how to run libp2p in the browser

[fgimenez]

Hello everyone, I have a question about a use case in which my team is planning to use libp2p, not sure if this is the right place to ask it (I didn't create an issue bc I'm not sure there's actually a problem), please let me know where to do it if not.

We are building a decentralized private computing network and we have started integrating libp2p to implement the networking layer. Some of the nodes are going to run on browsers and we would like to use the same code we use for regular nodes compiled to wasm. But the initial tests are giving us problems, we get a lot of issues related to timers, like this one:

Uncaught (in promise) TypeError: Illegal invocation                                                                                                                                           
    at __wbg_clearTimeout_5b4145302d77e5f3 (app.js:921:128)                                                                                                                                   
    at gloo_timers::callback::clear_timeout::he3ba6cd2af4169c5 (504de782943406928503.module.wasm:0x602c2c)                                                                                    
    at <gloo_timers::callback::Timeout as core::ops::drop::Drop>::drop::h8acab6ff95da9e30 (504de782943406928503.module.wasm:0x5b0f89)                                                         
    at core::ptr::drop_in_place<gloo_timers::callback::Timeout>::ha8c67498ae8bdbd9 (504de782943406928503.module.wasm:0x5fc61a)                                                                
    at core::ptr::drop_in_place<gloo_timers::future::TimeoutFuture>::h6b5b1c7dd8b208d5 (504de782943406928503.module.wasm:0x5fc58d)                                                            
    at core::ptr::drop_in_place<alloc::boxed::Box<gloo_timers::future::TimeoutFuture>>::h02b74368ff432dac (504de782943406928503.module.wasm:0x5fac58)                                         
    at <send_wrapper::SendWrapper<T> as core::ops::drop::Drop>::drop::h37d540aba2b1854b (504de782943406928503.module.wasm:0x55b01d)                                                           
    at core::ptr::drop_in_place<send_wrapper::SendWrapper<gloo_timers::future::TimeoutFuture>>::hd6e1468839135512 (504de782943406928503.module.wasm:0x614555)                                 
    at core::ptr::drop_in_place<futures_timer::wasm::Delay>::hb662a28372717eda (504de782943406928503.module.wasm:0x614521)                                                                    
    at core::ptr::drop_in_place<libp2p_ping::handler::Handler>::h1674f59f62d20874 (504de782943406928503.module.wasm:0x5aa5e6)                                                                 

This seems to be related to the usage of futures_timer::Delay and instant::Instant in libp2p, replacing them with the wasm_timer equivalents these errors are fixed. There are other errors related to timeouts and instant.now in other crates, but again replacing with wasm_timer equivalents all is fixed.

I’ve seen that in this PR #2320 wasm-timer support was removed and as I understand it all should be working fine without it. So the questions:

• Is there any way to have swarm configured with a simple behaviour (just ping) running on a browser and connecting with a desktop client using websockets as the transport without modifying the current code? Is there any example?
• If not, is it ok to enable wasm_timer just for the wasm32-unknown-unknown target?

Thanks!

[thomaseizinger]

Are you compiling your code with the wasm-bindgen feature? That may be necessary.

The state of wasm is kind of messy and it bothers me that it is not easy to make it work out of the box.

Any suggestions welcome, we definitely want to support running in wasm!

[fgimenez]

Are you compiling your code with the wasm-bindgen feature? That may be necessary.

Hi @thomaseizinger thanks a lot for your response, nope, I wasn't using the wasm-bindgen feature, running with it enabled all goes perfectly fine!! 🎉

Any suggestions welcome, we definitely want to support running in wasm!

Awesome, thanks! we will probably have more questions down the road