rust-performance: introduce FastHashMap type alias for HashMap
Rust's default hashing is slow, because it is meant for preventing collision
attacks.
For all of the current Rust code, we don't care about those attacks, because
if an person with bad intentions has write access to your repo, you have other
issues.
I've chosen to use the TwoXHash crate because it was made by a reputable member
of the Rust community and has very good benchmarks.
For now it does not seem to improve performance by much for the current code,
but it's something else to not worry about when benchmarking code: in a
previous experiment with copytracing in Rust, it accounted for more than 10%
of the time of the entire script.
Differential Revision: https://phab.mercurial-scm.org/D7116
Testing narrow clones when changesets modifying a matching file exist on
multiple branches
$ . "$TESTDIR/narrow-library.sh"
$ hg init master
$ cd master
$ cat >> .hg/hgrc <<EOF
> [narrow]
> serveellipses=True
> EOF
$ hg branch default
marked working directory as branch default
(branches are permanent and global, did you want a bookmark?)
$ for x in `$TESTDIR/seq.py 10`; do
> echo $x > "f$x"
> hg add "f$x"
> hg commit -m "Add $x"
> done
$ hg branch release-v1
marked working directory as branch release-v1
(branches are permanent and global, did you want a bookmark?)
$ hg commit -m "Start release for v1"
$ hg update default
0 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ for x in `$TESTDIR/seq.py 10`; do
> echo "$x v2" > "f$x"
> hg commit -m "Update $x to v2"
> done
$ hg update release-v1
10 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg branch release-v1
marked working directory as branch release-v1
$ for x in `$TESTDIR/seq.py 1 5`; do
> echo "$x v1 hotfix" > "f$x"
> hg commit -m "Hotfix $x in v1"
> done
$ hg update default
10 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg branch release-v2
marked working directory as branch release-v2
$ hg commit -m "Start release for v2"
$ hg update default
0 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg branch default
marked working directory as branch default
$ for x in `$TESTDIR/seq.py 10`; do
> echo "$x v3" > "f$x"
> hg commit -m "Update $x to v3"
> done
$ hg update release-v2
10 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg branch release-v2
marked working directory as branch release-v2
$ for x in `$TESTDIR/seq.py 4 9`; do
> echo "$x v2 hotfix" > "f$x"
> hg commit -m "Hotfix $x in v2"
> done
$ hg heads -T '{rev} <- {p1rev} ({branch}): {desc}\n'
42 <- 41 (release-v2): Hotfix 9 in v2
36 <- 35 (default): Update 10 to v3
25 <- 24 (release-v1): Hotfix 5 in v1
$ cd ..
We now have 3 branches: default, which has v3 of all files, release-v1 which
has v1 of all files, and release-v2 with v2 of all files.
Narrow clone which should get all branches
$ hg clone --narrow ssh://user@dummy/master narrow --include "f5"
requesting all changes
adding changesets
adding manifests
adding file changes
added 12 changesets with 5 changes to 1 files (+2 heads)
new changesets *:* (glob)
updating to branch default
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ cd narrow
$ hg log -G -T "{if(ellipsis, '...')}{node|short} ({branch}): {desc}\n"
o ...031f516143fe (release-v2): Hotfix 9 in v2
|
o 9cd7f7bb9ca1 (release-v2): Hotfix 5 in v2
|
o ...37bbc88f3ef0 (release-v2): Hotfix 4 in v2
|
| @ ...dae2f368ca07 (default): Update 10 to v3
| |
| o 9c224e89cb31 (default): Update 5 to v3
| |
| o ...04fb59c7c9dc (default): Update 4 to v3
|/
| o b2253e82401f (release-v1): Hotfix 5 in v1
| |
| o ...960ac37d74fd (release-v1): Hotfix 4 in v1
| |
o | 986298e3f347 (default): Update 5 to v2
| |
o | ...75d539c667ec (default): Update 4 to v2
|/
o 04c71bd5707f (default): Add 5
|
o ...881b3891d041 (default): Add 4
Narrow clone the first file, hitting edge condition where unaligned
changeset and manifest revnums cross branches.
$ hg clone --narrow ssh://user@dummy/master narrow --include "f1"
requesting all changes
adding changesets
adding manifests
adding file changes
added 10 changesets with 4 changes to 1 files (+2 heads)
new changesets *:* (glob)
updating to branch default
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ cd narrow
$ hg log -G -T "{if(ellipsis, '...')}{node|short} ({branch}): {desc}\n"
o ...031f516143fe (release-v2): Hotfix 9 in v2
|
| @ ...dae2f368ca07 (default): Update 10 to v3
| |
| o 1f5d184b8e96 (default): Update 1 to v3
|/
| o ...b2253e82401f (release-v1): Hotfix 5 in v1
| |
| o 133502f6b7e5 (release-v1): Hotfix 1 in v1
| |
o | ...79165c83d644 (default): Update 10 to v2
| |
o | c7b7a5f2f088 (default): Update 1 to v2
| |
| o ...f0531a3db7a9 (release-v1): Start release for v1
|/
o ...6a3f0f0abef3 (default): Add 10
|
o e012ac15eaaa (default): Add 1