[webkit-dev] setting a size limit for Application Cache

[Andrei Popescu]

Hi,

I was recently looking at

https://bugs.webkit.org/show_bug.cgi?id=22700

I have a small patch that attempts to fix this issue by

1. allowing the ChromeClient implementers to decide what the size
limit should be,
2. evicting caches (in LRU order) from the database when the size
limit is reached and a new cache needs to be saved.

After an initial discussion with Alexey Proskuryakov on IRC, we agreed
to ask webkit-dev for advice on this matter: is LRU eviction the
correct thing to do? It seems clear that the intended usage of
Application Cache is to act as a repository for Web applications that
can be used offline. However, when the disk space allowed for this is
completely used up, would it be ok to make room for new apps by
automatically evicting existing ones? The advantage of this is that it
allows this feature to function without any UI at all. The drawback is
that some apps would suddenly stop working offline. The alternative is
to simply throw an error when the size limit is reached and expect the
UA to provide some UI that allows users to free space by
"uninstalling" existing apps. However, having another setting for this
may turn out to be inconvenient (it's hard to discover and increases
the burden on users who already have to deal with cookies, normal HTTP
cache, databases, geolocation, etc).

Many thanks,
Andrei