encoding: fix trim() to be O(n) instead of O(n^2)
`encoding.trim()` iterated over the possible lengths smaller than the
input and created a slice for each. It then calculated the column
width of the result, which is of course O(n), so the overall algorithm
was O(n). This patch rewrites it to iterate over the unicode
characters, keeping track of the length so far. Also, the old
algorithm started from the end of the string, which made it much worse
when the input is large and the limit is small (such as the typical 72
we pass to it).
You can time it by running something like this:
```
time python3 -c 'from mercurial.utils import stringutil; print(stringutil.ellipsis(b"0123456789" * 1000, 5))'
```
That drops from 4.05 s to 83 ms with this patch (and most of that is
of course startup time).
Differential Revision: https://phab.mercurial-scm.org/D12089
$ cat >> $HGRCPATH << EOF
> [extensions]
> fastannotate=
> EOF
$ hg init repo
$ cd repo
a simple merge case
$ echo 1 > a
$ hg commit -qAm 'append 1'
$ echo 2 >> a
$ hg commit -m 'append 2'
$ echo 3 >> a
$ hg commit -m 'append 3'
$ hg up 1 -q
$ cat > a << EOF
> 0
> 1
> 2
> EOF
$ hg commit -qm 'insert 0'
$ hg merge 2 -q
$ echo 4 >> a
$ hg commit -m merge
$ hg log -G -T '{rev}: {desc}'
@ 4: merge
|\
| o 3: insert 0
| |
o | 2: append 3
|/
o 1: append 2
|
o 0: append 1
$ hg fastannotate a
3: 0
0: 1
1: 2
2: 3
4: 4
$ hg fastannotate -r 0 a
0: 1
$ hg fastannotate -r 1 a
0: 1
1: 2
$ hg fastannotate -udnclf a
test 3 d641cb51f61e Thu Jan 01 00:00:00 1970 +0000 a:1: 0
test 0 4994017376d3 Thu Jan 01 00:00:00 1970 +0000 a:1: 1
test 1 e940cb6d9a06 Thu Jan 01 00:00:00 1970 +0000 a:2: 2
test 2 26162a884ba6 Thu Jan 01 00:00:00 1970 +0000 a:3: 3
test 4 3ad7bcd2815f Thu Jan 01 00:00:00 1970 +0000 a:5: 4
$ hg fastannotate --linear a
3: 0
0: 1
1: 2
4: 3
4: 4
incrementally updating
$ hg fastannotate -r 0 a --debug
fastannotate: a: using fast path (resolved fctx: True)
0: 1
$ hg fastannotate -r 0 a --debug --rebuild
fastannotate: a: 1 new changesets in the main branch
0: 1
$ hg fastannotate -r 1 a --debug
fastannotate: a: 1 new changesets in the main branch
0: 1
1: 2
$ hg fastannotate -r 3 a --debug
fastannotate: a: 1 new changesets in the main branch
3: 0
0: 1
1: 2
$ hg fastannotate -r 4 a --debug
fastannotate: a: 1 new changesets in the main branch
3: 0
0: 1
1: 2
2: 3
4: 4
$ hg fastannotate -r 1 a --debug
fastannotate: a: using fast path (resolved fctx: True)
0: 1
1: 2
rebuild happens automatically if unable to update
$ hg fastannotate -r 2 a --debug
fastannotate: a: cache broken and deleted
fastannotate: a: 3 new changesets in the main branch
0: 1
1: 2
2: 3
config option "fastannotate.mainbranch"
$ hg fastannotate -r 1 --rebuild --config fastannotate.mainbranch=tip a --debug
fastannotate: a: 4 new changesets in the main branch
0: 1
1: 2
$ hg fastannotate -r 4 a --debug
fastannotate: a: using fast path (resolved fctx: True)
3: 0
0: 1
1: 2
2: 3
4: 4
config option "fastannotate.modes"
$ hg annotate -r 1 --debug a
0: 1
1: 2
$ hg annotate --config fastannotate.modes=fctx -r 1 --debug a
fastannotate: a: using fast path (resolved fctx: False)
0: 1
1: 2
$ hg fastannotate --config fastannotate.modes=fctx -h -q
hg: unknown command 'fastannotate'
(did you mean *) (glob)
[10]
rename
$ hg mv a b
$ cat > b << EOF
> 0
> 11
> 3
> 44
> EOF
$ hg commit -m b -q
$ hg fastannotate -ncf --long-hash b
3 d641cb51f61e331c44654104301f8154d7865c89 a: 0
5 d44dade239915bc82b91e4556b1257323f8e5824 b: 11
2 26162a884ba60e8c87bf4e0d6bb8efcc6f711a4e a: 3
5 d44dade239915bc82b91e4556b1257323f8e5824 b: 44
$ hg fastannotate -r 26162a884ba60e8c87bf4e0d6bb8efcc6f711a4e a
0: 1
1: 2
2: 3
fastannotate --deleted
$ hg fastannotate --deleted -nf b
3 a: 0
5 b: 11
0 a: -1
1 a: -2
2 a: 3
5 b: 44
4 a: -4
$ hg fastannotate --deleted -r 3 -nf a
3 a: 0
0 a: 1
1 a: 2
file and directories with ".l", ".m" suffixes
$ cd ..
$ hg init repo2
$ cd repo2
$ mkdir a.l b.m c.lock a.l.hg b.hg
$ for i in a b c d d.l d.m a.l/a b.m/a c.lock/a a.l.hg/a b.hg/a; do
> echo $i > $i
> done
$ hg add . -q
$ hg commit -m init
$ hg fastannotate a.l/a b.m/a c.lock/a a.l.hg/a b.hg/a d.l d.m a b c d
0: a
0: a.l.hg/a
0: a.l/a
0: b
0: b.hg/a
0: b.m/a
0: c
0: c.lock/a
0: d
0: d.l
0: d.m
empty file
$ touch empty
$ hg commit -A empty -m empty
$ hg fastannotate empty
json format
$ hg fastannotate -Tjson -cludn b a empty
[
{
"date": [0.0, 0],
"line": "a\n",
"line_number": 1,
"node": "1fd620b16252aecb54c6aa530dff5ed6e6ec3d21",
"rev": 0,
"user": "test"
},
{
"date": [0.0, 0],
"line": "b\n",
"line_number": 1,
"node": "1fd620b16252aecb54c6aa530dff5ed6e6ec3d21",
"rev": 0,
"user": "test"
}
]
$ hg fastannotate -Tjson -cludn empty
[
]
$ hg fastannotate -Tjson --no-content -n a
[
{
"rev": 0
}
]
working copy
$ echo a >> a
$ hg fastannotate -r 'wdir()' a
abort: cannot update linelog to wdir()
(set fastannotate.mainbranch)
[255]
$ cat >> $HGRCPATH << EOF
> [fastannotate]
> mainbranch = .
> EOF
$ hg fastannotate -r 'wdir()' a
0 : a
1+: a
$ hg fastannotate -cludn -r 'wdir()' a
test 0 1fd620b16252 Thu Jan 01 00:00:00 1970 +0000:1: a
test 1 720582f5bdb6+ *:2: a (glob)
$ hg fastannotate -cludn -r 'wdir()' -Tjson a
[
{
"date": [0.0, 0],
"line": "a\n",
"line_number": 1,
"node": "1fd620b16252aecb54c6aa530dff5ed6e6ec3d21",
"rev": 0,
"user": "test"
},
{
"date": [*, 0], (glob)
"line": "a\n",
"line_number": 2,
"node": null,
"rev": null,
"user": "test"
}
]