import { Logger } from '@chimera-monorepo/utils';
/**
 * Cache item used in ProviderCache schema property; either blocks to live (BTL) or time to live (TTL) must
 * be specified (the former is preferred but the latter can be used as a backup when a block listener will not
 * be actively updating the cache's block number).
 */
type ProviderCacheSchema<T> = {
    [K in keyof T]: {
        btl: number;
        ttl?: number;
    } | {
        btl?: number;
        ttl: number;
    };
};
/**
 * @classdesc A data structure for managing time-sensitive (expiring) cached information from chain
 * that expires after a set number of blocks or amount of time.
 */
export declare class ProviderCache<T> {
    private readonly logger;
    private readonly schema;
    private _blockNumber;
    get blockNumber(): number;
    private _data;
    get data(): Partial<T>;
    /**
     * @param schema - A schema for the cache that determines whether each item expires after a set period of
     * time (ttl, ms) or a set number of blocks (btl, number).
     */
    constructor(logger: Logger, schema: ProviderCacheSchema<T>);
    /**
     * Update the cache block number, and optionally the data.
     * @param blockNumber - Current block number.
     * @param data - Optional data to update the cache with.
     */
    update(blockNumber: number, data?: Partial<T>): void;
    /**
     * Set a value in the cache.
     * @param data - The data to set.
     */
    set(data: Partial<T>): void;
    /**
     * Helper for retrieving item from data depending on whether it's expired.
     * @param key - a key of the cache data schema.
     * @returns
     */
    private getItem;
}
export {};
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