tf.LayersModel.save fails in a worker as window object is absent

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TensorFlow.js version

1.13

Browser version

Chrome 79

Describe the problem

tf.LayersModel.save("indexeddb://my-model-1") does not work in a web worker as window object is not found. It is due https://github.com/tensorflow/tfjs/blob/master/tfjs-core/src/io/indexed_db.ts#L60 line

ReferenceError: window is not defined
    at sp (indexed_db.ts:60)
    at new t (indexed_db.ts:89)
    at cp (indexed_db.ts:242)
    at router_registry.ts:96
    at Array.forEach (<anonymous>)
    at Function.t.getHandlers (router_registry.ts:95)
    at Function.t.getSaveHandlers (router_registry.ts:71)
    at Object.getSaveHandlers (router_registry.ts:110)
    at e.<anonymous> (training.ts:1814)
    at common.ts:14

Code to reproduce the bug / link to feature request

Simply try to save a model in a worker. You can try the below example in a worker,

worker.js

const model = tf.sequential(
    {layers: [tf.layers.dense({units: 1, inputShape: [3]})]});
console.log('Prediction from original model:');
model.predict(tf.ones([1, 3])).print();

const saveResults = await model.save('indexeddb://my-model-1');

main-thread.js

const w = new Worker("worker.js");
...

const loadedModel = await tf.loadLayersModel('indexeddb://my-model-1');
console.log('Prediction from loaded model:');
loadedModel.predict(tf.ones([1, 3])).print();

[paulkre]

I still have this issue in version 2.0.0. I’m using workerize-loader in a project bootstrapped with create-react-app.

[Josef-Haupt]

As of Version 1.7.0 this issues still existed for me.

0.worker.js:106656 Uncaught (in promise) ReferenceError: window is not defined
    at Ef (0.worker.js:106656)
    at new t (0.worker.js:106656)
    at kf (0.worker.js:106656)
    at 0.worker.js:106656
    at Array.forEach (<anonymous>)
    at Function.t.getHandlers (0.worker.js:106656)
    at Function.t.getSaveHandlers (0.worker.js:106656)
    at Object.getSaveHandlers (0.worker.js:106656)
    at t.<anonymous> (0.worker.js:107602)
    at 0.worker.js:107602

If anybody else still has this problem, this worked for me:

I created a custom IOHandler, which is basically a copy of the existing BrowserIndexedDB class and I updated the getIndexedDBFactory function the handler uses like so:

function getIndexedDBFactory(): IDBFactory {
    if (!env().getBool('IS_BROWSER')) {
        // TODO(cais): Add more info about what IOHandler subtypes are available.
        //   Maybe point to a doc page on the web and/or automatically determine
        //   the available IOHandlers and print them in the error message.
        throw new Error(
            'Failed to obtain IndexedDB factory because the current environment' +
            'is not a web browser.');
    }
    // tslint:disable-next-line:no-any
    let theWindow;
    try {
        theWindow = window;
    }
    catch {
        theWindow = self;
    }
    const factory = theWindow.indexedDB || theWindow.mozIndexedDB ||
        theWindow.webkitIndexedDB || theWindow.msIndexedDB ||
        theWindow.shimIndexedDB;
    if (factory == null) {
        throw new Error(
            'The current browser does not appear to support IndexedDB.');
    }
    return factory;
}

Usage:

//saveurl without the indexeddb:// scheme
model.save(new IDBWorkerSaveHandler(saveUrl))