[RFC][Icedtea-Web]: Enforce cache limit based on deployment.properties

[Andrew Su]

----- Original Message -----
> On 03/21/2011 02:49 PM, Andrew Su wrote:
> >
> >
> > ----- Original Message -----
> >> On 03/20/2011 09:03 PM, Andrew Su wrote:
> >>> Hello,
> >>>
> >>> I have attached a patch which will properly drop the downloaded
> >>> files into the appropriate directory (temp and perm) inside the
> >>> cache folder. Where temp will be deleted upon jvm shutdown if no
> >>> other instances of plugin or javaws is running.
> >>>
> >>> I have did some testing with some applets and all seems to work.
> >>> Another patch for updating itw-settings's cache control should
> >>> be soon since it currently doesn't check for running instances
> >>> before allowing for deleting cache (also need to be modified to
> >>> work with new directory structure).
> >>>
> >>> Any comments questions or concerns?
> >>>
> >>
> >> I havent looked at the patch in detail, but I am wondering what
> >> happens when the (perm) cache is full? What cache replacement
> >> policy does it follow?
> 
> 
> > When the cache is full it will place any files to be downloaded into
> > the temp cache folder. In the event that the file already exist in
> > the perm cache, if the file we are to use is newer, it will check if
> > overwriting the old file will still put us within the limit set, if
> > so proceed (This is how we're doing it right now minus the check for
> > size). If it will go over the limit, file will be placed in temp.
> > When trying to access a file, it first checks temp first as temp
> > should in all cases contain the most updated version of the file.
> >
> 
> That seems a very, um, strange. So we have a file cache that's not
> really a cache? Even if the user never again uses files from the
> cache,
> they still stick around?
> 
> I agree that the behviour right now isnt perfect, but this patch seems
> like a particularly weird way to fix it.

I think I understand what you are saying.. If the file is old and it doesn't fit, old file stays and we only use new file but old file is not deleted?

I considered removing the old file, but that comes with it's own minor issue. Let's say I go to a webpage and it loads an applet, while I'm using this applet the owner of the applet decided to update it. Then when I open another instance of this webpage that runs the applet, it overwrites the jar and I lose what I had running before. I'm not saying this doesn't happen with the way I'm implementing it. Similar situation can happen.

TBH, I wouldn't even want overwrite any files while plugin/javaws is running.

Regards,
 Andrew

> 
> Omair