merge: cache unknown dir checks (
issue5716)
As mentioned in D1222, the recent pathconflicts change regresses update
performance in large repositories when many files are being updated.
To mitigate this, we introduce two caches of directories that have
already found to be either:
- unknown directories, but which are not aliased by files and
so don't need to be checked if they are files again; and
- missing directores, which cannot cause path conflicts, and
cannot contain a file that causes a path conflict.
When checking the paths of a file, testing against this caches means we can
skip tests that involve touching the filesystem.
Differential Revision: https://phab.mercurial-scm.org/D1224
$ hg init
$ echo This is file a1 > a
$ hg add a
$ hg commit -m "commit #0"
$ echo This is file b1 > b
$ hg add b
$ hg commit -m "commit #1"
$ hg update 0
0 files updated, 0 files merged, 1 files removed, 0 files unresolved
$ echo This is file c1 > c
$ hg add c
$ hg commit -m "commit #2"
created new head
$ hg merge 1
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
$ rm b
$ echo This is file c22 > c
Test hg behaves when committing with a missing file added by a merge
$ hg commit -m "commit #3"
abort: cannot commit merge with missing files
[255]