Re: [Relfs-devel] RelFS usage.

[Michael R. <fb0...@ra...>]

Vincenzo Ciancia wrote:
>> After creating one more set of scripts for RelFS, I decided to post it
>> here
> 
> Ok I am almost back. Will be completely back after a couple of
> deadlines. You are welcome posting scripts, I will soon create an
> "utils" directory with shell scripts to do ordinary stuff, even though I
Good idea.
> think we should write some simple GUI, after stabilizing about the kind
> of common relfs usage.
Scripts are good because of being quick-and-not-too-dirty. I agree that
after deciding what we do need and what was a bad idea we can try to
write some usable GUI (to give people something to tease disappointed
former WinFS believers?).

>> , as it gives easy interface (too simplistic, but yet more than a
>> standard search in file managers would give) to create search directory,
>> where will be found all files which satisfy condition (I count symbolic
>> links as files).
> 
> I still haven't been able to study your scripts in detail, but I have
> some preliminary comments and many questions:
I expected this.

> 1. I don't like the "_create_" scripts that add things to a schema,
> would rather prefer to have a state in relfs where it scans for new
> addons, and when it finds them, it runs initialization code. This state
For this some negotiation is needed about plugin interface. With *create
scripts someone passing by (we should act as if there are some, and I
hope there are - I will be glad if some of them replies with ideas of
possible bleeding-edge user) can say why I did everything wrong without
any effort right now.

> should be entered at least on startup, or better when a certain
> directory containing plugins is changed. Your tags table can be at right
> considered a plugin for relfs, even though there is no indexing. This
> can be a good addition for a next snapshot of relfs.
Well, a good idea. My script show 2 things: how something like tags can
work, and how something can be easily added by user to RelFS - even
without OCaml knowledge.

> 2. Can you explain the schema of "tags"? Why are there (path,filename)
> pairs? Didn't the id suffice to find the file name? Why did you prefer
Well, I want to simplify possible searches in this database. I leave
using lookup on each occasion to my enemies.

> to introduce a "tag_value"? I always think of tags as boolean
> attributes, not quantities, even if the second idea is more general and
> can be useful to implement classification directories, it seems harder
I thought "What do I want?". I wanted to have some different
classifications all easily accessible. I want to automatically have list
of all programming languages I mentioned in tags. With special virtual
folder for each. I also want to have list by functionality program
provides. This way command-line completion works better... And I have to
choose two times - both times between similar notions in bearable
quantity (not between "OCaml" and "file system", but between "language"
and "purpose" and later between "OCaml" and "Shell").

> to use for navigation. In your case, you list all the values as
> subdirectories of a tag, aren't them tags in their own right then? In
They are, but they are grouped by category.

> fact a tag name already can contain slashes, so the two namespaces
Er.. I don't filter it, by I don't think it works.

> "tag/value" and "tag" already overlap, don't them? Finally, what's the
> meaning of tag_id? Could "id, tag" be used as a primary key for the
> table?
Well, it can. But this is polishing. I didn't want to restrict myself
before I complete anything. I didn't want to design well - I wanted to
test features.

> 3. What's the _uniquedata_ stuff for?
I understood that file cannot have 2 real sizes (for symbolic link, as I
store mainly symbolic links here - RelFS is good at categorization, but
right now I am just not ready to store all data on it - just like I do
not store /home on funionfs), and if I want to tag project tarballs that
bear my contributions also, this tag can be assigned only once. But it
can be reasonable to make 2 programming language tags - like when
Mozilla applications are written in C++ + JavaScript. So I made a table
as an alternative to tags when there is one main tag_value and rarely
ever second. It makes some search queries simpler and it allows to get a
quick summary of multiple files at once.

> 4. What's the symlinkize_dir script? Maybe we already talked about that
> in the past.
It is easy to work with symbolic links in RelFS (I have right to say so,
I guess). There are many technical problems with directories (I see some
in processing something like name/#select/name/#select path). So an easy
workaround is to make directory that you want to appear in search
technically symbolic link, and hide content somewhere near it.

> 5. How should relfs_search_text be used?
It is used in relfs_create_search only. It was used when I wanted to
debug the scripts. You can also just feed its output to SQL pipe to see
listing one time, without creating directories. I agree that it is
exposing implementation, but for proof of concept it is not fatal.

>> PS. On the site it is stated that I learned OCaml for this project. That
>> is not entirely true - I didn't learn it well, and I knew some basics
>> before. But I think that I more than doubled my skill in OCaml.
> 
> Oops, fixed :) Thank you for your help with the project, I will surely
Funny design solution for fix.

> add an "util" directory with your scripts. We should agree a schema for
> tags and the rest, and then also create some simple GUI to perform the
> same operations as the scripts, dunno if in ocaml+gtk or in python.
I agree with that. Maybe then it will be possible also to promote
project a bit, say by discussion of possible improvements (together with
finding volunteers) on LinuxQuestions.org or somewhere.