/**
 * journal — journal-first persistence for task runtime (G-026 M1, ADR-0004 #10).
 *
 * Order: event append (events.jsonl, flush+fsync) → snapshot (runtime.json,
 * atomic write) → tasks.jsonl compatibility projection.
 * events.jsonl is the source of truth; runtime.json is a derived index;
 * tasks.jsonl is a read-only compatibility projection for legacy consumers.
 *
 * Corruption handling (fail closed):
 *  - half-written last line when the file ends without trailing newline → tolerated
 *    only if the line itself is parseable; otherwise RuntimeCorruptError.
 *  - non-sequential seq / duplicate seq / illegal state fields → RuntimeCorruptError.
 */
import { type RuntimeEvent, type RuntimeSnapshot, type TaskRuntimeLayout } from "./file-layout.js";
export interface JournalReadResult {
    events: RuntimeEvent[];
    lastSeq: number;
    /** Total number of physical lines read (partial/corrupt lines counted). */
    lineCount: number;
}
/**
 * Append a lifecycle event with monotonic seq persistence.
 * Marks the event committed, then caller writes snapshot.
 */
export declare function appendEvent(layout: TaskRuntimeLayout, event: Omit<RuntimeEvent, "seq" | "at">, opts?: {
    touch?: boolean;
}): Promise<RuntimeEvent>;
/**
 * Read and validate events.jsonl.
 *
 * - Empty/missing file → { events: [], lastSeq: 0 }.
 * - Trailing partial line WITHOUT newline terminator: if JSON.parse succeeds → keep;
 *   if it fails or the line is mid-write garbage → RuntimeCorruptError (fail closed).
 * - seq must be strictly increasing integers starting at 1.
 */
export declare function readJournal(layout: TaskRuntimeLayout, opts?: {
    toleratePartial?: boolean;
}): Promise<JournalReadResult>;
/**
 * Write the versioned runtime.json snapshot atomically.
 * runtime.json is an index derived from events + attempt dirs — NOT truth.
 */
export declare function writeSnapshot(layout: TaskRuntimeLayout, snapshot: RuntimeSnapshot): Promise<void>;
/** Read runtime.json; unknown/missing schema → fail closed. */
export declare function readSnapshot(layout: TaskRuntimeLayout): Promise<RuntimeSnapshot | null>;