ARROW-6960: [R] Add lz4 and zstd to R PKGBUILD

[gnguy]

Addressing https://issues.apache.org/jira/browse/ARROW-6960 by adding lz4 and zstd, which was added in rtools via r-windows/rtools-packages#47

[github-actions]

Thanks for opening a pull request!

Could you open an issue for this pull request on JIRA?
https://issues.apache.org/jira/browse/ARROW

Then could you also rename pull request title in the following format?

ARROW-${JIRA_ID}: [${COMPONENT}] ${SUMMARY}

See also:

• Other pull requests
• Contribution Guidelines - How to contribute patches

[github-actions]

https://issues.apache.org/jira/browse/ARROW-6960

[nealrichardson]

This part seems good (the C++ part built fine on Appveyor; the failure seemed to be a flaky download: https://ci.appveyor.com/project/ApacheSoftwareFoundation/arrow/builds/28808032/job/e8t2eneqoavufqx5) but you'll also need to add these new libs to https://github.com/apache/arrow/blob/master/ci/windows-pkg-arrow-for-r.sh, otherwise the compression libraries won't be bundled.

[nealrichardson]

There's a pretty big backup on https://ci.appveyor.com/project/ApacheSoftwareFoundation/arrow/, lots of builds fighting for too few workers, so feel free to post a link to a passing build on your fork, when you get there.

Also, you can verify that the compression support is working by downloading the r\arrow_0.15.1.9000.zip artifact (the binary R package) from the Appveyor job and installing it locally (see https://ci.appveyor.com/project/ApacheSoftwareFoundation/arrow/builds/28797790/job/6l2ewckvujk48vtb/artifacts for example artifacts).

You could also add a unit test that codec_is_available("lz4") or some other exercise of the compression that only runs on Appveyor.

[nealrichardson]

Thanks! One small note about the test, but aside from that, looks good (pending CI)!

[nealrichardson]

Thanks for adding this. A few points:

• I think you could put this under test-compressed.R where there are other codec tests
• Change the test name (in test_that() to something like "Compression codecs are included in the Windows build" because that's what we're testing, not that codec_is_available works
• Wrap the assertions (or even the whole test_that()) in if (identical(Sys.getenv("APPVEYOR"), "True")) { ... } (i.e. the inverse of what testthat::skip_on_appveyor() does) because we're testing that that Windows build is including the right stuff. It's not so much a test of the code as of the build system.

[nealrichardson]

@gnguy I'm heading out on vacation and didn't want to leave you hanging on this so I just did the test change I suggested. Will merge when CI is green. Thanks again!

[nealrichardson]

@ursabot crossbow submit macos-r-autobrew

[ursabot]

AMD64 Conda Crossbow Submit (#77866) builder has been succeeded.

Revision: c4d7e96

Submitted crossbow builds: ursa-labs/crossbow @ ursabot-333

Task	Status
macos-r-autobrew

[nealrichardson]

Watching appveyor on https://ci.appveyor.com/project/nealrichardson/arrow/builds/28950140, which will finish hours before the ASF job will start.

[nealrichardson]

Appveyor passed here: https://ci.appveyor.com/project/nealrichardson/arrow/builds/28950516

Everything else was green. Merging now.

Thanks @gnguy !

[gnguy]

Awesome, thanks so much @nealrichardson!