import { type DataSourceInstanceSettings, type DataSourceRef, type ScopedVars } from '@grafana/data';
import { type GetDataSourceListFilters } from '../dataSourceSrv';
/**
 * Populate the instance-settings cache from boot data. Intended to be called
 * exactly once at application startup via the `@grafana/runtime/internal` export.
 *
 * @internal
 */
export declare function initDataSourceInstanceSettings(settings: Record<string, DataSourceInstanceSettings>, defaultDsName: string): void;
export declare function reloadDataSourceInstanceSettings(): Promise<void>;
interface SyncDataSourceSettings {
    datasources: Record<string, DataSourceInstanceSettings>;
    defaultDatasource: string;
}
/**
 * Sync the instance-settings cache from an already-fetched `/api/frontend/settings`
 * payload, without issuing another backend request. Built-in (e.g. expression) and
 * runtime data sources survive because `populateMaps` re-applies them.
 *
 * Transition-period helper: while both the legacy `DataSourceSrv` and the new async
 * datasource APIs exist, `DataSourceSrv.reload()` calls this so a single fetch updates
 * both caches. Remove once `DataSourceSrv` is gone.
 *
 * @internal
 */
export declare function syncDataSourceInstanceSettings(settings: SyncDataSourceSettings): void;
/**
 * Look up the instance settings for a data source from the in-memory cache
 * populated at boot. Call {@link reloadDataSourceInstanceSettings} to refresh
 * the cache from the backend.
 *
 * `scopedVars` are used when `ref` contains a template variable (e.g. `$ds`).
 *
 * @public
 */
export declare function getDataSourceInstanceSettings(ref?: DataSourceRef | string | null, scopedVars?: ScopedVars): Promise<DataSourceInstanceSettings | undefined>;
/**
 * Search and filter data source instance settings from the in-memory cache.
 *
 * @internal
 */
export declare function getDataSourceInstanceSettingsList(filters?: GetDataSourceListFilters): Promise<DataSourceInstanceSettings[]>;
/**
 * Register the instance settings for a runtime data source so it is returned
 * by future lookups. Throws if the uid is already in use.
 *
 * @internal
 */
export declare function upsertRuntimeDataSourceInstanceSettings(settings: DataSourceInstanceSettings): void;
/**
 * Test helper — resets all module state. Should only be called from tests.
 *
 * @internal
 */
export declare function _resetForTests(): void;
export {};