export interface SessionStorageStat {
    size: number;
    mtimeMs: number;
    mtime: Date;
}
export interface SessionStorageWriter {
    writeLine(line: string): Promise<void>;
    /**
     * Synchronously append a single line. Returns once the bytes are handed to the kernel
     * (page cache), so the data survives a non-graceful process death (OOM, SIGKILL, etc.)
     * even though it has not yet been fsynced to the underlying disk.
     *
     * `line` MUST already include the trailing newline. Throws synchronously on I/O error.
     */
    writeLineSync(line: string): void;
    flush(): Promise<void>;
    fsync(): Promise<void>;
    close(): Promise<void>;
    getError(): Error | undefined;
}
export interface SessionStorage {
    ensureDirSync(dir: string): void;
    existsSync(path: string): boolean;
    writeTextSync(path: string, content: string): void;
    readTextSync(path: string): string;
    statSync(path: string): SessionStorageStat;
    listFilesSync(dir: string, pattern: string): string[];
    exists(path: string): Promise<boolean>;
    readText(path: string): Promise<string>;
    readTextPrefix(path: string, maxBytes: number): Promise<string>;
    writeText(path: string, content: string): Promise<void>;
    rename(path: string, nextPath: string): Promise<void>;
    unlink(path: string): Promise<void>;
    deleteSessionWithArtifacts(sessionPath: string): Promise<void>;
    openWriter(path: string, options?: {
        flags?: "a" | "w";
        onError?: (err: Error) => void;
    }): SessionStorageWriter;
}
export declare class FileSessionStorage implements SessionStorage {
    ensureDirSync(dir: string): void;
    existsSync(path: string): boolean;
    writeTextSync(fpath: string, content: string): void;
    readTextSync(fpath: string): string;
    statSync(path: string): SessionStorageStat;
    listFilesSync(dir: string, pattern: string): string[];
    exists(path: string): Promise<boolean>;
    readText(path: string): Promise<string>;
    readTextPrefix(path: string, maxBytes: number): Promise<string>;
    writeText(path: string, content: string): Promise<void>;
    rename(path: string, nextPath: string): Promise<void>;
    unlink(path: string): Promise<void>;
    openWriter(path: string, options?: {
        flags?: "a" | "w";
        onError?: (err: Error) => void;
    }): SessionStorageWriter;
    /**
     * Delete a session file and its artifacts directory.
     * Artifacts are stored in a sibling directory with the same name minus .jsonl extension.
     */
    deleteSessionWithArtifacts(sessionPath: string): Promise<void>;
}
export declare class MemorySessionStorage implements SessionStorage {
    #private;
    ensureDirSync(_dir: string): void;
    existsSync(path: string): boolean;
    writeTextSync(path: string, content: string): void;
    readTextSync(path: string): string;
    statSync(path: string): SessionStorageStat;
    listFilesSync(dir: string, pattern: string): string[];
    exists(path: string): Promise<boolean>;
    readText(path: string): Promise<string>;
    readTextPrefix(path: string, maxBytes: number): Promise<string>;
    writeText(path: string, content: string): Promise<void>;
    rename(path: string, nextPath: string): Promise<void>;
    unlink(path: string): Promise<void>;
    deleteSessionWithArtifacts(_sessionPath: string): Promise<void>;
    openWriter(path: string, options?: {
        flags?: "a" | "w";
        onError?: (err: Error) => void;
    }): SessionStorageWriter;
}