import { ReadStatSeek } from "./types.js";
export interface IoContext {
    /** Read up to `nbyte` bytes at the current cursor; returns actual bytes (may be shorter at EOF). */
    read(nbyte: number): Uint8Array;
    /** Move the cursor. Returns the new absolute offset, or -1 on error. */
    seek(offset: number, whence: ReadStatSeek): number;
    /** Current absolute offset. */
    tell(): number;
    /** Total size in bytes. */
    size(): number;
}
/** In-memory IO context backed by a Uint8Array. */
export declare class BufferIoContext implements IoContext {
    private data;
    private cursor;
    constructor(data: Uint8Array);
    read(nbyte: number): Uint8Array;
    seek(offset: number, whence: ReadStatSeek): number;
    tell(): number;
    size(): number;
}
/**
 * Read exactly `nbyte` bytes or throw. Mirrors the ubiquitous
 * `if (io->read(...) < len) { retval = READSTAT_ERROR_READ; }` pattern.
 * Returns a fresh copy so callers may retain it safely.
 */
export declare function ioReadExact(io: IoContext, nbyte: number): Uint8Array;
export declare class IoReadError extends Error {
    constructor(wanted: number, got: number);
}