type FindCallback<T> = (value: T) => boolean;
/**
 * Very simple least-recently-used cache implementation
 * that should be fast enough for very small cache sizes
 */
export declare class BaseLRUCache<T> {
    readonly limit: number;
    protected _entries: T[];
    constructor(limit: number);
    get size(): number;
    protected _get(findEntryFn: FindCallback<T>): T | undefined;
    protected _getByIndexAndMoveUp(idx: number): T | undefined;
    protected _set(value: T, findEntryFn?: FindCallback<T>): void;
    protected onEvictEntry(entry: T): void;
}
export declare class LRUCache<T, K> extends BaseLRUCache<T> {
    private _keyFn;
    constructor(limit: number, keyFn: (T: any) => K);
    get(key: K): T | undefined;
    set(value: T): void;
}
export declare function tests(): {
    "can retrieve added entries": (assert: any) => void;
    "first entry is evicted first": (assert: any) => void;
    "second entry is evicted if first is requested": (assert: any) => void;
    "setting an entry twice removes the first": (assert: any) => void;
    "evict callback is called": (assert: any) => void;
    "evict callback is called when replacing entry with same identity": (assert: any) => void;
};
export {};