Dear R-devel, I read with interest the recent blog post on how R will have parallel downloads, on blog.r-project.org (https://blog.r-project.org/2024/12/02/faster-downloads/index.html). Thanks Tomas!
The blog mentions that one of the areas where this will be observed is while installing them (which I did!). However, I noticed they might be downloaded multiple times: If one interrupts the install.packages (via Ctrl+C), or it fails due to some system dependency missing and I fix that on a different terminal session, or the internet connection is cut and I try again. One possible way to make installations/downloads faster and also reduce the bandwidth of repositories (and its mirrors) would be to check if they need to be downloaded (again). PACKAGES file on <repo>/src/contrib includes the MD5sum field that could be used to check packages on the local folder (But it might be faster to first check if any file exists there for the same package). In short, I propose: 1) Checking before downloading packages their existence on the destdir directory used by install.packages. 2) I suppose the most common scenario is to use install.packages with the default destdir parameter (NULL). If 1) is implemented it might be useful to keep the temporary directory common for a single R session. I would appreciate feedback on these ideas. Best, Lluís Revilla PD: New users encountering download & installation issues often keep seeing the progress bar (and in the future "trying URL 'https://...";) of the same packages. There are some ways to prevent/avoid repeated downloads, such as, using the system library dependency resolver, or having local mirrors. But they are not easy/available for new useRs, and sometimes they are difficult to avoid (like having a reliable internet connection). ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel
