Re: [lisp-snmp] Misc fiddles for new OID types

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

Hi, John

Thanks for these SIMPLE-OID related fixes, I'm appreciated about them.

Now, I'm thinking on another performance enhancement when we have  
SIMPLE-OID:

Using a "weak hash table" as a cache for holding SIMPLE-OID instances  
which already created in current lisp image, so that few SIMPLE-OID  
created when repeat do SNMP-WALK on same MIB node. The key of this  
hash table would be a "oid number list" as a list, and the value would  
be the correspond SIMPLE-OID instance.

Since "weak hash table" is not in CL standard, I'll support only a few  
implementations included at least LispWorks, AllegroCL and SBCL, and  
make a new "ASN.1 feature" (OID-CACHE) for this work. Do you think  
this features would be useful for you?

Regards,

Chun Tian (binghe)

在 2009-5-8，09:56， John Fremlin 写道：

> Dear Chun Tian,
>
> Here are the misc helpers I put in to deal with the new OID types.
>
> Maybe you would like to fix them up or correct them?
>
> ASN.1 patch
>
> Index: runtime/object-id.lisp
> ===================================================================
> --- runtime/object-id.lisp	(revision 766)
> +++ runtime/object-id.lisp	(working copy)
> @@ -113,8 +113,9 @@
>   (slot-boundp oid 'parent))
>
> (defun oid-module-p (oid)
> -  (declare (type object-id oid))
> -  (slot-boundp oid 'module))
> +  (typecase oid
> +    (object-id
> +     (slot-boundp oid 'module))))
>
> (defun oid-syntax-p (oid)
>   (declare (type object-id oid))
> @@ -124,17 +125,29 @@
>   (declare (type object-id oid))
>   (symbol-name (oid-name oid)))
>
> -(defun oid-name-list (oid)
> -  (declare (type object-id oid))
> +(defgeneric oid-name-list (oid))
> +(defmethod oid-name-list ((oid object-id))
>   (labels ((iter (o acc)
>              (if (slot-boundp o 'parent)
> -                 (iter (oid-parent o) (cons (if (slot-boundp o 'name)
> -                                                (oid-name-string o)
> -                                              (oid-value o))
> -                                            acc))
> -               acc)))
> +                 (iter (oid-parent o)
> +		       (cons (if (slot-boundp o 'name)
> +				 (oid-name-string o)
> +				 (oid-value o))
> +			     acc))
> +		 acc)))
>     (iter oid nil)))
>
> +(defun oid-number-sublist (oid)
> +  (nthcdr
> +   (if (oid-parent-p oid)
> +       (oid-length (oid-parent oid))
> +       0)
> +   (oid-number-list oid)))
> +
> +(defmethod oid-name-list ((oid simple-oid))
> +  (append (when (oid-parent-p oid) (oid-name-list (oid-parent oid)))
> +	  (oid-number-sublist oid)))
> +
> (defmethod plain-value ((object simple-oid) &key default)
>   (declare (ignore default))
>   (oid-number-list object))
> Index: runtime/oid-walk.lisp
> ===================================================================
> --- runtime/oid-walk.lisp	(revision 766)
> +++ runtime/oid-walk.lisp	(working copy)
> @@ -85,10 +85,25 @@
>        (zerop (hash-table-count (oid-children oid)))))
>
> (defun oid-trunk-p (oid)
> -  (declare (type object-id oid))
>   (and (slot-boundp oid 'name)
>        (plusp (hash-table-count (oid-children oid)))))
>
> +(defun oid-find-base (oid)
> +  (labels ((iter (o acc)
> +	     (typecase o
> +	       (null (values nil acc))
> +	       (object-id
> +		(if (slot-boundp o 'name)
> +		    (values o acc)
> +		    (let ((p (oid-parent o))
> +			  (v (oid-value o)))
> +		      (iter p (cons v acc)))))
> +	       (simple-oid
> +		(iter (when (oid-parent-p o) (oid-parent o))
> +		      (append (oid-number-sublist o) acc))))))
> +    (iter oid nil)))
> +
> +
> (defun oid-find-leaf (oid)
>   "Find the leaf node in a oid's all parents"
>   (declare (type object-id oid))
>
>
>
> PS. Thanks for fixing runtime/ipaddress to not barf on length != 4.
>
> BTW
> (loop for i from 1 upto length
>    collect (read-byte stream))
>
> is the same as
>
> (loop repeat length
>        collect (read-byte stream))
>