push: rework the computation of fallbackheads to be correct
The previous computation tried to be smart but ended up being wrong. This was
caught by phase movement test while reworking the phase discovery logic to be
faster.
The previous logic was failing to catch case where the pushed set was not based
on a common heads (i.e. when the discovery seemed to have "over discovered"
content, outside the pushed set)
In the following graph, `e` is a common head and we `hg push -r f`. We need to
detect `c` as a fallback heads and we previous failed to do so::
e
|
d f
|/
c
|
b
|
a
The performance impact of the change seems minimal. On the most impacted
repository at hand (mozilla-try), the slowdown seems mostly mixed in the
overall noise `hg push` but seems to be in the hundred of milliseconds order of
magnitude. When using rust, we seems to be a bit faster, probably because we
leverage more accelaratd internals.
I added a couple of performance related common for further investigation later
on.
plain
$ hg init
$ hg debugbuilddag '+2:f +3:p2 @temp <f+4 @default /p2 +2' \
> --config extensions.progress= --config progress.assume-tty=1 \
> --config progress.delay=0 --config progress.refresh=0 \
> --config progress.format=topic,bar,number \
> --config progress.width=60
\r (no-eol) (esc)
building [ ] 0/12\r (no-eol) (esc)
building [ ] 0/12\r (no-eol) (esc)
building [==> ] 1/12\r (no-eol) (esc)
building [==> ] 1/12\r (no-eol) (esc)
building [======> ] 2/12\r (no-eol) (esc)
building [=========> ] 3/12\r (no-eol) (esc)
building [=============> ] 4/12\r (no-eol) (esc)
building [=============> ] 4/12\r (no-eol) (esc)
building [=============> ] 4/12\r (no-eol) (esc)
building [================> ] 5/12\r (no-eol) (esc)
building [====================> ] 6/12\r (no-eol) (esc)
building [=======================> ] 7/12\r (no-eol) (esc)
building [===========================> ] 8/12\r (no-eol) (esc)
building [===========================> ] 8/12\r (no-eol) (esc)
building [==============================> ] 9/12\r (no-eol) (esc)
building [==================================> ] 10/12\r (no-eol) (esc)
building [=====================================> ] 11/12\r (no-eol) (esc)
\r (no-eol) (esc)
tags
$ cat .hg/localtags
66f7d451a68b85ed82ff5fcc254daf50c74144bd f
bebd167eb94d257ace0e814aeb98e6972ed2970d p2
dag
$ hg debugdag -t -b
+2:f
+3:p2
@temp*f+3
@default*/p2+2:tip
tip
$ hg id
000000000000
glog
$ hg log -G --template '{rev}: {desc} [{branches}] @ {date}\n'
o 11: r11 [] @ 11.00
|
o 10: r10 [] @ 10.00
|
o 9: r9 [] @ 9.00
|\
| o 8: r8 [temp] @ 8.00
| |
| o 7: r7 [temp] @ 7.00
| |
| o 6: r6 [temp] @ 6.00
| |
| o 5: r5 [temp] @ 5.00
| |
o | 4: r4 [] @ 4.00
| |
o | 3: r3 [] @ 3.00
| |
o | 2: r2 [] @ 2.00
|/
o 1: r1 [] @ 1.00
|
o 0: r0 [] @ 0.00
overwritten files, starting on a non-default branch
$ rm -r .hg
$ hg init
$ hg debugbuilddag '@start.@default.:f +3:p2 @temp <f+4 @default /p2 +2' -q -o
tags
$ cat .hg/localtags
f778700ebd50fcf282b23a4446bd155da6453eb6 f
bbccf169769006e2490efd2a02f11c3d38d462bd p2
dag
$ hg debugdag -t -b
@start+1
@default+1:f
+3:p2
@temp*f+3
@default*/p2+2:tip
tip
$ hg id
000000000000
glog
$ hg log -G --template '{rev}: {desc} [{branches}] @ {date}\n'
o 11: r11 [] @ 11.00
|
o 10: r10 [] @ 10.00
|
o 9: r9 [] @ 9.00
|\
| o 8: r8 [temp] @ 8.00
| |
| o 7: r7 [temp] @ 7.00
| |
| o 6: r6 [temp] @ 6.00
| |
| o 5: r5 [temp] @ 5.00
| |
o | 4: r4 [] @ 4.00
| |
o | 3: r3 [] @ 3.00
| |
o | 2: r2 [] @ 2.00
|/
o 1: r1 [] @ 1.00
|
o 0: r0 [start] @ 0.00
glog of
$ hg log -G --template '{rev}: {desc} [{branches}]\n' of
o 11: r11 []
|
o 10: r10 []
|
o 9: r9 []
|\
| o 8: r8 [temp]
| |
| o 7: r7 [temp]
| |
| o 6: r6 [temp]
| |
| o 5: r5 [temp]
| |
o | 4: r4 []
| |
o | 3: r3 []
| |
o | 2: r2 []
|/
o 1: r1 []
|
o 0: r0 [start]
tags
$ hg tags -v
tip 11:9ffe238a67a2
p2 4:bbccf1697690 local
f 1:f778700ebd50 local
cat of
$ hg cat of --rev tip
r11
new and mergeable files
$ rm -r .hg
$ hg init
$ hg debugbuilddag '+2:f +3:p2 @temp <f+4 @default /p2 +2' -q -mn
dag
$ hg debugdag -t -b
+2:f
+3:p2
@temp*f+3
@default*/p2+2:tip
tip
$ hg id
000000000000
glog
$ hg log -G --template '{rev}: {desc} [{branches}] @ {date}\n'
o 11: r11 [] @ 11.00
|
o 10: r10 [] @ 10.00
|
o 9: r9 [] @ 9.00
|\
| o 8: r8 [temp] @ 8.00
| |
| o 7: r7 [temp] @ 7.00
| |
| o 6: r6 [temp] @ 6.00
| |
| o 5: r5 [temp] @ 5.00
| |
o | 4: r4 [] @ 4.00
| |
o | 3: r3 [] @ 3.00
| |
o | 2: r2 [] @ 2.00
|/
o 1: r1 [] @ 1.00
|
o 0: r0 [] @ 0.00
glog mf
$ hg log -G --template '{rev}: {desc} [{branches}]\n' mf
o 11: r11 []
|
o 10: r10 []
|
o 9: r9 []
|\
| o 8: r8 [temp]
| |
| o 7: r7 [temp]
| |
| o 6: r6 [temp]
| |
| o 5: r5 [temp]
| |
o | 4: r4 []
| |
o | 3: r3 []
| |
o | 2: r2 []
|/
o 1: r1 []
|
o 0: r0 []
man r4
$ hg manifest -r4
mf
nf0
nf1
nf2
nf3
nf4
cat r4 mf
$ hg cat -r4 mf
0 r0
1
2 r1
3
4 r2
5
6 r3
7
8 r4
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
man r8
$ hg manifest -r8
mf
nf0
nf1
nf5
nf6
nf7
nf8
cat r8 mf
$ hg cat -r8 mf
0 r0
1
2 r1
3
4
5
6
7
8
9
10 r5
11
12 r6
13
14 r7
15
16 r8
17
18
19
20
21
22
23
man
$ hg manifest --rev tip
mf
nf0
nf1
nf10
nf11
nf2
nf3
nf4
nf5
nf6
nf7
nf8
nf9
cat mf
$ hg cat mf --rev tip
0 r0
1
2 r1
3
4 r2
5
6 r3
7
8 r4
9
10 r5
11
12 r6
13
14 r7
15
16 r8
17
18 r9
19
20 r10
21
22 r11
23