Fix the waiting process was called too much.

[mofneko]

The onLoadCompletedhls calling processLoadedPlaylist is triggered by loadPlaylist, but it fires at multiple events.
As a result, waiting for an excessive playlist rereading process not compliant with HLS spec v 20, section 6.3.4 "for more information on media playlist refreshing" was called. Therefore, since the acquisition process was excessive on the server side, measures were taken.

As for the correction contents, we implemented block processing with a flag between process wait start and wait end of processLoadedPlaylist to comply with hls reload specification.

Before:

22:43:52.298 processLoadedPlaylist call isPending: false MediaPlaylistBundle: 31471e2
22:43:52.299 processLoadedPlaylist(postDelayed) refreshDelayUs: 3000000
22:43:53.524 processLoadedPlaylist call isPending: false MediaPlaylistBundle: 31471e2
22:43:53.524 processLoadedPlaylist(postDelayed) refreshDelayUs: 3000000
22:43:54.013 processLoadedPlaylist call isPending: false MediaPlaylistBundle: 31471e2
22:43:54.013 processLoadedPlaylist(postDelayed) refreshDelayUs: 3000000
22:43:54.603 processLoadedPlaylist call isPending: false MediaPlaylistBundle: 3bd02fc
22:43:54.603 processLoadedPlaylist(postDelayed) refreshDelayUs: 3000000
22:43:55.416 processLoadedPlaylist call isPending: false MediaPlaylistBundle: 31471e2
22:43:55.973 processLoadedPlaylist call isPending: false MediaPlaylistBundle: 31471e2
22:43:55.973 processLoadedPlaylist(postDelayed) refreshDelayUs: 3000000
22:43:56.353 processLoadedPlaylist call isPending: false MediaPlaylistBundle: 3bd02fc
22:43:56.354 processLoadedPlaylist(postDelayed) refreshDelayUs: 6000000
22:43:56.440 processLoadedPlaylist call isPending: true MediaPlaylistBundle: 31471e2
22:43:56.440 processLoadedPlaylist(postDelayed) refreshDelayUs: 3000000
22:43:56.607 processLoadedPlaylist call isPending: false MediaPlaylistBundle: 31471e2
22:43:56.607 processLoadedPlaylist(postDelayed) refreshDelayUs: 3000000
22:43:57.089 processLoadedPlaylist call isPending: false MediaPlaylistBundle: 31471e2
22:43:57.089 processLoadedPlaylist(postDelayed) refreshDelayUs: 3000000
22:43:57.682 processLoadedPlaylist call isPending: false MediaPlaylistBundle: 3bd02fc

After:

22:34:40.251 processLoadedPlaylist call isPending: false MediaPlaylistBundle: 7e327ef
22:34:40.251 processLoadedPlaylist(postDelayed) refreshDelayUs: 6000000
22:34:40.387 processLoadedPlaylist call isPending: true MediaPlaylistBundle: 68bca2e
22:34:41.434 processLoadedPlaylist call isPending: false MediaPlaylistBundle: 68bca2e
22:34:41.978 processLoadedPlaylist call isPending: false MediaPlaylistBundle: 68bca2e
22:34:41.978 processLoadedPlaylist(postDelayed) refreshDelayUs: 3000000
22:34:45.066 processLoadedPlaylist call isPending: false MediaPlaylistBundle: 68bca2e
22:34:45.557 processLoadedPlaylist call isPending: false MediaPlaylistBundle: 68bca2e
22:34:45.557 processLoadedPlaylist(postDelayed) refreshDelayUs: 3000000
22:34:46.338 processLoadedPlaylist call isPending: false MediaPlaylistBundle: 7e327ef
22:34:46.338 processLoadedPlaylist(postDelayed) refreshDelayUs: 6000000
22:34:46.423 processLoadedPlaylist call isPending: true MediaPlaylistBundle: 68bca2e
22:34:48.655 processLoadedPlaylist call isPending: false MediaPlaylistBundle: 68bca2e
22:34:48.655 processLoadedPlaylist(postDelayed) refreshDelayUs: 3000000
22:34:51.748 processLoadedPlaylist call isPending: false MediaPlaylistBundle: 68bca2e
22:34:52.276 processLoadedPlaylist call isPending: false MediaPlaylistBundle: 68bca2e
22:34:52.276 processLoadedPlaylist(postDelayed) refreshDelayUs: 3000000
22:34:52.423 processLoadedPlaylist call isPending: false MediaPlaylistBundle: 7e327ef
22:34:52.423 processLoadedPlaylist(postDelayed) refreshDelayUs: 6000000
22:34:52.490 processLoadedPlaylist call isPending: true MediaPlaylistBundle: 68bca2e

• IsPending is the flag implemented this time when processLoadedPlaylist is executed
• RefreshDelayUs is the configured wait time at runtime
• MediaPlaylistBundle: xxxxxxx is the instance id of the running MediaPlaylistBundle
• The # EXT-X-TARGETDURATION of our playlist was set to 6.

Please note that postDelayed is running if isPending: true.

[mofneko]

I'm sorry, the explanation was missing.
The above log is output when processLoadedPlaylist is called the processLoadedPlaylist method.
processLoadedPlaylist (postDelayed) is not repelled by isPendingLoadPlaylist judgment,
It is output when playlistRefreshHandler.postDelayed is processed.

[AquilesCanta]

Thanks for the pull request! This is something I had noticed some time ago but hadn't gotten to measure. We already have an internal fix for this which prevents the initiating the premature load, instead of discarding the already loaded playlists. Please let me know if you still notice too many requests. There is one minor optimization that can still be done, but I don't know whether it is worth it, though.

[mofneko]

I appreciate your reply!
The one we surveyed the other day is the release-v2 branch, but is the dev-v2 branch that has been corrected?
It would be great if you could tell me about the commit of the target if possible. And let me investigate it again.

[AquilesCanta]

No, we have not yet pushed the fix to GitHub, it will happen soon. A reference to the commit should be automatically posted here.

[mofneko]

OK. I will wait for it. And the results are reported here.

[ojw28]

Fix is ref'd above. Closing this.

[mofneko]

Thank you.
I investigated it and confirmed that the result was the expected value.
By the way, I have a doubt about the change this time, so I made more PR.
See, #2564