[webkit-dev] Limiting the size of LocalStorage

[Darin Adler]

On Dec 4, 2008, at 10:47 AM, Yael.Aharon at nokia.com wrote:

> I'd be happy to fix this bug and submit a patch when I am done.  
> Before I can do that, I have a question - why is LocalStorgare  
> created and tracked per page group and not per process, like offline  
> storage databases are?

The reason page groups exist is that within the same process, WebKit  
can be used for multiple purposes. For example, imagine a web browser  
that has a separate help viewer within the same process. The page  
group allows the help viewer to use web views but not share the rest  
of its state with the web browser windows.

Ideally features like local storage can be separate for different page  
groups or can be shared if the page groups are closely related.

As to the specific question of why offline storage database is per- 
process and local storage is per-page-group, I can't really explain  
the difference. It would make sense to have both be per-page-group.

At present, none of this matters for major WebKit clients. Clients  
like Safari on Windows that use multiple page groups typically have  
one "like a browser" page group, and other page groups that have  
features like local storage and database disabled entirely.

     -- Darin