How to cleam memory in InDesign.

Question

Dear all,
We are developing a extension for Adobe InDesign and after many months of development we are still stuck with various things we cannot find a proper solution to them. The extension exports a lot of images, texts, creates new pages, basically we are exporting all the content in a document as long as 300-400 pages in different assets, in JPG and PNG formats. So is really memory consuming
When running the extension we have developed, the main thread is bloqued and the InDesign is not responding and if the export we are doing is really large it just crashes InDesign. We would like to reléase memory after each page is finished, but we cannot do so. Once the complete export is finished, then memory is released, but not while the export is happening
As we export the memory is increasing more and more without releasing anything, we have tried different options, but seems like we never get to release memory as everything is blocked
How can we release memory while the extension is running ? Or is there a way to stop the extension each iteration so it releases memory?
We use the extension manager and flash builder.
Thanks!
Cesar.

Answer 1

Hi Cesar,
I'm also making an export script, (not extension), mine seems to be quite different to yours but we'll might see when both are published.
Off the point.
The first thing you have to be aware of is using flash builder and extension manager, If you are making a flash based extension, from what I understand it's not going to work for the next version of InDesign which is switching to HTML5 based panels and dropping support for flash based panels (you'll still need the flash based panels to support the current version (9) and below. This is going to be a major pain for all extensions for the next lot of years that all of them will need 2 completely different interface bases to be compatible with CC(1), CS6 (which is going to be around for a long time for obvious reasons) and below on the one side and CC(2) + on the other.  I can't actually blame Adobe for this one as there should be some serious benefits in the HTML5 panels.
Back to the point.
See Ariel's Phenomenal optimization technique! which is based on the same Idea of breaking down the script into small parts.
See also Re: Big performance issue while removing tabs by indents including the link brought by Xavier in 7 over there. Loic reduced his script run time from 6 hours + to 90 seconds by using efficient techniques.
I made a script for making swatch books (sort of thing than Pantone publish - involved a quite a bit of maths and color conversions) it was workable for 3,000 - 4,000 swatches but when it got to 15,000 or so swatches the machines wouldn't budge one bit.  Separating the output into separate document  (which any I needed to do because the proofing and print machines can only handle up to 27 spot colors) resulted in the script working very efficiently.
As Uwe mentioned redraw can make a big difference and even more so hidden documents app.open(myFile, false)
Using myObjectCollection.everyItem().getElements().slice(0). Very significant for big collections.
Better still don't make big collections in the first place.  Don't if possible try process all the export items in the document myItems = doc.allGraphics or myItems = doc.spreads.everyItem().allGraphics rather make a collection myItems = doc.spread[n].allGraphics this will take up much less memory and work much quicker.
Try playing with $.memCache see if increasing or reducing the memory allocation makes a difference.  Please let me know if it does!
There's a very lot of methods that would depend on the actual script the differences can be huge, from scripts that just won't move to taking less than 2 minutes.
Don't forget to report back with the results
Trevor