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W dniu sob, 11.11.2017 o godzinie 12∶31 -0500, użytkownik Michael |
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Orlitzky napisał: |
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> > > and a meta-question, |
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> > > |
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> > > c) Seriously, empty directories are undefined behavior? |
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> > |
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> > ...and how could they be defined if a directory can be installed by |
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> > multiple packages and has no explicit ownership? |
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> |
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> I see the problem, but the package manager knows which packages are |
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> using a given directory. (Portage does, and it is at least easy to |
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> record that information.) |
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> |
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> Empty directories could be installed normally, and then during an |
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> unmerge, the package manager could check to see if the empty directory |
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> is used by any package. If it is, leave it -- if not, remove it. You |
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> might object that this would slow down the unmerge process, but a clever |
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> lookup scheme would let you map directory names to packages quickly. |
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> |
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> In fact, such a lookup scheme is already implemented in the filesystem |
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> itself, leading me full circle to the following idea: if the package |
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> manager is about to install an empty directory, it could create the |
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> ".keep" file itself. Then "ls -a $dir" is your lookup function that |
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> determines whether or not a directory is in use by a package. |
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What about a directory that is installed empty by multiple different |
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packages, and non-empty by some other packages? |
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> Having the package manager handle empty directories solves two problems, |
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> |
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> 1) Use of "keepdir" is inconsistent, because portage is happy to let |
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> you create an empty directory without it (even though that |
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> operation is illegal). |
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It is not. It is just not guaranteed to be meaningful. |
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> |
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> 2) The build systems of many packages will create empty directories |
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> during "make install", and it's unreasonable to expect developers |
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> to "keepdir" them all. |
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Not all of those directories are really meaningful. |
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> Essentially,we have two commands to create a directory, "dodir" and |
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> "do-empty-dir" (which we call "keepdir"). The latter is only necessary |
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> due to an implementation detail, so it doesn't belong in the user |
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> interface -- the PM should figure out what to do. |
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> |
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> As far as the actual implementation goes, I'm not sure that |
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> automatically-generated ".keep" files are better than having the package |
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> manager maintain its own database. The latter would be more complex, but |
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> would avoid littering everyone's filesystems with ".keep" files. |
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Do you care enough to spec this properly, introduce EAPI-conditional |
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behavior for it and prepare patches for the package managers? |
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-- |
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Best regards, |
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Michał Górny |
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