store: append to fncache if there are only new files to write
Before this patch, if we have to add a new entry to fncache, we write the whole
fncache again which slows things down on large fncache which have millions of
entries. Addition of a new entry is common operation while pulling new files or
commiting a new file.
This patch adds a new fncache.addls set which keeps track of the additions
happening and store them. When we write the fncache, we will just read the addls
set and append those entries at the end of fncache.
We make sure that the entries are new entries by loading the fncache and making
sure entry does not exists there. In future if we can check if an entry is new
without loading the fncache, that will speed up things more.
Performance numbers for commiting a new file:
mercurial repo
before: 0.
08784651756286621
after: 0.
08474504947662354
mozilla-central
before: 1.
83314049243927
after: 1.
7054164409637451
netbeans
before: 0.
7953150272369385
after: 0.
7202838659286499
pypy
before: 0.
17805707454681396
after: 0.
13431048393249512
In our internal repo, the performance improvement is in seconds.
I have used octobus's ASV perf benchmark thing to get the above numbers. I also
see some minute perf improvements related to creating a new commit without a new
file, but I believe that's just some noise.
Differential Revision: https://phab.mercurial-scm.org/D5301
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