export interface Sample {
    t: number;
    values: Record<string, number>;
}
export interface SignalStats {
    min: number;
    max: number;
    avg: number;
    last: number;
    slope: number;
    first_t: number;
    last_t: number;
    n: number;
}
export interface Point {
    t: number;
    v: number;
}
export declare class TraceBuffer {
    private signals;
    private capacity;
    private buf;
    constructor(signals: string[], capacity: number);
    push(s: Sample): void;
    count(): number;
    signalNames(): string[];
    /** Add a signal to the watched set (no-op if already present). Does not touch
     *  stored samples — history of a previously-removed signal survives in the ring. */
    addSignal(name: string): void;
    /** Drop a signal from the watched set (no-op if absent). Stored samples are
     *  left intact so already-captured history remains queryable until it ages out. */
    removeSignal(name: string): void;
    stats(sig: string): SignalStats | null;
    downsample(sig: string, maxPoints: number, window?: {
        fromT?: number;
        toT?: number;
    }): Point[];
    /** Read-only view of stored samples (oldest→newest). */
    samples(): readonly Sample[];
}