Central Locking

A NestJS library for distributed locking using Redis. This package helps you manage distributed locks in a NestJS application, ensuring that only one instance of a process runs at a time.

Table of Contents

• Installation
• Usage
  • Setup
  • Using the Locking Decorator
• API
  • CentralLock Decorator
  • LockingService
• Contributing
• Author
• License

Installation

To install the package, use npm or yarn:

npm install @gromo-fintech/central-locking-service

or

yarn add @gromo-fintech/central-locking-service

Usage

Setup

First, import the LockingModule into your NestJS application module:

import { Module } from '@nestjs/common';
import { LockingModule } from 'central-locking-service';

@Module({
  imports: [LockingModule],
})
export class AppModule {}

Using the Locking Decorator

You can use the CentralLock decorator to ensure a method acquires a lock before execution. This is useful for scenarios where only one instance of a method should run at a time across distributed systems.

import { CentralLock, LockingService } from 'central-locking-service';

export class SomeService {
  constructor(private lockingService: LockingService) {}

  @CentralLock({
    lockKey: 'unique-lock-key',
    lockDuration: 10000,
    shouldReleaseAfterExecution: true,
    shouldThrowErrorIfUnableToAcquireLock: true,
  })
  async handleTask() {
    console.log('Task is being handled.');
    // Your business logic here
  }
}

API

CentralLock Decorator

The CentralLock decorator is used to manage distributed locks on methods.

Options:

• lockKey (string): The key to identify the lock.
• lockDuration (number): The duration (in milliseconds) for which the lock should be held.
• shouldReleaseAfterExecution (boolean): Whether to release the lock after method execution.
• shouldThrowErrorIfUnableToAcquireLock (boolean): Whether to throw an error if unable to acquire the lock.

LockingService

The LockingService provides methods to acquire and release locks.

Methods:

• acquireLock(key: string, duration: number): Promise<void>: Acquires a lock for a specific duration.
• releaseLock(key: string): Promise<void>: Releases the lock for the specified key.

Contributing

Contributions are welcome! Please submit a pull request or open an issue to discuss any changes or improvements.

1. Fork the repository.
2. Create your feature branch: git checkout -b feature/your-feature
3. Commit your changes: git commit -m 'Add some feature'
4. Push to the branch: git push origin feature/your-feature
5. Open a pull request.

Author

Saket Anand

Lead Engineer
Saket Anand is the lead engineer behind the @gromo-fintech/nestjs-central-locking. With a deep focus on leveraging Redis, his work has been central to the efficient central locking provided by this library.

License

MIT licensed