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current transaction is aborted, commands ignored until end of transaction block

Analysis

Overview

The Sophie2 author's preview mode is really slow. It must be optimized so that it will be usable.

Task requirements

Look for and fix performance issues related to preview mode and reader. Describe the changes that will be made and some possible future improvements if found. For every issue found, explain why it is a problem, so that for the next revision could serve as manual what to look for. If possible, DO NOT change any logic and model things. It is well known that the model is fast enough, so the less it is changed, the smaller the possibility of breaking something is. Here are several main aspects that must be optimized:

• NativeAudioOutput is the class which performs changes on a regular basis in preview mode. It actually uses BookView.setTime() method to change the book's time, then gets some audio chunks. This method is incredibly slow, because it sets the time of every view in the book hierarchy, which causes updates in particularly every part of Sophie author that depends on the current book. In a page with 3 chained frames it needs about 800ms to complete (on my PC). For a smooth media playing with about 25 fps, a step should be performed for less that 40ms (примерно).
• A well known fact is that adding the timelines palette in the trunk reduced greatly the performance on both author and preview mode. Investigate the palette and the timelines hud.
• Try reducing as much as possible the time dependencies in the views, since their time will change at least 25 times a second. This includes ElementView and all derivatives.
• PagePreviewPalette and AllResourcesPalette depend on the current book, so they could slow down a lot setting the preview window as current. Try making them update as rarely as possible.
• Changing the current page for a book with more than 20 pages is a very slow operation.
• Text frames also have a lot of performance problems. There should be a task dedicated to text chaining, creating layout, ans so on. So, for this task just try to reduce the calculations if time has changed but the layout should be the same.
• Look for potentially problematic operations for preview mode, like frame move, text wrapping, etc.

Task result

Much more usable preview mode. For example, playing smoothly media in a book with at least 25 pages, templated objects, chained text and other frame types. Links must also work fast enough. The reader uses the same mechanism for playing a book, so it has the same requirements.

Implementation idea

Use auto properties to reduce unnecessary calculations, memoization of some elements (be careful with it) is needed. BFS`s in the views are dangerous for the performance (findNearestElement).

Related

^{(Add links to related tasks that could be useful or helpful.)}

How to demo

Start author, create a book with 50 pages (could use script: "var i; for(i=0;i<50;i++) book.newPage()"), fill with various content, open preview and enjoy.

Design

^{(Describe your design here.)}

Implementation

^{(Describe and link the implementation results here (from the wiki or the repository).)}

Testing

^{(Place the testing results here.)}

Comments

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