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/*
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 { openDB, deleteDB } from 'idb';
import '../_version.js';
const DB_NAME = 'workbox-expiration';
const CACHE_OBJECT_STORE = '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._db = null;
this._cacheName = cacheName;
}
/**
* Performs an upgrade of indexedDB.
*
* @param {IDBPDatabase<CacheDbSchema>} db
*
* @private
*/
_upgradeDb(db) {
// 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(CACHE_OBJECT_STORE, { 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 });
}
/**
* Performs an upgrade of indexedDB and deletes deprecated DBs.
*
* @param {IDBPDatabase<CacheDbSchema>} db
*
* @private
*/
_upgradeDbAndDeleteOldDbs(db) {
this._upgradeDb(db);
if (this._cacheName) {
void deleteDB(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),
};
const db = await this.getDb();
const tx = db.transaction(CACHE_OBJECT_STORE, 'readwrite', {
durability: 'relaxed',
});
await tx.store.put(entry);
await tx.done;
}
/**
* Returns the timestamp stored for a given URL.
*
* @param {string} url
* @return {number | undefined}
*
* @private
*/
async getTimestamp(url) {
const db = await this.getDb();
const entry = await db.get(CACHE_OBJECT_STORE, this._getId(url));
return entry === null || entry === void 0 ? void 0 : 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 db = await this.getDb();
let cursor = await db
.transaction(CACHE_OBJECT_STORE)
.store.index('timestamp')
.openCursor(null, 'prev');
const entriesToDelete = [];
let entriesNotDeletedCount = 0;
while (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 = await cursor.continue();
}
// 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 db.delete(CACHE_OBJECT_STORE, 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);
}
/**
* Returns an open connection to the database.
*
* @private
*/
async getDb() {
if (!this._db) {
this._db = await openDB(DB_NAME, 1, {
upgrade: this._upgradeDbAndDeleteOldDbs.bind(this),
});
}
return this._db;
}
}
export { CacheTimestampsModel };