LinkCloudDev/server/Utility/db.js

import * as mysql from "mysql2";
import { event } from "./eventHandler.js";
import { Debug, Log, Warn, Err, logger, profilerDone } from "./loggerUtility.js";

let pool;

export let queryCount = 0;

export const setup = ({ user, host, database, password, connectionLimit }) => {
	/**
	 * Creates a MySQL connection pool with the provided configuration options.
	 * @param {Object} config - The configuration object for creating the pool.
	 * @param {string} config.host - The host of the MySQL server.
	 * @param {string} config.user - The user to authenticate as.
	 * @param {string} config.database - The name of the database to use for the connection.
	 * @param {string} config.password - The password of the user.
	 * @param {boolean} config.waitForConnections - Determines if the pool should wait for connections.
	 * @param {number} config.connectionLimit - The maximum number of connections to create at once.
	 * @param {number} config.maxIdle - The maximum number of idle connections
	 */
	pool = mysql.createPool({
		host,
		user,
		database,
		password,
		waitForConnections: true,
		connectionLimit,
		maxIdle: 10, // max idle connections, the default value is the same as `connectionLimit`
		idleTimeout: 60000, // idle connections timeout, in milliseconds, the default value 60000
		queueLimit: 0,
		enableKeepAlive: true,
		keepAliveInitialDelay: 0,
	});
	try{
		runPrepQuery("SELECT 1 FROM linkshells", [], (r,f,e) => {
			if(!e) {
				event.emit("DATABASE_CONNECTED");
			} else {
				Err('MYSQL_FAILED_NO_TABLES')
				event.emit("MYSQL_FAILED_NO_TABLES");
				event.emit("MYSQL_FAILED_TO_CONNECT");
			}
		})
	} catch (e) {
		console.log(e)
		event.emit("MYSQL_FAILED_TO_CONNECT");
	}
};

export const runPrepQuery = (sql, data, callback) => {
	/**
	 * Establishes a connection to the MySQL database pool and executes a SQL query.
	 * @param {Error} err - The error object returned from the connection attempt.
	 * @param {Connection} conn - The connection object to the MySQL database pool.
	 * @returns None
	 */
	pool.getConnection((err, conn) => {
		if (err) {
			Err(`MYSQL ERROR (${err?.errno}): ${err?.code} ${err?.sqlMessage}`);
			if (queryCount === 0) {
				event.emit("MYSQL_FAILED_TO_CONNECT");
			}
		}
		if (!err) {
			conn.execute(sql, data, (e, r, f) => {
				if (typeof callback === "function") callback(r, f, e);
				queryCount++;
				pool.releaseConnection(conn);
			});
		} else if (typeof callback === "function") callback(false, false, err);
	});
};

export const numRows = (rows) => {
	/**
	 * Returns the number of rows if rows exist, otherwise returns false.
	 * @param {Array} rows - The array of rows to check.
	 * @returns {number|boolean} The number of rows if rows exist, otherwise false.
	 */
	if (rows) return rows.length;
	return false;
};