/// <reference types="node" />
import DataSource from "./DataSource";
/**
 * Node.js based file data source using single internal read buffer.
 *
 * When specifying internal buffer size (i.e. not relying on the default value), keep in mind that
 * every read request that can't fit inside that buffer will result in a new buffer allocation.
 */
export default class FileSource implements DataSource {
    /**
     * File descriptor.
     */
    private fileDesc;
    /**
     * Current read position.
     */
    private filePosition;
    /**
     * Source data buffer.
     */
    private sourceBuffer;
    /**
     * Cursor position inside source buffer.
     */
    private bufferOffset;
    /**
     * Actual data length inside source buffer.
     */
    private bufferLength;
    /**
     * @param path Source file path.
     * @param bufferSize Size of the internal source buffer.
     */
    constructor(path: string, bufferSize?: number);
    /**
     * Read another portion of the file into the target buffer.
     */
    private readFile;
    /**
     * Read data using the internal source buffer.
     */
    private readBuffer;
    read(length: number): Buffer;
    skip(length: number): void;
    close(): void;
    cursor(): number;
}