feat: add RAMLock to utils

Author: ivictbor

adminforth/index.ts

@@ -6,7 +6,7 @@ import SQLiteConnector from './dataConnectors/sqlite.js';
 import CodeInjector from './modules/codeInjector.js';
 import ExpressServer from './servers/express.js';
 // import FastifyServer from './servers/fastify.js';
-import { ADMINFORTH_VERSION, listify, suggestIfTypo, RateLimiter, getClientIp } from './modules/utils.js';
+import { ADMINFORTH_VERSION, listify, suggestIfTypo, RateLimiter, RAMLock, getClientIp } from './modules/utils.js';
 
 import { 
   type AdminForthConfig, 
@@ -42,7 +42,7 @@ export * from './types/Common.js';
 export * from './types/Adapters.js';
 export { interpretResource };
 export { AdminForthPlugin };
-export { suggestIfTypo, RateLimiter, getClientIp };
+export { suggestIfTypo, RateLimiter, RAMLock, getClientIp };
 
 
 class AdminForth implements IAdminForth {
@@ -478,7 +478,6 @@ class AdminForth implements IAdminForth {
     { resource, recordId, record, oldRecord, adminUser, extra }:
     { resource: AdminForthResource, recordId: any, record: any, oldRecord: any, adminUser: AdminUser, extra?: HttpExtra }
   ): Promise<{ error?: string }> {
-
     const err = this.validateRecordValues(resource, record);
     if (err) {
       return { error: err };

adminforth/modules/utils.ts

@@ -455,4 +455,36 @@ export class RateLimiter {
     }
   }
 
+}
+
+export class RAMLock {
+  private locks: Map<string, { locked: boolean; queue: Function[] }>;
+
+  constructor() {
+    this.locks = new Map();
+  }
+
+  _getLock(key) {
+    if (!this.locks.has(key)) {
+      this.locks.set(key, { locked: false, queue: [] });
+    }
+    return this.locks.get(key);
+  }
+
+  async run(key, fn) {
+    const lock = this._getLock(key);
+    while (lock.locked) {
+      await new Promise(resolve => lock.queue.push(resolve));
+    }
+    lock.locked = true;
+    try {
+      return await fn();
+    } finally {
+      lock.locked = false;
+      if (lock.queue.length > 0) {
+        const next = lock.queue.shift();
+        next();
+      }
+    }
+  }
 }