Bug 65306 – WebKitInitializeStorageIfNecessary() can take awhile performing i/o, isn't necessary for every WebView

• Component: WebCore Misc.
• Status: RESOLVED FIXED

[Brady Eidson]

WebKitInitializeStorageIfNecessary() can take awhile performing i/o, isn't necessary for every WebView

Right now we blindly call WebKitInitializeStorageIfNecessary the moment the first WebView is created.  Since it can do some (sync) i/o, this can be a waste of time if storage tracking will never be needed (APIs aren't called, or LocalStorage is never used).

There's room to make it better by making it asynchronously initialize on a background thread, but in the meantime let's defer it until it's actually needed.

In radar as <rdar://problem/9714337>

[Brady Eidson]

By moving the "one time initialization" code into StorageTracker::tracker(), this ensures that the initialization will take place:
1 - Before anyone in WebCore needs to use the shared StorageTracker object
2 - Before any API in WebKit/WebKit2 needs to use the shared StorageTracker object

[Brady Eidson]

Filed https://bugs.webkit.org/show_bug.cgi?id=65308 since I noticed that StorageTracker::setClient() and the associated client guard mutex are pretty much irrelevant.

[Brady Eidson]

Created attachment 102240 [details]
Patch v1 - Move the hefty work from StorageTracker::initializeTracker() until the first time the global tracker is actually accessed.

[Maciej Stachowiak]

Comment on attachment 102240 [details]
Patch v1 - Move the hefty work from StorageTracker::initializeTracker() until the first time the global tracker is actually accessed.

r=me

[Brady Eidson]

http://trac.webkit.org/changeset/91931

[Joseph Pecoraro]

Comment on attachment 102240 [details]
Patch v1 - Move the hefty work from StorageTracker::initializeTracker() until the first time the global tracker is actually accessed.

View in context: https://bugs.webkit.org/attachment.cgi?id=102240&action=review

> Source/WebCore/storage/StorageTracker.h:115
> +    bool m_isInitialized;

What value does this boolean add, or is there more planned for it in the future?

[Brady Eidson]

(In reply to comment #6)
> (From update of attachment 102240 [details])
> View in context: https://bugs.webkit.org/attachment.cgi?id=102240&action=review
> 
> > Source/WebCore/storage/StorageTracker.h:115
> > +    bool m_isInitialized;
> 
> What value does this boolean add, or is there more planned for it in the future?

Initialization has to be separate from construction - that's the purpose of the patch.

There is one case where we construct a "dummy" tracker and immediately initialize it, but in the StorageTracker::initializeTracker(const String&, StorageTrackerClient*) case, we construct with the intent to initialize later.