status: prefer relative paths in Rust code
… when the repository root is under the current directory,
so the kernel needs to traverse fewer directory in every call
to `read_dir` or `symlink_metadata`.
Better yet would be to use libc functions like `openat` and `fstatat`
to remove such repeated traversals entirely, but the standard library
does not provide APIs based on those.
Maybe with a crate like https://crates.io/crates/openat instead?
Benchmarks of `rhg status` show that this patch is neutral in some configurations,
and makes the command up to ~20% faster in others.
Below is semi-arbitrary subset of results. The four numeric columns are:
time (in seconds) with this changeset’s parent, time with this changeset,
time difference (negative is better), time ratio (less than 1 is better).
```
mercurial-dirstate-v1 | default-plain-clean.no-iu.pbr | 0.0061 -> 0.0059: -0.0002 (0.97)
mercurial-dirstate-v2 | default-plain-clean.no-iu.pbr | 0.0029 -> 0.0028: -0.0001 (0.97)
mozilla-dirstate-v1 | default-plain-clean.no-iu.pbr | 0.2110 -> 0.2102: -0.0007 (1.00)
mozilla-dirstate-v2 | default-copies-clean.ignored.pbr | 0.0489 -> 0.0401: -0.0088 (0.82)
mozilla-dirstate-v2 | default-copies-clean.no-iu.pbr | 0.0479 -> 0.0393: -0.0085 (0.82)
mozilla-dirstate-v2 | default-copies-large.all.pbr | 0.1262 -> 0.1210: -0.0051 (0.96)
mozilla-dirstate-v2 | default-copies-small.ignored-unknown.pbr | 0.1262 -> 0.1200: -0.0062 (0.95)
mozilla-dirstate-v2 | default-copies-small.ignored.pbr | 0.0536 -> 0.0417: -0.0119 (0.78)
mozilla-dirstate-v2 | default-copies-small.no-iu.pbr | 0.0482 -> 0.0393: -0.0089 (0.81)
mozilla-dirstate-v2 | default-plain-clean.ignored.pbr | 0.0518 -> 0.0402: -0.0116 (0.78)
mozilla-dirstate-v2 | default-plain-clean.no-iu.pbr | 0.0481 -> 0.0392: -0.0088 (0.82)
mozilla-dirstate-v2 | default-plain-large.all.pbr | 0.1271 -> 0.1218: -0.0052 (0.96)
mozilla-dirstate-v2 | default-plain-small.ignored-unknown.pbr | 0.1225 -> 0.1202: -0.0022 (0.98)
mozilla-dirstate-v2 | default-plain-small.ignored.pbr | 0.0510 -> 0.0418: -0.0092 (0.82)
mozilla-dirstate-v2 | default-plain-small.no-iu.pbr | 0.0480 -> 0.0394: -0.0086 (0.82)
netbeans-dirstate-v1 | default-plain-clean.no-iu.pbr | 0.1442 -> 0.1422: -0.0020 (0.99)
netbeans-dirstate-v2 | default-plain-clean.no-iu.pbr | 0.0325 -> 0.0282: -0.0043 (0.87)
```
Differential Revision: https://phab.mercurial-scm.org/D12175
Path conflict checking is currently disabled by default because of issue5716.
Turn it on for this test.
$ cat >> $HGRCPATH << EOF
> [experimental]
> merge.checkpathconflicts=True
> EOF
$ hg init repo
$ cd repo
$ echo base > base
$ hg add base
$ hg commit -m "base"
$ hg bookmark -i base
$ echo 1 > a
$ hg add a
$ hg commit -m "file"
$ hg bookmark -i file
$ echo 2 > a
$ hg commit -m "file2"
$ hg bookmark -i file2
$ hg up -q 0
$ mkdir a
$ echo 2 > a/b
$ hg add a/b
$ hg commit -m "dir"
created new head
$ hg bookmark -i dir
Basic merge - local file conflicts with remote directory
$ hg up -q file
$ hg bookmark -i
$ hg merge --verbose dir
resolving manifests
a: path conflict - a file or link has the same name as a directory
the local file has been renamed to a~853701544ac3
resolve manually then use 'hg resolve --mark a'
moving a to a~853701544ac3
getting a/b
1 files updated, 0 files merged, 0 files removed, 1 files unresolved
use 'hg resolve' to retry unresolved file merges or 'hg merge --abort' to abandon
[1]
$ hg update --clean .
1 files updated, 0 files merged, 1 files removed, 0 files unresolved
$ rm a~853701544ac3
Basic update - local directory conflicts with remote file
$ hg up -q 0
$ mkdir a
$ echo 3 > a/b
$ hg up file
a: untracked directory conflicts with file
abort: untracked files in working directory differ from files in requested revision
[20]
$ hg up --clean file
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
(activating bookmark file)
Repo state is ok
$ hg sum
parent: 1:853701544ac3
file
branch: default
bookmarks: *file
commit: (clean)
update: 2 new changesets (update)
phases: 4 draft
Basic update - untracked file conflicts with remote directory
$ hg up -q 0
$ echo untracked > a
$ hg up --config merge.checkunknown=warn dir
a: replacing untracked file
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
(activating bookmark dir)
$ cat a.orig
untracked
$ rm -f a.orig
Basic clean update - local directory conflicts with changed remote file
$ hg up -q file
$ rm a
$ mkdir a
$ echo 4 > a/b
$ hg up file2
abort: *: *$TESTTMP/repo/a* (glob)
[255]
$ hg up --clean file2
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
(activating bookmark file2)
Repo state is ok
$ hg sum
parent: 2:f64e09fac717
file2
branch: default
bookmarks: *file2
commit: (clean)
update: 1 new changesets, 2 branch heads (merge)
phases: 4 draft