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12744 :: SVG parsing generates massive memory allocation

• zack (orginal) [2025-03-27T08:13:58+01:00] view original

  I use the pixie lib to parse an svg file (https://commons.wikimedia.org/wiki/File:1_42_polytope_7-cube.svg)

  
  let svgFile = readFile("1_42_polytope_7-cube.svg")
  let svg = parseSvg(svgFile)
  Run

  • Before parsing (getOccupiedMem()): ~30 MB
  • After parsing (getOccupiedMem()) : ~154 MB
  • getTotalMem: : ~2.5 GB

  On the Nim side what could I do, are there any functions that could help me decrease getTotalMem() ?

  Note : I had to modify this line viewBox='0 0 800 800' in the svg to make it work.

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• ingo (orginal) [2025-03-27T08:32:53+01:00] view original

  This one? https://commons.wikimedia.org/wiki/File:1_42_polytope_7-cube.svg It has quite a lot of lines.

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• zack (orginal) [2025-03-27T08:53:13+01:00] view original

  This one?

  Yes, I would like to understand, with this example file, if it is possible to decrease this value.

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• Araq (orginal) [2025-03-27T09:20:55+01:00] view original

  Maybe with -d:useMalloc but then the memory reporting doesn't work properly and you need some OS tool to determine the memory usage.

  But I think either way this requires a patch to pixie so that it frees some intermediate data structures earlier or avoid its creation.

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• zack (orginal) [2025-03-28T11:01:42+01:00] view original

  -d:useMalloc

  It solves my massive memory problem, but impressively, I didn't want so much ! From ~2.5 GB, I'm down to about ~230 MB after parsing my Svg file.

  I don't have the impression of a reduction in performance, but I'll read the documention about -d:useMalloc

  Thanks.

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