Test if MediaFile exists

[dflachbart]

Supposed I have a reference to a MediaFile object, and this file gets delete by DeleteFile().

Is there any simple method which can tell me if the reference I have is still in the database, pointing to an existing file ? I tried a few methods of the MediaFile API, but all worked as if the file still existed. I am currently calling GetMediaFiles() again and do a lookup, but I am wondering if there is a less expensive approach ...

Thanks,

Dirk

[Opus4]

You said you tried a few calls... what have you tried? GetSize()? GetSegmentsFiles()? I think the default STV just does a refresh after deleting a file.

- Andy

[nielm]

How about:
GetMediaFileForID(GetMediaFileID(DeletedMediaFile))
(returns null if the ID of the DeletedMediaFile is not in the DB)

Alternatively
GetMediaFileSize(DeletedMediaFile)==0
(but I dont know what this does if the file still exists, but is on an offline drive)

[BobPhoenix]

Couldn't you use IsFilePath in the Utility class?

BobP.

Edit: Think I mis-understood the problem - sorry.

[Opus4]

Originally Posted by BobPhoenix

Couldn't you use IsFilePath in the Utility class?

You could do that after a call to GetFileForSegment(MediaFile,0)... and if that returns nothing, there is no need to check the file path. If the file is deleted outside SageTV, this combo might work decently.

- Andy

[dflachbart]

Originally Posted by nielm

How about:
GetMediaFileForID(GetMediaFileID(DeletedMediaFile))
(returns null if the ID of the DeletedMediaFile is not in the DB)

I actually got up to GetMediaFileID(DeletedMediaFile), but when this returned a valid ID I didn't take this a step further ...

I'll also try the other suggestions posted here, thanks again to everyone !


Dirk

[Opus4]

I'm told that a lot of the MediaFile info is cached, but GetSize() checks the file size at the moment it is called. As Niel mentioned, you probably won't get a good response on offline files.

You can also do the check on the file segments, but offline files won't exist there either, so GetSize may be all that is needed.

Due to the possibility of files being offline, I would make sure to only remove the item from your list as opposed to trying to get SageTV to remove actually it via any further deletion.

- Andy

[dflachbart]

Originally Posted by Opus4

I'm told that a lot of the MediaFile info is cached, but GetSize() checks the file size at the moment it is called.

Thanks Andy for the inquiry, this is good to know ...

Originally Posted by Opus4

Due to the possibility of files being offline, I would make sure to only remove the item from your list as opposed to trying to get SageTV to remove actually it via any further deletion.

Actually it's the other way around, after a deletion action initiated by the user on a played mediafile the file has to be removed from a list (which is the base for a display table) so that it wont show up any more. So yes, I would only remove it from the list, and it is guaranteed not to be an offline file, so the GetSize() solution seems perfect ...

Thanks again,

Dirk

[GKusnick]

Maybe I'm missing something, but if you just want to know whether the file still exists on disk, it seems like the most authoritative test would be

java_io_File_exists(GetFileForSegment(MediaFile, 0))

On the other hand, if you're trying to detect whether the MediaFile object has been removed from wiz.bin, then Niel's GetMediaFileForID test seems like the obvious way to go.

[Opus4]

Originally Posted by GKusnick

Maybe I'm missing something, but if you just want to know whether the file still exists on disk, it seems like the most authoritative test would be

java_io_File_exists(GetFileForSegment(MediaFile, 0))

Yes and no... that will check for the file, but if you are doing this on the client, it will check for the file as if the path is relative to the client, i.e.: local.

To access any files that the server manages, such as recordings, you have to use the API file access calls to make sure a client will be able to 'see' it correctly. I added a blurb about this to the last couple pages of the v5 Studio manual... since I had to do a whole bunch of fixes for the default STV, I figured it would be good for others to know about.

- Andy