You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
46 lines
1.7 KiB
46 lines
1.7 KiB
/*
|
|
* Copyright 2020 Google LLC
|
|
*
|
|
* Licensed under the Apache License, Version 2.0 (the "License");
|
|
* you may not use this file except in compliance with the License.
|
|
* You may obtain a copy of the License at
|
|
*
|
|
* https://www.apache.org/licenses/LICENSE-2.0
|
|
*
|
|
* Unless required by applicable law or agreed to in writing, software
|
|
* distributed under the License is distributed on an "AS IS" BASIS,
|
|
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
* See the License for the specific language governing permissions and
|
|
* limitations under the License.
|
|
*/
|
|
/**
|
|
* Takes a performance entry type and a callback function, and creates a
|
|
* `PerformanceObserver` instance that will observe the specified entry type
|
|
* with buffering enabled and call the callback _for each entry_.
|
|
*
|
|
* This function also feature-detects entry support and wraps the logic in a
|
|
* try/catch to avoid errors in unsupporting browsers.
|
|
*/
|
|
export const observe = (type, callback, opts) => {
|
|
try {
|
|
if (PerformanceObserver.supportedEntryTypes.includes(type)) {
|
|
const po = new PerformanceObserver((list) => {
|
|
// Delay by a microtask to workaround a bug in Safari where the
|
|
// callback is invoked immediately, rather than in a separate task.
|
|
// See: https://github.com/GoogleChrome/web-vitals/issues/277
|
|
Promise.resolve().then(() => {
|
|
callback(list.getEntries());
|
|
});
|
|
});
|
|
po.observe(Object.assign({
|
|
type,
|
|
buffered: true,
|
|
}, opts || {}));
|
|
return po;
|
|
}
|
|
}
|
|
catch (e) {
|
|
// Do nothing.
|
|
}
|
|
return;
|
|
};
|
|
|