view CONTRIBUTORS @ 49579:15a89b722937 stable

tags-fnode-cache: do not repeatedly open the filelog in a loop

While getting multiple hgtagsfnodecache entries, we were opening (and closing)
the `.hgtags` filelog for each iteration. The meant repeatedly reading and
parsing the version same information from disk. A quite costly operation.

We no longer do this, leading to a sizable improvement in `hg debugupdatecache`
run for an already warm repositories.

### data-env-vars.name           = mercurial-2018-08-01-zstd-sparse-revlog
  # benchmark.name               = debug-update-cache
  # benchmark.variants.pre-state = warm
before:  1.711778 seconds
after:   0.213229 seconds  (-87.54%)
  # data-env-vars.name           = pypy-2018-08-01-zstd-sparse-revlog
before:  4.010817 seconds
after:   0.381141 seconds  (-90.50%)
  # data-env-vars.name           = netbeans-2018-08-01-zstd-sparse-revlog
before: 13.574141
after:   1.023007 seconds  (-92.46%)
  # data-env-vars.name           = mozilla-central-2018-08-01-zstd-sparse-revlog
before: 18.884656
after:   1.465735 seconds  (-92.24%)
  # data-env-vars.name           = mozilla-try-2019-02-18-zstd-sparse-revlog
before: 88.924823
after:   6.511771 seconds  (-92.68%)

[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>