Re: rvoFastFormatting sometimes not so fast

Author

Message

David Novo

Posted: 06/12/2005 21:40:39

Hi Rob,

Let me explain my situation in a bit more detail. I can send you a

compiled version of the program with the option turned on and off, and

you will see it takes about 4x longer to load with rvoFastFormatting

turned on.

Let me explain my situation in a bit more detail to see if this

triggers something. Imagine my application like MS powerpoint. You can

have different slides, and put as many text boxes as you like on a

slide. I use one style object per document, and share the style among

the different richviews. (Thanks to Sergey for recently adding the

capability to delete unused styles when the style object is shared).

I used to create one richview per textbox, therefore for this persons

document, there would be 600 richviews open when the document was

loaded. This was an incredible drain on system resources. I have

recently modified it so that when a text box becomes visible, it

requests a richview from a cache that I have. When it becomes invisible

(i.e. the user switches to a different page), the richview is returned

to the cache.

When loading, it loads the RVF from a stream each textbox, formats it

to make sure that everything is okay, and then saves the RVF to a

temporary stream and returns the richview to the cache. This happens

about 600x. With rvoFastFormatting on, this takes about 4 minutes. With

rvoFastFormatting off, this takes about 1 minute. (note, there are many

other objects aside from richview in the document, so richview is not

taking all the time, however, it is responsible for the increase from

1-4 minutes).

My suspicion is a bulk of the time is being take requesting resources

from windows. The document is 55 pages long. Each page has roughly the

same number of objects on it. But the first few pages go by very

quickly, and you can see that it takes longer and longer as more pages

are loaded. So, from what I gleaned from the newsgroup, you are

requesting a GDI object for each item, to calculate a textwidth or

something. Could it be the thousands of GDI objects that I am

requesting and returning when each richview is requested, then

returned, to the cache is slowing things down?