From dac6f4b07388675c23658f9e338270351c74fb3e Mon Sep 17 00:00:00 2001
From: Joshua Lochner <admin@xenova.com>
Date: Sat, 23 Sep 2023 03:34:10 +0200
Subject: [PATCH] Improve example browser extension template (#325)

Removes unnecessary complexity
---
 examples/extension/src/background.js |  6 ---
 examples/extension/src/cache.js      | 80 ----------------------------
 2 files changed, 86 deletions(-)
 delete mode 100644 examples/extension/src/cache.js

diff --git a/examples/extension/src/background.js b/examples/extension/src/background.js
index cc7dc8692..db3ffee35 100644
--- a/examples/extension/src/background.js
+++ b/examples/extension/src/background.js
@@ -1,12 +1,6 @@
 // background.js - Handles requests from the UI, runs the model, then sends back a response
 
 import { pipeline, env } from '@xenova/transformers';
-import { CustomCache } from "./cache.js";
-
-// Define caching parameters
-env.useBrowserCache = false;
-env.useCustomCache = true;
-env.customCache = new CustomCache('transformers-cache');
 
 // Skip initial check for local models, since we are not loading any local models.
 env.allowLocalModels = false;
diff --git a/examples/extension/src/cache.js b/examples/extension/src/cache.js
deleted file mode 100644
index 833475e0d..000000000
--- a/examples/extension/src/cache.js
+++ /dev/null
@@ -1,80 +0,0 @@
-// Design a caching API to be used by the extension which implements the same interface as
-// the browser's native Cache API (https://developer.mozilla.org/en-US/docs/Web/API/Cache)
-// but uses the browser's local storage API (https://developer.chrome.com/docs/extensions/reference/storage/).
-// 
-// Since the local storage API requires all data to be stored as JSON (which doesn't allow some ASCII chars),
-// one of the better approaches is to store the response body as a base64-encoded string. This is not ideal,
-// as it increases the size of the response body by ~33%, but it's the best we can do with the local storage API.
-// See https://stackoverflow.com/a/1443240/13989043 for more information about this.
-// 
-// For serialization (arraybuffer -> string) and unserialization (string -> arraybuffer),
-// use the `FileReader` and `Blob` APIs. Although other options are also possible, this approach
-// is considered to be better for larger files (like models).
-// 
-// Other references:
-//  - https://developer.chrome.com/docs/extensions/reference/storage/#property-local
-//  - https://stackoverflow.com/questions/6965107/converting-between-strings-and-arraybuffers
-
-export class CustomCache {
-    /**
-     * Instantiate a `CustomCache` object.
-     * @param {string} path 
-     */
-    constructor(cacheName) {
-        this.cacheName = cacheName;
-    }
-
-    /**
-     * Checks whether the given request is in the cache.
-     * @param {Request|string} request 
-     * @returns {Promise<Response | undefined>}
-     */
-    async match(request) {
-        const url = request instanceof Request ? request.url : request;
-        const cached = await chrome.storage.local.get([url]);
-
-        if (cached[url]) {
-            return await fetch(cached[url]._body);
-        } else {
-            return undefined;
-        }
-    }
-
-    /**
-     * Adds the given response to the cache.
-     * @param {Request|string} request 
-     * @param {Response} response 
-     * @returns {Promise<void>}
-     */
-    async put(request, response) {
-        const url = request instanceof Request ? request.url : request;
-        const buffer = await response.arrayBuffer();
-
-        const body = await new Promise((resolve, reject) => {
-            const reader = new FileReader();
-            reader.onload = e => resolve(e.target.result);
-            reader.onerror = e => reject(e.target.error);
-            reader.readAsDataURL(new Blob([buffer], { type: 'application/octet-stream' }));
-        });
-
-        try {
-            await chrome.storage.local.set({
-                [url]: {
-                    _body: body,
-
-                    // Save original response in case
-                    status: response.status,
-                    statusText: response.statusText,
-                    headers: Object.fromEntries(response.headers.entries()),
-                    url: response.url,
-                    redirected: response.redirected,
-                    type: response.type,
-                    ok: response.ok,
-                }
-            });
-
-        } catch (err) {
-            console.warn('An error occurred while writing the file to cache:', err)
-        }
-    }
-}