/** Number of consecutive unexpected full redraws that constitute a "storm". */
export declare const REPAINT_STORM_THRESHOLD = 3;
/** Hard cap on retained metric label keys; overflow is aggregated under `other`. */
export declare const MAX_LABEL_MAP_ENTRIES = 128;
export interface DurationStats {
    count: number;
    meanMs: number;
    p50Ms: number;
    p95Ms: number;
    p99Ms: number;
    maxMs: number;
}
export interface RssStats {
    samples: number;
    baselineBytes: number | null;
    lastBytes: number | null;
    peakBytes: number;
    growthBytes: number;
    /** RSS sampled after the run + a forced GC (informational). */
    returnBytes: number | null;
    /** Heap used at baseline and after the run + forced GC (reclaimable signal). */
    heapBaselineBytes: number | null;
    heapReturnBytes: number | null;
    /** (heapReturn - heapBaseline) / heapBaseline; <= tolerance means heap returned. */
    returnWithinBaselineFraction: number | null;
}
export interface HelperStat {
    count: number;
    totalMs: number;
    meanMs: number;
}
export interface LineCountGauge {
    last: number;
    max: number;
}
export interface RenderMetricsSnapshot {
    enabled: boolean;
    renderCount: number;
    renderDurations: DurationStats;
    durationsTruncated: boolean;
    requestSources: Record<string, number>;
    fullRedrawCount: number;
    fullRedrawCauses: Record<string, number>;
    repaintStorms: number;
    maxConsecutiveFullRedraws: number;
    rss: RssStats;
    ownerGauges: Record<string, number>;
    timerGauges: Record<string, number>;
    helperStats: Record<string, HelperStat>;
    lineCounts: Record<string, LineCountGauge>;
    structuralCounters: Record<string, number>;
}
export declare class RenderMetrics {
    #private;
    constructor(enabled?: boolean);
    get enabled(): boolean;
    enable(): void;
    disable(): void;
    /** Reset all collected data (keeps the enabled state). */
    reset(): void;
    /** High-resolution clock for timing render passes. Returns 0 when disabled. */
    now(): number;
    /** Record that a render was requested, attributed to a caller source. */
    recordRequest(source?: string): void;
    /** Record one completed `#doRender` pass duration (ms). */
    recordRender(durationMs: number): void;
    /** Record a full-redraw event and classify its cause for storm detection. */
    recordFullRedraw(cause: string): void;
    /** Sample current RSS. Records baseline on first sample, tracks peak/last. */
    sampleRss(): number;
    setOwnerGauge(name: string, value: number): void;
    setTimerGauge(name: string, value: number): void;
    /** Accumulate timing/count for a named render helper (e.g. "renderTree"). */
    recordHelper(name: string, durationMs: number): void;
    /** Record a per-render line-count gauge (e.g. "rendered", "normalized", "diffed"). */
    recordLineCount(name: string, value: number): void;
    /** Accumulate deterministic structural render work without retaining frame data. */
    recordStructuralCounter(name: string, value?: number): void;
    /**
     * Force a GC when the runtime exposes one and sample RSS as the post-run
     * "return" value used by the memory-leak gate. Callers should drop large
     * references before calling so reclaimable memory is actually freed.
     */
    sampleReturn(): number;
    snapshot(): RenderMetricsSnapshot;
}
/** Shared metrics instance used by the TUI render loop. */
export declare const renderMetrics: RenderMetrics;