wasmtime/runtime/component/bindgen_examples/
_7_async.rs

1bindgen!({
2    inline: r#"
3package example:resource-async;
4
5interface logging {
6    enum level {
7        debug,
8        info,
9        warn,
10        error,
11    }
12
13    resource logger {
14        constructor(max-level: level);
15        get-max-level: func() -> level;
16        set-max-level: func(level: level);
17        /// May block if the host's log buffer is full (i.e. backpressure).
18        log: async func(level: level, msg: string);
19    }
20}
21
22world app {
23    import logging;
24    /// Because `logging.logger.log` is async, `run` must also be async; otherwise,
25    /// a trap will occur at runtime if `run` calls `log` and it blocks.
26    export run: async func();
27}
28"#,
29
30    imports: {
31
32        // This is the notation that's used to flag individual methods:
33        //
34        // "example:resource-async/logging.[constructor]logger": trappable,
35        // "example:resource-async/logging.[method]logger.get-max-level": trappable,
36        // "example:resource-async/logging.[method]logger.set-max-level": trappable,
37        // "example:resource-async/logging.[method]logger.log": trappable,
38        //
39        // Note that if one resource method specifies a flag, the remaining resource methods
40        // are no longer covered by e.g. `default: trappable`, and must be flagged
41        // individually.
42        default: trappable,
43    },
44
45    with: {
46         // Specify that our host resource is going to point to the `MyLogger`
47        // which is defined just below this macro.
48        "example:resource-async/logging.logger": MyLogger,
49    },
50});
51
52/// A sample host-defined type which contains arbitrary host-defined data.
53///
54/// In this case this is relatively simple but there's no restrictions on what
55/// this type can hold other than that it must be `'static + Send`.
56pub struct MyLogger {
57    pub max_level: example::resource_async::logging::Level,
58}
wasmtime/runtime/component/bindgen_examples/_7_async.rs

wasmtime/runtime/component/bindgen_examples/
_7_async.rs
