alef 0.23.39

Opinionated polyglot binding generator for Rust libraries
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31

/// Drive `{{ service_pascal }}::{{ ep_pascal }}` from Java/Kotlin.
///
/// Parameters:
///   owner_handle: jlong returned by the service constructor entry point
///   ep params: as defined in the service entrypoint signature
#[no_mangle]
pub extern "system" fn {{ symbol }}(
    _env: EnvUnowned,
    _class: JClass,
    owner_handle: jlong{{ params_decl }}
) -> jlong {
    // Validate owner handle
    if owner_handle == 0 {
        return 0; // Error: null pointer
    }

    // SAFETY: owner_handle was allocated by the constructor and is valid
    // until freed. The caller is responsible for not using after free.
    unsafe {
        let owner_opaque = owner_handle as *mut {{ opaque_name }};
        let owner_ref = &mut (*owner_opaque).inner;
        let rt = match tokio::runtime::Runtime::new() {
            Ok(runtime) => runtime,
            Err(_) => return 0, // Error: failed to create tokio runtime
        };

        let _result = rt.block_on(owner_ref.{{ ep_method }}({{ call_args }}));
        // Finalize returns the transformed result; caller decides what to do with it
        owner_handle
    }
}