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Re: svn_io_open_unique_file: quadratic cost

From: Greg Hudson <ghudson_at_MIT.EDU>
Date: 2003-10-15 18:19:43 CEST

On Wed, 2003-10-15 at 09:17, Julian Foad wrote:
> The cost of opening N similar temporary files with
> svn_io_open_unique_file is proportional to N squared, and with a high
> constant of proportionality. Its cost scales linearly with the number
> of temp files of the same pattern that exist already, so the total
> cost of opening N such temp files is quadratic. If the application
> creates say 200 temp files of the same pattern, it will perform
> (200+199+...+1) = 20100 iterations of its loop which contains:

That might explain why imports seem to get slower and slower as they go
on. (And why memory usage was so high back when we were opening those
temp files using a long-lived pool.) I'd always figured it was an FS

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Received on Wed Oct 15 18:21:32 2003

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