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
basic:
* neither file exists
creating
* neither file still exists
* empty file x created
creating
* file x changed size
creating
* nothing changed with either file
* file x changed inode
creating
* empty file y created
creating
* file y changed size
creating
* file y changed inode
creating
* both files changed inode
creating
fakeuncacheable:
* neither file exists
creating
* neither file still exists
creating
* empty file x created
creating
* file x changed size
creating
* nothing changed with either file
creating
* file x changed inode
creating
* empty file y created
creating
* file y changed size
creating
* file y changed inode
creating
* both files changed inode
creating
repository tip rolled back to revision -1 (undo commit)
working directory now based on revision -1
repository tip rolled back to revision -1 (undo commit)
working directory now based on revision -1
setbeforeget:
* neither file exists
string set externally
* file x created
creating
string from function
* string set externally again
string 2 set externally
* file y created
creating
string from function
antiambiguity: