refactor(infra): directory structure (#4615)

packages/backend/server/src/session.ts

@@ -0,0 +1,73 @@
+import KeyvRedis from '@keyv/redis';
+import {
+  FactoryProvider,
+  Global,
+  Inject,
+  Injectable,
+  Module,
+} from '@nestjs/common';
+import Redis from 'ioredis';
+import Keyv from 'keyv';
+
+import { Config } from './config';
+
+export const KeyvProvide = Symbol('KeyvProvide');
+
+export const KeyvProvider: FactoryProvider<Keyv> = {
+  provide: KeyvProvide,
+  useFactory(config: Config) {
+    if (config.redis.enabled) {
+      return new Keyv({
+        store: new KeyvRedis(
+          new Redis(config.redis.port, config.redis.host, {
+            username: config.redis.username,
+            password: config.redis.password,
+            db: config.redis.database + 2,
+          })
+        ),
+      });
+    } else {
+      return new Keyv();
+    }
+  },
+  inject: [Config],
+};
+
+@Injectable()
+export class SessionService {
+  private readonly prefix = 'session:';
+  private readonly sessionTtl = 30 * 60 * 1000; // 30 min
+
+  constructor(@Inject(KeyvProvide) private readonly cache: Keyv) {}
+
+  /**
+   * get session
+   * @param key session key
+   * @returns
+   */
+  async get(key: string) {
+    return this.cache.get(this.prefix + key);
+  }
+
+  /**
+   * set session
+   * @param key session key
+   * @param value session value
+   * @param sessionTtl session ttl (ms), default 30 min
+   * @returns return true if success
+   */
+  async set(key: string, value?: any, sessionTtl = this.sessionTtl) {
+    return this.cache.set(this.prefix + key, value, sessionTtl);
+  }
+
+  async delete(key: string) {
+    return this.cache.delete(this.prefix + key);
+  }
+}
+
+@Global()
+@Module({
+  providers: [KeyvProvider, SessionService],
+  exports: [KeyvProvider, SessionService],
+})
+export class SessionModule {}