view CONTRIBUTORS @ 34279:53fb09c73ba8

revset: remove "small" argument from "_optimize"

`_optimize` calculates weights of subtrees. "small" affects some weight
calculation (either 1 or 0.5). The weights are now only useful in `and`
optimization where we might swap two arguments and use `andsmally`.

In the real world, it seems unlikely that revsets with weight of 0.5 or 1
matters the `and` order optimization. I think the important thing is to get
weights of expensive revsets right (ex. `contains`).

This patch removes the `small` argument to simplify the interface.

As for choosing between 0.5 vs 1, things returning a single revision
(`ancestor`, `string`) has a weight of 0.5. Things returning multiple
revisions returns 1. This could be sometimes useful in the `andsmally`
optimization, ex.

  (((:)-2) & expensive()) & ((1-2) & expensive())
    ^^^                       ^
   ^^^^^^^                   ^^^^^
  ^^^^^^^^^^^^^^^^^^^^^^^   ^^^^^^^^^^^^^^^^^^^^^
    weight=1                 weight=0.5

would have an `andsmally` optimization so `1-2` gets executed first, which
seems to be desirable.

Differential Revision: https://phab.mercurial-scm.org/D656

[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 Seguí 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>