feat: implement connection pooling in DatabasePlugin for improved database connection management

src/vm/plugins/database.plugin.ts

@@ -2,6 +2,8 @@ import { Plugin } from "../plugin.class";
 import * as mysql from "mysql2/promise";
 
 export class DatabasePlugin extends Plugin {
+  private static connectionPool: Map<string, any> = new Map();
+
   constructor(name: string, private dbConnection: any) {
     if (!dbConnection || typeof dbConnection.execute !== "function") {
       throw new Error(
@@ -24,6 +26,14 @@ export class DatabasePlugin extends Plugin {
       connectTimeout: number;
     }
   ): Promise<DatabasePlugin> {
+    const connectionKey = `${config.host}:${config.port}:${config.user}:${config.database}`;
+
+    if (DatabasePlugin.connectionPool.has(connectionKey)) {
+      const existingConnection =
+        DatabasePlugin.connectionPool.get(connectionKey);
+      return new DatabasePlugin(name, existingConnection);
+    }
+
     const dbConnection = await mysql.createConnection({
       host: config.host,
       user: config.user,
@@ -37,6 +47,7 @@ export class DatabasePlugin extends Plugin {
 
     // await dbConnection.query("SET SESSION MAX_EXECUTION_TIME=2000;");
 
+    DatabasePlugin.connectionPool.set(connectionKey, dbConnection);
     return new DatabasePlugin(name, dbConnection);
   }