Method set

src/response-cache.ts:190–231

* Cache a response with optional custom TTL.

(
    key: string,
    response: {
      body: Buffer;
      status: number;
      headers: Record<string, string>;
      model: string;
    },
    ttlSeconds?: number,
  )

   * Cache a response with optional custom TTL.
   */
  set(
    key: string,
    response: {
      body: Buffer;
      status: number;
      headers: Record<string, string>;
      model: string;
    },
    ttlSeconds?: number,
  ): void {
    // Don't cache if disabled or maxSize is 0
    if (!this.config.enabled || this.config.maxSize <= 0) return;

    // Don't cache if item too large
    if (response.body.length > this.config.maxItemSize) {
      console.log(`[ResponseCache] Skipping cache - item too large: ${response.body.length} bytes`);
      return;
    }

    // Don't cache error responses
    if (response.status >= 400) {
      return;
    }

    // Evict if at capacity
    if (this.cache.size >= this.config.maxSize) {
      this.evict();
    }

    const now = Date.now();
    const ttl = ttlSeconds ?? this.config.defaultTTL;
    const expiresAt = now + ttl * 1000;

    const entry: CachedLLMResponse = {
      ...response,
      cachedAt: now,
      expiresAt,
    };

    this.cache.set(key, entry);
    this.expirationHeap.push({ expiresAt, key });
  }

  /**
   * Evict expired and oldest entries to make room.