import { UnixTimestamp } from '@thermopylae/core.declarations';
import { EntryExpiredCallback, ExpirableEntry, GarbageCollector } from './interface';
import { HeapNode } from '../data-structures/heap';
/**
 * @private
 */
interface HeapExpirableEntry extends ExpirableEntry, HeapNode {
}
/**
 * {@link GarbageCollector} which uses a binary min heap to keep entries that needs to be evicted. <br/>
 * Each heap node is represent by cache entry which contains expiration time. <br/>
 * Eviction timer is always synchronized with heap root and fires at expiration time of root entry.
 * When it fires, will evict root and other nodes that have expiration time equal to root.
 * After that, timer will fire again at the expiration time of the newest root.
 *
 * @template T	Type of the cache entry.
 */
declare class HeapGarbageCollector<T extends HeapExpirableEntry> implements GarbageCollector<T> {
    private readonly entries;
    private cleanUpInterval;
    private entryExpiredCb;
    constructor(entryExpiredCb?: EntryExpiredCallback<T>);
    get size(): number;
    get idle(): boolean;
    manage(entry: T): void;
    update(_oldExpiration: UnixTimestamp, entry: T): void;
    leave(entry: T): void;
    clear(): void;
    setEntryExpiredCallback(cb: EntryExpiredCallback<T>): void;
    /**
     * This method synchronizes garbage collection. <br/>
     * It needs to be called every time expirable keys heap is altered.
     */
    private synchronizeEvictionTimer;
    private scheduleNextGc;
    private evictExpiredEntries;
    private static defaultEntryExpiredCallback;
}
export { HeapGarbageCollector, HeapExpirableEntry };