[elephant-devel] btree slot of pset becomes unbound when re-opening store

[Ian Eslick]

Well, that was a silly bug.  I just checked in a patch.  Please let  
me know if it works for you now.

Ian

On Jun 8, 2007, at 8:49 PM, Brian Seitz wrote:

> Hey,
>
> I've been experimenting with Elephant, and it's been really great  
> so far.
>
> But I've had one strange issue.  When I make a pset, its btree slot
> always becomes unbound after I've closed and re-opened the store.
> I've tried this with bdb, sqlite, and postgresql, all with the same
> result.  Using Elephant 0.9 and SBCL 1.0.
>
> Here's a self contained instance (using the "friends" example from  
> the docs):
>
> CL-USER> (require 'elephant)
> NIL
> CL-USER> (in-package :ele)
> #<PACKAGE "ELEPHANT">
> ELE> (open-store '(:bdb "/home/bseitz/eletest/"))
> #<BDB-STORE-CONTROLLER /home/bseitz/eletest/>
> ELE> (defpclass person ()
>  ((name :accessor person-name :initarg :name)
>   (friends :accessor person-friends :initarg :friends
> 	    :initform (make-pset))))
> #<PERSISTENT-METACLASS PERSON>
> ELE> (defmethod add-friend ((me person) (them person))
>  (insert-item them (person-friends me)))
> #<STANDARD-METHOD ADD-FRIEND (PERSON PERSON) {B24FC59}>
> ELE> (defmethod remove-friend ((me person) (them person))
>  (remove-item them (person-friends me)))
> #<STANDARD-METHOD REMOVE-FRIEND (PERSON PERSON) {B288FD9}>
> ELE> (defmethod map-friends (fn (me person))
>  (map-pset fn (person-friends me)))
> #<STANDARD-METHOD MAP-FRIENDS (T PERSON) {B2BA3C1}>
> ELE> (setf me (make-instance 'person :name "Brian"))
> #<PERSON oid:100>
> ELE> (setf amigo (make-instance 'person :name "Waldo"))
> #<PERSON oid:102>
> ELE> (add-friend me amigo)
> #<PERSON oid:102>
> ELE> (map-friends #'print me)
>
> #<PERSON oid:102>
> #<DEFAULT-PSET oid:101>
> ELE> (add-to-root "me" me)
> #<PERSON oid:100>
> ELE> (add-to-root "amigo" amigo)
> #<PERSON oid:102>
> ELE> (close-store)
> NIL
> ELE> (setf me nil)
> NIL
> ELE> (setf amigo nil)
> NIL
> ELE> (open-store '(:bdb "/home/bseitz/eletest/"))
> #<BDB-STORE-CONTROLLER /home/bseitz/eletest/>
> ELE> (setf me (get-from-root "me"))
> #<PERSON oid:100>
> ELE> (setf amigo (get-from-root "amigo"))
> #<PERSON oid:102>
> ELE> (describe me)
> #<PERSON oid:100> is an instance of class #<PERSISTENT-METACLASS  
> PERSON>.
> The following slots have :INSTANCE allocation:
> %OID                     100
> DBCONNECTION-SPEC-PST    (:BDB "/home/bseitz/eletest/")
> The following slots have allocation as shown:
> NAME :DATABASE                  "Brian"
> FRIENDS :DATABASE               #<DEFAULT-PSET oid:101>
> ; No value
> ELE> (map-friends #'print me)
> The slot BTREE is unbound in the object #<DEFAULT-PSET oid:101>.
> ; Evaluation aborted
> ELE> (describe (person-friends me))
> #<DEFAULT-PSET oid:101>
> is an instance of class #<STANDARD-CLASS DEFAULT-PSET>.
> The following slots have :INSTANCE allocation:
> %OID                     101
> DBCONNECTION-SPEC-PST    (:BDB "/home/bseitz/eletest/")
> BTREE                    #<unbound slot>
>
> So the BTREE that indexes (?) the persistent set is now gone?  I've
> tried to make the slot that holds the pset indexed, but that doesn't
> seem to make a difference.
>
> I greatly appreciate any help you could give.
>
> Thanks,
>
> Brian
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