Redis Client (Node.js)

1import redis from 'redis';
2import moment from 'moment';
3import { promisify } from 'util';
4
5import logService from '../services/log';
6class MemoryCache {
7  // private fallbackMemoryClient: Map<string, any> = new Map();
8  public redisClient: redis.RedisClient;
9  public regisGetAsync: Promise<any>;
10
11  constructor() {
12    logService.log('info', 'Memory cache singleton running');
13    const options = {
14      host: process.env.REDIS_URI,
15      port: 6379,
16      max_attempts: 1,
17    };
18    this.redisClient = redis.createClient(options);
19    this.regisGetAsync = promisify(this.redisClient.get).bind(this.redisClient);
20    this.redisClient.on('error', (err) => {
21      logService.log('error', 'Redis client failed', err);
22    });
23    this.redisClient.on('connect', () => {
24      logService.log('info', 'Redis client created');
25    });
26  }
27  setCache(key: string, data: any, ttl?: number, checkSum?: string) {
28    if (this.redisClient.connected) {
29      if (key && data) {
30        const stringifiedData = JSON.stringify(data);
31        this.redisClient.del(key);
32        this.redisClient.set(key, stringifiedData);
33        this.redisClient.expire(key, ttl || 172800); // 48h
34        logService.log('info', 'Data store in cache', { key, ttl });
35      } else {
36        logService.log('error', 'Failed to store in cache - Invalid payload');
37      }
38    }
39  }
40
41  getCache(key: string, checkSum?: string) {
42    return new Promise((resolve, reject) => {
43      if (!this.redisClient.connected) {
44        return reject('Cache disconnected');
45      }
46      this.redisClient.get(key, (err, res) => {
47        if (err) {
48          logService.log('warning', 'Failed to retrieve', err);
49          return reject('No data found');
50        }
51        if (!res) {
52          logService.log('warning', 'Failed to retrieve / Cache miss');
53          return reject('No data found');
54        }
55        if (res) {
56          logService.log('info', 'Attempting to parse result');
57          try {
58            const parsedData = JSON.parse(res);
59            logService.log('info', 'Completed parsing');
60            if (!parsedData) {
61              logService.log('error', 'Failed to parse result');
62              reject('No data found');
63            }
64            resolve(parsedData);
65          } catch (err) {
66            logService.log('error', 'Failed to parse result');
67            reject('No data found');
68          }
69        }
70      });
71    });
72  }
73  clearCache(key: string) {
74    logService.log('info', `Cache invalidated for ${key}`);
75    return this.redisClient.del(key); // don't wait
76  }
77}
78
79const mc = new MemoryCache();
80export { mc as MemoryCache };
81
82
83
84// Cache Invalidator
85import { UserFacingError } from '../classes/errors';
86import { MemoryCache } from '../services/memory-cache';
87
88export function InvalidateCache(cacheKeys: string[]) {
89  return function validator(target: any, key: any, descriptor: any) {
90    const fn = descriptor.value;
91    descriptor.value = function (...args: any[]) {
92      cacheKeys.forEach((cacheKey) => {
93        MemoryCache.clearCache(cacheKey);
94      });
95      return fn.apply(this, args);
96    };
97  };
98}
99