/**
 * Caps the combined serialized size of `web.fetch` metadata (headers, TLS,
 * timing, redirect chain, cookies) at {@link METADATA_BUDGET_BYTES} (64 KiB),
 * trimming in order: trailing cookies, then longest header values (down to
 * 1024 chars, keys always kept), then trailing redirect hops. Pure function;
 * bounded iteration count so a pathological input can't loop indefinitely.
 */
import { type CookieInfo, type HeaderMap, type RedirectChain, type TimingInfo, type TlsInfo, METADATA_BUDGET_BYTES } from "./types.js";
/**
 * Inputs accepted by {@link enforce}.
 *
 * Each field corresponds to one slice of {@link WebFetchMetadata}.
 * Fields that the caller chose not to include (for example because the
 * user passed `includeHeaders=false`) may be omitted or set to
 * `undefined`; they are passed through to the result unchanged.
 */
export interface BudgetInput {
    headers?: HeaderMap | undefined;
    tls?: TlsInfo | undefined;
    timing?: TimingInfo | undefined;
    redirectChain?: RedirectChain | undefined;
    cookies?: CookieInfo[] | undefined;
}
/**
 * Result returned by {@link enforce}. Optional fields are present iff
 * the corresponding input field was present (an empty array is still
 * "present"). `metadataBytes` is the UTF-8 byte length of
 * `JSON.stringify({headers, tls, timing, redirectChain, cookies})` after
 * the truncation loop has finished. `cap` mirrors the constant from
 * `types.ts` so consumers can render `metadataBytes / cap` without
 * importing it themselves.
 */
export interface BudgetResult {
    headers?: HeaderMap;
    tls?: TlsInfo;
    timing?: TimingInfo;
    redirectChain?: RedirectChain;
    cookies?: CookieInfo[];
    metadataBytes: number;
    cap: typeof METADATA_BUDGET_BYTES;
}
/**
 * Enforce the 64 KiB metadata budget on the supplied fields.
 *
 * Returns a fresh {@link BudgetResult} containing (possibly shortened)
 * copies of `headers`, `redirectChain`, and `cookies`, alongside `tls`
 * and `timing` passed through unchanged, plus the final
 * `metadataBytes` count.
 *
 * The returned arrays/maps are independent of the caller's inputs — the
 * function does not mutate `input`.
 */
export declare function enforce(input: BudgetInput): BudgetResult;