[prev in list] [next in list] [prev in thread] [next in thread] 

List:       nsbasic-palm
Subject:    [nsbasic-palm] Re: memo database contains more records than shown
From:       "carmine_castiglia" <ccastiglia () infosystemspro ! com>
Date:       2006-08-28 8:44:14
Message-ID: ecuacu+u64i () eGroups ! com
[Download RAW message or body]

Mike,

But, in fact, my test project (the "More MemoDb Stuff" thread)does 
exactly that (read past end of record) without crashing or erroring 
in either POSE (wiith all error checking options checked) or the 5.4 
Simulator.

 Carmine

--- In nsbasic-palm@yahoogroups.com, Michael Verive <mverive@...> 
wrote:
>
> Doug,
> 
> Attempting to read past the end of a record should
> give a fatal error, so it's conceivable that that is
> the source of the error here.  I forgot that he was
> attempting to read a string, and haven't seen the
> actual source pasted from a successfully compiled
> project yet, so I'll hold off further comment until
> then.  But, as usual, you're probably correct...
> 
> Mike
> 
> --- Douglas Handy <dhandy1@...> wrote:
> 
> > Mike,
> > 
> > >However, it reads these memos
> > >easily, so Carmine's right - something else is
> > going
> > >on here.  
> > 
> > If you had deleted the memo with the "archive copy
> > on PC" option, the memo
> > contents would still be in the record and presumably
> > readable.  However, if the
> > archive option was not set, the data portion of the
> > record would be lost and
> > trying to read the contents of the memo into a
> > string would be similar to
> > listing too many fields on a DbRead statement.   If
> > you attempt to read beyond
> > the end of the record, do I remember that NSB
> > crashes?
> > 
> > So in tests of trying to recreate this (which I have
> > not done), make sure you do
> > *not* flag it to archive a copy on the PC.
> > 
> > >Besides, dbPosition will create "missing"
> > >records as needed, so even if the records had been
> > >truly deleted, new records will be created to fill
> > the
> > >void.
> > 
> > If the records had been *removed* (like DbDelete
> > does but not the Memo app) then
> > DbPosition would create a "missing" record. 
> > However, in this case the record
> > count did not exceed the number of record list
> > entries in the pdb's header.  The
> > RRN was valid -- it just pointed to a deleted record
> > which may or may not have
> > also had a data segment.  That would depend on
> > whether the memo was "deleted" or
> > "archived".
> > 
> > That said, the offset portion of DbPosition will
> > extend a record if necessary.
> > However, I don't know if it will *create* a data
> > segment if none exists.  That
> > would require tests to find out how the runtime
> > handles it.
> > 
> > Doug
> > 
> > 
> > 
> > Complete Searchable Archive:
> > 
> > http://marc.theaimsgroup.com/?l=nsbasic-palm&r=1&w=2
> > 
> > Shortcut URL to this page:
> >  http://groups.yahoo.com/group/nsbasic-palm  
> > Yahoo! Groups Links
> > 
> > 
> >     nsbasic-palm-unsubscribe@yahoogroups.com
> > 
> >  
> > 
> > 
> >
>








Complete Searchable Archive:
 http://marc.theaimsgroup.com/?l=nsbasic-palm&r=1&w=2

Shortcut URL to this page:
 http://groups.yahoo.com/group/nsbasic-palm  
Yahoo! Groups Links

<*> To visit your group on the web, go to:
    http://groups.yahoo.com/group/nsbasic-palm/

<*> To unsubscribe from this group, send an email to:
    nsbasic-palm-unsubscribe@yahoogroups.com

<*> Your use of Yahoo! Groups is subject to:
    http://docs.yahoo.com/info/terms/
 



[prev in list] [next in list] [prev in thread] [next in thread]