import type { SSRManifest } from '../app/types.js';
/**
 * Shared helpers for "derived once per process per manifest" memoization.
 * Manifest-keyed WeakMaps are the sanctioned memoization primitive of the
 * request core: each derivation lives in its owning module with its own memo —
 * there is deliberately no central registry and no "get all derived state"
 * function anywhere.
 *
 * Note: values are scoped per manifest OBJECT. Two `App`s constructed over the
 * same manifest object (e.g. the cloudflare custom-fetch worker) share every
 * memoized derivation.
 */
export interface ManifestMemo<T> {
    get(manifest: SSRManifest): T;
    /** Whether a value is currently stored for the manifest (derived or set). */
    has(manifest: SSRManifest): boolean;
    /** Replaces the stored value atomically (HMR replacement). */
    set(manifest: SSRManifest, value: T): void;
    invalidate(manifest: SSRManifest): void;
}
export declare function createManifestMemo<T>(derive: (manifest: SSRManifest) => T): ManifestMemo<T>;
export interface AsyncManifestMemo<T> {
    get(manifest: SSRManifest): Promise<T>;
    invalidate(manifest: SSRManifest): void;
}
/**
 * Caches the PROMISE (single-flight: concurrent callers share one derivation).
 * On rejection the entry is DELETED so the next call retries a failed lazy
 * resolve instead of caching the failure forever.
 */
export declare function createAsyncManifestMemo<T>(derive: (manifest: SSRManifest) => Promise<T>): AsyncManifestMemo<T>;