saikatdutta1991

interface Student {
  id: number;
  name: string;
  dateOfBirth: Date;
}

class StudentRepository {
  someDbClient: any;

  constructor() {

saikatdutta1991

import { Inject } from '@nestjs/common';
import { DEFAULT_LOCK_SECONDS } from '../common/constants';
import { UseKeyGenerator } from '../common/types';
import { LockAcquireException } from '../exceptions/lock-acquire.exception';
import { LockService } from '../lock.service';

export function ConcurrencyLock(options: {
  useKey: string | UseKeyGenerator;
  releaseAfterSeconds?: number;
  errorMessage?: string;

saikatdutta1991

Class SomeClass {

  ConcurrencyLock({
    useKey: (input: CreateHelpSessionInput) => `create_help_session_${input.userId}`
    releaseAfterSeconds: 30,
    errorMessage?: `Failed to acquire lock for the create help session. Try after sometime.`
  })
  public createHelpSession(input: CreateHelpSessionInput) {
    // Existing code.. No changes here.
  }

saikatdutta1991

Class SomeClass {

  public createHelpSession(input: CreateHelpSessionInput) {
    const key = `create_help_session_${input.userId}`
    await this.lockService.acquireLock(key);
    try {
      // entire existing code goes here
    } finally() {
      await this.releaseLock(key);
    }

saikatdutta1991

import { Inject, Injectable, Logger } from '@nestjs/common';
import { CustomLogger } from 'src/common/decorators/custom-logger.decorator';
import { Redis } from '../redis/redis';
import { LockAcquireException } from './exceptions/lock-acquire.exception';

@Injectable()
export class LockService {
  @CustomLogger()
  private readonly logger: Logger;