export type FramePerfReason = "scroll" | "input" | "stream" | "resize" | "data" | "selection" | "manual" | "unknown";
export type FramePerfRowBucketFallback = Readonly<{
    plane: string;
    reason: "dirty-ratio" | "candidate-ratio";
    dirtyRows: number;
    planeNodes: number;
    candidates?: number;
}>;
export type FramePerfMailboxFailure = Readonly<{
    id: string;
    queued: number;
    dropped: number;
}>;
export type FramePerfSample = Readonly<{
    frameId: number;
    reason: FramePerfReason;
    startedAt: number;
    durationMs: number;
    renderManagerMs: number;
    commitMs: number;
    domFlushMs?: number;
    stdoutFlushMs?: number;
    dirtyRows: number | null;
    activePlanes: readonly string[] | null;
    scannedNodes: number;
    paintedNodes: number;
    rowBucketFallbacks?: readonly FramePerfRowBucketFallback[];
    coalescedInvalidates: number;
    frameTaskCount: number;
    coalescedFrameTasks: number;
    frameTaskQueueDepthBeforeRun: number;
    frameTaskQueueDepthAfterRun: number;
    remainingFrameTasks: number;
    droppedUpdates: number;
    mailboxFailure?: FramePerfMailboxFailure;
    queueDepth: number;
    liveReasons?: readonly string[];
}>;
export type FramePerfMetricStats = Readonly<{
    avg: number;
    max: number;
    min: number;
}>;
export type FramePerfDirtyRowsStats = Readonly<{
    avg: number;
    max: number;
    sampledFrames: number;
    fullFrames: number;
}>;
export type FramePerfSummary = Readonly<{
    frames: number;
    firstFrameId: number | null;
    latestFrameId: number | null;
    windowMs: number;
    durationMs: FramePerfMetricStats;
    renderManagerMs: FramePerfMetricStats;
    commitMs: FramePerfMetricStats;
    domFlushMs: FramePerfMetricStats;
    stdoutFlushMs: FramePerfMetricStats;
    dirtyRows: FramePerfDirtyRowsStats;
    scannedNodes: FramePerfMetricStats;
    paintedNodes: FramePerfMetricStats;
    coalescedInvalidates: number;
    coalescedFrameTasks: number;
    droppedUpdates: number;
    maxQueueDepth: number;
    rowBucketFallbacks: number;
    reasons: Partial<Record<FramePerfReason, number>>;
    activePlanes: Record<string, number>;
}>;
export declare function summarizeFramePerf(samples: readonly FramePerfSample[]): FramePerfSummary;
export declare function framePerfNow(): number;
export declare function mergeFramePerfReason(prev: FramePerfReason | undefined, next: FramePerfReason | undefined): FramePerfReason;