@webmachinelearning/webnn-polyfill
v0.1.10
Published
WebNN API polyfill
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WebNN Polyfill
A JavaScript implementation of the Web Neural Network API.
Backends
The implementation of this webnn-polyfill is based on TensorFlow.js that supports the following 3 backends:
- TensorFlow.js CPU Backend, pure-JS backend for Node.js and the browser.
- TensorFlow.js WebGL Backend, WebGL backend for the browser.
- TensorFlow.js WASM Backend, WebAssembly backend for the browser.
Notes
- CPU backend is the only supported backend for Node.js.
- WASM backend does not support all the ops and some test failures are thus expected.
Usage
Import the packages
Via NPM
import '@webmachinelearning/webnn-polyfill';
Via a script tag
<script src="https://cdn.jsdelivr.net/npm/@webmachinelearning/webnn-polyfill/dist/webnn-polyfill.js"></script>
Set backend
WebNN Polyfill requires setting backend to enable TensorFlow.js.
- When running in Node.js, recommend using CPU backend for its higher numerical precision.
const backend = 'cpu';
const context = await navigator.ml.createContext();
const tf = context.tf;
await tf.setBackend(backend);
await tf.ready();
- When running in browsers, recommend using WebGL backend for better performance.
const backend = 'webgl'; // 'cpu' or 'wasm'
const context = await navigator.ml.createContext();
const tf = context.tf;
await tf.setBackend(backend);
await tf.ready();
- When running in browsers with WASM backend.
const backend = 'wasm';
const context = await navigator.ml.createContext();
const wasm = context.wasm;
// 1- Enforce use Wasm SIMD binary
wasm.setWasmPath(`${path}/tfjs-backend-wasm-simd.wasm`);
// 2- Use Wasm SIMD + Threads bianry if supported both SIMD and Threads
// 2.1- Configure by the path to the directory where the WASM binaries are located
// wasm.setWasmPaths(`https://unpkg.com/@tensorflow/tfjs-backend-wasm@${tf.version_core}/dist/`);
// or mapping from names of WASM binaries to custom full paths specifying the locations of those binaries
// wasm.setWasmPaths({
// 'tfjs-backend-wasm.wasm': 'renamed.wasm',
// 'tfjs-backend-wasm-simd.wasm': 'renamed-simd.wasm',
// 'tfjs-backend-wasm-threaded-simd.wasm': 'renamed-threaded-simd.wasm'
// });
wasm.setWasmPaths(${prefixOrFileMap});
// 2.2- Configure threads number manually, or it will use the number of logical CPU cores as the threads count by default
wasm.setThreadsCount(n); // n can be 1, 2, ...
const tf = context.tf;
await tf.setBackend(backend);
await tf.ready();
Please refer to the setPolyfillBackend()
usage in tests for concrete examples on how to best implement backend switching for your project.
Samples
Web Machine Learning Community Group provides various Samples (GitHub repo) that make use of the WebNN API. These samples fall back to the webnn-polyfill if the browser does not have a native implementation of the WebNN API available by default.
Build and Test
Setup
> git clone --recurse-submodules https://github.com/webmachinelearning/webnn-polyfill
> cd webnn-polyfill & npm install
Build
Development build
> npm run build
Production build
> npm run build-production
Test
Run tests in node.js.
> npm test
Run tests in web browser.
> npm start
Open the web browser and navigate to http://localhost:8080/test
Default backend is CPU backend, you could change to use WebGL backend by http://localhost:8080/test?backend=webgl
,
or use Wasm backend by http://localhost:8080/test?backend=wasm
Run only CTS tests in node.js.
> npm run test-cts
Run only CTS tests in web browser.
> npm start
Open the web browser and navigate to http://localhost:8080/test/cts.html
Other scripts
Build docs
> npm run build-docs
Lint
> npm run lint
Format
> npm run format
Start dev server
> npm run dev
Watch files
> npm run watch
License
This project is licensed under the Apache License Version 2.0.