import { DifferentialWatchedQuery, DifferentialWatchedQueryComparator, DifferentialWatchedQuerySettings, WatchedQueryDifferential } from '@powersync/common';
import { AbstractQueryProcessor, AbstractQueryProcessorOptions, LinkQueryOptions } from './AbstractQueryProcessor.js';
/**
 * @internal
 */
export interface DifferentialQueryProcessorOptions<RowType> extends AbstractQueryProcessorOptions<RowType[], DifferentialWatchedQuerySettings<RowType>> {
    rowComparator?: DifferentialWatchedQueryComparator<RowType>;
}
type DataHashMap<RowType> = Map<string, {
    hash: string;
    item: RowType;
}>;
/**
 * An empty differential result set.
 * This is used as the initial state for differential incrementally watched queries.
 *
 * @internal
 */
export declare const EMPTY_DIFFERENTIAL: {
    added: never[];
    all: never[];
    removed: never[];
    updated: never[];
    unchanged: never[];
};
/**
 * Default implementation of the {@link DifferentialWatchedQueryComparator} for watched queries.
 * It keys items by their `id` property if available, alternatively it uses JSON stringification
 * of the entire item for the key and comparison.
 *
 * @internal
 */
export declare const DEFAULT_ROW_COMPARATOR: DifferentialWatchedQueryComparator<any>;
/**
 * Uses the PowerSync onChange event to trigger watched queries.
 * Results are emitted on every change of the relevant tables.
 * @internal
 */
export declare class DifferentialQueryProcessor<RowType> extends AbstractQueryProcessor<ReadonlyArray<Readonly<RowType>>, DifferentialWatchedQuerySettings<RowType>> implements DifferentialWatchedQuery<RowType> {
    protected options: DifferentialQueryProcessorOptions<RowType>;
    protected comparator: DifferentialWatchedQueryComparator<RowType>;
    constructor(options: DifferentialQueryProcessorOptions<RowType>);
    protected differentiate(current: RowType[], previousMap: DataHashMap<RowType>): {
        diff: WatchedQueryDifferential<RowType>;
        map: DataHashMap<RowType>;
        hasChanged: boolean;
    };
    protected linkQuery(options: LinkQueryOptions<WatchedQueryDifferential<RowType>>): Promise<void>;
}
export {};