Make IdentityCMaps more compact. #5135
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IdentityCMap uses an array to represent a 16-bit unsigned identity function. This is very space-inefficient, and some files cause multiple IdentityCMaps to be instantiated (e.g. the one from mozilla#4580 has 74). This patch make the representation implicit. When loading the PDF from issue mozilla#4580, this change reduces peak RSS from ~370 to ~280 MiB. It also improves overall speed on that PDF by ~30%, going from 522 ms to 366 ms.
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/botio-linux preview |
From: Bot.io (Linux)ReceivedCommand cmd_preview from @timvandermeij received. Current queue size: 0 Live output at: http://107.21.233.14:8877/2a1b63b66634ec9/output.txt |
From: Bot.io (Linux)SuccessFull output at http://107.21.233.14:8877/2a1b63b66634ec9/output.txt Total script time: 0.75 mins Published
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/botio test |
From: Bot.io (Linux)ReceivedCommand cmd_test from @timvandermeij received. Current queue size: 0 Live output at: http://107.21.233.14:8877/6add700436da8e4/output.txt |
From: Bot.io (Windows)ReceivedCommand cmd_test from @timvandermeij received. Current queue size: 0 Live output at: http://107.22.172.223:8877/5536969f090a58a/output.txt |
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Nice; this patch also improves the performance of #4935. |
From: Bot.io (Windows)SuccessFull output at http://107.22.172.223:8877/5536969f090a58a/output.txt Total script time: 19.63 mins
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From: Bot.io (Linux)SuccessFull output at http://107.21.233.14:8877/6add700436da8e4/output.txt Total script time: 22.57 mins
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The rendering time for #4935 went down from 12225 ms to 7077 ms, a 43% decrease! |
And peak RSS dropped from ~2800 MiB to ~2400. Still too high, though; I'll do some more profiling. |
Make IdentityCMaps more compact.
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Really good. Thank you for the patch. |
IdentityCMap uses an array to represent a 16-bit unsigned identity
function. This is very space-inefficient, and some files cause multiple
IdentityCMaps to be instantiated (e.g. the one from #4580 has 74).
This patch make the representation implicit.
When loading the PDF from issue #4580, this change reduces peak RSS from
~370 to ~280 MiB. It also improves overall speed on that PDF by ~30%,
going from 522 ms to 366 ms.