import { RenderResult } from '../types.js';
export interface CachedPage extends RenderResult {
    readonly key: string;
    readonly bitmap: ImageBitmap | HTMLCanvasElement;
    readonly byteSize: number;
    lastAccessed: number;
}
export declare class PageCache {
    private cache;
    private totalBytes;
    private readonly maxBytes;
    constructor(maxBytes?: number);
    get(key: string): CachedPage | null;
    set(key: string, page: CachedPage): void;
    has(key: string): boolean;
    delete(key: string): void;
    clear(): void;
    get bytes(): number;
    get size(): number;
    shrinkTo(targetBytes: number): void;
    /** Drop least-recently-used pages down to a fraction of the budget. */
    trim(fraction?: number): void;
    private dispose;
}
/**
 * Build a cache key for a rendered page.
 */
export declare function makeCacheKey(format: string, pageIndex: number, zoom: number, rotation: number, dpr?: number): string;
/** Estimate the byte size of an ImageBitmap or canvas. */
export declare function estimateBitmapByteSize(width: number, height: number, dpr?: number): number;