import type { FeedBlock } from "./feed-blocks.js";
/** One blank row separates committed blocks; nothing inside a block. */
export declare const BLOCK_GAP_ROWS = 1;
export declare function blockHeight(block: FeedBlock): number;
/** Rows a run of blocks occupies once inter-block gaps are counted. */
export declare function totalHeight(blocks: readonly FeedBlock[], gap?: number): number;
/**
 * Newest-first walk: how many trailing blocks fit in `budget` rows. Always at
 * least one when the budget is positive, so the newest block is never dropped
 * entirely — the live-tail policy bounds it instead.
 */
export declare function trailingBlocksWithin(blocks: readonly FeedBlock[], budget: number, gap?: number): number;