Check whether memory leaks on a stream error

README.md

Result

There were not memory leaks detected for:

• error on the unzip stream
• error on the request object

Couldn't get error on the response object. When the connection is destroyed, request object emits an error.

How to

Run servers:

npm install -S express comporession
node --inspect proxy.js
node server.js

Error on unzip stream:

ab -n 10000 -c 10 http://localhost:8080/fake
# Take snapshot
ab -n 10000 -c 10 http://localhost:8080/fake
# Take snapshot

Error on connection:

ab -n 10000 -c 10 http://localhost:8080/error
# Take snapshot
ab -n 10000 -c 10 http://localhost:8080/error
# Take snapshot

proxy.js

const zlib = require('zlib');
const stream = require('stream');
const http = require('http');

http.createServer((req, res) => {
  const request = http.request({
    hostname: 'localhost',
    port: 8081,
    path: req.url,
    method: 'GET',
    headers: {
      'accept-encoding': 'gzip, deflate'
    }
  }, (response) => {
    let bodyStream = response;
    const encoding = response.headers['content-encoding'];
    console.log(req.url, encoding);
    if (encoding === 'gzip' || encoding === 'deflate') {
      response.on('error', (e) => {
        res.writeHead(500);
        res.end('response error: ' + e.message);
      });
      bodyStream = response.pipe(zlib.createUnzip());
    }
    const chunks = [];
    bodyStream.on('error', (e) => {
      res.writeHead(500);
      res.end('body stream error: ' + e.message);
    });
    bodyStream.on('data', (chunk) => {
      chunks.push(chunk);
    });
    bodyStream.on('end', () => {
      res.end(Buffer.concat(chunks).toString('utf8'));
    });
    if (req.url === '/error') {
      response.destroy(new Error('destroy connection'));
    }
  });
  request.end();
  request.on('error', (e) => {
    res.writeHead(500);
    res.end('request error: ' + e.message);
  });
}).listen(8080);

server.js

const express = require('express');
const compression = require('compression');

const app = express();
app.use(compression({
  filter(req, res) {
    return req.url !== '/fake';
  }
}));
app.get('/', (req, res) => {
  for (let i = 0; i < 100; i++) {
    res.write('hello');
  }
  res.end();
});
app.get('/fake', (req, res) => {
  res.set('content-encoding', 'gzip');
  for (let i = 0; i < 100; i++) {
    res.write('hello');
  }
  res.end();
});
app.get('/error', (req, res) => {
  for (let i = 0; i < 100; i++) {
    res.write('hello');
  }
  res.end();
});
app.listen(8081);