Always store the original string form and convert it to the desired type
on demand. In most cases this is significantly faster as typically only
a few of the parameters in a line are actually read. In addition, this
makes it so that parameters which did not actually change are always
reserialized in their original form.
Delete VariableData as it's no longer used by anything.
Closes#1513.
Now that all the other junk is being dropped from the file, script info
lines are the only thing left which was a concrete AssEntry, and
AssEntry wasn't actually a very good way to store them.
Character counts are a pretty terrible measure of anything, but it's
still the main measure of length used in most subtitling standards
(because subtitling standards are written under the assumption that the
tools are terrible (which is generally an accurate assumption)).
100 no-op non-amend commits on a subtitle file with 6689 dialogue lines,
with the undo limit set to 100:
Without flyweight:
No video open:
Initial memory usage: 30.6 MB
Final memory usage: 498.0 MB
Elapsed time: 6.3 seconds
Video open, using libass:
Initial memory usage: 54.3 MB
Final memory usage: 653.3 MB
Elapsed time: 23.7 seconds
With flyweight:
No video open:
Initial memory usage: 26.0 MB
Final memory usage: 104.5 MB
Elapsed time: 3.0 seconds
Video open, using libass:
Initial memory usage: 46.7 MB
Final memory usage: 251.8 MB
Elapsed time: 13.0 seconds
No video open:
Memory usage: -79%
Time: -52%
Video open:
Memory usage: -61.5%
Time: -45%
100 no-op amend commits on a line in the middle of a subtitle file with
6689 dialogue lines, with video open:
Without flyweight:
Initial memory usage: 48.2 MB
Final memory usage: 182.3 MB
Elapsed time: 22.3 seconds
With flyweight:
Initial memory usage: 39.8 MB
Final memory usage: 165.8 MB
Elapsed time: 13.8 seconds
Note: The large jump in memory usage here is due to that the benchmark
is blocking the main thread, so at the end there are ~100 video frames
waiting to be displayed.
This eliminates the need to explicitly delete the parsed blocks.
Also go ahead and remove AssDialogue::Blocks since it's really not a
very good idea in general.
