/**
 * Private replay/live-drain algorithm shared by every `createReplayLiveFeed()`
 * instance (`workflow-event-feed.ts`'s per-workflow feed and
 * `fleet-event-feed.ts`'s fleet-wide feed). Split out of
 * `workflow-event-feed.ts` purely to keep that file under the repository's
 * implementation-file line limit — nothing here is public API.
 *
 * @module server/replay-live-feed-internals
 */
import type { ReplayLiveFeedBackend, ReplayLiveSubscribeOptions, SequencedEventEnvelope } from './workflow-event-feed.ts';
export declare function createSerialOperationQueue(): <T>(operation: () => Promise<T>) => Promise<T>;
type DurableSubscriptionOptions = {
    readonly pollIntervalMs: number;
    readonly lifecycleSignal?: AbortSignal;
};
export declare function createDurableSubscription<TEnvelope extends SequencedEventEnvelope>(backend: ReplayLiveFeedBackend<TEnvelope>, options: DurableSubscriptionOptions, args?: ReplayLiveSubscribeOptions<TEnvelope>): AsyncIterable<TEnvelope>;
/** Thrown when a replay window exceeds the caller's configured limit. */
export declare class ReplayWindowExceededError extends Error {
    readonly count: number;
    readonly limit: number;
    constructor(count: number, limit: number);
}
export declare function replayUpTo<TEnvelope extends SequencedEventEnvelope>(backend: ReplayLiveFeedBackend<TEnvelope>, afterSequence: number, snapshot: number, signal: AbortSignal | undefined, replayOptions: ReplayLiveSubscribeOptions<TEnvelope> | undefined): AsyncIterable<TEnvelope>;
export declare function shouldDeliverEnvelope<TEnvelope extends SequencedEventEnvelope>(envelope: TEnvelope, replayOptions: ReplayLiveSubscribeOptions<TEnvelope> | undefined): boolean;
export declare function drainLive<TEnvelope extends SequencedEventEnvelope>(buffer: TEnvelope[], snapshot: number, signal: AbortSignal | undefined, overflowed: () => boolean, installWaker: (fn: (() => void) | null) => void): AsyncIterable<TEnvelope>;
export {};