NotebookApp.websocket_compression_options config

[minrk]

expose passthrough for WebSocketHandler.get_compression_options

adds NotebookApp.websocket_compression_options configurable as a passthrough for setting the return value for WebSocketHandler.get_compression_options() with a default of None (no compression).

This works, but marked WIP while waiting for a decision on default from #2490. Other options:

• default: 'auto' so that compression is off for localhost by default and on for remote connections (as identified via remote_ip)
• allow setting a callable instead of a scalar, so that config could enable custom logic (such as 'auto' based on remote_ip)

closes #2490

[blink1073]

Revert ccba3bd in favor of #2501?

[jasongrout]

+1 to the default being no compression, like the current PR has.

[maartenbreddels]

If this goes into a release, we can 'advertise' with a 100x data transfer rate improvement for ipywidgets.

[takluyver]

@minrk I think there's a consensus in favour of what you've implemented here. Do you want to do anything else on this before we merge it?

[minrk]

@takluyver no, sorry, I should have taken WIP off a while back.

[maartenbreddels]

great 🎉