Tracking which ports were installed explicitly

[Ryan Schmidt]

On Dec 3, 2008, at 20:46, Rainer Müller wrote:

> Joshua Root wrote:
>
>> If it's done as proposed in the ticket, you would do 'port dependents
>> foo' (or rather its internal equivalent) to see whether foo is  
>> orphaned.
>> If it has no dependents, it's orphaned. Explicitly installing a port
>> adds 'world' as a dependent.
>
> Using a pseudo-port like 'world' sounds like a very nice and elegant
> idea to me. But checking for dependents is currently a very expensive
> operation. To find all dependents the current code iterates over the
> whole dep_map, which can grow very large depending on the number of
> ports being installed.
>
> If you never heard about dep_map, take a look in your own install:
>   bzless /opt/local/var/macports/receipts/dep_map.bz2
> And then you will see why searching and modifying this file is so  
> expensive.
>
> Therefore we should focus on finishing registry2.0. This was already
> started by Chris Pickel (sfiera) in Google Summer of Code 2007. The  
> code
> was merged to trunk, and it is also already distributed with releases,
> but it is not used at all yet.
>
> registry2.0 plans to use a sqlite db instead of plain text files for
> dependency tracking (dep_map) and receipts. This should hopefully make
> such search operations a lot faster and also make the registry more
> extensible.
>
> I tried to get a statement about the status of registry2.0 from Chris
> some time ago in April, but the only response was that he is busy.  
> So I
> don't know what is left to complete registry2.0.

We also need to consider that changes have probably occurred in  
registry1.0 since then which may not have been merged into registry2.0.