import { FallbackPumpState } from "./stream-pump-state.js";
import type { ResolvedEntry } from "./stream-types.js";
export declare abstract class FallbackPumpAdmission extends FallbackPumpState {
    protected abstract discardDeferredConcurrencySkip(idx: number): void;
    protected abstract emitSkippedAttempt(idx: number, reason: "concurrency" | "cooldown"): void;
    protected admitNext(retry: boolean, withinAttemptBudget: boolean, nextIndex: number): Promise<{
        acquired?: {
            index: number;
            inFlight?: number;
        };
        error?: unknown;
    }>;
    protected backoffBeforeAdmission(): Promise<void>;
    protected nextAvailableIndex(startIndex: number): number;
    protected prepareCandidateBeforeAdmission(candidate: ResolvedEntry): boolean;
    protected prepareOwnedCandidate(candidate: ResolvedEntry): boolean;
    protected invokePrepareCandidate(candidate: ResolvedEntry): unknown;
    protected acquirePreparedCandidate(candidate: ResolvedEntry): number | undefined;
    protected availableAfterAdmission(candidate: ResolvedEntry): boolean;
    protected acquireNext(startIndex: number): Promise<{
        index: number;
        inFlight?: number;
    } | undefined>;
    protected waitForCapacity(index: number): Promise<{
        index: number;
        inFlight?: number;
    } | undefined>;
    protected assertWaitDeadline(): void;
}