import { Readable } from 'stream';
import { PipeDecoder } from './charset';
/**
 * The still-delivering input, like less's non-seekable ch file: the
 * entry paths set it before contentPager attaches it.
 */
export declare const pipeInput: {
    source: Readable | null;
    decoder: PipeDecoder | null;
};
export declare function pipeRetained(): number;
/**
 * True while less's initial forw() would still be blocked reading the
 * input: the first screenful is not painted and the length is not
 * learned. Keys arriving now queue like less's check_poll ungetting
 * tty chars, and the prompt row stays unwritten.
 */
export declare function pipeFilling(): boolean;
/**
 * The --intr char (or ^C) breaks out of the wait, like less's
 * check_poll returning READ_INTR: the fill stops, the queued keys
 * are discarded (getcc_clear), and less lands at the bottom of the
 * buffered data — clear + home, null-line tildes above BOF, the
 * partial content bottom-anchored (jump_loc's !full_screen lclear
 * + forw painting nblank lines first).
 */
export declare function abortPipeFill(): void;
export declare function attachPipe(): void;
/**
 * --file-size reads the whole pipe before the terminal initializes,
 * like edit() calling scan_eof under want_filesize: less blocks the
 * first paint until the length is known, painting "Determining
 * length of file" on the main screen once the scan runs LONGTIME
 * (2s); ^X or ^C abandons the scan and pages with it unknown.
 */
export declare function pipeFullProbe(): Promise<void>;
/**
 * Reads the pipe until the content exceeds one screen or it ends,
 * growing the session silently, like less's get_one_screen blocking
 * in forw_line before the terminal initializes.
 */
export declare function pipeOneScreenProbe(): Promise<void>;
/**
 * Wakes the pipe for a forward move that clamped short, like less's
 * forw_line starting its blocking read: the stream resumes (it may
 * have paused on back-pressure) and a 4s data stall shows the wait
 * message on the cleared command line.
 */
export declare function startPendingScroll(): void;
/**
 * Abandons a blocked forward move, like less's READ_INTR breaking the
 * forw loop: queued keys are discarded (getcc_clear), and with no
 * line painted forw's nlines == 0 rings the eof bell.
 *
 * @param sigint - True for ^C, whose u_interrupt handler also bells.
 */
export declare function abortPendingScroll(sigint: boolean): void;
/** Resumes a paused pipe when the view nears the buffered end. */
export declare function pipeDemand(): void;
/**
 * G and % on a streaming pipe read to end-of-file first, like less's
 * ch_end_seek loop; the interrupt key cancels it. less's G runs with
 * a blank command line, % with ierror's "Determining length" note.
 *
 * @param jump - The jump to run once the pipe ends.
 * @param note - The ierror text shown while reading (less's %).
 * @param cancelMessage - The message an interrupt reports.
 * @returns True when the jump waits for the pipe to drain.
 */
export declare function pipeDrain(jump: () => void, note: string, cancelMessage: string): boolean;