Digest-Based Cache Reader

/**
 * Reads cached content by its integrity digest and returns the bytes plus any stored metadata.
 *
 * @param {string} cacheDir path to the cache directory
 * @param {string} digest integrity digest (e.g., sha512-...)
 * @param {{ expectedSize?: number, memoize?: boolean }} [options]
 * @returns {Promise<{ data: Buffer, metadata?: any, size: number, integrity: string }>}
 */
export async function fetchByDigest(cacheDir, digest, options);

/**
 * Returns a readable stream of cached content identified only by the digest.
 *
 * @param {string} cacheDir path to the cache directory
 * @param {string} digest integrity digest (e.g., sha512-...)
 * @param {{ memoize?: boolean }} [options]
 * @returns {NodeJS.ReadableStream}
 */
export function streamByDigest(cacheDir, digest, options);

/**
 * Copies cached content addressed by digest to a destination file path.
 *
 * @param {string} cacheDir path to the cache directory
 * @param {string} digest integrity digest (e.g., sha512-...)
 * @param {string} destination absolute or relative destination file path
 * @param {{ mode?: number, memoize?: boolean }} [options]
 * @returns {Promise<{ size: number, integrity: string }>}
 */
export async function copyByDigest(cacheDir, digest, destination, options);