import { StoryRuntime } from './story-types.js';
/**
 * A bounded LRU cache for {@link StoryRuntime} instances.
 *
 * Entries are keyed by canonical story key (produced by {@link buildStoryKey}).
 * The cache maintains insertion/access order via a doubly linked list so that
 * eviction targets the least recently used non-body entry.
 *
 * @example
 * ```ts
 * const cache = new StoryRuntimeCache(10);
 * cache.set('fn:12', footnoteRuntime);
 * const rt = cache.get('fn:12'); // promotes to most-recently-used
 * ```
 */
export declare class StoryRuntimeCache {
    private readonly capacity;
    private readonly map;
    /** Sentinel head (most recently used). */
    private readonly head;
    /** Sentinel tail (least recently used). */
    private readonly tail;
    constructor(capacity?: number);
    /**
     * Retrieves a cached runtime by story key.
     *
     * Accessing an entry promotes it to the most-recently-used position.
     *
     * @param storyKey - Canonical story key.
     * @returns The cached runtime, or `undefined` if not present.
     */
    get(storyKey: string): StoryRuntime | undefined;
    /**
     * Inserts or updates a runtime in the cache.
     *
     * If the cache is at capacity, the least recently used non-body entry
     * is evicted first.
     *
     * @param storyKey - Canonical story key.
     * @param runtime  - The runtime to cache.
     */
    set(storyKey: string, runtime: StoryRuntime): void;
    /**
     * Removes a runtime from the cache.
     *
     * The runtime's `dispose` callback is **not** called — this is an
     * explicit removal, not an eviction.
     *
     * @param storyKey - Canonical story key.
     * @returns `true` if the entry existed and was removed.
     */
    delete(storyKey: string): boolean;
    /**
     * Removes all entries from the cache.
     *
     * Calls `dispose` on every cached runtime that has one.
     */
    clear(): void;
    /**
     * Removes an entry and disposes its runtime.
     *
     * Unlike {@link delete}, this calls `dispose` on the removed runtime,
     * making it suitable for cache invalidation after part mutations.
     *
     * @param storyKey - Canonical story key.
     * @returns `true` if the entry existed and was invalidated.
     */
    invalidate(storyKey: string): boolean;
    /**
     * Invalidates all entries whose keys start with the given prefix.
     *
     * Useful for bulk-invalidating all notes (`'fn:'`, `'en:'`) or all
     * header/footer runtimes (`'hf:'`) after a part mutation.
     *
     * @param prefix - The key prefix to match (e.g., `'fn:'`).
     * @returns The number of entries invalidated.
     */
    invalidateByPrefix(prefix: string): number;
    /**
     * Returns `true` if the cache contains an entry for the given story key.
     *
     * Does NOT promote the entry — use {@link get} if you intend to read it.
     *
     * @param storyKey - Canonical story key.
     */
    has(storyKey: string): boolean;
    /** The number of entries currently in the cache. */
    get size(): number;
    /** Detaches a node from its current position in the list. */
    private detach;
    /** Inserts a node immediately after the head sentinel (most recent). */
    private attachAfterHead;
    /**
     * Evicts the least recently used non-body entry.
     *
     * Scans backward from the tail sentinel to find the first eviction
     * candidate (any entry whose key is not the body story key).
     */
    private evictLru;
}
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