fix: use blank page when window isn't active

[hacdias]

This addresses #1196 by changing to a blank page whenever the window is not visible. For this, we use the Page Visibility API.

Requires ipfs/ipfs-webui#1259.

This reduced significantly the CPU usage on my end.

License: MIT
Signed-off-by: Henrique Dias hacdias@gmail.com

[autonome]

Looks good! Two questions:

• How does this impact performance of webui load and render?

• This feels a bit like giant hammer, without knowing more about the underlying cause of webui chewing cpu. Have you profiled why webui is doing that in the first place? Are there other issues tracking that?

[hacdias]

How does this impact performance of webui load and render?

It doesn't. We are always on the Web UI, but it's just an empty page.

This feels a bit like giant hammer, without knowing more about the underlying cause of webui chewing cpu. Have you profiled why webui is doing that in the first place? Are there other issues tracking that?

The problem is that we were, by default, on status page. And when we're on the status page, we're continuously fetching repo and bandwidth stats to update the graphs. That creates load on the Web UI and ipfs itself.

[lidel]

I can confirm this works on Linux (opened Status page and closed it):

hidden (without fix)

GPU proces still does something, as reported in #1196:

hidden (with fix)

Fix seems to work.
GPU process stays at 0%, renderer is at 0% and jumps to 0.7 only every ~5s seconds
(probably when gets status update from HTTP API?)

[autonome]

The problem is that we were, by default, on status page. And when we're on the status page, we're continuously fetching repo and bandwidth stats to update the graphs. That creates load on the Web UI and ipfs itself.

Can you file a followup issue in webui repo for reducing the cost of having the status page open? You've reduced the cost on desktop in this PR, which is awesome. But if someone leaves the page open in a tab in the browser, they'll still have the problem.

[hacdias]

@autonome done: ipfs/ipfs-webui#1260!