Re: Async broadcast to websocket handles using internal function -25! - KX Learning Hub

rocuinneagain

Member
May 5, 2023 at 12:00 am
-25! is for use with IPC handles only. Not websocket handles.

The reason is for IPC handles there is a serialization step and here -25! is efficient in allowing this to only be run once for many handles.

For websocket handles data is sent directly without any serialization step, -25! would offer no benefit here.
- https://code.kx.com/q/basics/internal/#-25x-async-broadcast
- https://code.kx.com/q/basics/internal/#-38x-socket-table
```
q){([]h)!-38!h:.z.H}[] 
h  | p f 
---| --- 
612| w t 
580| q t 

q)-25!(enlist 612i;"test") 
'612 is not an ipc handle [0] 
-25!(enlist 612i;"test") ^ 

q)-25!(enlist 580i;"test")
```
For websockets if there is a large operation like converting a table to JSON you can control this being done once and then sent to multiple websockets:

neg[webSockethandles]@:.j.j bigTable

Wrapping the same in a helper:

wsBroadcast:{[handles;data] neg[(),handles]@:data} wsBroadcast[myWebsocketHandles] .j.j bigTable