Improve memSize calculation in [WebView _setCacheModel]

[Pratik Solanki]

In [WebView _setCacheModel], we use a fudge factor for the memory size


    // As a fudge factor, use 1000 instead of 1024, in case the reported byte 
    // count doesn't align exactly to a megabyte boundary.
    uint64_t memSize = WebMemorySize() / 1024 / 1000;

Instead of doing that, we should just round up the memSize to a multiple of 2 and update the code to check for 4MB/2MB/1MB/512KB memory levels.

[Pratik Solanki]

Created attachment 72118 [details]
Patch

[Darin Adler]

Comment on attachment 72118 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=72118&action=review

Changes look fine. I have a comment or two, but nothing we couldn’t tweak later.

> WebKit/mac/WebView/WebView.mm:5324
> +    static uint64_t memSize = roundUpToPowerOf2(WebMemorySize() / 1024 / 1024);

Is it really worthwhile to store this in a global? Paying 8 bytes of global memory to avoid doing this math more than once might be the wrong tradeoff since we do this computation only when the cache model is changed.

[WebKit Commit Bot]

Comment on attachment 72118 [details]
Patch

Clearing flags on attachment: 72118

Committed r70732: <http://trac.webkit.org/changeset/70732>

[WebKit Commit Bot]

All reviewed patches have been landed.  Closing bug.