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Web IndexedDB Helper

浏览器数据库工具类

Dieses Skript sollte nicht direkt installiert werden. Es handelt sich hier um eine Bibliothek für andere Skripte, welche über folgenden Befehl in den Metadaten eines Skriptes eingebunden wird // @require https://update.greasyfork.org/scripts/473362/1237033/Web%20IndexedDB%20Helper.js 

// ==UserScript==
// @name        Web IndexedDB Helper
// @namespace   web-indexed-database-helper
// @version     1.0.0
// @description 浏览器数据库工具类
// @author      如梦Nya
// @license     MIT
// @match       *://*/*
// ==/UserScript==

class _WebIndexedDBHelper {
    constructor() {
        /** @type {IDBDatabase} */
        this.db = undefined
    }

    /**
     * 打开数据库
     * @param {string} dbName 数据库名
     * @param {number | undefined} dbVersion 数据库版本
     * @returns {Promise<WebDB, any>}
     */
    open(dbName, dbVersion) {
        let self = this
        return new Promise(function (resolve, reject) {
            /** @type {IDBFactory} */
            const indexDB = window.indexedDB || window.webkitIndexedDB || window.mozIndexedDB
            let req = indexDB.open(dbName, dbVersion)
            req.onerror = reject
            req.onsuccess = function () {
                self.db = this.result
                resolve(self)
            }
        })
    }

    /**
     * 查出一条数据
     * @param {string} tableName 表名
     * @param {string} key 键名
     * @returns {Promise<any, any>}
     */
    get(tableName, key) {
        let self = this
        return new Promise(function (resolve, reject) {
            let req = self.db.transaction([tableName]).objectStore(tableName).get(key)
            req.onerror = reject
            req.onsuccess = function () {
                resolve(this.result)
            }
        })
    }

    /**
     * 插入、更新一条数据
     * @param {string} tableName 表名
     * @param {string} key 键名
     * @param {any} value 数据
     * @returns {Promise<IDBValidKey, any>}
     */
    put(tableName, key, value) {
        let self = this
        return new Promise(function (resolve, reject) {
            let req = self.db.transaction([tableName], 'readwrite').objectStore(tableName).put(value, key)
            req.onerror = reject
            req.onsuccess = function () {
                resolve(this.result)
            }
        })
    }

    /**
     * 关闭数据库
     */
    close() {
        this.db.close()
        delete this.db
    }
}

const WebDB = {
    /**
     * 打开数据库
     * @param {string} dbName 数据库名
     * @param {number | undefined} dbVersion 数据库版本
     * @returns {Promise<WebDB, any>}
     */
    open: function (dbName, dbVersion) {
        return new _WebIndexedDBHelper().open(dbName, dbVersion)
    }
}