GoScrobble/web/node_modules/workbox-expiration/models/CacheTimestampsModel.js

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2022-04-25 02:47:15 +00:00
/*
Copyright 2018 Google LLC
Use of this source code is governed by an MIT-style
license that can be found in the LICENSE file or at
https://opensource.org/licenses/MIT.
*/
import { DBWrapper } from 'workbox-core/_private/DBWrapper.js';
import { deleteDatabase } from 'workbox-core/_private/deleteDatabase.js';
import '../_version.js';
const DB_NAME = 'workbox-expiration';
const OBJECT_STORE_NAME = 'cache-entries';
const normalizeURL = (unNormalizedUrl) => {
const url = new URL(unNormalizedUrl, location.href);
url.hash = '';
return url.href;
};
/**
* Returns the timestamp model.
*
* @private
*/
class CacheTimestampsModel {
/**
*
* @param {string} cacheName
*
* @private
*/
constructor(cacheName) {
this._cacheName = cacheName;
this._db = new DBWrapper(DB_NAME, 1, {
onupgradeneeded: (event) => this._handleUpgrade(event),
});
}
/**
* Should perform an upgrade of indexedDB.
*
* @param {Event} event
*
* @private
*/
_handleUpgrade(event) {
const db = event.target.result;
// TODO(philipwalton): EdgeHTML doesn't support arrays as a keyPath, so we
// have to use the `id` keyPath here and create our own values (a
// concatenation of `url + cacheName`) instead of simply using
// `keyPath: ['url', 'cacheName']`, which is supported in other browsers.
const objStore = db.createObjectStore(OBJECT_STORE_NAME, { keyPath: 'id' });
// TODO(philipwalton): once we don't have to support EdgeHTML, we can
// create a single index with the keyPath `['cacheName', 'timestamp']`
// instead of doing both these indexes.
objStore.createIndex('cacheName', 'cacheName', { unique: false });
objStore.createIndex('timestamp', 'timestamp', { unique: false });
// Previous versions of `workbox-expiration` used `this._cacheName`
// as the IDBDatabase name.
deleteDatabase(this._cacheName);
}
/**
* @param {string} url
* @param {number} timestamp
*
* @private
*/
async setTimestamp(url, timestamp) {
url = normalizeURL(url);
const entry = {
url,
timestamp,
cacheName: this._cacheName,
// Creating an ID from the URL and cache name won't be necessary once
// Edge switches to Chromium and all browsers we support work with
// array keyPaths.
id: this._getId(url),
};
await this._db.put(OBJECT_STORE_NAME, entry);
}
/**
* Returns the timestamp stored for a given URL.
*
* @param {string} url
* @return {number}
*
* @private
*/
async getTimestamp(url) {
const entry = await this._db.get(OBJECT_STORE_NAME, this._getId(url));
return entry.timestamp;
}
/**
* Iterates through all the entries in the object store (from newest to
* oldest) and removes entries once either `maxCount` is reached or the
* entry's timestamp is less than `minTimestamp`.
*
* @param {number} minTimestamp
* @param {number} maxCount
* @return {Array<string>}
*
* @private
*/
async expireEntries(minTimestamp, maxCount) {
const entriesToDelete = await this._db.transaction(OBJECT_STORE_NAME, 'readwrite', (txn, done) => {
const store = txn.objectStore(OBJECT_STORE_NAME);
const request = store.index('timestamp').openCursor(null, 'prev');
const entriesToDelete = [];
let entriesNotDeletedCount = 0;
request.onsuccess = () => {
const cursor = request.result;
if (cursor) {
const result = cursor.value;
// TODO(philipwalton): once we can use a multi-key index, we
// won't have to check `cacheName` here.
if (result.cacheName === this._cacheName) {
// Delete an entry if it's older than the max age or
// if we already have the max number allowed.
if ((minTimestamp && result.timestamp < minTimestamp) ||
(maxCount && entriesNotDeletedCount >= maxCount)) {
// TODO(philipwalton): we should be able to delete the
// entry right here, but doing so causes an iteration
// bug in Safari stable (fixed in TP). Instead we can
// store the keys of the entries to delete, and then
// delete the separate transactions.
// https://github.com/GoogleChrome/workbox/issues/1978
// cursor.delete();
// We only need to return the URL, not the whole entry.
entriesToDelete.push(cursor.value);
}
else {
entriesNotDeletedCount++;
}
}
cursor.continue();
}
else {
done(entriesToDelete);
}
};
});
// TODO(philipwalton): once the Safari bug in the following issue is fixed,
// we should be able to remove this loop and do the entry deletion in the
// cursor loop above:
// https://github.com/GoogleChrome/workbox/issues/1978
const urlsDeleted = [];
for (const entry of entriesToDelete) {
await this._db.delete(OBJECT_STORE_NAME, entry.id);
urlsDeleted.push(entry.url);
}
return urlsDeleted;
}
/**
* Takes a URL and returns an ID that will be unique in the object store.
*
* @param {string} url
* @return {string}
*
* @private
*/
_getId(url) {
// Creating an ID from the URL and cache name won't be necessary once
// Edge switches to Chromium and all browsers we support work with
// array keyPaths.
return this._cacheName + '|' + normalizeURL(url);
}
}
export { CacheTimestampsModel };