Feature request: customize the value of CURLOPT_MAXREDIRS on a per-call basis

[DilumAluthge]

It looks like CURLOPT_MAXREDIRS is currently hard-coded to 50:

Downloads.jl/src/Curl/Easy.jl

Line 51 in 43899e7

setopt(easy, CURLOPT_MAXREDIRS, 50)

This makes sense, since 50 is also the default for the command-line curl.

However, it would be nice if users could customize the value of CURLOPT_MAXREDIRS on a per-call basis. By "per-call basis", I mean that users could do something like this:

julia> resp_1 = request(url_1; maxredirs = 25)

julia> resp_2 = request(url_2; maxredirs = 100)

In this example, the value of maxredirs passed as a kwarg to the request function will only affect that individual call.

[StefanKarpinski]

Why would you need to change it?

[StefanKarpinski]

At a higher level, we could expose every single option that libcurl has. I don't want to do that, which is why it's possible to add an easy_hook to directly set arbitrary curl options.

[DilumAluthge]

which is why it's possible to add an easy_hook to directly set arbitrary curl options

That's probably what I should do. Do you have any example code for this?

[DilumAluthge]

From looking at the test suite, I'm guessing it'll be something like this:

import Downloads

easy_hook = (easy, info) -> begin
    timeout_seconds = 120
    timeout_milliseconds = round(Clong, timeout_seconds * 1_000)
    Downloads.Curl.setopt(easy, Downloads.Curl.CURLOPT_TIMEOUT_MS, timeout_milliseconds)
end
downloader = Downloads.Downloader()
downloader.easy_hook = easy_hook

output_tempfile = Downloads.download("https://julialang.org/"; downloader = downloader)
output_contents = read(output_tempfile, String)

[DilumAluthge]

I think that the ability to provide a custom easy_hookis exactly what I was looking for.