limit on number of packages as argument to cran_downloads

[adfi]

Hi,

I tried to do get download counts for 8000 packages and ran into a HTTP 414 (Request-URI Too Long). After some trial and error it seems the limit is at 905 packages, reproducable with following code:

cran_downloads(package = rep('cranlogs', 906))

I can split up the requests but it would be nicer to have that done by the package. Also the limit is not documented. Let me know if I'm doing something the package wasn't intended for.

[gaborcsardi]

Well, that's the URL length limit I guess, because the package names are sent in the URL. We could have a POST API, and then there is no limit.

[adfi]

So where does the change need to happen? In cranlogs.app?

[gaborcsardi]

Everywhere. Frankly, it is simpler to return all packages, if you want 8000, then you might as well get all of them. :)

[bschilder]

@gaborcsardi This could be done within cranlogs by submitting the list of packages in batches, right?

[bschilder]

Would need to know what the max batch size can be (ie at what point does the URI get too long, on average):

batch_size =1000
v <- rownames(utils::available.packages())
batches <- split(v, ceiling(seq_along(v)/batch_size))
     cran <- lapply(seq_len(length(batches)),
                           function(i){
                               b <- batches[[i]]
                               message(paste("Batch:",i,"/",length(batches)))
                               dt <-  cran <- cranlogs::cran_downloads(
                                   packages = b, 
                                   from = "1990-01-01", 
                                   to = Sys.Date()-1)   
                               return(dt)
                           }) |> 
            data.table::rbindlist(fill=TRUE) 

Should be an easy fix. Happy to make a PR.

[bschilder]

@adfi , I agree this should be handled internally by the package or at least documented to note the limitation.

[bschilder]

Done here @adfi : https://github.com/r-hub/cranlogs/pull/67