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 serve
$ hg init a
$ cd a
$ echo a > a
$ hg ci -Ama -d '1123456789 0'
adding a
$ hg serve --config server.uncompressed=True -p $HGPORT -d --pid-file=hg.pid
$ cat hg.pid >> $DAEMON_PIDS
$ cd ..
$ tinyproxy.py $HGPORT1 localhost 2>proxy.log >/dev/null </dev/null &
$ while [ ! -f proxy.pid ]; do sleep 0; done
$ cat proxy.pid >> $DAEMON_PIDS
url for proxy, stream
$ http_proxy=http://localhost:$HGPORT1/ hg --config http_proxy.always=True clone --stream http://localhost:$HGPORT/ b
streaming all changes
6 files to transfer, 412 bytes of data (reporevlogstore !)
4 files to transfer, 330 bytes of data (reposimplestore !)
transferred * bytes in * seconds (*/sec) (glob)
updating to branch default
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ cd b
$ hg verify
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
checked 1 changesets with 1 changes to 1 files
$ cd ..
url for proxy, pull
$ http_proxy=http://localhost:$HGPORT1/ hg --config http_proxy.always=True clone http://localhost:$HGPORT/ b-pull
requesting all changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files
new changesets 83180e7845de
updating to branch default
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ cd b-pull
$ hg verify
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
checked 1 changesets with 1 changes to 1 files
$ cd ..
host:port for proxy
$ http_proxy=localhost:$HGPORT1 hg clone --config http_proxy.always=True http://localhost:$HGPORT/ c
requesting all changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files
new changesets 83180e7845de
updating to branch default
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
proxy url with user name and password
$ http_proxy=http://user:passwd@localhost:$HGPORT1 hg clone --config http_proxy.always=True http://localhost:$HGPORT/ d
requesting all changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files
new changesets 83180e7845de
updating to branch default
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
url with user name and password
$ http_proxy=http://user:passwd@localhost:$HGPORT1 hg clone --config http_proxy.always=True http://user:passwd@localhost:$HGPORT/ e
requesting all changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files
new changesets 83180e7845de
updating to branch default
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
bad host:port for proxy ("Protocol not supported" can happen on
misconfigured hosts)
$ http_proxy=localhost:$HGPORT2 hg clone --config http_proxy.always=True http://localhost:$HGPORT/ f
abort: error: (Connection refused|Protocol not supported|.* actively refused it|\$EADDRNOTAVAIL\$|No route to host) (re)
[100]
do not use the proxy if it is in the no list
$ http_proxy=localhost:$HGPORT1 hg clone --config http_proxy.no=localhost http://localhost:$HGPORT/ g
requesting all changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files
new changesets 83180e7845de
updating to branch default
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ cat proxy.log
* - - [*] "GET http://localhost:$HGPORT/?cmd=capabilities HTTP/1.1" - - (glob)
$LOCALIP - - [$LOGDATE$] "GET http://localhost:$HGPORT/?cmd=batch HTTP/1.1" - - x-hgarg-1:cmds=heads+%3Bknown+nodes%3D x-hgproto-1:0.1 0.2 comp=$USUAL_COMPRESSIONS$ partial-pull (glob)
$LOCALIP - - [$LOGDATE$] "GET http://localhost:$HGPORT/?cmd=getbundle HTTP/1.1" - - x-hgarg-1:bookmarks=1&$USUAL_BUNDLE_CAPS$&cg=0&common=0000000000000000000000000000000000000000&heads=83180e7845de420a1bb46896fd5fe05294f8d629&listkeys=bookmarks&stream=1 x-hgproto-1:0.1 0.2 comp=$USUAL_COMPRESSIONS$ partial-pull (glob)
* - - [*] "GET http://localhost:$HGPORT/?cmd=capabilities HTTP/1.1" - - (glob)
$LOCALIP - - [$LOGDATE$] "GET http://localhost:$HGPORT/?cmd=batch HTTP/1.1" - - x-hgarg-1:cmds=heads+%3Bknown+nodes%3D x-hgproto-1:0.1 0.2 comp=$USUAL_COMPRESSIONS$ partial-pull (glob)
$LOCALIP - - [$LOGDATE$] "GET http://localhost:$HGPORT/?cmd=getbundle HTTP/1.1" - - x-hgarg-1:bookmarks=1&$USUAL_BUNDLE_CAPS$&cg=1&common=0000000000000000000000000000000000000000&heads=83180e7845de420a1bb46896fd5fe05294f8d629&listkeys=bookmarks&phases=1 x-hgproto-1:0.1 0.2 comp=$USUAL_COMPRESSIONS$ partial-pull (glob)
* - - [*] "GET http://localhost:$HGPORT/?cmd=capabilities HTTP/1.1" - - (glob)
$LOCALIP - - [$LOGDATE$] "GET http://localhost:$HGPORT/?cmd=batch HTTP/1.1" - - x-hgarg-1:cmds=heads+%3Bknown+nodes%3D x-hgproto-1:0.1 0.2 comp=$USUAL_COMPRESSIONS$ partial-pull (glob)
$LOCALIP - - [$LOGDATE$] "GET http://localhost:$HGPORT/?cmd=getbundle HTTP/1.1" - - x-hgarg-1:bookmarks=1&$USUAL_BUNDLE_CAPS$&cg=1&common=0000000000000000000000000000000000000000&heads=83180e7845de420a1bb46896fd5fe05294f8d629&listkeys=bookmarks&phases=1 x-hgproto-1:0.1 0.2 comp=$USUAL_COMPRESSIONS$ partial-pull (glob)
* - - [*] "GET http://localhost:$HGPORT/?cmd=capabilities HTTP/1.1" - - (glob)
$LOCALIP - - [$LOGDATE$] "GET http://localhost:$HGPORT/?cmd=batch HTTP/1.1" - - x-hgarg-1:cmds=heads+%3Bknown+nodes%3D x-hgproto-1:0.1 0.2 comp=$USUAL_COMPRESSIONS$ partial-pull (glob)
$LOCALIP - - [$LOGDATE$] "GET http://localhost:$HGPORT/?cmd=getbundle HTTP/1.1" - - x-hgarg-1:bookmarks=1&$USUAL_BUNDLE_CAPS$&cg=1&common=0000000000000000000000000000000000000000&heads=83180e7845de420a1bb46896fd5fe05294f8d629&listkeys=bookmarks&phases=1 x-hgproto-1:0.1 0.2 comp=$USUAL_COMPRESSIONS$ partial-pull (glob)
* - - [*] "GET http://localhost:$HGPORT/?cmd=capabilities HTTP/1.1" - - (glob)
$LOCALIP - - [$LOGDATE$] "GET http://localhost:$HGPORT/?cmd=batch HTTP/1.1" - - x-hgarg-1:cmds=heads+%3Bknown+nodes%3D x-hgproto-1:0.1 0.2 comp=$USUAL_COMPRESSIONS$ partial-pull (glob)
$LOCALIP - - [$LOGDATE$] "GET http://localhost:$HGPORT/?cmd=getbundle HTTP/1.1" - - x-hgarg-1:bookmarks=1&$USUAL_BUNDLE_CAPS$&cg=1&common=0000000000000000000000000000000000000000&heads=83180e7845de420a1bb46896fd5fe05294f8d629&listkeys=bookmarks&phases=1 x-hgproto-1:0.1 0.2 comp=$USUAL_COMPRESSIONS$ partial-pull (glob)