import type * as RDF from '@rdfjs/types';
import type { QuadTermName } from 'rdf-terms';
import type { IQuadSink } from '../io/IQuadSink';
/**
 * Buffers quads with blank nodes keys, and makes connections to non-blank node keys.
 */
export declare class FragmentationBlankNodeBuffer<TA extends QuadTermName, TB extends QuadTermName> {
    private readonly keyKey;
    private readonly keyValue;
    private readonly valueKeyLinks;
    private readonly pendingBlankKeyQuads;
    private readonly eagerFlushing;
    /**
     * @param keyKey @ignored The quad term key that should be checked for blank nodes.
     * @param keyValue @ignored The quad term value that may have a connection to the key.
     * @param eagerFlushing @ignored If the pending quads in the buffer should be flushed as soon as possible.
     */
    constructor(keyKey: TA, keyValue: TB, eagerFlushing: boolean);
    /**
     * Add the given quad into the buffer.
     * If the quad's key is a blank node, it will be stored inside the internal buffer.
     * @param quad An RDF quad.
     * @param quadSink The quad sink to push into.
     */
    push(quad: RDF.Quad, quadSink: IQuadSink): Promise<void>;
    /**
     * If the given term value is a blank node, it will be stored in the internal link registry.
     * @param value A quad value term.
     * @param key A quad key term.
     * @param quadSink The quad sink to push into.
     */
    materializeValueForNamedKey(value: RDF.Term, key: RDF.NamedNode, quadSink: IQuadSink): Promise<void>;
    /**
     * Try to flush all quads connected to the given blank node label.
     * All flushed quads will be removed from the queue (`pendingBlankKeyQuads`).
     * The value key links will remain unchanged.
     * @param blankNodeLabel A blank node label.
     * @param quadSink The sink to push into.
     */
    protected attemptFlushQuadsForLabel(blankNodeLabel: string, quadSink: IQuadSink): Promise<boolean>;
    /**
     * Iterate over the buffer, and emit all quads with blank node keys that have a connection to a non-blank node key.
     * @param quadSink The quad sink to push into.
     */
    flush(quadSink: IQuadSink): Promise<void>;
}