fastannotate: initial import from Facebook's hg-experimental
I made as few changes as I could to get the tests to pass, but this
was a bit involved due to some churn in the blame code since someone
last gave fastannotate any TLC.
There's still follow-up work here to rip out support for old versions
of hg and to integrate the protocol with modern standards.
Some performance numbers (all on my 2016 MacBook Pro with a 2.6Ghz i7):
Mercurial mercurial/manifest.py
traditional blame
time: real 1.050 secs (user 0.990+0.000 sys 0.060+0.000)
build cache
time: real 5.900 secs (user 5.720+0.000 sys 0.110+0.000)
fastannotate
time: real 0.120 secs (user 0.100+0.000 sys 0.020+0.000)
Mercurial mercurial/localrepo.py
traditional blame
time: real 3.330 secs (user 3.220+0.000 sys 0.070+0.000)
build cache
time: real 30.610 secs (user 30.190+0.000 sys 0.230+0.000)
fastannotate
time: real 0.180 secs (user 0.160+0.000 sys 0.020+0.000)
mozilla-central dom/ipc/ContentParent.cpp
traditional blame
time: real 7.640 secs (user 7.210+0.000 sys 0.380+0.000)
build cache
time: real 98.650 secs (user 97.000+0.000 sys 0.950+0.000)
fastannotate
time: real 1.580 secs (user 1.340+0.000 sys 0.240+0.000)
mozilla-central dom/base/nsDocument.cpp
traditional blame
time: real 17.110 secs (user 16.490+0.000 sys 0.500+0.000)
build cache
time: real 399.750 secs (user 394.520+0.000 sys 2.610+0.000)
fastannotate
time: real 1.780 secs (user 1.530+0.000 sys 0.240+0.000)
So building the cache is expensive (but might be faster with xdiff
enabled), but the blame results are *way* faster.
Differential Revision: https://phab.mercurial-scm.org/D3994
$ cat >> $HGRCPATH << EOF
> [ui]
> ssh = $PYTHON "$TESTDIR/dummyssh"
> [extensions]
> fastannotate=
> [fastannotate]
> mainbranch=@
> EOF
$ HGMERGE=true; export HGMERGE
setup the server repo
$ hg init repo-server
$ cd repo-server
$ cat >> .hg/hgrc << EOF
> [fastannotate]
> server=1
> EOF
$ for i in 1 2 3 4; do
> echo $i >> a
> hg commit -A -m $i a
> done
$ [ -d .hg/fastannotate ]
[1]
$ hg bookmark @
$ cd ..
setup the local repo
$ hg clone 'ssh://user@dummy/repo-server' repo-local -q
$ cd repo-local
$ cat >> .hg/hgrc << EOF
> [fastannotate]
> client=1
> clientfetchthreshold=0
> EOF
$ [ -d .hg/fastannotate ]
[1]
$ hg fastannotate a --debug
running * (glob)
sending hello command
sending between command
remote: * (glob) (?)
remote: capabilities: * (glob)
remote: * (glob) (?)
sending protocaps command
fastannotate: requesting 1 files
sending getannotate command
fastannotate: writing 112 bytes to fastannotate/default/a.l (?)
fastannotate: server returned
fastannotate: writing 112 bytes to fastannotate/default/a.l (?)
fastannotate: writing 94 bytes to fastannotate/default/a.m
fastannotate: a: using fast path (resolved fctx: True)
0: 1
1: 2
2: 3
3: 4
the cache could be reused and no download is necessary
$ hg fastannotate a --debug
fastannotate: a: using fast path (resolved fctx: True)
0: 1
1: 2
2: 3
3: 4
if the client agrees where the head of the master branch is, no re-download
happens even if the client has more commits
$ echo 5 >> a
$ hg commit -m 5
$ hg bookmark -r 3 @ -f
$ hg fastannotate a --debug
0: 1
1: 2
2: 3
3: 4
4: 5
if the client has a different "@" (head of the master branch) and "@" is ahead
of the server, the server can detect things are unchanged and does not return
full contents (not that there is no "writing ... to fastannotate"), but the
client can also build things up on its own (causing diverge)
$ hg bookmark -r 4 @ -f
$ hg fastannotate a --debug
running * (glob)
sending hello command
sending between command
remote: * (glob) (?)
remote: capabilities: * (glob)
remote: * (glob) (?)
sending protocaps command
fastannotate: requesting 1 files
sending getannotate command
fastannotate: server returned
fastannotate: a: 1 new changesets in the main branch
0: 1
1: 2
2: 3
3: 4
4: 5
if the client has a different "@" which is behind the server. no download is
necessary
$ hg fastannotate a --debug --config fastannotate.mainbranch=2
fastannotate: a: using fast path (resolved fctx: True)
0: 1
1: 2
2: 3
3: 4
4: 5
define fastannotate on-disk paths
$ p1=.hg/fastannotate/default
$ p2=../repo-server/.hg/fastannotate/default
revert bookmark change so the client is behind the server
$ hg bookmark -r 2 @ -f
in the "fctx" mode with the "annotate" command, the client also downloads the
cache. but not in the (default) "fastannotate" mode.
$ rm $p1/a.l $p1/a.m
$ hg annotate a --debug | grep 'fastannotate: writing'
[1]
$ hg annotate a --config fastannotate.modes=fctx --debug | grep 'fastannotate: writing' | sort
fastannotate: writing 112 bytes to fastannotate/default/a.l
fastannotate: writing 94 bytes to fastannotate/default/a.m
the fastannotate cache (built server-side, downloaded client-side) in two repos
have the same content (because the client downloads from the server)
$ diff $p1/a.l $p2/a.l
$ diff $p1/a.m $p2/a.m
in the "fctx" mode, the client could also build the cache locally
$ hg annotate a --config fastannotate.modes=fctx --debug --config fastannotate.mainbranch=4 | grep fastannotate
fastannotate: requesting 1 files
fastannotate: server returned
fastannotate: a: 1 new changesets in the main branch
the server would rebuild broken cache automatically
$ cp $p2/a.m $p2/a.m.bak
$ echo BROKEN1 > $p1/a.m
$ echo BROKEN2 > $p2/a.m
$ hg fastannotate a --debug | grep 'fastannotate: writing' | sort
fastannotate: writing 112 bytes to fastannotate/default/a.l
fastannotate: writing 94 bytes to fastannotate/default/a.m
$ diff $p1/a.m $p2/a.m
$ diff $p2/a.m $p2/a.m.bak
use the "debugbuildannotatecache" command to build annotate cache
$ rm -rf $p1 $p2
$ hg --cwd ../repo-server debugbuildannotatecache a --debug
fastannotate: a: 4 new changesets in the main branch
$ hg --cwd ../repo-local debugbuildannotatecache a --debug
running * (glob)
sending hello command
sending between command
remote: * (glob) (?)
remote: capabilities: * (glob)
remote: * (glob) (?)
sending protocaps command
fastannotate: requesting 1 files
sending getannotate command
fastannotate: server returned
fastannotate: writing * (glob)
fastannotate: writing * (glob)
$ diff $p1/a.l $p2/a.l
$ diff $p1/a.m $p2/a.m
with the clientfetchthreshold config option, the client can build up the cache
without downloading from the server
$ rm -rf $p1
$ hg fastannotate a --debug --config fastannotate.clientfetchthreshold=10
fastannotate: a: 3 new changesets in the main branch
0: 1
1: 2
2: 3
3: 4
4: 5
if the fastannotate directory is not writable, the fctx mode still works
$ rm -rf $p1
$ touch $p1
$ hg annotate a --debug --traceback --config fastannotate.modes=fctx
fastannotate: a: cache broken and deleted
fastannotate: prefetch failed: * (glob)
fastannotate: a: cache broken and deleted
fastannotate: falling back to the vanilla annotate: * (glob)
0: 1
1: 2
2: 3
3: 4
4: 5
with serverbuildondemand=False, the server will not build anything
$ cat >> ../repo-server/.hg/hgrc <<EOF
> [fastannotate]
> serverbuildondemand=False
> EOF
$ rm -rf $p1 $p2
$ hg fastannotate a --debug | grep 'fastannotate: writing'
[1]