Mercurial > hg
view CONTRIBUTORS @ 25647:46a96dd4d976
revset: improves time complexity of 'roots(xxx)'
The canonical way of doing 'roots(X)' is 'X - children(X)'. This is what the
implementation used to be. However, computing children is expensive because it
is unbounded. Any changesets in the repository may be a children of '0' so you
have to look at all changesets in the repository to compute children(0).
Moreover the current revsets implementation for children is not lazy, leading to
bad performance when fetching the first result.
There is a more restricted algorithm to compute roots:
roots(X) = [r for r in X if not parents(r) & X]
This achieve the same result while only looking for parent/children relation in
the X set itself, making the algorithm 'O(len(X))' membership operation.
Another advantages is that it turns the check into a simple filter, preserving
all laziness property of the underlying revsets.
The speed is very significant and some laziness is restored.
-) revset without 'roots(...)' to compare to base line
0) before this change
1) after this change
revset #0: roots((tip~100::) - (tip~100::tip))
plain min last
-) 0.001082 0.000993 0.000790
0) 0.001366 0.001385 0.001339
1) 0.001257 92% 0.001028 74% 0.000821 61%
revset #1: roots((0::) - (0::tip))
plain min last
-) 0.134551 0.144682 0.068453
0) 0.161822 0.171786 0.157683
1) 0.137583 85% 0.146204 85% 0.070012 44%
revset #2: roots(tip~100:)
plain min first last
-) 0.000219 0.000225 0.000231 0.000229
0) 0.000513 0.000529 0.000507 0.000539
1) 0.000463 90% 0.000269 50% 0.000267 52% 0.000463 85%
revset #3: roots(:42)
plain min first last
-) 0.000119 0.000146 0.000146 0.000146
0) 0.000231 0.000254 0.000253 0.000260
1) 0.000216 93% 0.000186 73% 0.000184 72% 0.000244 93%
revset #4: roots(not public())
plain min first
-) 0.000478 0.000502 0.000504
0) 0.000611 0.000639 0.000634
1) 0.000604 0.000560 87% 0.000558
revset #5: roots((0:tip)::)
plain min max first last
-) 0.057795 0.004905 0.058260 0.004908 0.038812
0) 0.132845 0.118931 0.130306 0.114280 0.127742
1) 0.111659 84% 0.005023 4% 0.111658 85% 0.005022 4% 0.092490 72%
revset #6: roots(0::tip)
plain min max first last
-) 0.032971 0.033947 0.033460 0.032350 0.033125
0) 0.083671 0.081953 0.084074 0.080364 0.086069
1) 0.074720 89% 0.035547 43% 0.077025 91% 0.033729 41% 0.083197
revset #7: 42:68 and roots(42:tip)
plain min max first last
-) 0.006827 0.000251 0.006830 0.000254 0.006771
0) 0.000337 0.000353 0.000366 0.000350 0.000366
1) 0.000318 94% 0.000297 84% 0.000353 0.000293 83% 0.000351
revset #8: roots(0:tip)
plain min max first last
-) 0.002119 0.000145 0.000147 0.000147 0.000147
0) 0.047441 0.040660 0.045662 0.040284 0.043435
1) 0.038057 80% 0.000187 0% 0.034919 76% 0.000186 0% 0.035097 80%
revset #0: roots(:42 + tip~42:)
plain min max first last sort
-) 0.000321 0.000317 0.000319 0.000308 0.000369 0.000343
0) 0.000772 0.000751 0.000811 0.000750 0.000802 0.000783
1) 0.000632 81% 0.000369 49% 0.000617 76% 0.000358 47% 0.000601 74% 0.000642 81%
author | Pierre-Yves David <pierre-yves.david@fb.com> |
---|---|
date | Mon, 22 Jun 2015 10:19:12 -0700 |
parents | c29efd272395 |
children |
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[This file is here for historical purposes, all recent contributors should appear in the changelog directly] Andrea Arcangeli <andrea at suse.de> Thomas Arendsen Hein <thomas at intevation.de> Goffredo Baroncelli <kreijack at libero.it> Muli Ben-Yehuda <mulix at mulix.org> Mikael Berthe <mikael at lilotux.net> Benoit Boissinot <bboissin at gmail.com> Brendan Cully <brendan at kublai.com> Vincent Danjean <vdanjean.ml at free.fr> Jake Edge <jake at edge2.net> Michael Fetterman <michael.fetterman at intel.com> Edouard Gomez <ed.gomez at free.fr> Eric Hopper <hopper at omnifarious.org> Alecs King <alecsk at gmail.com> Volker Kleinfeld <Volker.Kleinfeld at gmx.de> Vadim Lebedev <vadim at mbdsys.com> Christopher Li <hg at chrisli.org> Chris Mason <mason at suse.com> Colin McMillen <mcmillen at cs.cmu.edu> Wojciech Milkowski <wmilkowski at interia.pl> Chad Netzer <chad.netzer at gmail.com> Bryan O'Sullivan <bos at serpentine.com> Vicent SeguĂ Pascual <vseguip at gmail.com> Sean Perry <shaleh at speakeasy.net> Nguyen Anh Quynh <aquynh at gmail.com> Ollivier Robert <roberto at keltia.freenix.fr> Alexander Schremmer <alex at alexanderweb.de> Arun Sharma <arun at sharma-home.net> Josef "Jeff" Sipek <jeffpc at optonline.net> Kevin Smith <yarcs at qualitycode.com> TK Soh <teekaysoh at yahoo.com> Radoslaw Szkodzinski <astralstorm at gorzow.mm.pl> Samuel Tardieu <sam at rfc1149.net> K Thananchayan <thananck at yahoo.com> Andrew Thompson <andrewkt at aktzero.com> Michael S. Tsirkin <mst at mellanox.co.il> Rafael Villar Burke <pachi at mmn-arquitectos.com> Tristan Wibberley <tristan at wibberley.org> Mark Williamson <mark.williamson at cl.cam.ac.uk>