time-to-botec

Benchmark sampling in different programming languages
Log | Files | Refs | README

index.js (1489B)

      1 'use strict';
      2 const {constants: BufferConstants} = require('buffer');
      3 const stream = require('stream');
      4 const {promisify} = require('util');
      5 const bufferStream = require('./buffer-stream');
      6 
      7 const streamPipelinePromisified = promisify(stream.pipeline);
      8 
      9 class MaxBufferError extends Error {
     10 	constructor() {
     11 		super('maxBuffer exceeded');
     12 		this.name = 'MaxBufferError';
     13 	}
     14 }
     15 
     16 async function getStream(inputStream, options) {
     17 	if (!inputStream) {
     18 		throw new Error('Expected a stream');
     19 	}
     20 
     21 	options = {
     22 		maxBuffer: Infinity,
     23 		...options
     24 	};
     25 
     26 	const {maxBuffer} = options;
     27 	const stream = bufferStream(options);
     28 
     29 	await new Promise((resolve, reject) => {
     30 		const rejectPromise = error => {
     31 			// Don't retrieve an oversized buffer.
     32 			if (error && stream.getBufferedLength() <= BufferConstants.MAX_LENGTH) {
     33 				error.bufferedData = stream.getBufferedValue();
     34 			}
     35 
     36 			reject(error);
     37 		};
     38 
     39 		(async () => {
     40 			try {
     41 				await streamPipelinePromisified(inputStream, stream);
     42 				resolve();
     43 			} catch (error) {
     44 				rejectPromise(error);
     45 			}
     46 		})();
     47 
     48 		stream.on('data', () => {
     49 			if (stream.getBufferedLength() > maxBuffer) {
     50 				rejectPromise(new MaxBufferError());
     51 			}
     52 		});
     53 	});
     54 
     55 	return stream.getBufferedValue();
     56 }
     57 
     58 module.exports = getStream;
     59 module.exports.buffer = (stream, options) => getStream(stream, {...options, encoding: 'buffer'});
     60 module.exports.array = (stream, options) => getStream(stream, {...options, array: true});
     61 module.exports.MaxBufferError = MaxBufferError;