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Re: Ref-counting for pristine texts

From: Branko Čibej <brane_at_xbc.nu>
Date: Wed, 19 Jan 2011 00:58:42 +0100

On 18.01.2011 16:58, Julian Foad wrote:
> On Thu, 2011-01-13, Branko Čibej wrote:
>> This would indicate that the reference counting happens too soon ... in
>> other words, that a pristine can be dereferenced whilst some part of the
>> code (or database) still refers to it. That breaks database consistency
>> -- what happens if the user aborts a commit and then calls 'svn
>> cleanup', for example?
> If what I said about 'commit' is correct, then yes, that's bad and we
> should look for a better way. But I haven't tested it properly; I
> noticed that the commit failed saying that the DB failed a 'REFERENCES'
> clause, and what I said here is a hypothesis about how that happened.
>
> Investingating this is the second thing I would want to do next.

I beg to differ, it should be the first thing, because it's a
correctness issue. If the references in the database are maintained
correctly, then it should be safe to delete after each successful
transaction commit.

That's assuming that any high-level operation involves a single
transaction, e.g., that a commit can't fail in some way that would
require the pristine to still be in place in order to recover, even if
the reference count in the database is 0.

-- Brane
Received on 2011-01-19 00:59:29 CET

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