import type { IActionHttp, IActorHttpOutput, IActorHttpArgs } from '@comunica/bus-http';
import { ActorHttp } from '@comunica/bus-http';
import type { ActorHttpInvalidateListenable } from '@comunica/bus-http-invalidate';
import type { TestResult } from '@comunica/core';
import type { IMediatorTypeTime } from '@comunica/mediatortype-time';
export declare class ActorHttpFetch extends ActorHttp {
    private readonly fetchInitPreprocessor;
    private static readonly userAgent;
    constructor(args: IActorHttpFetchArgs);
    test(_action: IActionHttp): Promise<TestResult<IMediatorTypeTime>>;
    run(action: IActionHttp): Promise<IActorHttpOutput>;
    /**
     * Prepares the request headers, taking into account the environment.
     * @param {IActionHttp} action The HTTP action
     * @returns {Headers} Headers
     */
    prepareRequestHeaders(action: IActionHttp): Headers;
    /**
     * Converts a string, including ones with Unicode symbols, to Base64 encoding.
     * This function was adapted from the MDN example function here:
     * https://developer.mozilla.org/en-US/docs/Glossary/Base64#the_unicode_problem
     * @param {string} value The string value to encode
     * @returns {string} The Base64-encoded value
     */
    static stringToBase64(value: string): string;
}
export interface IActorHttpFetchArgs extends IActorHttpArgs {
    /**
     * Maximum size of the cache (in bytes).
     * Defaults to 100MB.
     * @range {integer}
     * @default {104857600}
     */
    cacheMaxSize: number;
    /**
     * Maximum number of documents to store in the cache.
     * @range {integer}
     * @default {1000}
     */
    cacheMaxCount: number;
    /**
     * Maximum size of an entry in the cache (in bytes).
     * Defaults to 5MB.
     * @range {integer}
     * @default {5242880}
     */
    cacheMaxEntrySize: number;
    /**
     * An actor that listens to HTTP invalidation events
     * @default {<default_invalidator> a <npmd:@comunica/bus-http-invalidate/^5.0.0/components/ActorHttpInvalidateListenable.jsonld#ActorHttpInvalidateListenable>}
     */
    httpInvalidator: ActorHttpInvalidateListenable;
    /**
     * The agent options for the HTTP agent
     * @range {json}
     * @default {{ "keepAlive": true, "maxSockets": 5 }}
     */
    agentOptions?: Record<string, any>;
}