@naturalcycles/nodejs-lib/dist/stream/transform/transformBuffer.js

Standard library for Node.js

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.transformBuffer = void 0;
const stream_1 = require("stream");
/**
 * Similar to RxJS bufferCount()
 *
 * @default batchSize is 10
 */
function transformBuffer(opt) {
    const { batchSize } = opt;
    let buf = [];
    return new stream_1.Transform({
        objectMode: true,
        ...opt,
        transform(chunk, _, cb) {
            buf.push(chunk);
            if (buf.length >= batchSize) {
                cb(null, buf);
                buf = [];
            }
            else {
                cb();
            }
        },
        final(cb) {
            if (buf.length) {
                this.push(buf);
                buf = [];
            }
            cb();
        },
    });
}
exports.transformBuffer = transformBuffer;