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On Tue, 24 Feb 2009 17:04:28 +0100 |
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Luca Barbato <lu_zero@g.o> wrote: |
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> Ciaran McCreesh wrote: |
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> > On Tue, 24 Feb 2009 08:08:23 +0100 |
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> > Uh, your benchmarks are nonsense. |
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> |
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> Provide your nonsensical ones. |
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You're doubling the number of files that have to be read for an |
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operation that's almost purely i/o bound. On top of that, you're |
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introducing a whole bunch of disk seeks in what's otherwise a nice |
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linear operation. |
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> > That is not how metadata checks work. |
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> |
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> Explain how they work, regen works that way... |
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If metadata is valid, ebuilds aren't opened at all. An optimal |
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implementation can slurp up the entire directory in one go and then |
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start pulling out cache entries as it needs them, not having to go back |
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to the ebuild directory or read its contents at all. Then it can open |
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and read cache files in a carefully selected order to avoid having to |
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do any more opens than necessary. |
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> > By parsing the ebuilds you're talking doubling the number of file |
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> > reads required to get the job done, and massively increasing the |
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> > number of seeks required. |
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> |
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> Apparently it doesn't impact anything. |
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Please show the patch you created (for Paludis, since Portage doesn't |
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yet do a lot of the optimisations it could here) that demonstrates this. |
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> > But that isn't even the main issue. The main issue is that even if |
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> > you retroactively pretend that all ebuilds are in a format they're |
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> > not, and ignore the breakage, and then wait for a year for package |
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> > managers to try to parse your new format, you *still* can't change |
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> > name or versioning rules. |
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> |
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> why? when portage would breanch if I put an ebuild with a wacky |
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> version AND there is a valid cache for that telling its eapi 99 ? |
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Because it has to parse that version. Also, the package manager can't |
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tell whether or not a cache entry is valid if it doesn't recognise the |
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EAPI in the cache entry. |
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> > Again, these are all things that have been discussed at length |
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> > previously. Please either come up with a legitimate technical |
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> > objection, or admit that you've seen the light. |
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> |
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> the glep doesn't show any of those nor reference to it, as I said |
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> before, do your homework and probably more people will be happier |
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> with your proposals. |
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Why should it? The C++ standard doesn't explain why you should use it |
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instead of Java... |
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-- |
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Ciaran McCreesh |
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