Skip to content

perf: use a random pool #1986

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Closed
ronag wants to merge 2 commits into from
Closed

perf: use a random pool #1986

Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
79eae6f
perf: use a random pool
ronag Dec 17, 2021
238a723
fixup
ronag Dec 17, 2021
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
39 changes: 33 additions & 6 deletions lib/sender.js
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -4,7 +4,7 @@

const net = require('net');
const tls = require('tls');
const { randomFillSync } = require('crypto');
const { randomBytes } = require('crypto');

const PerMessageDeflate = require('./permessage-deflate');
const { EMPTY_BUFFER } = require('./constants');
Expand All @@ -13,6 +13,22 @@ const { mask: applyMask, toBuffer } = require('./buffer-util');

const mask = Buffer.alloc(4);

const RANDOM_POOL_SIZE = 8192;
const RANDOM_POOL_REFRESH = 1024;

let randomPool = Buffer.alloc(0);
let randomPoolIdx = 0;
let randomPending = true;

function onRandomBytes(err, buf) {
randomPending = false;
if (!err) {
randomPool = buf;
randomPoolIdx = 0;
}
}
randomBytes(RANDOM_POOL_SIZE, onRandomBytes);

/**
* HyBi Sender implementation.
*/
Expand Down Expand Up @@ -81,13 +97,24 @@ class Sender {

if (!options.mask) return [target, data];

randomFillSync(mask, 0, 4);
Comment thread
ronag marked this conversation as resolved.
if (randomPool.length - randomPoolIdx < 4) {
randomPool = randomBytes(32);

@lpinca lpinca Dec 17, 2021

Copy link
Copy Markdown
Member

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

I'm not convinced this is much better than the status quo. It would only take 8 WebSocket each sending a single message to empty the pool and there is a new Buffer allocation every time.

@ronag ronag Dec 17, 2021 •
edited
Loading

Copy link
Copy Markdown
Contributor Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

This is just the fallback path. We shouldn't hit this often, if at all.

@ronag ronag Dec 17, 2021

Copy link
Copy Markdown
Contributor Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

I think you are misunderstanding something here...?

randomPoolIdx = 0;
}

target[1] |= 0x80;
target[offset - 4] = mask[0];
target[offset - 3] = mask[1];
target[offset - 2] = mask[2];
target[offset - 1] = mask[3];
target[offset - 4] = mask[0] = randomPool[randomPoolIdx++];
target[offset - 3] = mask[1] = randomPool[randomPoolIdx++];
target[offset - 2] = mask[2] = randomPool[randomPoolIdx++];
target[offset - 1] = mask[3] = randomPool[randomPoolIdx++];

if (
!randomPending &&
randomPool.length - randomPoolIdx < RANDOM_POOL_REFRESH
) {
randomPending = true;
randomBytes(RANDOM_POOL_SIZE, onRandomBytes);
}

if (merge) {
applyMask(data, mask, target, offset, data.length);
Expand Down