Cache — spf.cache

The response cache: an in-memory LRU (SPF semantics) plus a Cache API durable tier. See the Caching guide for the policy.

// Internal module type (not re-exported from the package entry):
type CacheType = 'new' | 'history' | 'prefetch';

Methods

get(url, navType)

function get(url: string, navType: SpfNavigationType): SingleResponse | null;

Reads the first eligible cached entry for a navigation, checking prefetch, then history, then new types. Expired entries are dropped. A prefetch hit is consumed — the entry becomes history-only. Returns null on miss.

set(url, response, type?)

function set(url: string, response: SingleResponse, type?: CacheType): string;

Stores a response, honoring a server cacheType hint over the caller's default type. Evicts expired entries and LRU overflow (cache-max). Returns the cache key ("<type> <url>").

remove(key)

function remove(key: string): void;

Removes an entry by cache key or by its response.cacheKey, including its durable-tier copy.

clear()

function clear(): void;

Clears all entries, including the durable tier.

size()

function size(): number;

Number of live in-memory entries (tests/telemetry).

durableGet(url, navType)

function durableGet(url: string, navType: SpfNavigationType): Promise<SingleResponse | null>;

Durable-tier lookup honoring the policy: the Cache API store only serves history navigations (unless cache-unified), preserving the "new navigations hit the server" guarantee. Returns null when unavailable.

persistent

const persistent: {
  put(url: string, response: SingleResponse): Promise<void>;
  match(url: string): Promise<SingleResponse | null>;
  delete(url: string): Promise<boolean>;
};

Raw Cache API tier (store name modern-spf). Entries carry a timestamp and expire per cache-lifetime. Feature-detects caches — in non-secure contexts all methods are safe no-ops (match returns null).

Note: durableGet and persistent are exposed for testing and advanced use; the primary surface is get/set/remove/clear.