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view tests/test-convert-p4.t @ 42743:8c9a6adec67a
rust-discovery: using the children cache in add_missing
The DAG range computation often needs to get back to very old
revisions, and turns out to be disproportionately long, given
that the end goal is to remove the descendents of the given
missing revisons from the undecided set.
The fast iteration capabilities available in the Rust case make
it possible to avoid the DAG range entirely, at the cost of
precomputing the children cache, and to simply iterate on
children of the given missing revisions.
This is a case where staying on the same side of the interface
between the two languages has clear benefits.
On discoveries with initial undecided sets
small enough to bypass sampling entirely, the total cost of
computing the children cache and the subsequent iteration
becomes better than the Python + C counterpart, which relies on
reachableroots2.
For example, on a repo with more than one million revisions with
an initial undecided set of 11 elements, we get these figures:
Rust version with simple iteration
addcommons: 57.287us
first undecided computation: 184.278334ms
first children cache computation: 131.056us
addmissings iteration: 42.766us
first addinfo total: 185.24 ms
Python + C version
first addcommons: 0.29 ms
addcommons 0.21 ms
first undecided computation 191.35 ms
addmissings 45.75 ms
first addinfo total: 237.77 ms
On discoveries with large undecided sets, the initial price paid
makes the first addinfo slower than the Python + C version,
but that's more than compensated by the gain in sampling and
subsequent iterations.
Here's an extreme example with an undecided set of a million revisions:
Rust version:
first undecided computation: 293.842629ms
first children cache computation: 407.911297ms
addmissings iteration: 34.312869ms
first addinfo total: 776.02 ms
taking initial sample
query 2: sampling time: 1318.38 ms
query 2; still undecided: 1005013, sample size is: 200
addmissings: 143.062us
Python + C version:
first undecided computation 298.13 ms
addmissings 80.13 ms
first addinfo total: 399.62 ms
taking initial sample
query 2: sampling time: 3957.23 ms
query 2; still undecided: 1005013, sample size is: 200
addmissings 52.88 ms
Differential Revision: https://phab.mercurial-scm.org/D6428
author | Georges Racinet <georges.racinet@octobus.net> |
---|---|
date | Tue, 16 Apr 2019 01:16:39 +0200 |
parents | 78ac8acfc4bd |
children |
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#require p4 $ echo "[extensions]" >> $HGRCPATH $ echo "convert = " >> $HGRCPATH create p4 depot $ P4ROOT=`pwd`/depot; export P4ROOT $ P4AUDIT=$P4ROOT/audit; export P4AUDIT $ P4JOURNAL=$P4ROOT/journal; export P4JOURNAL $ P4LOG=$P4ROOT/log; export P4LOG $ P4PORT=localhost:$HGPORT; export P4PORT $ P4DEBUG=1; export P4DEBUG start the p4 server $ [ ! -d $P4ROOT ] && mkdir $P4ROOT $ p4d -f -J off >$P4ROOT/stdout 2>$P4ROOT/stderr & $ echo $! >> $DAEMON_PIDS $ trap "echo stopping the p4 server ; p4 admin stop" EXIT $ # wait for the server to initialize $ while ! p4 ; do > sleep 1 > done >/dev/null 2>/dev/null create a client spec $ P4CLIENT=hg-p4-import; export P4CLIENT $ DEPOTPATH=//depot/test-mercurial-import/... $ p4 client -o | sed '/^View:/,$ d' >p4client $ echo View: >>p4client $ echo " $DEPOTPATH //$P4CLIENT/..." >>p4client $ p4 client -i <p4client Client hg-p4-import saved. populate the depot $ echo a > a $ mkdir b $ echo c > b/c $ p4 add a b/c //depot/test-mercurial-import/a#1 - opened for add //depot/test-mercurial-import/b/c#1 - opened for add $ p4 submit -d initial Submitting change 1. Locking 2 files ... add //depot/test-mercurial-import/a#1 add //depot/test-mercurial-import/b/c#1 Change 1 submitted. change some files $ p4 edit a //depot/test-mercurial-import/a#1 - opened for edit $ echo aa >> a $ p4 submit -d "change a" Submitting change 2. Locking 1 files ... edit //depot/test-mercurial-import/a#2 Change 2 submitted. $ p4 edit b/c //depot/test-mercurial-import/b/c#1 - opened for edit $ echo cc >> b/c $ p4 submit -d "change b/c" Submitting change 3. Locking 1 files ... edit //depot/test-mercurial-import/b/c#2 Change 3 submitted. convert $ hg convert -s p4 $DEPOTPATH dst initializing destination dst repository scanning source... reading p4 views collecting p4 changelists 1 initial 2 change a 3 change b/c sorting... converting... 2 initial 1 change a 0 change b/c $ hg -R dst log --template 'rev={rev} desc="{desc}" tags="{tags}" files="{files}"\n' rev=2 desc="change b/c" tags="tip" files="b/c" rev=1 desc="change a" tags="" files="a" rev=0 desc="initial" tags="" files="a b/c" change some files $ p4 edit a b/c //depot/test-mercurial-import/a#2 - opened for edit //depot/test-mercurial-import/b/c#2 - opened for edit $ echo aaa >> a $ echo ccc >> b/c $ p4 submit -d "change a b/c" Submitting change 4. Locking 2 files ... edit //depot/test-mercurial-import/a#3 edit //depot/test-mercurial-import/b/c#3 Change 4 submitted. convert again $ hg convert -s p4 $DEPOTPATH dst scanning source... reading p4 views collecting p4 changelists 4 change a b/c sorting... converting... 0 change a b/c $ hg -R dst log --template 'rev={rev} desc="{desc}" tags="{tags}" files="{files}"\n' rev=3 desc="change a b/c" tags="tip" files="a b/c" rev=2 desc="change b/c" tags="" files="b/c" rev=1 desc="change a" tags="" files="a" rev=0 desc="initial" tags="" files="a b/c" interesting names $ echo dddd > "d d" $ mkdir " e" $ echo fff >" e/ f" $ p4 add "d d" " e/ f" //depot/test-mercurial-import/d d#1 - opened for add //depot/test-mercurial-import/ e/ f#1 - opened for add $ p4 submit -d "add d e f" Submitting change 5. Locking 2 files ... add //depot/test-mercurial-import/ e/ f#1 add //depot/test-mercurial-import/d d#1 Change 5 submitted. convert again $ hg convert -s p4 $DEPOTPATH dst scanning source... reading p4 views collecting p4 changelists 5 add d e f sorting... converting... 0 add d e f $ hg -R dst log --template 'rev={rev} desc="{desc}" tags="{tags}" files="{files}"\n' rev=4 desc="add d e f" tags="tip" files=" e/ f d d" rev=3 desc="change a b/c" tags="" files="a b/c" rev=2 desc="change b/c" tags="" files="b/c" rev=1 desc="change a" tags="" files="a" rev=0 desc="initial" tags="" files="a b/c" empty commit message $ p4 edit a //depot/test-mercurial-import/a#3 - opened for edit $ echo aaaaa >> a $ p4 submit -d "" Submitting change 6. Locking 1 files ... edit //depot/test-mercurial-import/a#4 Change 6 submitted. $ hg convert -s p4 $DEPOTPATH dst scanning source... reading p4 views collecting p4 changelists 6 **empty changelist description** sorting... converting... 0 exit trap: stopping the p4 server