Re: [lisp-snmp] Changing the representation of OIDs

[Chun T. (binghe) <bin...@gm...>]

在 2009-5-1，16:29， John Fremlin 写道：

> Dear Chun Tian,
>
> Thanks again, I will test your new patch after the Golden Week
>
> "Chun Tian (binghe)" <bin...@gm...> writes:
> [...]
>> A SIMPLE-OID is a special ASN.1 object ID which have less slots  
>> than a
>> normal OBJECT-ID:
>>
>> (defclass base-oid (asn.1-type)
>>  ((parent      :type object-id
>>                :reader oid-parent
>>                :initarg :parent)))
>>
>> (defclass simple-oid (base-oid)
>>  ((values      :type list
>>                :reader oid-number-list
>>                :initarg :values)
>>   (length      :type fixnum
>>                :reader oid-length))
>
> Seeing as the complex OID also has these slots, why not include them  
> in
> base-oid?

SIMPLE-OID is a super class of OBJECT-ID :)

>
>
> With a vector representation you only need one slot as the length is  
> O(1)
>
>>  (:documentation "A simple OID implementation"))
>>
>> I still use a LIST to hold the oid number list because this can best
>> fit most of exist code.
>
> Would you accept a patch to convert it over to vectors

Yes, I would like to see this patch. But I hope the change be as small  
as possible.

>
>
> There are many places where we might better use vectors than lists
> (e.g. ber-decode-type which unfortunately does plenty of unnecessary
> consing).
>
> [...]
>
>> You can see, for (OID "sysDescr.0") and (OID '(1 3 6 1 2 1 1 1 0)) ,
>> it returns a SIMPLE-OID instance instead of OBJECT-ID now. The rule
>> is: if the object id ends with unnamed number lists, a SIMPLE-OID  
>> will
>> return instead. I think lots of work can be saved here.
>
> Thanks, I this is we have taken out the top memory wasters out of our
> program, which might be enough to make the customer a bit happier.
>
> Mr Kuroda was threatening to try to get me to specify the amount of
> memory required by the program -- perhaps that will be a bit simpler  
> now
> (but not much ;-).
>
> [...]
>