react-native/local-cli/server/util/debugger-ui/deltaUrlToBlobUrl.js

72 lines
1.8 KiB
JavaScript

/**
* Copyright (c) 2015-present, Facebook, Inc.
*
* This source code is licensed under the MIT license found in the
* LICENSE file in the root directory of this source tree.
*
* @flow strict
* @format
*/
/* global Blob, URL: true */
(function(global) {
'use strict';
let cachedBundleUrls = new Map();
/**
* Converts the passed delta URL into an URL object containing already the
* whole JS bundle Blob.
*/
async function deltaUrlToBlobUrl(deltaUrl) {
const client = global.DeltaPatcher.get(deltaUrl);
const deltaBundleId = client.getLastBundleId()
? `&deltaBundleId=${client.getLastBundleId()}`
: '';
const data = await fetch(deltaUrl + deltaBundleId);
const bundle = await data.json();
const deltaPatcher = client.applyDelta({
id: bundle.id,
pre: new Map(bundle.pre),
post: new Map(bundle.post),
delta: new Map(bundle.delta),
reset: bundle.reset,
});
let cachedBundle = cachedBundleUrls.get(deltaUrl);
// If nothing changed, avoid recreating a bundle blob by reusing the
// previous one.
if (deltaPatcher.getLastNumModifiedFiles() === 0 && cachedBundle) {
return cachedBundle;
}
// Clean up the previous bundle URL to not leak memory.
if (cachedBundle) {
URL.revokeObjectURL(cachedBundle);
}
// To make Source Maps work correctly, we need to add a newline between
// modules.
const blobContent = deltaPatcher
.getAllModules()
.map(module => module + '\n');
// Build the blob with the whole JS bundle.
const blob = new Blob(blobContent, {
type: 'application/javascript',
});
const bundleContents = URL.createObjectURL(blob);
cachedBundleUrls.set(deltaUrl, bundleContents);
return bundleContents;
}
global.deltaUrlToBlobUrl = deltaUrlToBlobUrl;
})(window || {});