yesusers wrote:In my AJAX application I have a "SyncOnText" that runs at 100 Hz. How much overhead does that impose on my playbacks?
That 100 Hz figure (rechecking the page every 0.01 seconds) was set as an engineering compromise between resolution of time values when you want to know how long the synchronization actually took, and keeping the product overhead to within the 1:1000 target.
We did a lot of thinking about this, and concluded that for a 3-30 second page download, knowing the total time it took to the nearest 0.01 seconds was sufficient precision (and well within the 1:1000 limit).
At the same time, the overhead of having eValid check the entire visible text of the current page is certainly not zero, and we found that if we limited the rate to a maximum of 100 Hz then you probably would not see the slight error
that overhead introduces to a 3-30 second page download/synchronization sequence.
eValid actually takes several tenths of a milliseconds to spin through the DOM to determine if there is or isn't a match -- with the time consumed increasing as the size of the visible text grows.
Incidently the
SyncNotOnElementProperty command, which kind of does the reverse of the
SyncOnText command, takes about the same time because for all except the last scan the same DOM scan has to happen.
The eValid Team
by yesusers » Thu Jul 29, 2010 11:39 am