import type { LanguageModelV4StreamPart, LanguageModelV4StreamResult } from "@ai-sdk/provider";
import type { HealthTransition } from "./health-store.js";
import { type FallbackPumpConfig } from "./stream-config.js";
import { StreamLifecycleValidator } from "./stream-lifecycle-validator.js";
import type { StreamJsonBudget } from "./stream-part-json.js";
import { type CapturedReader } from "./stream-reader.js";
import type { FallbackStreamArgs, ResolvedEntry } from "./stream-types.js";
import type { FailureClassification, OnRouterAttempt, RouterOrderingToken } from "./types.js";
export declare abstract class FallbackPumpContext {
    protected committed: boolean;
    protected candidateCommitted: boolean;
    protected finished: boolean;
    protected readonly metadataNodeCounts: WeakMap<object, number>;
    protected readonly opaquePartTypes: WeakMap<object, string>;
    protected readonly streamJsonBudget: {
        remainingFileBytes: number;
        remaining: number;
        remainingCharacters: number;
        remainingMetadataCharacters: number;
    };
    protected candidateBudgetCheckpoint: StreamJsonBudget;
    protected prelude: LanguageModelV4StreamPart[];
    protected preludeMetadataNodes: number;
    protected preludeTextChars: number;
    protected cancelled: boolean;
    protected cancelReason: unknown;
    protected readonly errors: unknown[];
    protected activeReader: CapturedReader | null;
    protected resumeDemand?: () => void;
    protected readonly candidates: ResolvedEntry[];
    protected readonly config: FallbackPumpConfig;
    protected readonly acquireCandidate: FallbackStreamArgs["acquireCandidate"];
    protected readonly candidateAvailable: FallbackStreamArgs["candidateAvailable"];
    protected readonly candidateInFlight: FallbackStreamArgs["candidateInFlight"];
    protected readonly concurrencyLimit: FallbackStreamArgs["concurrencyLimit"];
    protected readonly prepareCandidate: FallbackStreamArgs["prepareCandidate"];
    protected readonly releaseCandidate: FallbackStreamArgs["releaseCandidate"];
    protected readonly releaseProbeCandidate: FallbackStreamArgs["releaseProbeCandidate"];
    protected readonly waitForCandidate: FallbackStreamArgs["waitForCandidate"];
    protected readonly classifyFailure: FallbackStreamArgs["classifyFailure"];
    protected readonly isBudgetFailure: FallbackStreamArgs["isBudgetFailure"];
    protected readonly nextOrderingToken: FallbackStreamArgs["nextOrderingToken"];
    protected readonly onAdvance: FallbackStreamArgs["onAdvance"];
    protected readonly onAttempt: FallbackStreamArgs["onAttempt"];
    protected readonly onCandidateFailure: FallbackStreamArgs["onCandidateFailure"];
    protected readonly onCandidateSuccess: FallbackStreamArgs["onCandidateSuccess"];
    protected readonly onError: FallbackStreamArgs["onError"];
    protected readonly onRequestOutcome: FallbackStreamArgs["onRequestOutcome"];
    protected readonly shouldRetry: FallbackStreamArgs["shouldRetry"];
    protected readonly setActive: (result: LanguageModelV4StreamResult) => void;
    protected readonly controller: ReadableStreamDefaultController<LanguageModelV4StreamPart>;
    protected attemptsStarted: number;
    protected attemptStartedAt: number;
    protected attemptOrderingToken: RouterOrderingToken;
    protected validator: StreamLifecycleValidator;
    protected activeInFlight?: number;
    protected activeIndex?: number;
    protected pendingFallbackIndex?: number;
    protected waitingIndex?: number;
    protected cancelledPendingIndex?: number;
    protected budgetFailureObserved: boolean;
    protected budgetSuppressed: boolean;
    protected deferSkippedAttemptEvents: boolean;
    protected readonly deferredSkippedAttemptEvents: Parameters<OnRouterAttempt>[0][];
    protected requestOutcomeObserved: boolean;
    protected readonly operationAbort: AbortController;
    protected removeCallerAbort?: () => void;
    protected callerAbortObserved: boolean;
    protected callerAbortReason: unknown;
    protected abstract captureCallerAbortReason(signal: AbortSignal | undefined): unknown;
    protected abstract cleanupAbortForwarding(): void;
    protected abstract emitAttempt(idx: number, outcome: "success" | "failure" | "cancelled", error?: unknown, failure?: FailureClassification, willRetry?: boolean, healthTransition?: HealthTransition, inFlight?: number): void;
    protected abstract finishRequest(success: boolean): void;
    protected abstract pump(result: LanguageModelV4StreamResult, idx: number): Promise<void>;
    protected abstract releaseActiveCandidate(): void;
    constructor(args: FallbackStreamArgs, setActive: (result: LanguageModelV4StreamResult) => void, controller: ReadableStreamDefaultController<LanguageModelV4StreamPart>, firstResult: LanguageModelV4StreamResult);
}