index.js

'use strict';
const mysql = require('mysql');

const CREATE_STATEMENT = 'CREATE  TABLE IF NOT EXISTS `_mysql_session_store` (`id` VARCHAR(255) NOT NULL, `expires` BIGINT NULL, `data` TEXT NULL, PRIMARY KEY (`id`), KEY `_mysql_session_store__expires` (`expires`));'
    , GET_STATEMENT = 'SELECT * FROM `_mysql_session_store` WHERE id  = ? AND expires > ?'
    , SET_STATEMENT = 'INSERT INTO _mysql_session_store(id, expires, data) VALUES(?, ?, ?) ON DUPLICATE KEY UPDATE expires=?, data =?'
    , DELETE_STATEMENT = 'DELETE FROM `_mysql_session_store` WHERE id  = ?'
    , CLEANUP_STATEMENT = 'DELETE FROM `_mysql_session_store` WHERE expires  < ?';

const FORTY_FIVE_MINUTES = 45 * 60 * 1000;
const FIFTEEN_MINUTES = 15 * 60 * 1000;

let getExpiresOn = function (session, ttl) {
    let expiresOn = null;
    ttl = ttl || FORTY_FIVE_MINUTES

    if (session && session.cookie && session.cookie.expires) {
        if (session.cookie.expires instanceof Date) {
            expiresOn = session.cookie.expires
        } else {
            expiresOn = new Date(session.cookie.expires)
        }
    } else {
        let now = new Date();
        expiresOn = new Date(now.getTime() + ttl);
    }
    return expiresOn
}

var MysqlStore = function (options) {
    let pool = null
    let cleanInterval = (!options.clean) ? FIFTEEN_MINUTES : options.clean;
    this.getPool = function () {
        if (!pool) {
            pool = mysql.createPool(options);
        }
        return pool;
    }

    this.cleanup = async function () {
        let now = new Date().getTime();
        let results = this.queryPromise(CLEANUP_STATEMENT, [now]);
    };

    this.queryPromise(CREATE_STATEMENT);

    setInterval(this.cleanup.bind(this), cleanInterval);
};

MysqlStore.prototype.get = async function (sid) {
    let results =await this.queryPromise(GET_STATEMENT, [sid, Date.now()]);
    let session = null;
    if (results && results[0] && results[0] && results[0].data) {
        session = JSON.parse(results[0].data);
    }
    return session
};

MysqlStore.prototype.set = async function (sid, session, ttl) {
    let expires = getExpiresOn(session, ttl).valueOf()
    let data = JSON.stringify(session);
    let results = this.queryPromise(SET_STATEMENT, [sid, expires, data, expires, data]);
    await results.then(res => {
    })
        .catch(err => {
            this.logger(err);
        })
    return results
};

MysqlStore.prototype.destroy = async function (sid) {
    let results = await this.queryPromise(DELETE_STATEMENT, [sid])
};

MysqlStore.prototype.queryPromise = async function (sqlStr, paramArray) {
    let connection = this.getPool()
    return new Promise((resolve, reject) => {
        connection.getConnection((err, connection)=>{
            connection.query(sqlStr, paramArray, function (err, result) {
                if (result) {
                    resolve(result);
                }
                else {
                    reject(err);
                }

                // 释放连接
                connection.release();
            });
        });

    })
}

MysqlStore.prototype.logger = function (data) {
    console.info(`path:${__filename}:\n`, data);
}

module.exports = MysqlStore;