Hi Graeme, its always fun to go randomly through a mail box - you'll ALWAYS find mails you did not answer, but should have... Well, this is another one, comments are included. Cheers, Andre. Quoting [G.E.POUND@soton.ac.uk] (Jan 24 2006):
Andre,
Thanks for the feedback. I have added a few further comments below.
Graeme
Quoting Andre Merzky <andre@merzky.net>:
[... vector attributes etc.]
A use case is, as pointed out by Hrabri for instance, the specification of a list of email addresse to be notified on job completion:
[perl]
job.set_vector_attributes ('SAGA_JobContact', ('a@mai.com', 'b@mailcom'));
If a vector attribute key is set/queried with the scalar attribute call, and exception should be raised (NoSuchKey). Same for the other case.
Actually, I think that this model is not very nice. For one thing, we need an inspection interface (does that attribute exist? Is it a scalar or vector?). Also, we need to be clear if attribute can be scalars or vectors (if you set only one email?).
Sorry for not having a better answer...
It may be simpler to consider that all non-string attributes (including vectors of strings) are a special case.
Many of the Attribute based interfaces require attributes of a specific type, in the current spec it is up to the user to cast to and from a String themselves. In the longer list of comments I raised the possibility that these interfaces could provide specific get and set methods for these attributes. Casting (or storing) values of a different type is then an issue for the implementation provider.
Yes, a note about setters/getters in language bindings made it to the spec by now.
- contextType does not appear to be very extensible, how would different security models be specified?
The spec states that
A implementation CAN implement various types of Security contexts. or just one type.
and
Other types MAY be specified by a SAGA implementation.
which basically means that out of the types specified in the spec, and any other types you can think of, a non empty subset has to be implemented by the SAGA implementation.
So would an implementation extend (or redefine) the enumeration of context types?
Yes, exactly - extend would be better I guess, or at least use values which are not taken by the spec.
- capitalise ivec, openDirFlags, openFlags?
Well, ask 2 people about that and you get 5 answers ;-) Fact is, capitalization should be consistent through the API, and it is not currently. I think it is best if you choose a native java scheme for naming, I guess there is one?
Yes consistency within the API is important.
Java has a well defined set of naming conventions (http://java.sun.com/docs/codeconv/html/CodeConventions.doc8.html#367). Where the SAGA API differs from the conventions of different languages, will the API be altered to meet those conventions in the language bindings?
The language bindings should meet the conventions for the specific language, if possible.
- The enumerations openDirFlags and openFlags exist in the following packages SAGA.Namespace, SAGA.File and SAGA.LogicalFile (although SAGA.Namespace is imported by SAGA.File and SAGA.LogicalFile). Is this duplication required?
They are gone in the namespace by now, as the namespace has no open calls anyway...
The flags for Files and LogicalFiles might well be different, so the duplication is needed there I think.
Yes that sounds sensible.
Well, that changed again :-P As namespace was changed into a class, and HAS constructors and open methods, the flags are needed there as well. So flags are now indeed duplicated through the API. SIDL does not support it, but the language bindings should probably do something like (Hartmut introduced that in our implementation): class saga::ns_entry { enum open_flags { Read = 0, ... } ... }; class saga::file : public ns_entry { typedef open_flags saga::ns_entry::open_flags; ... }; in order to avoid duplication. That won't be possible in all places I guess, as flags might differ slightly. I don't see a better solution though...
- the interfaces Stream and StreamServer implements Attributes, however Attributes does not exist. Is this Attribute (perhaps Attributes is a better name for this class)?
Good catch: we need to define these attributes. They are (for example) 'buffer size', 'reliable', etc. I have the list somewhere buried in my mail, and need to update the spec. Sorry...
I actually raising the issue of the typo 'Attributes', but I prefer the typo to the interface name 'Attribute' (which is something of a misnomer).
I agree. However, we decided at one point to stick to singular names: stream, file, attribute, job etc - we hade that mixed before... Thanks, Andre. -- "So much time, so little to do..." -- Garfield