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
# Extension dedicated to test patch.diff() upgrade modes
from __future__ import absolute_import
from mercurial import (
error,
logcmdutil,
patch,
pycompat,
registrar,
scmutil,
)
cmdtable = {}
command = registrar.command(cmdtable)
@command(
b'autodiff',
[(b'', b'git', b'', b'git upgrade mode (yes/no/auto/warn/abort)')],
b'[OPTION]... [FILE]...',
)
def autodiff(ui, repo, *pats, **opts):
opts = pycompat.byteskwargs(opts)
diffopts = patch.difffeatureopts(ui, opts)
git = opts.get(b'git', b'no')
brokenfiles = set()
losedatafn = None
if git in (b'yes', b'no'):
diffopts.git = git == b'yes'
diffopts.upgrade = False
elif git == b'auto':
diffopts.git = False
diffopts.upgrade = True
elif git == b'warn':
diffopts.git = False
diffopts.upgrade = True
def losedatafn(fn=None, **kwargs):
brokenfiles.add(fn)
return True
elif git == b'abort':
diffopts.git = False
diffopts.upgrade = True
def losedatafn(fn=None, **kwargs):
raise error.Abort(b'losing data for %s' % fn)
else:
raise error.Abort(b'--git must be yes, no or auto')
ctx1, ctx2 = logcmdutil.revpair(repo, [])
m = scmutil.match(ctx2, pats, opts)
it = patch.diff(
repo,
ctx1.node(),
ctx2.node(),
match=m,
opts=diffopts,
losedatafn=losedatafn,
)
for chunk in it:
ui.write(chunk)
for fn in sorted(brokenfiles):
ui.write((b'data lost for: %s\n' % fn))