | |
..   A ø⇠◔ A'
..     |/
..     ●

  $ . $TESTDIR/testlib/push-checkheads-util.sh

Test setup
----------

  $ mkdir E1
  $ cd E1
  $ setuprepos
  creating basic server and client repo
  updating to branch default
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cd client
  $ hg branch Z
  marked working directory as branch Z
  (branches are permanent and global, did you want a bookmark?)
  $ mkcommit B0
  $ hg branch default --force
  marked working directory as branch default
  $ mkcommit C0
  created new head
  $ hg push --new-branch
  pushing to $TESTTMP/E1/server
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 2 changesets with 2 changes to 2 files
  $ hg up 0
  0 files updated, 0 files merged, 3 files removed, 0 files unresolved
  $ mkcommit A1
  created new head
  $ mkcommit C1
  $ hg debugobsolete `getid "desc(A0)" ` `getid "desc(A1)"`
  1 new obsolescence markers
  obsoleted 1 changesets
  2 new orphan changesets
  $ hg debugobsolete `getid "desc(C0)" ` `getid "desc(C1)"`
  1 new obsolescence markers
  obsoleted 1 changesets
  $ hg log -G --hidden
  @  0c76bc104656 (draft): C1
  |
  o  f6082bc4ffef (draft): A1
  |
  | x  afc55ba2ce61 (draft): C0
  | |
  | *  93e5c1321ece (draft): B0
  | |
  | x  8aaa48160adc (draft): A0
  |/
  o  1e4be0697311 (public): root
  

Actual testing
--------------

  $ hg push -r 'desc("C1")'
  pushing to $TESTTMP/E1/server
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 2 changesets with 2 changes to 2 files (+1 heads)
  2 new obsolescence markers
  obsoleted 2 changesets
  1 new orphan changesets

  $ cd ../..