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On Tue, 24 Feb 2009 18:16:54 +0100 |
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Luca Barbato <lu_zero@g.o> wrote: |
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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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> |
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> I see words, not numbers. |
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Number: double. That's a '2 times'. |
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> >>> That is not how metadata checks work. |
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> >> Explain how they work, regen works that way... |
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> > |
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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 |
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> > back to the ebuild directory or read its contents at all. Then it |
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> > can open and read cache files in a carefully selected order to |
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> > avoid having to do any more opens than necessary. |
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> |
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> So? if the cache is valid then you don't have to source them at all. |
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> If you have to regen it, well you have to read everything. |
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You don't know whether the cache is valid until you know the EAPI. It |
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only works currently because EAPIs don't change inherit behaviour. |
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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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> >> Apparently it doesn't impact anything. |
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> > |
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> > Please show the patch you created (for Paludis, since Portage |
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> > doesn't yet do a lot of the optimisations it could here) that |
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> > demonstrates this. |
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> |
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> Paludis isn't portage. |
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So you have patches for Portage? Please show them. |
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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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> >> 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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> > |
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> > Because it has to parse that version. Also, the package manager |
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> > can't tell whether or not a cache entry is valid if it doesn't |
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> > recognise the EAPI in the cache entry. |
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> |
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> unknown isn't unsupported? |
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Huh? Please explain what you mean. |
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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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> >> 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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> > |
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> > Why should it? The C++ standard doesn't explain why you should use |
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> > it instead of Java... |
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> |
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> In fact many people do wonderful things with java and many more just |
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> do over engineered mess with C++? |
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Your trolling is going rapidly downhill. |
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-- |
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Ciaran McCreesh |
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