[Monotone-devel] restrictions rewrite

[Derek Scherger]

Hi folks, in case no one has noticed, sometime during the rosters 
rewrite I got going again with restrictions and have updated things to 
take advantage of the new rosters code. It was a nice little project to 
figure out the rosters code and as I was doing the conversion it became 
very apparent to me how much better the new rosters code is at 
representing what's going on behind the scenes.

The new restrictions code is on the branch (aptly, if not longly) named 
net.venge.monotone.experiment.rosters.restrictions and I think it's 
pretty much ready to go. There should be no user visible changes with 
the code on this branch. It does fix one XFAIL'ed test but otherwise 
passes the existing testsuite.

The basic idea is that a restriction holds a set of node_id's and the 
state of each, so given a roster, determining which nodes are included 
is quite simple. Unfortunately, for ls unknown and ls ignored there are 
no node_id's so there is also a set of split_path's to handle these 
cases which introduces a bit of duplication.

It would be great if people could have a look at the new code to see 
what they think, suggest improvements, etc. Here's a list of things to 
be done:

- add support for the --depth option and handle ignored files
  properly to fix two remaining test failures
- the constructors are still a bit awkward and can probably
  be improved
- test the performance of restricted operations on big trees. the old
  restrictions code fairs poorly on these and I hope the new code will
  do much better but I have not done any tests yet.
- decide what to do with the "implicit" inclusion of "required" parent
  directories business. this supports things like add a; add a/b; add
  a/b/c; followed by a restricted commit of a/b/c which requires the
  addition of a and a/b before c can exist. the right thing to do here
  is probably to change things a bit so that containing directories must
  be explicitly specified.

There is also another branch off of this called 
net.venge.monotone.restrictions.wildcard-paths where I've replaced the 
--depth argument with optional recursive directories using a dir/... 
syntax suggested by njs on the wiki.

        http://venge.net/monotone/wiki/RostersTodo

None of the testsuite has been updated to work with this branch yet so 
I'm sure there are lots of failures. This syntax may be slightly less 
flexible than the current --depth option. Presumably "dir/..." would 
match a directory and recursively anything contained within it. Without 
the trailing "/..." a directory could match only itsself (--depth=0) or 
possibly itsself and all of its immediate children non-recursively 
(--depth=1). Both of these seem like useful cases particularly in the 
"required parent" directory cases so some feedback on this would be great.

Cheers,
Derek