LoRaWAN-Signal-Mapping/client_src/js/WorkerWrapper.mjs

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"use strict";
import Config from './ClientConfig.mjs';
class WorkerWrapper {
constructor() {
this.worker = new Worker("worker.js"); // We could pass { type: "module" } as the 2nd argument here to allow Rollup code splitting to function as normal, but it's not supported by browsers yet
}
/**
* Sets up the Web Worker that does the TensorFlow prediction.
* Using a web worker avoids hanging the main thread.
* @return {Promise} A Promise that resolves when setup is complete.
*/
setup(map_bounds, index) {
// Arrow functions inherit the parent scope, including the "this"
// special variable.
return new Promise((resolve, reject) => {
// Attach the listener first
this.worker.addEventListener("message", (event) => {
if(event.data.event !== "setup-complete") {
reject(`Error: AIWorker responded with event ${event.data.event}, but 'setup-complete' was expected.`, event.data);
return;
}
resolve();
}, { once: true });
// Ask the web worker to set itself up
this.worker.postMessage({
event: "setup",
setup_info: {
bounds: map_bounds,
index,
Config
}
});
})
}
/**
* Uses the Web Worker to predict a row of signal strength values.
* @param {number} latitude The latitude for which predictions should be made.
* @return {Promise<number[]>} A Promise returning the array of predictions calculated by the web worker.
*/
predict_row(latitude) {
return new Promise((resolve, reject) => {
// Attach the event listener....
this.worker.addEventListener("message", (event) => {
if(event.data.event !== "result") {
reject(`Error: AIWorker responded with event ${event.data.event}, but 'result' was expected.`, event.data);
return;
}
resolve(event.data);
}, { once: true });
// ....and send the request
this.worker.postMessage({
event: "predict-row",
latitude
});
});
}
end() {
this.worker.postMessage({
event: "end"
})
}
}
export default WorkerWrapper;