All files / src/platform/cache cache.service.ts

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
import { Injectable, Logger, Inject, Optional } from '@nestjs/common';
import Redis from 'ioredis';
import { CacheNamespace, NAMESPACE_POLICIES } from './cache-namespace.registry';
 
export const REDIS_CLIENT = 'REDIS_CLIENT';
 
const MAX_VALUE_SIZE_BYTES = 512 * 1024; // 512 KB limit per cached object
 
@Injectable()
export class CacheService {
  private readonly logger = new Logger(CacheService.name);
  private readonly inMemoryFallback = new Map<
    string,
    { value: string; expiresAt: number }
  >();
  private redisAvailable = true;
 
  constructor(
    @Optional() @Inject(REDIS_CLIENT) private readonly redis: Redis | null,
  ) {
    if (this.redis) {
      this.redis.on('error', (err) => {
        if (this.redisAvailable) {
          this.logger.warn(
            `Redis unavailable — falling back to in-memory cache: ${err.message}`,
          );
          this.redisAvailable = false;
        }
      });
 
      this.redis.on('ready', () => {
        if (!this.redisAvailable) {
          this.logger.log('Redis reconnected — resuming Redis cache');
          this.redisAvailable = true;
        }
      });
    } else {
      this.redisAvailable = false;
    }
  }
 
  async get<T>(key: string): Promise<T | null> {
    try {
      if (this.redisAvailable && this.redis) {
        const raw = await this.redis.get(key);
        return raw ? (JSON.parse(raw) as T) : null;
      }
    } catch (err) {
      this.logger.error(`Cache GET failed for key ${key}: ${err.message}`);
    }
 
    // Fallback to in-memory
    const record = this.inMemoryFallback.get(key);
    if (!record || Date.now() > record.expiresAt) {
      this.inMemoryFallback.delete(key);
      return null;
    }
    return JSON.parse(record.value) as T;
  }
 
  async set(
    key: string,
    value: any,
    ttlSeconds?: number,
    namespace?: CacheNamespace,
  ): Promise<void> {
    const ttl =
      ttlSeconds ??
      (namespace ? NAMESPACE_POLICIES[namespace]?.ttlSeconds : 60) ??
      60;
 
    const serialized = JSON.stringify(value);
    if (Buffer.byteLength(serialized) > MAX_VALUE_SIZE_BYTES) {
      this.logger.warn(
        `Cache SET skipped — value exceeds size limit for key ${key}`,
      );
      return;
    }
 
    try {
      if (this.redisAvailable && this.redis) {
        await this.redis.set(key, serialized, 'EX', ttl);
        return;
      }
    } catch (err) {
      this.logger.error(`Cache SET failed for key ${key}: ${err.message}`);
    }
 
    // Fallback
    this.inMemoryFallback.set(key, {
      value: serialized,
      expiresAt: Date.now() + ttl * 1000,
    });
  }
 
  async del(key: string): Promise<void> {
    try {
      if (this.redisAvailable && this.redis) {
        await this.redis.del(key);
      }
    } catch (err) {
      this.logger.error(`Cache DEL failed for key ${key}: ${err.message}`);
    }
    this.inMemoryFallback.delete(key);
  }
 
  async invalidatePattern(pattern: string): Promise<void> {
    try {
      if (this.redisAvailable && this.redis) {
        const keys = await this.redis.keys(pattern);
        if (keys.length > 0) {
          await this.redis.del(...keys);
          this.logger.log(
            `Invalidated ${keys.length} keys matching pattern: ${pattern}`,
          );
        }
      }
    } catch (err) {
      this.logger.error(
        `Cache pattern invalidation failed for ${pattern}: ${err.message}`,
      );
    }
  }
 
  async withCache<T>(
    key: string,
    factory: () => Promise<T>,
    ttlSeconds?: number,
    namespace?: CacheNamespace,
  ): Promise<T> {
    const cached = await this.get<T>(key);
    if (cached !== null) return cached;
 
    const value = await factory();
    await this.set(key, value, ttlSeconds, namespace);
    return value;
  }
 
  async acquireLock(lockKey: string, ttlSeconds = 30): Promise<boolean> {
    if (!this.redisAvailable || !this.redis) return true; // optimistic in-memory mode
    const result = await this.redis.set(
      `lock:${lockKey}`,
      '1',
      'EX',
      ttlSeconds,
      'NX',
    );
    return result === 'OK';
  }
 
  async releaseLock(lockKey: string): Promise<void> {
    if (this.redisAvailable && this.redis) {
      await this.redis.del(`lock:${lockKey}`);
    }
  }
 
  isRedisAvailable(): boolean {
    return this.redisAvailable;
  }
}