[tlbuild] zstd as package compressor

[Norbert Preining]

Hi Henri,

> installation in nytprof.  The results are available here:

Thanks.

> looks like by far the most time is spent in TLUtils::download_file.  The

Indeed,

# spent 16678s within TeXLive::TLUtils::CORE:system which was called 21993 times, avg 758ms/call:
# 9151 times (220s+0s) by TeXLive::TLUtils::system_pipe at line 661, avg 24.0ms/call
# 9150 times (37.4s+0s) by TeXLive::TLUtils::untar at line 2371, avg 4.09ms/call
# 3681 times (16419s+0s) by TeXLive::TLUtils::_download_file_program at line 2848, avg 4.46s/call
#    5 times (13.6ms+0s) by TeXLive::TLUtils::setup_system_one at line 2584, avg 2.73ms/call
#    3 times (1.05s+0s) by TeXLive::TLUtils::wsystem at line 596, avg 351ms/call
#    3 times (491ms+0s) by TeXLive::TLUtils::_do_postaction_script at line 1762, avg 164ms/call

Yes, downloading is the biggest problem. I have already started thinking
about async downloading, but this is a big can of worms which needs a
lot of restructuring of the current code ...

Best

Norbert

--
PREINING Norbert                              https://www.preining.info
Accelia Inc. + IFMGA ProGuide + TU Wien + JAIST + TeX Live + Debian Dev
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