import { ExportResult } from '@opentelemetry/core';
import { ReadableSpan as OTelReadableSpan, SpanExporter } from '@opentelemetry/sdk-trace-base';
import { WalRecord } from './types';
/**
 * Hook-side submit function. Returns once the daemon has fsynced the
 * record to `queue.log` (ack-after-fsync). Injectable so tests can
 * swap in a stub without spinning up an actual daemon.
 */
export type SubmitRecord = (record: WalRecord) => Promise<void>;
/**
 * Asynchronous SpanExporter that decouples the user's Stop hook from
 * backend latency for MlflowSpanProcessor.
 *
 * {@link forceFlush} awaits only the IPC submits, *not* the upstream
 * upload. That gives the Stop hook the exact "trace is durable on this
 * machine, then return" semantics it needs to bound its runtime.
 */
export declare class MlflowWalSpanExporter implements SpanExporter {
    private _pendingSubmits;
    private _submit;
    private _shuttingDown;
    constructor(opts?: {
        submit?: SubmitRecord;
    });
    export(spans: OTelReadableSpan[], resultCallback: (result: ExportResult) => void): void;
    /**
     * Resolves once every IPC submit that was in flight when this method
     * was called has been acknowledged (post-fsync). Matches OTel's
     * "flush currently pending" semantic — concurrent `export()` calls
     * during the await are not waited on, and the next `forceFlush` will
     * pick them up. For "drain everything before exit" semantics, use
     * {@link shutdown}.
     */
    forceFlush(): Promise<void>;
    /**
     * Stop accepting new exports and drain every in-flight IPC submit to
     * convergence before resolving.
     */
    shutdown(): Promise<void>;
}