wasmtime / Issue #2728 Fetch context data from `Caller` i... · git-wasmtime

Stream: git-wasmtime

Topic: wasmtime / Issue #2728 Fetch context data from `Caller` i...

Wasmtime GitHub notifications bot (Mar 15 2021 at 17:32):

Hi there, I'm using your Rust implementation.

I'm having hard times trying to pass a structure reference from the host (before entering the wasm) to a host function (called from the wasm).

The idea is to be able to fetch a reference to the data once I'm in the host function callback (actually a solution can be pass the data as a serialized byte array, but that option has been excluded for performance reasons).

Is there a way to attach a reference to my structure to the Caller structure that I receive in the host function?

I think that the issue has already being partially covered by #2491 (using lambdas) . But I was wandering if some other alternative method is available.

Thank you so much for your awesome work

Wasmtime GitHub notifications bot (Mar 15 2021 at 17:50):

fitzgen commented on Issue #2728:

The next release of wasmtime will let you configure Store-specific context data, and you can get the Store from a Caller:

https://github.com/bytecodealliance/wasmtime/blob/main/crates/wasmtime/src/store.rs#L216-L242

https://docs.rs/wasmtime/0.24.0/wasmtime/struct.Caller.html#method.store

Wasmtime GitHub notifications bot (Mar 16 2021 at 06:12):

davxy commented on Issue #2728:

Awesome!!!

Just to know how to move with my project (i.e. wait for the release or make a temporary hack). When do you think that the new version will be published on crates.io?
No pressure :-)

Thanks a lot

Wasmtime GitHub notifications bot (Mar 16 2021 at 06:24):

davxy edited Issue #2728:

Hi there, I'm using your Rust implementation.

I'm having hard times trying to pass a structure reference from the host (before entering the wasm) to a host function (called from the wasm).

The idea is to be able to fetch a reference to the data once I'm in the host function callback (actually a solution can be pass the data as a serialized byte array, but that option has been excluded for performance reasons).

Is there a way to attach a reference to my structure to the Caller structure that I receive in the host function?

I think that the issue has already being partially covered by #2491 (using lambdas) . But I was wandering if some other alternative method is available.

Thank you so much for your awesome work

Wasmtime GitHub notifications bot (Mar 16 2021 at 16:54):

fitzgen commented on Issue #2728:

I'll double check with the team to see if there's anything we need to finish up first before we can cut a new release.

In the meantime, you can add this to your Cargo.toml:
[patch.crates-io]
wasmtime = { git = "https://github.com/bytecodealliance/wasmtime.git", branch = "main" }
# And do the same for any other wasmtime crates you're using that need to be
# the same version, eg `wasmtime-wasi`

Wasmtime GitHub notifications bot (Mar 16 2021 at 20:29):

fitzgen commented on Issue #2728:

wasmtime 0.25.0 is now published on crates.io: https://crates.io/crates/wasmtime/0.25.0

Wasmtime GitHub notifications bot (Mar 16 2021 at 20:29):

fitzgen closed Issue #2728:

Hi there, I'm using your Rust implementation.

I'm having hard times trying to pass a structure reference from the host (before entering the wasm) to a host function (called from the wasm).

The idea is to be able to fetch a reference to the data once I'm in the host function callback (actually a solution can be pass the data as a serialized byte array, but that option has been excluded for performance reasons).

Is there a way to attach a reference to my structure to the Caller structure that I receive in the host function?

I think that the issue has already being partially covered by #2491 (using lambdas) . But I was wandering if some other alternative method is available.

Thank you so much for your awesome work

Last updated: Dec 23 2024 at 12:05 UTC