[vdr] Speed of VDR 1.3.12 recording menu

[Emil Naepflein <Emil.Naepflein@philosys.de>]

Hi,

recently I have updated one of my VDR clients to 1.3.12 to see how the
improvements are. The stability of this version is already good and the
new functionality is nice. But, I recognized that there is still one
issue I already had with the old version. 

The speed of the update of the recordings menu is still very slow in
some cases so that the response time of VDR is very large. Please notice
that I have more than 500! recordings on the server and the client has
access to this by NFS over 54 Mb WLAN. So this is a worst case scenario.

After startup of VDR it immediatly loads the recordings. This takes
approximately 10-30 s depending on the state on the server. If the
server has to read the tree from disk it is the longer time. As my
clients are turned off after use, it is really annoying to have to wait
so long even someone wants to view TV only. 

One thinks, ok if everything is loaded during startup then the recording
menu should come up immediately. But, when I access the recording menu
it takes approximately 10-15 s until the recordings menu appears. As
there is no OSD output and VDR doesn't respond to any IR command it just
looks like VDR is dead. The reason for this additional delay seems to be
the read of all resume files in order to display the new indicator.

I have also noticed that some minutes after startup VDR scans the
recordings again, even the .update file didn't change. During this time
VDR is dead. This is caused by the call to RemoveDeletedRecordings().
This takes more than 70 s because the algorithm used in ScanVideoDir()
doesn't stop when a directory ending with ".rec" is found. So this scan
reads all the directories.

So, how could that all be fixed?

Here are some ideas:
1. Stop search in ScanVideoDir() when a directory is reached that is
ending on .rec or on .del.

2. Update both recordings and deleted files in one scan.

3. Read resume status in ScanVideoDir() and update the status on every
change of the resume file.

4. After startup don't do the Load in one step, do only partly every
second. Only if someone wants to view the recording menu then finish the
scan. 

5. Display OSD before starting Load to give the user a response.

6. When stopping save the current recording list to disk and read it
after start.

7. For client/server setups it would be nice to be able to read the
recording list through svdrp from the server. This would be much faster
than through NFS. 

Any further ideas?

I think it is very important that all the information displayed in the
recording menu is cached and updated internally on changes (resume,
deleted files, ...).

Cheers,
Emil