Report crates.io metrics?

[epage]

cargo-info includes a lot of different metrics exposed via the crates.io API (so separate from the Index and Cargo.toml)

Looking at the list, some that might be useful include

• recent download count (popularity)
• last updated (give a feel for how active development is)

Unsure how we should handle third-party registries.

[Rustin170506]

Unsure how we should handle third-party registries.

1. Can we have some features only for creats.io?
2. What about the rate limitation? crates.io has very strict rate limits for those APIs.

[epage]

Can we have some features only for creats.io?

I wonder if we can rely on the status code if a registry doesn't support it. We could then document it and note that it is optional.

What about the rate limitation? crates.io has very strict rate limits for those APIs.

We'd likely need to hear from crates.io people for insight on user workflows mixed with rate limits. If nothing else, if we get rate limited, I'm assuming there is a relevant status code and we can skip it with a warning?

[Rustin170506]

I discussed it with the crates.io team last night, they thought it is OK to use the /api/v1/crates/:crate_id/:version API to get the download and update information. It wouldn't cause too much pressure on crates.io.

[Rustin170506]

I am working on this.