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Re: [RFC] A libsvn_wc properties optimisation

From: Barry Scott <barry_at_barrys-emacs.org>
Date: 2004-11-06 14:52:47 CET

On Nov 6, 2004, at 12:35, Philip Martin wrote:

> Barry Scott <barry@barrys-emacs.org> writes:
>
>> If you are going to change things go for a bigger win.
>>
>> Use a single file for the props of all the files in a directory.
>> And lose the .svn/props and .svn/props-base directories.
>
> It's been suggested before, but I'm not convinced it's a win. At
> present properties are not cached in memory (ignoring any caching by
> the OS). If all the properties are in one file, the whole properties
> file would need to be read to get the properties each time they were
> needed for any one versioned file (in theory I suppose one need only
> read half the file on average). Caching the properties in memory is a
> bit of an unknown, because there can be an arbitrary number of them
> and the property values can be an arbitrary size.

The win is that you only have to do a file open on one file rather then
lots of files/directory. I'm sure that parsing one file is far faster
then open
10 files. The file sizes are trivial. I have 1856 bytes for 54 files in
my
repo for example.

And remember that on windows file opens are slowed by anti-virus
software. You will get an even bigger win then on unix systems.

I not sure what you are getting at with caching in memory. A command
like svn_client_proplist will open the file, read and parse and return
the info in an apr array alloc'ed in a pool. Where is the caching?

Barry

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Received on Sat Nov 6 14:54:08 2004

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