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
from __future__ import absolute_import
import os
from mercurial import (
hg,
ui as uimod,
)
from mercurial.hgweb import hgwebdir_mod
hgwebdir = hgwebdir_mod.hgwebdir
os.mkdir(b'webdir')
os.chdir(b'webdir')
webdir = os.path.realpath(b'.')
u = uimod.ui.load()
hg.repository(u, b'a', create=1)
hg.repository(u, b'b', create=1)
os.chdir(b'b')
hg.repository(u, b'd', create=1)
os.chdir(b'..')
hg.repository(u, b'c', create=1)
os.chdir(b'..')
paths = {
b't/a/': b'%s/a' % webdir,
b'b': b'%s/b' % webdir,
b'coll': b'%s/*' % webdir,
b'rcoll': b'%s/**' % webdir,
}
config = os.path.join(webdir, b'hgwebdir.conf')
configfile = open(config, 'wb')
configfile.write(b'[paths]\n')
for k, v in paths.items():
configfile.write(b'%s = %s\n' % (k, v))
configfile.close()
confwd = hgwebdir(config)
dictwd = hgwebdir(paths)
assert len(confwd.repos) == len(dictwd.repos), 'different numbers'
assert len(confwd.repos) == 9, 'expected 9 repos, found %d' % len(confwd.repos)
found = dict(confwd.repos)
for key, path in dictwd.repos:
assert key in found, 'repository %s was not found' % key
assert found[key] == path, 'different paths for repo %s' % key