sockjs-client and websocket continuation frames?

[rmelick]

Hi All,

Summary: Does the sockjs-client support websocket continuation frames?

We have been doing some work in the vertx sockjs server implementation to support continuation frames at the websocket level (eclipse-vertx/vert.x#1808, vert-x3/vertx-web#520). Continuation frames are used in the websocket protocol to allow you to send a message that would be larger than the maximum frame size supported by a server or client by breaking it up into multiple pieces. Two popular java websocket implementations have the following default frame sizes:

• netty: defaults to 65536 bytes
• tomcat defaults to 8192 bytes.

This means if you want to send a large websocket message (say 100kb) from a server using tomcat, the server will need to split it into multiple websocket frames before passing it to the tomcat library. I believe this is very similar to http chunking.

My question is, does the sockjs-client javascript library support websocket continuation frames? Would it make sense to add additional tests to the protocol definition about support for large messages (which would probably require continuation frames)? My understanding is that this would not require the addition of chunking to the sockjs protocol as mentioned in #205, since this is specific to websockets. Basically, the implementation requires buffering the received partial (continuation) frames until the complete message is received, and then passing it to the client code.

[brycekahle]

Isn't this something the browser should take care of when using WebSockets? We do not have control of what opcode is used when sending data from a browser.

[brycekahle]

In Node.js mode, this is something faye-websocket-node should be handling, if they do not already.

[leolux]

Why does the client side library make use of the max frame size then? See

sockjs-client/lib/utils/escape.js

Line 17 in 336cf32

for (i = 0; i < 65536; i++) {

[brycekahle]

@leolux That is not the max frame size. That code is generating an array of every character from 0 to 65535.

[brycekahle]

Closing due to inactivity.