WASM regression: Usage of std::time::Instant

[fusetim]

While creating my custom node based on rust-libp2p, I rediscovered some uses of std::time::Instant in the Gossipsub and Kadmelia modules. As previously done by the PR #1071 (issue #900), the remaining std::time::Instant should again be replaced with wasm_timer::Instant to allow Wasm compatibility.

The spotted ones:

• rust-libp2p/protocols/gossipsub/src/time_cache.rs

  Line 29 in ee11922

  use std::time::{Duration, Instant};

• rust-libp2p/protocols/gossipsub/src/peer_score.rs

  Line 30 in ee11922

  use std::time::{Duration, Instant};

• rust-libp2p/protocols/mdns/src/behaviour.rs

  Line 45 in ee11922

  time::{Duration, Instant},

• rust-libp2p/protocols/kad/src/kbucket.rs

  Line 80 in ee11922

  use std::time::{Duration, Instant};

[fusetim]

We will need an update of wasm-timer, I think, but otherwise nothing seems to break and in every case, the use of Instant was inside the crate only.

Compiling libp2p-gossipsub v0.32.0 (/mnt/storagedisk/Developing/IntelliJ/rust-libp2p/protocols/gossipsub)
error[E0599]: no method named `checked_add` found for struct `wasm_timer::Instant` in the current scope
   --> /mnt/storagedisk/Developing/IntelliJ/rust-libp2p/protocols/gossipsub/src/peer_score.rs:848:34
    |
848 | ...                   .checked_add(topic_params.mesh_message_deliveries_window)
    |                        ^^^^^^^^^^^ method not found in `wasm_timer::Instant`

error: aborting due to previous error

For more information about this error, try `rustc --explain E0599`.
error: could not compile `libp2p-gossipsub

EDIT: And here is the changes needed: tomaka/wasm-timer#17

[fusetim]

Fixed by #2245.

However, I am still worried about this import in Kadmelia in "master" (f701b24 at the time).

rust-libp2p/protocols/kad/src/kbucket.rs

Line 80 in f701b24

use std::time::{Duration, Instant};

rust-libp2p/protocols/kad/src/kbucket.rs

Line 721 in f701b24

let elapsed = Instant::now() - Duration::from_secs(1);

I might be missing something, but it seems to me, that KAD should be WASM-compatible, and the other inner modules seems to use a correct instant::Intant import. May @wngr could enlighten this ?

[wngr]

From what I see this is only used in a test, that's why I didn't change it. Should have changed the import scope, though.

[fusetim]

Oh you're right, I missed the #[test], the issue can be closed now. Thank you for your time 👍