sqlitestore: support for storing revisions without their parents
This commit kinda/sorta implements the equivalent of ellipsis nodes for
the SQLite storage backend.
Without implementing full blown ellipsis nodes (and the necessary support for
them in the wire protocol), we instead teach the store to rewrite the p1 and
p2 nodes to nullid when the incoming parent isn't in the local store. This allows
servers to remain dumb and send the real parent and have the clients deal
with the missing parent problem.
This obviously isn't ideal because a benefit of ellipsis nodes is we can
insert a fake parent to ellide missing changesets. But neither solution is
ideal because it drops the original parent from storage. We could probably
teach the SQLite store to retain the original parent and handle missing
parents at read time. However, parent revisions are stored as integers and
it isn't trivial to store an "empty" revision in the store yet, which would
be necessary to represent the "missing" parent.
The store is somewhat intelligent in trying to remove the missing parents
metadata when the revision is re-added. But, revision numbers will be all
messed up in that case, so I'm not sure it is worth it. At some point we'll
likely want to remove the concept of revision numbers from the database and
have the store invent them at index generation time. Or even better, we can
do away with revision numbers from the file storage interface completely.
We'll get there eventually...
Differential Revision: https://phab.mercurial-scm.org/D5168
============================================
Testing obsolescence markers push: Cases B.3
============================================
Mercurial pushes obsolescences markers relevant to the "pushed-set", the set of
all changesets that requested to be "in sync" after the push (even if they are
already on both side).
This test belongs to a series of tests checking such set is properly computed
and applied. This does not tests "obsmarkers" discovery capabilities.
Category B: pruning case
TestCase 3: Pruned changeset on non-pushed part of the history
B.3 Pruned changeset on non-pushed part of the history
======================================================
.. {{{
.. ⊗ C
.. |
.. ○ B
.. | ◔ A
.. |/
.. ● O
.. }}}
..
.. Marker exists from:
..
.. * C (prune)
..
.. Commands run:
..
.. * hg push -r A
..
.. Expected exchange:
..
.. * ø
..
.. Expected exclude:
..
.. * chain from B
Setup
-----
$ . $TESTDIR/testlib/exchange-obsmarker-util.sh
initial
$ setuprepos B.3
creating test repo for test case B.3
- pulldest
- main
- pushdest
cd into `main` and proceed with env setup
$ cd main
$ mkcommit A
$ hg up --quiet 0
$ mkcommit B
created new head
$ mkcommit C
$ hg prune -qd '0 0' .
$ hg log -G --hidden
x e56289ab6378 (draft): C
|
@ 35b183996678 (draft): B
|
| o f5bc6836db60 (draft): A
|/
o a9bdc8b26820 (public): O
$ inspect_obsmarkers
obsstore content
================
e56289ab6378dc752fd7965f8bf66b58bda740bd 0 {35b1839966785d5703a01607229eea932db42f87} (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'}
$ cd ..
$ cd ..
Actual Test
-----------------------------------
$ dotest B.3 A
## Running testcase B.3
# testing echange of "A" (f5bc6836db60)
## initial state
# obstore: main
e56289ab6378dc752fd7965f8bf66b58bda740bd 0 {35b1839966785d5703a01607229eea932db42f87} (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'}
# obstore: pushdest
# obstore: pulldest
## pushing "A" from main to pushdest
pushing to pushdest
searching for changes
remote: adding changesets
remote: adding manifests
remote: adding file changes
remote: added 1 changesets with 1 changes to 1 files
## post push state
# obstore: main
e56289ab6378dc752fd7965f8bf66b58bda740bd 0 {35b1839966785d5703a01607229eea932db42f87} (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'}
# obstore: pushdest
# obstore: pulldest
## pulling "f5bc6836db60" from main into pulldest
pulling from main
searching for changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files
new changesets f5bc6836db60 (1 drafts)
(run 'hg update' to get a working copy)
## post pull state
# obstore: main
e56289ab6378dc752fd7965f8bf66b58bda740bd 0 {35b1839966785d5703a01607229eea932db42f87} (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'}
# obstore: pushdest
# obstore: pulldest