Method __init__

src/urllib3/contrib/emscripten/fetch.py:201–227

(self)

class _StreamingFetcher:
    def __init__(self) -> None:
        # make web-worker and data buffer on startup
        self.streaming_ready = False
        streaming_worker_code = (
            files(__package__)
            .joinpath("emscripten_fetch_worker.js")
            .read_text(encoding="utf-8")
        )
        js_data_blob = js.Blob.new(
            to_js([streaming_worker_code], create_pyproxies=False),
            _obj_from_dict({"type": "application/javascript"}),
        )

        def promise_resolver(js_resolve_fn: JsProxy, js_reject_fn: JsProxy) -> None:
            def onMsg(e: JsProxy) -> None:
                self.streaming_ready = True
                js_resolve_fn(e)

            def onErr(e: JsProxy) -> None:
                js_reject_fn(e)  # Defensive: never happens in ci

            self.js_worker.onmessage = onMsg
            self.js_worker.onerror = onErr

        js_data_url = js.URL.createObjectURL(js_data_blob)
        self.js_worker = js.globalThis.Worker.new(js_data_url)
        self.js_worker_ready_promise = js.globalThis.Promise.new(promise_resolver)

    def send(self, request: EmscriptenRequest) -> EmscriptenResponse:
        headers = {