Feature Proposals » Control over formfield rendering in a formatted SEARCH

Motivation

I noticed a poor performance on TWiki site that upgraded from TWiki-5.1.4 to TWiki-6.0.1. The site has topics with a number of embedded searches.

Page load time in a sample dashboard:

• TWiki-5.1.4: 9.6 sec
• TWiki-6.0.1: 27.1 sec to 30 sec

E.g. a 3 fold increase in page load time.

Support.SID-01982 also reports slow SEARCH.

I did some debugging with enabled Monitor.

One of the culprits I found is sub displayFormField in TWiki::Search. It used 0.2 wallclock secs in TWiki-5.1, and 13.5 wallclock secs in TWiki-6.0. The sub in TWiki-5.1 extracted form field values directly; in TWiki-6.0 it calls $meta->renderFormFieldForDisplay(). When reverting that sub to 5.1 the aforementioned dashboard loads in 13.8 sec, e.g cutting the page load time in half, but still 40% slower than TWiki-5.1.

TWiki-5.1 extracted form field values directly from meta, TWiki-6.1 calls renderFormFieldForDisplay(), e.g. lets field handlers render the value for display. For example the color field has a value, such as #ff33ff (shown as such in a formatted search in TWiki-5.1). The TWiki::Form::Color renders this as a colored square box (shown as such in a formatted search in TWiki-6.0).

Description and Documentation

We want better performance, but we also want proper rendering of form fields in a FormattedSearch. I did some optimization to bypass renderFormFieldForDisplay() where feasible, e.g. when sorting by form field, and if no form field break and no encoding is specified:

• sort by form field => fast (search extracts value from meta data)
• $formfield(Some Name) => fast (search extracts value from meta data)
• $formfield(Some Name, 20, <br />) => slow (call renderFormFieldForDisplay())
• $formfield(Some Name, encode:html) => slow (call renderFormFieldForDisplay())
• $formfield(Some Color) => fast, but: Only color value is shown

Now the question: Shall we add a new token to $formfield() to select speed or proper rendering? Which one should be the default?

Examples

Note 2015-03-05: Option 1 was implemented, consensus at KampalaReleaseMeeting2015x03x05

Option 1, preferred: Default is fast rendering, but only with raw value:

• $formfield(Some Color) => fast, but raw value, such as #334466
• $formfield(Some Color, render:display) => slow, rendered colored square box
• $formfield(Some Color, render:edit) => possible feature enhancement: render form field for edit
  • Note 2015-03-05: The render:edit was not implemented as part of this feature proposal

Option 2: Default is proper, but slow rendering:

• $formfield(Some Color) => slow, rendered colored square box
• $formfield(Some Color, render:display) => fast (identical to above example)
• $formfield(Some Color, render:raw) => fast, raw value, such as #334466
• $formfield(Some Color, render:edit) => possible feature enhancement: render form field for edit

Which one is the better option? I prefer option 1, e.g. performance first, and back to behavior of TWiki-5.1.

Impact

Implementation

-- Contributors: Peter Thoeny - 2015-02-25

Discussion

This would be a "no-brainer" fix, except that I would like to get the input from the community on the best option to fix the performance issue.

-- Peter Thoeny - 2015-02-25

Discussed at KampalaReleaseMeeting2015x03x05 on option 1 vs 2. Consensus: Use option 1 as implemented.

-- Peter Thoeny - 2015-03-05