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
*** Test in-uri schemes
CFG: {b'x.prefix': b'http://example.org'}
URI: http://example.org/foo
('x', 'x')
URI: http://example.org/foo/bar
('x', 'x')
URI: http://example.org/bar
('x', 'x')
URI: https://example.org/foo
abort
URI: https://example.org/foo/bar
abort
URI: https://example.org/bar
abort
URI: https://x@example.org/bar
abort
URI: https://y@example.org/bar
abort
CFG: {b'x.prefix': b'https://example.org'}
URI: http://example.org/foo
abort
URI: http://example.org/foo/bar
abort
URI: http://example.org/bar
abort
URI: https://example.org/foo
('x', 'x')
URI: https://example.org/foo/bar
('x', 'x')
URI: https://example.org/bar
('x', 'x')
URI: https://x@example.org/bar
('x', 'x')
URI: https://y@example.org/bar
abort
CFG: {b'x.prefix': b'http://example.org', b'x.schemes': b'https'}
URI: http://example.org/foo
('x', 'x')
URI: http://example.org/foo/bar
('x', 'x')
URI: http://example.org/bar
('x', 'x')
URI: https://example.org/foo
abort
URI: https://example.org/foo/bar
abort
URI: https://example.org/bar
abort
URI: https://x@example.org/bar
abort
URI: https://y@example.org/bar
abort
CFG: {b'x.prefix': b'https://example.org', b'x.schemes': b'http'}
URI: http://example.org/foo
abort
URI: http://example.org/foo/bar
abort
URI: http://example.org/bar
abort
URI: https://example.org/foo
('x', 'x')
URI: https://example.org/foo/bar
('x', 'x')
URI: https://example.org/bar
('x', 'x')
URI: https://x@example.org/bar
('x', 'x')
URI: https://y@example.org/bar
abort
*** Test separately configured schemes
CFG: {b'x.prefix': b'example.org', b'x.schemes': b'http'}
URI: http://example.org/foo
('x', 'x')
URI: http://example.org/foo/bar
('x', 'x')
URI: http://example.org/bar
('x', 'x')
URI: https://example.org/foo
abort
URI: https://example.org/foo/bar
abort
URI: https://example.org/bar
abort
URI: https://x@example.org/bar
abort
URI: https://y@example.org/bar
abort
CFG: {b'x.prefix': b'example.org', b'x.schemes': b'https'}
URI: http://example.org/foo
abort
URI: http://example.org/foo/bar
abort
URI: http://example.org/bar
abort
URI: https://example.org/foo
('x', 'x')
URI: https://example.org/foo/bar
('x', 'x')
URI: https://example.org/bar
('x', 'x')
URI: https://x@example.org/bar
('x', 'x')
URI: https://y@example.org/bar
abort
CFG: {b'x.prefix': b'example.org', b'x.schemes': b'http https'}
URI: http://example.org/foo
('x', 'x')
URI: http://example.org/foo/bar
('x', 'x')
URI: http://example.org/bar
('x', 'x')
URI: https://example.org/foo
('x', 'x')
URI: https://example.org/foo/bar
('x', 'x')
URI: https://example.org/bar
('x', 'x')
URI: https://x@example.org/bar
('x', 'x')
URI: https://y@example.org/bar
abort
*** Test prefix matching
CFG: {b'x.prefix': b'http://example.org/foo', b'y.prefix': b'http://example.org/bar'}
URI: http://example.org/foo
('x', 'x')
URI: http://example.org/foo/bar
('x', 'x')
URI: http://example.org/bar
('y', 'y')
URI: https://example.org/foo
abort
URI: https://example.org/foo/bar
abort
URI: https://example.org/bar
abort
URI: https://x@example.org/bar
abort
URI: https://y@example.org/bar
abort
CFG: {b'x.prefix': b'http://example.org/foo', b'y.prefix': b'http://example.org/foo/bar'}
URI: http://example.org/foo
('x', 'x')
URI: http://example.org/foo/bar
('y', 'y')
URI: http://example.org/bar
abort
URI: https://example.org/foo
abort
URI: https://example.org/foo/bar
abort
URI: https://example.org/bar
abort
URI: https://x@example.org/bar
abort
URI: https://y@example.org/bar
abort
CFG: {b'x.prefix': b'*', b'y.prefix': b'https://example.org/bar'}
URI: http://example.org/foo
abort
URI: http://example.org/foo/bar
abort
URI: http://example.org/bar
abort
URI: https://example.org/foo
('x', 'x')
URI: https://example.org/foo/bar
('x', 'x')
URI: https://example.org/bar
('y', 'y')
URI: https://x@example.org/bar
('x', 'x')
URI: https://y@example.org/bar
('y', 'y')
*** Test user matching
CFG: {b'x.password': b'xpassword', b'x.prefix': b'http://example.org/foo', b'x.username': None}
URI: http://y@example.org/foo
('y', 'xpassword')
CFG: {b'x.password': b'xpassword', b'x.prefix': b'http://example.org/foo', b'x.username': None, b'y.password': b'ypassword', b'y.prefix': b'http://example.org/foo', b'y.username': b'y'}
URI: http://y@example.org/foo
('y', 'ypassword')
CFG: {b'x.password': b'xpassword', b'x.prefix': b'http://example.org/foo/bar', b'x.username': None, b'y.password': b'ypassword', b'y.prefix': b'http://example.org/foo', b'y.username': b'y'}
URI: http://y@example.org/foo/bar
('y', 'xpassword')
*** Test user matching with name in prefix
CFG: {b'x.password': b'xpassword', b'x.prefix': b'https://example.org/foo', b'x.username': None, b'y.password': b'ypassword', b'y.prefix': b'http://y@example.org/foo', b'y.username': b'y'}
URI: http://y@example.org/foo
('y', 'ypassword')
CFG: {b'y.password': b'ypassword', b'y.prefix': b'http://z@example.org/foo', b'y.username': b'y'}
URI: http://y@example.org/foo
abort
CFG: {b'y.password': b'ypassword', b'y.prefix': b'http://z@example.org/foo'}
URI: http://y@example.org/foo
abort
CFG: {b'y.password': b'ypassword', b'y.prefix': b'http://y@example.org/foo', b'y.username': b'z'}
URI: http://y@example.org/foo
abort
CFG: {b'y.password': b'ypassword', b'y.prefix': b'http://y@example.org/foo'}
URI: http://y@example.org/foo
('y', 'ypassword')
CFG: {b'y.password': b'ypassword', b'y.prefix': b'http://y@example.org/foo'}
URI: http://example.org/foo
abort
*** Test urllib2 and urlutil.url
URIs: http://user@example.com:8080/foo http://example.com:8080/foo
('user', '')