Re: Question about code in HibernateUserManagerImpl

[Mitesh Meswani]

Anil Gangolli wrote:

Mitesh.  Sorry I was not clear.  I meant that we should be removing 
the queue entries.  That function should ideally be performed by 
calling the PinqQueueManager and implementing the removal there in a 
new method to remove all queue entries by website.  That method could 
be implemented with a bulk delete.

If that's too much of a detour, you could defer that and just fix it 
locally by adding the individual remove call in the code you showed.
I want the code in Datamapper*ManagerImpl to be as similar as possible 
to Hibernate*MangerImpl for the first pass. So, I will go with the 
current code pattern for now (deleting using individual remove call). I 
have a note in the code to start using bulk deletes from respective 
managers when this code stabilizes.

Thanks,
Mitesh

--a



----- Original Message ----- From: "Mitesh Meswani" 
<[EMAIL PROTECTED]>
To: <roller-dev@incubator.apache.org>
Sent: Thursday, October 05, 2006 9:32 AM
Subject: Re: Question about code in HibernateUserManagerImpl




Anil Gangolli wrote:
Inline.  Maybe Allen can comment too?

----- Original Message ----- From: "Mitesh Meswani" 
<[EMAIL PROTECTED]>
To: <roller-dev@incubator.apache.org>
Sent: Wednesday, October 04, 2006 2:48 PM
Subject: Question about code in HibernateUserManagerImpl


Hi,

I am working (along with Craig) on developing a persistence layer
abstraction for roller. While converting the code, I had following
questions about code in 
HibernateUserManagerImpl#removeWebsiteContents()

1. The list queueEntries is retrieved but not used.
   I think the intention would have been to remove the queueEntries
   from database is that correct?

Yes; it seems incomplete.

Removing the website's custom ping target will remove the associated 
queue
entries, but you can have queue entries from common ping targets as 
well, so
this is probably good to do.
If it is ok to not delete queue entries here we should either the 
unnecessary database access to fetch queueEntries. I will remove the 
entries in DatamapperUserManagerImpl.

2. All the removals below (For example removing of auto ping
    configurations) can be replaced by bulk deletes.
   That is deleting directly from database instead of getting them 
into
   memory and than deleting.I saw
           HibernateRefererManagerImpl#clearReferrers using the "bulk
   delete" pattern. Is there any reason
  (apart from historic code) why "bulk delete" is not used here ?


I think you just have to be careful that the object's manager 
doesn't itself
have some cascading delete logic that expects to be called whenever an
object it manages is removed.

It seems to me that the current pattern for handling cascading 
deletion in
the managers seems to expect this; that is, the bulk deletion 
shortcut can
only be used (safely) if it is in the manager that manages that 
object type directly.
Good point. I think than it makes sense to use current pattern.

Thanks,
Mitesh

--a.


Thanks,
Mitesh


<code_Of_the_method_for_quick_referece>

   private void removeWebsiteContents(WebsiteData website)
   throws HibernateException, RollerException {

       Session session = this.strategy.getSession();

       BookmarkManager bmgr =
RollerFactory.getRoller().getBookmarkManager();
       WeblogManager wmgr = 
RollerFactory.getRoller().getWeblogManager();

       // Remove the website's ping queue entries
       Criteria criteria =
session.createCriteria(PingQueueEntryData.class);
       criteria.add(Expression.eq("website", website));
       List queueEntries = criteria.list();  *<--------1*

       // Remove the website's auto ping configurations   *<------ 2.*
       AutoPingManager autoPingMgr =
RollerFactory.getRoller().getAutopingManager();
       List autopings = autoPingMgr.getAutoPingsByWebsite(website);
       Iterator it = autopings.iterator();
       while(it.hasNext()) {
           this.strategy.remove((AutoPingData) it.next());
       }

       // Remove the website's custom ping targets
       PingTargetManager pingTargetMgr =
RollerFactory.getRoller().getPingTargetManager();
       List pingtargets = pingTargetMgr.getCustomPingTargets(website);
       it = pingtargets.iterator();
       while(it.hasNext()) {
           this.strategy.remove((PingTargetData) it.next());
       }

       // remove entries
       Criteria entryQuery =
session.createCriteria(WeblogEntryData.class);
       entryQuery.add(Expression.eq("website", website));
       List entries = entryQuery.list();
       for (Iterator iter = entries.iterator(); iter.hasNext();) {
           WeblogEntryData entry = (WeblogEntryData) iter.next();

           this.strategy.remove(entry);
       }

       // remove associated referers
       Criteria refererQuery = 
session.createCriteria(RefererData.class);
       refererQuery.add(Expression.eq("website", website));
       List referers = refererQuery.list();
       for (Iterator iter = referers.iterator(); iter.hasNext();) {
           RefererData referer = (RefererData) iter.next();
           this.strategy.remove(referer);
       }


       // remove associated pages
       Criteria pageQuery = 
session.createCriteria(WeblogTemplate.class);
       pageQuery.add(Expression.eq("website", website));
       List pages = pageQuery.list();
       for (Iterator iter = pages.iterator(); iter.hasNext();) {
           WeblogTemplate page = (WeblogTemplate) iter.next();
           this.strategy.remove(page);
       }

       // remove folders (including bookmarks)
       FolderData rootFolder = bmgr.getRootFolder(website);
       if (null != rootFolder) {
           this.strategy.remove(rootFolder);

           // Still cannot get all Bookmarks cleared!
           Iterator allFolders = 
bmgr.getAllFolders(website).iterator();
           while (allFolders.hasNext()) {
               FolderData aFolder = (FolderData)allFolders.next();
               bmgr.removeFolderContents(aFolder);
               this.strategy.remove(aFolder);
           }
       }

       // remove categories
       WeblogCategoryData rootCat = 
wmgr.getRootWeblogCategory(website);
       if (null != rootCat) {
           this.strategy.remove(rootCat);
       }

   }


</code_Of_the_method_for_quick_referece>