russiantux/uWebSockets

`µWS` is one of the most lightweight, efficient & scalable WebSocket & HTTP server implementations available. It features an easy-to-use, fully async object-oriented interface and scales to millions of connections using only a fraction of memory compared to the competition. While performance and scalability are two of our top priorities, we consider security, stability and standards compliance paramount. License is zlib/libpng (very permissive & suits commercial applications).

Autobahn tests all pass.
One million WebSockets require ~122mb of user space memory (112 bytes per WebSocket).
By far one of the fastest in both HTTP and WebSocket throughput (see table below).
Linux, OS X, Windows & Node.js support.
Runs with raw epoll, libuv or ASIO (C++17-ready).
Valgrind & AddressSanitizer clean.
Permessage-deflate, SSL/TLS support & integrates with foreign HTTP(S) servers.
Multi-core friendly.

Simple & modern

The C++ interface has been designed for simplicity and only requires you to write a few lines of code to get a working server:

#include <uWS/uWS.h>

int main() {
    uWS::Hub h;

    h.onMessage([](uWS::WebSocket<uWS::SERVER> ws, char *message, size_t length, uWS::OpCode opCode) {
        ws.send(message, length, opCode);
    });

    h.onHttpRequest([](uWS::HttpResponse *res, uWS::HttpRequest req, char *data, size_t length, size_t remainingBytes) {
        res->end(const char *, size_t);
    });

    h.listen(3000);
    h.run();
}

Get the sources of the uws.chat server here. Learn from the tests here.

Widely adopted

Not your average server

Implementation	User space memory scaling	Connection performance	Short message throughput	Huge message throughput
Beast 1.0.0 b17	µWS is 7x as lightweight	µWS is 4x as performant	µWS is 22x as performant	µWS is 3x as performant
libwebsockets 2.0	µWS is 11x as lightweight	µWS is equal in performance	µWS is 6x as performant	µWS is 4x as performant
Crow [Sep 21]	µWS is 13x as lightweight	µWS is 2x as performant	µWS is 12x as performant	data missing
Gorilla e8f0f8a	µWS is 46x as lightweight	µWS is 3x as performant	µWS is 5x as performant	data missing
ws v1.1.0 + binary addons	µWS is 47x as lightweight	µWS is 18x as performant	µWS is 33x as performant	µWS is 2x as performant
Kaazing Gateway Community 5.0.0	µWS is 62x as lightweight	µWS is 15x as performant	µWS is 18x as performant	data missing
Socket.IO 1.5.1	µWS is 62x as lightweight	µWS is 42x as performant	µWS is 61x as performant	data missing
WebSocket++ v0.7.0	µWS is 63x as lightweight	µWS is 4x as performant	µWS is 3x as performant	µWS is 2x as performant

Benchmarks are run with default settings in all libraries, except for ws which is run with the native performance addons. Read more about the benchmarks here.

Getting started

Dependencies

First of all you need to install the required dependencies. This is very easily done with a good open source package manager like Homebrew for OS X, vcpkg for Windows or your native Linux package manager.

Always required:

OpenSSL 1.0.x
zlib 1.x

Not required on Linux systems:

libuv 1.3+
Boost.Asio 1.x

On Linux systems you don't necessarily need any third party event-loop library, but can run directly on the high performance epoll backend (this gives by far the best performance and memory usage). Non-Linux systems will automatically fall back to libuv.

If you wish to integrate with a specific event-loop you can define USE_ASIO or USE_LIBUV as a global compilation flag and then link to respective libraries.

Compilation

Clone and enter the repo:

git clone https://github.com/uWebSockets/uWebSockets.git && cd uWebSockets

OS X & Linux

Compile with Make:

make
sudo make install

Windows

Compile with Visual C++ Community Edition 2015 or later. This workflow requires previous usage of vcpkg:

Open the VC++ project file
Click Build

russiantux / uWebSockets