[Rd] Duplicated mirrors on available packages

[Colin Gillespie]

Hi

When there are duplicated repos, available.packages() takes
significantly longer to run.

For example

mirror = "https://cloud.r-project.org/"
system.time(available.packages(repos = mirror))
#   user  system elapsed
# 1.054   0.031   1.245
system.time(available.packages(repos = c(mirror, mirror)))
#   user  system elapsed
# 22.389   0.037  22.429

Best wishes,

Colin


> sessionInfo()
R version 4.2.0 (2022-04-22)
Platform: x86_64-pc-linux-gnu (64-bit)
Running under: Ubuntu 22.04.1 LTS

Matrix products: default
BLAS:   /usr/lib/x86_64-linux-gnu/openblas-pthread/libblas.so.3
LAPACK: /usr/lib/x86_64-linux-gnu/openblas-pthread/libopenblasp-r0.3.20.so

locale:
 [1] LC_CTYPE=en_GB.UTF-8       LC_NUMERIC=C
 [3] LC_TIME=en_GB.UTF-8        LC_COLLATE=en_GB.UTF-8
 [5] LC_MONETARY=en_GB.UTF-8    LC_MESSAGES=en_GB.UTF-8
 [7] LC_PAPER=en_GB.UTF-8       LC_NAME=C
 [9] LC_ADDRESS=C               LC_TELEPHONE=C
[11] LC_MEASUREMENT=en_GB.UTF-8 LC_IDENTIFICATION=C

attached base packages:
[1] stats     graphics  grDevices utils     datasets  methods   base

loaded via a namespace (and not attached):
[1] compiler_4.2.0 tools_4.2.0


Dr Colin Gillespie
https://twitter.com/csgillespie