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Re: Another thought on Subversion as a changeset engine

From: Branko Čibej <brane_at_xbc.nu>
Date: 2002-12-19 17:46:15 CET

Alon Ziv wrote:

> It has occured to me that Subversion is already "almost" a changeset
> database, as the "deltas" it stores are equivalent to
> changesets---only they are reversed (i.e. they create the preceeding
> version from the following one, instead of the other way around).
> Now, if we could just create an algorithm for reversing deltas,
> Subversion can become a "real" changeset database without almost any
> change in the existing semantics.
> Is this possible? Or are deltas fundamentally irreversible? (I do
> recall something was said about it on the list once, but I can't
> remember what... And couldn't find it in the archives :-( )

1) Deltas are reversible in general, provided you have both source and
target text at hand. Which we don't, obviously, because we have deltas.

2) You've totally missed the point. The storage format has nothing
whatsoever to do with whether Subversion is a changeset engine or not.
Being a changeset engine is about semantics, not about physically
storing changesets.

3) A changeset is not the same as a set of diffs.

Brane Čibej   <brane_at_xbc.nu>   http://www.xbc.nu/brane/
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Received on Fri Dec 20 02:46:58 2002

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