import { HTMLString } from './escape.js';
/**
 * LRU (Least Recently Used) cache for HTMLString objects.
 *
 * This cache reduces memory allocations by reusing identical HTMLString objects
 * across both recursive rendering (.astro files) and queue rendering (MDX files).
 *
 * When the cache reaches maxSize, the least recently used item is evicted.
 * This keeps memory usage bounded while maintaining good cache hit rates.
 *
 * Example:
 * - 10,000 identical `<li class="foo">` tags → single cached HTMLString object
 * - Memory savings: ~30KB (10,000 objects) → ~3 bytes (1 object + Map overhead)
 */
export declare class HTMLStringCache {
    private cache;
    private readonly maxSize;
    constructor(maxSize?: number);
    /**
     * Get or create an HTMLString for the given content.
     * If cached, the existing object is returned and moved to end (most recently used).
     * If not cached, a new HTMLString is created, cached, and returned.
     *
     * @param content - The HTML string content
     * @returns HTMLString object (cached or newly created)
     */
    getOrCreate(content: string): HTMLString;
    /**
     * Get current cache size
     */
    size(): number;
    /**
     * Pre-warms the cache with common HTML patterns.
     * This ensures first-render cache hits for frequently used tags.
     *
     * @param patterns - Array of HTML strings to pre-cache
     */
    warm(patterns: string[]): void;
    /**
     * Clear the entire cache
     */
    clear(): void;
}
/**
 * Common HTML patterns that appear frequently in Astro pages.
 * Pre-warming the cache with these patterns ensures first-render cache hits.
 */
export declare const COMMON_HTML_PATTERNS: string[];