[WW-3750] ScopesHashModel calls OgnlValueStack.findValue too many times during rendering freemarker templates

• Type: Improvement
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 2.3.1.1
• Fix Version/s: 2.3.3
• Component/s: Value Stack
• Labels: patch performance
• Flags: Patch
• Assignee: Johannes Geppert
• Reporter: Pelladi Gabor
• Created: 27/Jan/12 09:51
• Updated: 14/Apr/12 07:15
• Resolved: 30/Mar/12 21:04

Description

I saw using a profiler, that OgnlValueStack.findValue(String) gets called about a thousand times during rendering a page. Most of the calls are coming from ScopesHashModel.
All freemarker templates contain a lot of references to e.g. "parameters". This variable is evaluated in ScopesHashModel over and over again, which takes about 10% time of total page load.
I think we can assume, that the top-level objects on the value stack will not change during rendering a single struts2 tag. So with a little caching, we can eliminate most of the findValue method calls.

In my application I tested this modification and didn't notice any side effects or bugs. The OgnlValueStack.findValue(String) calls on a test page went down from a thousand to a hundred. This improved overall page rendering time from about 400ms to 360ms.

Patch is attached.
Please review it.

Issue Links

• breaks: WW-3776 Config browser generates wrong links when used with Convention plugin