[Digikam-users] Metadata

[Remco Viëtor]

On Sunday 30 June 2013 15:58:29 Anders Lund wrote:
...
> 
> I don't know if "delayed" is any good. 
> 
> In my workflow, I typically import, select, tag, process and export 
images. 
> When exporting, having those metadata writte to the image is smart.
> 
> Writing meta data to images, I assume, is a question of copying data from 
the 
> digikam db into the image or sidecar file. So everytime an images data 
> changes, it should go into the queue, unless it is allready there. Now if 
the 
> actual data writing is done by a spearate process, what is the problem? 
That 
> process must then be throtteled, so that it does not take the system 
down.
>  
> When exporting, it could be checked if the image is in the metadata 
writing 
> queue, so it can be processed there prior to exporting.
> 
> 
The problem can occur if you start a background job, and then, while it is 
running, do something like:
- add or remove tags from a subset of the images in the queue (starting a 
second background job)
- or process an image that hasn't had its tags written yet.
In both cases there are scenarios where the tags stored in the image can 
end up being different from the tags as stored in the database.

There shouldn't be any need to throttle the background queue, that's why 
you have task switching in any modern operating system. The queue might get 
a lower priority ('nice' value under UNIX-likes).