/**
 * Fixed bucket boundaries in milliseconds, roughly 2-3x steps. Fixed rather than
 * configurable because two ranges holding different layouts cannot be merged into one
 * percentile without layout versioning, and the merge is what makes multi-day queries work.
 *
 * The tail past 10 minutes exists for wait time, where a stalled queue genuinely sits for
 * hours. Without it p99 wait collapses to "over 10 minutes" exactly when it needs to be
 * actionable.
 */
export declare const BUCKET_BOUNDS: number[];
/** One bucket per bound, plus a final overflow bucket for anything past the last bound. */
export declare const BUCKET_COUNT: number;
export declare function bucketIndex(ms: number): number;
export declare function emptyVector(): number[];
export declare function packVector(vector: number[]): string;
export declare function unpackVector(raw: string | null): number[];
export declare function mergeVectors(a: number[], b: number[]): number[];
export declare function vectorTotal(vector: number[]): number;
/**
 * Prometheus-style histogram_quantile: find the bucket holding the rank, then interpolate
 * linearly across that bucket's span. The result is an estimate bounded by bucket width,
 * never more precise than the layout allows.
 *
 * Samples in the overflow bucket have no upper bound to interpolate towards, so they report
 * the last finite bound rather than inventing a ceiling.
 */
export declare function quantile(vector: number[], p: number): number;