Re: What tools do people use to hack on PostgreSQL?

Florian G. Pflug wrote:
> Hi
>
> I'm very excited that my project for implementing read-only queries
> on PITR slaves was accepted for GSoC,

Congratulations.

> and I'm now trying to work
> out what tools I'll use for that job.
>
> I'd like to be able to create some sort of branches and tags for
> my own work (only inside my local repository of course).
>
> I've considered using git, but I couldn't make the cvs->git gateway
> work - neither using the postgresql CVS repository directly, nor with
> a private copy obtained with CVSup.
>
> There is also svk, but I think I'd need a svn repo that mirrors
> the postgresql CVS for that to work. I think Joshua Drake created
> one once, but I don't now if it is kept up-to-date.
>
> What do you guys use for your development work?
>

You can create a CVS mirror very easily (some info on how is below, 
copied from the buildfarm HOWTO.)

The problem will be keeping things in sync with upstream if you commit 
changes.

I'd be tempted to use some other system (svn would work fine, I think) 
to do your personal checkpointing, if that's what you want to do, so 
your checkpoint procedure would be something like:
 cvs update <resolve merge problems> svn ci

A lower tech model might just cut a nightly CVS diff and archive it.

Normally I don't bother with any of this, I just keep a separate tree 
for each development which I periodically update but don't do anything 
else until I'm ready to commit or cut a patch. It depends what you're 
comfortable with. I haven't very often wished I could roll back.

cheers

andrew

----------------------

11. Almost all the bandwidth issues disappear if you use a local CVS repository
instead of the one at postgresql.org. The way to do this (or at least the
way I did it) is using CVSup. Since building CVSup is non-trivial, the
best way to start this is to get a binary package for some system it will
run on. In my case this was a Linux system running Fedora Core/1. After a
few false starts, I got it working replicating the entire repo at 
postgresql.org, including the CVSROOT directory. Then I commented out the
entries in CVSROOT/loginfo and CVSROOT/commitinfo, and set up the LockDir
directive as I wanted it it CVSROOT/config. Then I checked out the CVSROOT
module and did that all over again, and checked the module back in. Then
to make sure CVSup didn't overwrite those files, I made entries for them
in <mirror-home>/sup/repository/refuse. With that done, I was able to
change the build config on that machine so that the config variable "cvsrepo"
was just the name of the mirror root directory. Everything worked fine.
After that I set up an anonymous cvs pserver against the mirror, so that
my other machine could also get the source from there instead of from
postgresql.org. I did a "cvs login", changed the "cvsrepo" config
variable on that machine, and it worked happily too. Finally, I set up a
cron job on the mirror machine to update the mirror. The anonymous repository 
is only updated from the master once every hour, so there is no point in 
running the cron job more often than that. This should not be too big a deal, 
as CVSup is extremely efficient, and even doing this so frequently should 
not incur a lot of bandwidth use.

12. CVSup is not universally available. For example, it does not seem to
be available any longer in Fedora Extras, and there are platforms for which 
it has never been available. However, a similar procedure to the above can be 
done with rsync, which is pretty universally available. Here is what I did.
First I made a repo location, and get an initial repo copy: mkdir -p /home/cvsmirror/pg rsync -avzCH --delete
anoncvs.postgresql.org::pgsql-cvs/home/cvsmirror/pg
 
Then remove the sup directory and set up an rsync exclude file: rm -rf /home/cvsmirror/pg/sup echo /sup/ >
/home/cvsmirror/pg-excludeecho '/CVSROOT/loginfo*' >> /home/cvsmirror/pg-exclude echo '/CVSROOT/commitinfo*' >>
/home/cvsmirror/pg-excludeecho '/CVSROOT/config*' >> /home/cvsmirror/pg-exclude
 
Then edit the CVSROOT as in step 11.
The add a job to cron something like this: 43 * * * * rsync -avzCH --delete --exclude-from=/home/cvsmirror/pg-exclude
anoncvs.postgresql.org::pgsql-cvs/home/cvsmirror/pg
 
Finally, add a pserver if other local buildfarm member machines need access.