@naturalcycles/nodejs-lib/dist/stream/writable/writableLimit.js

Standard library for Node.js

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.writableLimit = void 0;
const stream_1 = require("stream");
/**
 * Allows to stop the Readable stream after the pipeline has processed X number of rows.
 * It counts OUTPUT rows (not input), because this Writable is always at the end of the Pipeline.
 * It ensures that everything has been processed before issuing a STOP on the readable.
 */
function writableLimit(readable, limit) {
    let i = 0;
    return new stream_1.Writable({
        objectMode: true,
        write(chunk, _, cb) {
            if (limit === 0)
                return cb(); // no limit, just passthrough
            i++;
            if (i === limit) {
                console.log(`writableLimit of ${limit} reached`);
                readable.destroy();
                cb(); // do we need it?
            }
            else {
                cb(); // passthrough
            }
        },
    });
}
exports.writableLimit = writableLimit;