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
#require no-windows
$ . "$TESTDIR/remotefilelog-library.sh"
generaldelta to generaldelta interactions with bundle2 but legacy clients
without changegroup2 support
$ cat > testcg2.py << EOF
> import sys
> from mercurial import changegroup, registrar, util
> cmdtable = {}
> command = registrar.command(cmdtable)
> @command('testcg2', norepo=True)
> def testcg2(ui):
> if not util.safehasattr(changegroup, 'cg2packer'):
> sys.exit(80)
> EOF
$ cat >> $HGRCPATH << EOF
> [extensions]
> testcg2 = $TESTTMP/testcg2.py
> EOF
$ hg testcg2 || exit 80
$ cat > disablecg2.py << EOF
> from mercurial import changegroup, error, util
> deleted = False
> def reposetup(ui, repo):
> global deleted
> if deleted:
> return
> packermap = changegroup._packermap
> # protect against future changes
> if len(packermap) != 3:
> raise error.Abort('packermap has %d versions, expected 3!' % len(packermap))
> for k in ['01', '02', '03']:
> if not packermap.get(k):
> raise error.Abort("packermap doesn't have key '%s'!" % k)
>
> del packermap['02']
> deleted = True
> EOF
$ hg init master
$ hg debugrequires -R master | grep generaldelta
generaldelta
$ cd master
preferuncompressed = False so that we can make both generaldelta and non-generaldelta clones
$ cat >> .hg/hgrc <<EOF
> [remotefilelog]
> server=True
> [experimental]
> bundle2-exp = True
> [server]
> preferuncompressed = False
> EOF
$ echo x > x
$ hg commit -qAm x
$ cd ..
$ hgcloneshallow ssh://user@dummy/master shallow -q --pull --config experimental.bundle2-exp=True
1 files fetched over 1 fetches - (1 misses, 0.00% hit ratio) over *s (glob)
$ cd shallow
$ cat >> .hg/hgrc << EOF
> [extensions]
> disablecg2 = $TESTTMP/disablecg2.py
> EOF
$ cd ../master
$ echo y > y
$ hg commit -qAm y
$ cd ../shallow
$ hg pull -u
pulling from ssh://user@dummy/master
searching for changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 0 changes to 0 files
new changesets d34c38483be9
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
1 files fetched over 1 fetches - (1 misses, 0.00% hit ratio) over *s (glob)
$ echo a > a
$ hg commit -qAm a
$ hg push
pushing to ssh://user@dummy/master
searching for changes
remote: adding changesets
remote: adding manifests
remote: adding file changes
remote: added 1 changesets with 1 changes to 1 files