import type { BudgetReservationRecord, BudgetReservationStatus } from '../types/lifecycle.js';
/**
 * A change to one recorded reservation: where it moves, what it charges once there, and the
 * statuses it may move from. A store applies the status and the difference in what it charges to its
 * total together, or not at all.
 */
export interface BudgetReservationChange {
    /** Where it moves. */
    status: Exclude<BudgetReservationStatus, 'reserved'>;
    /** What it adds to its total once moved. */
    charged: number;
    /** The statuses it may move from. From any other, the change is refused. */
    from: readonly BudgetReservationStatus[];
    /** When, epoch milliseconds. */
    at: number;
    /** What its operation cost, when settled. */
    actual?: number;
}
/**
 * Reservations in process memory, beside the totals of the store that holds them: what
 * `MemoryBudgetUsage` and `MemoryTenantUsage` keep them in. Each change and its total move together,
 * since nothing runs between them on one thread.
 */
export declare class MemoryReservationBook {
    private readonly add;
    private readonly now;
    private readonly records;
    private prunedAt;
    constructor(add: (key: string, amount: number, resetAt: number) => number, now: () => number);
    /** Records a reservation and adds what it charges to its total. */
    hold(record: BudgetReservationRecord): number;
    /** Moves a reservation, and its total by what it charges differently, if it stands where `from` allows. */
    settle(id: string, change: BudgetReservationChange): boolean;
    /** Extends a reserved reservation's lease. */
    renew(id: string, leasedUntil: number): boolean;
    /** Reserved reservations whose lease lapsed by `now`, soonest lapsed first. */
    lapsed(now: number, limit: number, operation?: string): BudgetReservationRecord[];
    /** One reservation. */
    get(id: string): BudgetReservationRecord | undefined;
    /**
     * Forgets what no report can change any more, at most once a minute: anything whose period has
     * ended, and a settled, released, or expired reservation after an hour. An uncertain one is kept
     * for its period, until its operation says what it cost.
     */
    private prune;
}