/**
 * Group-commit writer for WAL lines.
 */
import { WalRecord } from './types';
export declare class BatchingWriter {
    private pending;
    private flushScheduled;
    /**
     * Enqueue an append for `record`. Resolves once the record (and its
     * batch-mates) have been fsynced to `queue.log`.
     */
    submit(record: WalRecord): Promise<void>;
    /**
     * Enqueue a tombstone for `id`. Resolves once the tombstone (and its
     * batch-mates) have been fsynced to `queue.log`.
     */
    submitTombstone(id: string): Promise<void>;
    private enqueue;
    private scheduleFlush;
    private drainAndFlush;
}