import type { CacheControlMetadata, CacheEntry } from '@conduit-client/service-cache/v1';
export type CacheUpdate = {
    type: CacheOperation;
};
export type CacheOperation = 'invalidate' | 'evict';
/**
 * Processes a cache update operation and determines the appropriate modification.
 *
 * This function analyzes the provided `update` and the `existing` cache entry
 * to determine the necessary update type. It returns one of three possible outcomes:
 *
 * - `{ type: 'entry', entry }`: A full cache entry update, including both value and metadata.
 * - `{ type: 'metadata', metadata }`: A metadata-only update, leaving the value unchanged.
 * - `{ type: 'no-op' }`: No changes are needed, and the cache should remain as is.
 *
 * @param update - The cache update operation to apply.
 * @param existing - The existing cache entry being modified.
 * @returns An object indicating the type of update:
 *   - A full cache entry update (`type: 'entry'`)
 *   - A metadata-only update (`type: 'metadata'`)
 *   - A delete update if eviction is called for (`type: 'delete'`)
 *   - A no-op (`type: 'no-op'`) if no changes are required.
 */
export declare function buildUpdate(update: CacheUpdate, existing: CacheEntry<unknown>): {
    type: 'entry';
    entry: CacheEntry<unknown>;
} | {
    type: 'metadata';
    metadata: CacheControlMetadata;
} | {
    type: 'delete';
} | {
    type: 'no-op';
};