import { ValveConfig } from '@deepstream/types';
export default class RuleCache {
    private data;
    private purgeInterval;
    /**
     * This cache stores rules that are frequently used. It removes
     * unused rules after a preset interval
     */
    constructor(config: ValveConfig);
    close(): void;
    /**
     * Empties the rulecache completely
     */
    reset(): void;
    /**
     * Checks if an entry for a specific rule in a specific section is
     * present
     */
    has(section: string, name: string, type: string): boolean;
    /**
     * Resets the usage flag and returns an entry from the cache
     */
    get(section: string, name: string, type: string): string | undefined;
    /**
     * Adds an entry to the cache
     */
    set(section: string, name: string, type: string, rule: string): void;
    /**
     * This method is called repeatedly on an interval, defined by
     * cacheEvacuationInterval.
     *
     * If a rule in the cache has been used in the last interval, it sets its isUsed flag to false.
     * Whenever the rule is used, the isUsed flag will be set to true
     * Any rules that haven't been used in the next cycle will be removed from the cache
     */
    private purge;
}