Edge Sample

A sample project to run a serverless application in the Cloudflare Edge network using WebAssembly

On receiving a POST request with an array of numeric pairs (x, y) (training data) and an array of values x to predict for, it calculates and returns the prediction using simple linear regression on that data.

Format of input body:

{
    "input":[  // Input data to use to calculate the linear regression coeficients
        {"x":1,"y":1},
        {"x":2,"y":2}
    ],
    "predict":[1,2]  // Array of values (x) for which we want to predict a result (y) using the linear regression coeficients calculated from the input 
}

Example of requests:

$  wrangler preview post '{"input":[{"x":1,"y":1},{"x":2,"y":2}],"predict":[1,2]}' 
Your worker responded with: {"coeficient":1,"intercept":0,"accuracy":0,"y_predictions":[1,2]}

See the bottom of this file for an example with more data.

Based on a template for kick starting a Cloudflare worker project using wasm-pack.

Linear regression code based on this blog post

Requirements

Install wasm-pack
Install wrangler via cargo install wrangler

Useful Commands

Build: wrangler build
Preview in Chrome: wrangler preview
Run tests: wasm-pack test --node
Test in headless Safari: wasm-pack test --headless --safari

Included dependencies

wasm-bindgen for communicating between WebAssembly and JavaScript.
console_error_panic_hook for logging panic messages to the developer console.
wee_alloc, an allocator optimized for small code size.

License

This code is open source software licensed under the Apache 2.0 License.

Example for testing with more data

This is just a bigger sample to test performance. It runs under 5ms in Cloudflare workers so it can be used with the 'free' Cloudflare plan

Input:

wrangler preview post '{"input":[{"x":5.1,"y":3.5},{"x":4.9,"y":3.0},{"x":4.7,"y":3.2},{"x":4.6,"y":3.1},{"x":5.0,"y":3.6},{"x":5.4,"y":3.9},{"x":4.6,"y":3.4},{"x":5.0,"y":3.4},{"x":4.4,"y":2.9},{"x":4.9,"y":3.1},{"x":5.4,"y":3.7},{"x":4.8,"y":3.4},{"x":4.8,"y":3.0},{"x":4.3,"y":3.0},{"x":5.8,"y":4.0},{"x":5.7,"y":4.4},{"x":5.4,"y":3.9},{"x":5.1,"y":3.5},{"x":5.7,"y":3.8},{"x":5.1,"y":3.8},{"x":5.4,"y":3.4},{"x":5.1,"y":3.7},{"x":4.6,"y":3.6},{"x":5.1,"y":3.3},{"x":4.8,"y":3.4},{"x":5.0,"y":3.0},{"x":5.0,"y":3.4},{"x":5.2,"y":3.5},{"x":5.2,"y":3.4},{"x":4.7,"y":3.2},{"x":4.8,"y":3.1},{"x":5.4,"y":3.4},{"x":5.2,"y":4.1},{"x":5.5,"y":4.2},{"x":4.9,"y":3.1},{"x":5.0,"y":3.2},{"x":5.5,"y":3.5},{"x":4.9,"y":3.1},{"x":4.4,"y":3.0},{"x":5.1,"y":3.4},{"x":5.0,"y":3.5},{"x":4.5,"y":2.3},{"x":4.4,"y":3.2},{"x":5.0,"y":3.5},{"x":5.1,"y":3.8},{"x":4.8,"y":3.0},{"x":5.1,"y":3.8},{"x":4.6,"y":3.2},{"x":5.3,"y":3.7},{"x":5.0,"y":3.3},{"x":7.0,"y":3.2},{"x":6.4,"y":3.2},{"x":6.9,"y":3.1},{"x":5.5,"y":2.3},{"x":6.5,"y":2.8},{"x":5.7,"y":2.8},{"x":6.3,"y":3.3},{"x":4.9,"y":2.4},{"x":6.6,"y":2.9},{"x":5.2,"y":2.7},{"x":5.0,"y":2.0},{"x":5.9,"y":3.0},{"x":6.0,"y":2.2},{"x":6.1,"y":2.9},{"x":5.6,"y":2.9},{"x":6.7,"y":3.1},{"x":5.6,"y":3.0},{"x":5.8,"y":2.7},{"x":6.2,"y":2.2},{"x":5.6,"y":2.5},{"x":5.9,"y":3.2},{"x":6.1,"y":2.8},{"x":6.3,"y":2.5},{"x":6.1,"y":2.8},{"x":6.4,"y":2.9},{"x":6.6,"y":3.0},{"x":6.8,"y":2.8},{"x":6.7,"y":3.0},{"x":6.0,"y":2.9},{"x":5.7,"y":2.6},{"x":5.5,"y":2.4},{"x":5.5,"y":2.4},{"x":5.8,"y":2.7},{"x":6.0,"y":2.7},{"x":5.4,"y":3.0},{"x":6.0,"y":3.4},{"x":6.7,"y":3.1},{"x":6.3,"y":2.3},{"x":5.6,"y":3.0},{"x":5.5,"y":2.5},{"x":5.5,"y":2.6},{"x":6.1,"y":3.0},{"x":5.8,"y":2.6},{"x":5.0,"y":2.3},{"x":5.6,"y":2.7},{"x":5.7,"y":3.0},{"x":5.7,"y":2.9},{"x":6.2,"y":2.9},{"x":5.1,"y":2.5},{"x":5.7,"y":2.8},{"x":6.3,"y":3.3},{"x":5.8,"y":2.7},{"x":7.1,"y":3.0},{"x":6.3,"y":2.9},{"x":6.5,"y":3.0},{"x":7.6,"y":3.0},{"x":4.9,"y":2.5},{"x":7.3,"y":2.9},{"x":6.7,"y":2.5},{"x":7.2,"y":3.6},{"x":6.5,"y":3.2},{"x":6.4,"y":2.7},{"x":6.8,"y":3.0},{"x":5.7,"y":2.5},{"x":5.8,"y":2.8},{"x":6.4,"y":3.2},{"x":6.5,"y":3.0},{"x":7.7,"y":3.8},{"x":7.7,"y":2.6},{"x":6.0,"y":2.2},{"x":6.9,"y":3.2},{"x":5.6,"y":2.8},{"x":7.7,"y":2.8},{"x":6.3,"y":2.7},{"x":6.7,"y":3.3},{"x":7.2,"y":3.2},{"x":6.2,"y":2.8},{"x":6.1,"y":3.0},{"x":6.4,"y":2.8},{"x":7.2,"y":3.0},{"x":7.4,"y":2.8},{"x":7.9,"y":3.8},{"x":6.4,"y":2.8},{"x":6.3,"y":2.8},{"x":6.1,"y":2.6},{"x":7.7,"y":3.0},{"x":6.3,"y":3.4},{"x":6.4,"y":3.1},{"x":6.0,"y":3.0},{"x":6.9,"y":3.1},{"x":6.7,"y":3.1},{"x":6.9,"y":3.1},{"x":5.8,"y":2.7},{"x":6.8,"y":3.2},{"x":6.7,"y":3.3},{"x":6.7,"y":3.0},{"x":6.3,"y":2.5},{"x":6.5,"y":3.0},{"x":6.2,"y":3.4},{"x":5.9,"y":3.0}],"predict":[4.5,6.5]}'

Output: