Re: Proposed branch tag performance patch for feature and stable releases

[Mark D. Baushke]

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Kelly F. Hickel <kfh@mqsoftware.com> writes:

> <snip>
> > > > > >     b) if the rev has numdots+2 (ex: 2
> > > > > > "1.1.0.4") AND the strings are identical
> > > > > > up to the numdots+2 dot (ex:
> > > > > > strncmp("1.1.0.2", "1.1.12", 5) AND the
> > > > > > final term is an even number, AND the term
> > > > > > before the final term matches
> > > > > > RCS_MAGIC_BRANCH, insert the integer value
> > > > > > of the final term into the list.
> > > >
> > > > So, if you observed the following tags
> > > >
> > > >     q:1.23.0.10
> > > >     p:1.23.0.4
> > > >     o:1.1.12.1.0.4002
> > > >     n:1.1.0.18
> > > >     m:1.1.14.22.0.2
> > > >     l:1.1.14.22.0.4
> > > >     k:1.1.0.14
> > > >     j:1.1.12.1.0.4
> > > >     i:1.1.0.10
> > > >     h:1.1.0.1000
> > > >     g:1.1.8.1.0.2
> > > >     f:1.1.0.8
> > > >     e:1.1.0.6
> > > >     d:1.1.0.4
> > > >     c:1.1.0.2
> > > >     b:1.1.0.2000
> > > >     a:1.1.1.1.0.2
> > >
> > > [Kelly F. Hickel] What's the significance of the
> > > letters before the colon in the tags above? Is
> > > that the symbolic name of the tag, or something
> > > else?
> > 
> > Symbolic name of the tag... I just came up with a
> > random sampling of tags. It must be presumed that
> > the 1.1.0.12 magic branch tag was deleted and
> > likewise with 1.23.0.2, 1.23.0.6, and 1.23.0.8
> > magic branches.
> 
> [Kelly F. Hickel] OK, so how does one determine that 1.1.0.12, 1.23.0.2,
> 1.23.0.6 and 1.23.0.8 existed at one point?  (I'm assuming that it would
> be bad to reuse those magic branch tags)

CVS would not have created a magic branch tag 1.1.0.14 unless a 1.1.0.12
existed previously.

The fact that there also appears to be a branch 1.1.12.1.0.4002
indicates that a 1.1.12.1 revision exists and has a local branch for it
in the 4002 range. This may either have been the starting revision
provided by the user via the CVS_LOCAL_BRANCH_NUM environment variable,
or there may have once been a 1.1.12.1.0.4000 branch. We won't be able
to tell unless there happens to be a 1.1.12.1.4000.<num> revision in the
file.

It may not be bad to reuse branch tags provided that there are no
revisions created under them. In fact, I believe that CVS would choose
1.1.0.12 as a candidate revision and only the fact that the tagging code
would parse the entire RCS file and reject 1.1.0.12 as a revision for a
new tag forcing the march to 1.1.0.14, etc.

        -- Mark

> > > > for a particular RCS file, what magic branch
> > > > revision would your programv generate as the
> > > > next revision for each of the given revisions:
> > > >
> > > >   1.1.1.2
> > > >   1.1
> > > >   1.24
> > > >   1.1.2000.1
> > > >   1.1.18.12
> > > >
> > > > are you able to make any assumptions about the
> > > > existence of tags like:
> > > >
> > > >  aa:1.1.2.23
> > > >  ab:1.1.12.14
> > > >  ac:1.23.2.16
> > > >  ad:1.1.6.1
> > > >
> > > > > > 4) Call sortlist on the list, sorting it
> > > > > > into ascending order of integer values.
> > > >
> > > > > > 5) go through the list, find the first
> > > > > > gap, that's the new magic revision number.
> > > > > >
> > > > > > Then I'll have to figure out enough of
> > > > > > sanity.sh to add a test case for the old
> > > > > > code, make sure the released codes passes,
> > > > > > and that my previous patch fails, and that
> > > > > > the new patch passes.
> > 
> > It can be tricky, if you have cvs commands you
> > think will demonstrate what you need, feel free to
> > ask for help turning them into tests.
> > 
> >     -- Mark

        -- Mark
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