[Pvfs2-developers] request unify and cleanup

[Sam Lang]

On Feb 9, 2008, at 4:29 PM, Pete Wyckoff wrote:

> slang at mcs.anl.gov wrote on Sat, 09 Feb 2008 15:59 -0600:
>> I would do that if I could think of a way.  Those functions have to  
>> access
>> the request specific field in the request structure. delete for  
>> example
>> needs to get at:
>>
>> req->u.delete.handle
>>
>> I couldn't come up with a generic function for doing that.  I was  
>> tempted
>> to move the fsid+handle to the common parts of the request, so that  
>> every
>> request had those fields (for some they would just be NULL), but  
>> that would
>> have been a much larger change, and a protocol change to boot.
>>
>> If I were able to assume that the fsid and handle were always the  
>> first two
>> fields in the request (for the requests that operated on a handle),  
>> I could
>> just operate on the req->u union (a poor man's polymorphism), but I  
>> don't
>> know if that's an assumption/requirement we want to make (and would  
>> be
>> another protocol change for the requests that don't have those as  
>> the first
>> two).
>>
>> If we wanted to go down this path further, I would probably want to  
>> work up
>> some sort of bindings generator that would do a lot of the manual  
>> labor for
>> us.
>
> Oh, I see.  Missed that.  Yeah, the unions are a real pain.  Not
> worth trying to fix that here too, I agree.  Funny, there already is
> a target_handle in the server structure which may store exactly the
> individual u.delete.handle you are working hard to extract.  Still,
> not worth the change if there is any risk of bugs here.

The server struct (defined in pvfs2-server.h) has the target_handle/ 
target_fs_id fields, but its the server request struct (defined in  
pvfs2-req-proto.h) that we need to extract the handle and fsid out of.

>
>
> I see now that PINT_server_req_get_object_ref() returns NULL handle
> and fs_id when no get_object_ref method is defined.  Which means at
> least you don't need special methods for mgmt_event_mon, get_config,
> noop, etc.  If you want to excise those at least.

Yep, can do.
-sam
>
>
> 		-- Pete
>