/**
* JSON dispatch wrapper for [I{{ trait_name }}] implementations, called from the
* native trait bridge. Decodes each trait call's arguments, invokes the typed
* implementation (bridging suspend methods via runBlocking), and encodes the
* result as {"ok": ...} on success or {"err": "..."} on failure.
*
* Public because the generated `<Crate>Bridge` object declares public
* `external fun nativeRegister*` functions that take this type as a parameter;
* Kotlin forbids a public function from exposing an `internal` type. The native
* `external fun`s cannot be made `internal` without Kotlin name-mangling their
* JVM symbols and breaking JNI binding, so the dispatcher is the surface that
* opens up instead.
*/
class {{ trait_name }}JniDispatcher(private val impl: I{{ trait_name }}) {
private val mapper = jacksonObjectMapper()
.setPropertyNamingStrategy(com.fasterxml.jackson.databind.PropertyNamingStrategies.SNAKE_CASE)
/** JSON array of the Rust-side names of the methods this host provides. */
fun implementedMethods(): String =
mapper.writeValueAsString(
listOf(
{% for name in implemented %}
"{{ name }}",
{% endfor %}
),
)
@Suppress("UNUSED_PARAMETER", "CyclomaticComplexMethod")
fun dispatch(method: String, argsJson: String): String =
try {
val args = mapper.readTree(argsJson)
val result: Any? =
when (method) {
{% for m in methods %}
"{{ m.rust_name }}" -> {{ m.call_expr }}
{% endfor %}
{% if has_super_trait %}
"name" -> impl.name()
"version" -> impl.version()
"initialize" -> {
impl.initialize()
null
}
"shutdown" -> {
impl.shutdown()
null
}
{% endif %}
else -> throw IllegalArgumentException("unknown trait method: $method")
}
mapper.writeValueAsString(mapOf("ok" to result))
} catch (t: Throwable) {
mapper.writeValueAsString(mapOf("err" to (t.message ?: t.toString())))
}
}