[BridgeJS] Pass String parameters unretained by default

Abierto

#677 abierto el 26/2/2026 1 comentario 0 reacciones 0 asignados Ver en GitHub

Nadie ha tomado este issue todavía.

Evaluación

Dificultad: 5/5
Tiempo estimado: Más de una semana
Aptitud para principiantes: 28/100

Tipo de issue: Refactorización
Claridad: Bastante claro
Estado de actividad: Estancado
Stack tecnológico: javascript, swift, wasm
Área: api, performance, web-dev

Línea de trabajo

Start by tracing _swift_js_make_js_string, bridgeJSLowerParameter, and the generated bjs_hello thunk shown in the issue, then inspect how JSString references are represented. Done means ordinary String parameters cross the bridge without a JS memory-store retain/release cycle while JSString still supports caller-controlled by-reference reuse; verify the impact against the ElementaryUI performance benchmarks.

Escrito por el modelo de indexación a partir del texto del issue.

Descripción

When calling a JS function through BridgeJS with String parameters, every String is

lowered by calling _swift_js_make_js_string
which decodes and retains in JS object store (new entry, new ref = 1)
the object store ref is passed as wasm parameter
the JS thunk immediately get the object and releases (count--, remove from store)

this is very wasteful, and makes retain the number one bottleneck in current ElementaryUI performance benchmarks.

Example:

@JSFunction func hello(_ v: String) throws

// generates
func _$hello(_ v: String) throws(JSException) -> Void {
    let vValue = v.bridgeJSLowerParameter()
    bjs_hello(vValue)
    if let error = _swift_js_take_exception() {
        throw error
    }
}

function bjs_hello(v) {
    try {
        const vObject = swift.memory.getObject(v);
        swift.memory.release(v);
        imports.hello(vObject);
    } catch (error) {
        setException(error);
    }
}

I suggest:

passing String always "in-line" (ie: as address + length) without retaining in the JS memory store
still support JSString by-ref to control Swift caller caching (ie: retain once and use same ref multiple times)

Lenguaje dominante: Swift
Estrellas: 986
Forks: 76
Merge medio: 21 h 11 min
PR fusionados (30 d): 4