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eAdapter Notifications Batched ? [message #420134]

Wed, 18 June 2008 17:55

Alan

Messages: 44
Registered: July 2009

Member

Hello all,

I am having a problem with notifications in EMF.
Basically I have a situation where all the objects in a model may be being
listened to by any number of others objects.
I have a transaction where I delete a number of these objects.
A notification is sent every time I delete an individual object but this is
causing a performance problem.
What I was wondering is if there is a way to only send these notifications
when this transaction is committed ?

thanks.

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Re: eAdapter Notifications Batched ? [message #420135 is a reply to message #420134]

Wed, 18 June 2008 18:04

Eclipse User

Originally posted by: cdamus.zeligsoft.com

--=-lrSKAcsCRhyhyr+M0tYh
Content-Type: text/plain
Content-Transfer-Encoding: 7bit

Hi, Alan,

That is exactly the purpose of the ResourceSetListener interface. Have
a look at its documentation in Javadoc and the EMF Model Transaction
Developer Guide in the SDK's on-line help.

An additional benefit of this transactional style of listening is that
you won't be notified of any changes in the event that they are rolled
back by the transaction.

HTH,

Christian

On Wed, 2008-06-18 at 18:55 +0100, Alan wrote:

> Hello all,
>
> I am having a problem with notifications in EMF.
> Basically I have a situation where all the objects in a model may be being
> listened to by any number of others objects.
> I have a transaction where I delete a number of these objects.
> A notification is sent every time I delete an individual object but this is
> causing a performance problem.
> What I was wondering is if there is a way to only send these notifications
> when this transaction is committed ?
>
> thanks.
>
>

--=-lrSKAcsCRhyhyr+M0tYh
Content-Type: text/html; charset=utf-8

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 TRANSITIONAL//EN">
<HTML>
<HEAD>
<META HTTP-EQUIV="Content-Type" CONTENT="text/html; CHARSET=UTF-8">
<META NAME="GENERATOR" CONTENT="GtkHTML/3.16.0">
</HEAD>
<BODY>
Hi, Alan, 
 
That is exactly the purpose of the ResourceSetListener interface.  Have a look at its documentation in Javadoc and the EMF Model Transaction Developer Guide in the SDK's on-line help. 
 
An additional benefit of this transactional style of listening is that you won't be notified of any changes in the event that they are rolled back by the transaction. 
 
HTH, 
 
Christian 
 
 
On Wed, 2008-06-18 at 18:55 +0100, Alan wrote:
<BLOCKQUOTE TYPE=CITE>
<PRE>
Hello all,

I am having a problem with notifications in EMF.
Basically I have a situation where all the objects in a model may be being 
listened to by any number of others objects.
I have a transaction where I delete a number of these objects.
A notification is sent every time I delete an individual object but this is 
causing a performance problem.
What I was wondering is if there is a way to only send these notifications 
when this transaction is committed ?

thanks. 

</PRE>
</BLOCKQUOTE>
</BODY>
</HTML>

--=-lrSKAcsCRhyhyr+M0tYh--

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Re: eAdapter Notifications Batched ? [message #420165 is a reply to message #420135]

Thu, 19 June 2008 17:18

Alan

Messages: 44
Registered: July 2009

Member

This is a multi-part message in MIME format.

------=_NextPart_000_000D_01C8D238.CF689BC0
Content-Type: text/plain;
charset="utf-8"
Content-Transfer-Encoding: quoted-printable

Hi Christian,

I followed up on that and it looks promising.
Basically what I have is a central controller (for my central model =
which you may remember from previous posts about ChangeRecorder and =
ChangeDescs etc)
Anyway this controller listens for changes and sends them out.
So I have a listener that is listening to the resource set filtered to =
only the central model changes.
Then I run a command which calls the controller and the controller =
reacts by sending out these notifications.

I am having one issue though. When I delete an object from a GMF diagram =
everything underneath is being deleted correctly but the view object =
does not go away until I open another editor and then flick back to the =
first one.
I know this is not the GMF forum but I was wondering if you have any =
idea what is going on here ?

thanks,
Alan.

"Christian W. Damus" <cdamus@zeligsoft.com> wrote in message =
news:1213812277.6416.29.camel@cwdlappy...
Hi, Alan,

That is exactly the purpose of the ResourceSetListener interface. =
Have a look at its documentation in Javadoc and the EMF Model =
Transaction Developer Guide in the SDK's on-line help.

An additional benefit of this transactional style of listening is that =
you won't be notified of any changes in the event that they are rolled =
back by the transaction.

HTH,

Christian

On Wed, 2008-06-18 at 18:55 +0100, Alan wrote:=20
Hello all,

I am having a problem with notifications in EMF.
Basically I have a situation where all the objects in a model may be =
being=20
listened to by any number of others objects.
I have a transaction where I delete a number of these objects.
A notification is sent every time I delete an individual object but this =
is=20
causing a performance problem.
What I was wondering is if there is a way to only send these =
notifications=20
when this transaction is committed ?

thanks.=20

------=_NextPart_000_000D_01C8D238.CF689BC0
Content-Type: text/html;
charset="utf-8"
Content-Transfer-Encoding: quoted-printable

=EF=BB=BF<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML><HEAD>
<META http-equiv=3DContent-Type content=3D"text/html; CHARSET=3DUTF-8">
<META content=3D"MSHTML 6.00.6000.16640" name=3DGENERATOR>
<STYLE></STYLE>
</HEAD>
<BODY bgColor=3D#ffffff>
<DIV>Hi Christian,</DIV>
<DIV> </DIV>
<DIV>I followed up on that and it looks=20
promising.</DIV>
<DIV>Basically what I have is a central =
controller (for=20
my central model which you may remember from previous posts about =
ChangeRecorder=20
and ChangeDescs etc)</DIV>
<DIV>Anyway this controller listens for =
changes and=20
sends them out.</DIV>
<DIV>So I have a listener that is listening =
to the=20
resource set filtered to only the central model changes.</DIV>
<DIV>Then I run a command which calls the =
controller and=20
the controller reacts by sending out these notifications.</DIV>
<DIV> </DIV>
<DIV>I am having one issue though. When I =
delete an=20
object from a GMF diagram everything underneath is being deleted =
correctly but=20
the view object does not go away until I open another editor and then =
flick back=20
to the first one.</DIV>
<DIV>I know this is not the GMF forum but I =
was=20
wondering if you have any idea what is going on here ?</DIV>
<DIV> </DIV>
<DIV>thanks,</DIV>
<DIV>Alan.</DIV>
<DIV> </DIV>
<BLOCKQUOTE dir=3Dltr=20
style=3D"PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; =
BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px">
<DIV>"Christian W. Damus" <<A=20
href=3D"mailto:cdamus@zeligsoft.com">cdamus@zeligsoft.com</A>> =
wrote in=20
message <A=20
=
href=3D"news:1213812277.6416.29.camel@cwdlappy">news:1213812277.6416.29.c=
amel@cwdlappy</A>...</DIV>Hi,=20
Alan, That is exactly the purpose of the ResourceSetListener=20
interface.  Have a look at its documentation in Javadoc and the =
EMF Model=20
Transaction Developer Guide in the SDK's on-line help. An =
additional=20
benefit of this transactional style of listening is that you won't be =
notified=20
of any changes in the event that they are rolled back by the=20
transaction. HTH, Christian On Wed, =
2008-06-18 at=20
18:55 +0100, Alan wrote:=20
<BLOCKQUOTE TYPE=3D"CITE"><PRE>Hello all,

I am having a problem with notifications in =
EMF.
Basically I have a situation where all the objects =
in a model may be being 
listened to by any number of others =
objects.
I have a transaction where I delete a number of =
these objects.
A notification is sent every time I delete an =
individual object but this is 
causing a performance problem.
What I was wondering is if there is a way to only =
send these notifications 
when this transaction is committed ?

thanks. 

</PRE></BLOCKQUOTE></BLOCKQUOTE></BODY></HTML>

------=_NextPart_000_000D_01C8D238.CF689BC0--

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Re: eAdapter Notifications Batched ? [message #420180 is a reply to message #420135]

Fri, 20 June 2008 13:02

Alan

Messages: 44
Registered: July 2009

Member

This is a multi-part message in MIME format.

------=_NextPart_000_0010_01C8D2DE.515CD470
Content-Type: text/plain;
charset="utf-8"
Content-Transfer-Encoding: quoted-printable

Hi,

Is there a way to react to changes only once the transaction has =
committed ?
transactionAboutToCommit is before it commits obviously.
Also if this can be done will I still be able to write to model. (i.e. =
non-read-only transaction) ?

thanks

"Christian W. Damus" <cdamus@zeligsoft.com> wrote in message =
news:1213812277.6416.29.camel@cwdlappy...
Hi, Alan,

That is exactly the purpose of the ResourceSetListener interface. =
Have a look at its documentation in Javadoc and the EMF Model =
Transaction Developer Guide in the SDK's on-line help.

An additional benefit of this transactional style of listening is that =
you won't be notified of any changes in the event that they are rolled =
back by the transaction.

HTH,

Christian

On Wed, 2008-06-18 at 18:55 +0100, Alan wrote:=20
Hello all,

I am having a problem with notifications in EMF.
Basically I have a situation where all the objects in a model may be =
being=20
listened to by any number of others objects.
I have a transaction where I delete a number of these objects.
A notification is sent every time I delete an individual object but this =
is=20
causing a performance problem.
What I was wondering is if there is a way to only send these =
notifications=20
when this transaction is committed ?

thanks.=20

------=_NextPart_000_0010_01C8D2DE.515CD470
Content-Type: text/html;
charset="utf-8"
Content-Transfer-Encoding: quoted-printable

=EF=BB=BF<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML><HEAD>
<META http-equiv=3DContent-Type content=3D"text/html; CHARSET=3DUTF-8">
<META content=3D"MSHTML 6.00.6000.16640" name=3DGENERATOR>
<STYLE></STYLE>
</HEAD>
<BODY bgColor=3D#ffffff>
<DIV>Hi,</DIV>
<DIV> </DIV>
<DIV>Is there a way to react to changes only =
once the=20
transaction has committed ?</DIV>
<DIV>transactionAboutToCommit is before it =
commits=20
obviously.</DIV>
<DIV>Also if this can be done will I still =
be able to=20
write to model. (i.e. non-read-only transaction) ?</DIV>
<DIV> </DIV>
<DIV>thanks</DIV>
<DIV> </DIV>
<DIV> </DIV>
<BLOCKQUOTE dir=3Dltr=20
style=3D"PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; =
BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px">
<DIV>"Christian W. Damus" <<A=20
href=3D"mailto:cdamus@zeligsoft.com">cdamus@zeligsoft.com</A>> =
wrote in=20
message <A=20
=
href=3D"news:1213812277.6416.29.camel@cwdlappy">news:1213812277.6416.29.c=
amel@cwdlappy</A>...</DIV>Hi,=20
Alan, That is exactly the purpose of the ResourceSetListener=20
interface.  Have a look at its documentation in Javadoc and the =
EMF Model=20
Transaction Developer Guide in the SDK's on-line help. An =
additional=20
benefit of this transactional style of listening is that you won't be =
notified=20
of any changes in the event that they are rolled back by the=20
transaction. HTH, Christian On Wed, =
2008-06-18 at=20
18:55 +0100, Alan wrote:=20
<BLOCKQUOTE TYPE=3D"CITE"><PRE>Hello all,

I am having a problem with notifications in =
EMF.
Basically I have a situation where all the objects =
in a model may be being 
listened to by any number of others =
objects.
I have a transaction where I delete a number of =
these objects.
A notification is sent every time I delete an =
individual object but this is 
causing a performance problem.
What I was wondering is if there is a way to only =
send these notifications 
when this transaction is committed ?

thanks. 

</PRE></BLOCKQUOTE></BLOCKQUOTE></BODY></HTML>

------=_NextPart_000_0010_01C8D2DE.515CD470--

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Re: eAdapter Notifications Batched ? [message #420181 is a reply to message #420165]

Fri, 20 June 2008 13:05

Eclipse User

Originally posted by: cdamus.zeligsoft.com

--=-WwDUg9j8nLF5YLHoJFId
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: quoted-printable

Hi, Alan,

Good! I'm glad things are looking up.

Are you running a command within the context of a
ResourceSetListener::resourceSetChanged(...) invocation? You shouldn't
be able to do that, as listeners are invoked in read-only transactions.

I'm not sure about your GMF problem. AFAIK, the extensible "destroy"
command should already be advised with a command to destroy views of the
semantic element that is being destroyed. I'd start by looking for an
exception in an EditPart, which is causing the diagram views not to be
updated. Is this a canonical diagram? Probably best to follow up on
the GMF newsgroup.

cW

On Thu, 2008-06-19 at 18:18 +0100, Alan wrote:

> =EF=BB=BF=20
>=20
> Hi Christian,
> =20
> I followed up on that and it looks promising.
> Basically what I have is a central controller (for my central model
> which you may remember from previous posts about ChangeRecorder and
> ChangeDescs etc)
> Anyway this controller listens for changes and sends them out.
> So I have a listener that is listening to the resource set filtered to
> only the central model changes.
> Then I run a command which calls the controller and the controller
> reacts by sending out these notifications.
> =20
> I am having one issue though. When I delete an object from a GMF
> diagram everything underneath is being deleted correctly but the view
> object does not go away until I open another editor and then flick
> back to the first one.
> I know this is not the GMF forum but I was wondering if you have any
> idea what is going on here ?
> =20
> thanks,
> Alan.
> =20
> "Christian W. Damus" <cdamus@zeligsoft.com> wrote in message
> news:1213812277.6416.29.camel@cwdlappy...
> =20
> Hi, Alan,
> =20
> That is exactly the purpose of the ResourceSetListener
> interface. Have a look at its documentation in Javadoc and
> the EMF Model Transaction Developer Guide in the SDK's on-line
> help.
> =20
> An additional benefit of this transactional style of listening
> is that you won't be notified of any changes in the event that
> they are rolled back by the transaction.
> =20
> HTH,
> =20
> Christian
> =20
> =20
> On Wed, 2008-06-18 at 18:55 +0100, Alan wrote:=20
> =20
> > Hello all,
> >=20
> > I am having a problem with notifications in EMF.
> > Basically I have a situation where all the objects in a model m=
ay be being=20
> > listened to by any number of others objects.
> > I have a transaction where I delete a number of these objects.
> > A notification is sent every time I delete an individual object=
but this is=20
> > causing a performance problem.
> > What I was wondering is if there is a way to only send these no=
tifications=20
> > when this transaction is committed ?
> >=20
> > thanks.=20
> >=20
> >=20

--=-WwDUg9j8nLF5YLHoJFId
Content-Type: text/html; charset=utf-8

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 TRANSITIONAL//EN">
<HTML>
<HEAD>
<META HTTP-EQUIV="Content-Type" CONTENT="text/html; CHARSET=UTF-8">
<META NAME="GENERATOR" CONTENT="GtkHTML/3.16.0">
</HEAD>
<BODY BGCOLOR="#ffffff">
Hi, Alan, 
 
Good!  I'm glad things are looking up. 
 
Are you running a command within the context of a ResourceSetListener::resourceSetChanged(...) invocation?  You shouldn't be able to do that, as listeners are invoked in read-only transactions. 
 
I'm not sure about your GMF problem.  AFAIK, the extensible "destroy" command should already be advised with a command to destroy views of the semantic element that is being destroyed.  I'd start by looking for an exception in an EditPart, which is causing the diagram views not to be updated.  Is this a canonical diagram?  Probably best to follow up on the GMF newsgroup. 
 
cW 
 
On Thu, 2008-06-19 at 18:18 +0100, Alan wrote: 
<BLOCKQUOTE TYPE=CITE>
 
</BLOCKQUOTE>
<BLOCKQUOTE TYPE=CITE>
Hi Christian,
</BLOCKQUOTE>
<BLOCKQUOTE TYPE=CITE>
 
</BLOCKQUOTE>
<BLOCKQUOTE TYPE=CITE>
I followed up on that and it looks promising.
</BLOCKQUOTE>
<BLOCKQUOTE TYPE=CITE>
Basically what I have is a central controller (for my central model which you may remember from previous posts about ChangeRecorder and ChangeDescs etc)
</BLOCKQUOTE>
<BLOCKQUOTE TYPE=CITE>
Anyway this controller listens for changes and sends them out.
</BLOCKQUOTE>
<BLOCKQUOTE TYPE=CITE>
So I have a listener that is listening to the resource set filtered to only the central model changes.
</BLOCKQUOTE>
<BLOCKQUOTE TYPE=CITE>
Then I run a command which calls the controller and the controller reacts by sending out these notifications.
</BLOCKQUOTE>
<BLOCKQUOTE TYPE=CITE>
 
</BLOCKQUOTE>
<BLOCKQUOTE TYPE=CITE>
I am having one issue though. When I delete an object from a GMF diagram everything underneath is being deleted correctly but the view object does not go away until I open another editor and then flick back to the first one.
</BLOCKQUOTE>
<BLOCKQUOTE TYPE=CITE>
I know this is not the GMF forum but I was wondering if you have any idea what is going on here ?
</BLOCKQUOTE>
<BLOCKQUOTE TYPE=CITE>
 
</BLOCKQUOTE>
<BLOCKQUOTE TYPE=CITE>
thanks,
</BLOCKQUOTE>
<BLOCKQUOTE TYPE=CITE>
Alan.
</BLOCKQUOTE>
<BLOCKQUOTE TYPE=CITE>
 
</BLOCKQUOTE>
<BLOCKQUOTE TYPE=CITE>
<BLOCKQUOTE>
"Christian W. Damus" <<A HREF="mailto:cdamus@zeligsoft.com">cdamus@zeligsoft.com</A>> wrote in message <A HREF="news:1213812277.6416.29.camel@cwdlappy">news:1213812277.6416.29.camel@cwdlappy</A>...
</BLOCKQUOTE>
</BLOCKQUOTE>
<BLOCKQUOTE TYPE=CITE>
<BLOCKQUOTE>
Hi, Alan, 
 
That is exactly the purpose of the ResourceSetListener interface.  Have a look at its documentation in Javadoc and the EMF Model Transaction Developer Guide in the SDK's on-line help. 
 
An additional benefit of this transactional style of listening is that you won't be notified of any changes in the event that they are rolled back by the transaction. 
 
HTH, 
 
Christian 
 
 
On Wed, 2008-06-18 at 18:55 +0100, Alan wrote: 
<BLOCKQUOTE TYPE=CITE>
<PRE>
Hello all,

I am having a problem with notifications in EMF.
Basically I have a situation where all the objects in a model may be being 
listened to by any number of others objects.
I have a transaction where I delete a number of these objects.
A notification is sent every time I delete an individual object but this is 
causing a performance problem.
What I was wondering is if there is a way to only send these notifications 
when this transaction is committed ?

thanks. 

</PRE>
</BLOCKQUOTE>
</BLOCKQUOTE>
</BLOCKQUOTE>
</BODY>
</HTML>

--=-WwDUg9j8nLF5YLHoJFId--

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Re: eAdapter Notifications Batched ? [message #420182 is a reply to message #420180]

Fri, 20 June 2008 13:17

Eclipse User

Originally posted by: cdamus.zeligsoft.com

--=-CG1EhRtlw+cCDlNX2egk
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: quoted-printable

Hi, Alan,

What you need is the resourceSetChanged() method of the
ResourceSetListener. It is triggered after changes have been
successfully committed by a transaction.

All listener call-backs are performed in a read-only transaction. This
ensures that no surprising new changes will occur during the processing
of change notifications, ensuring that all listeners get the same view
of the data. The transaction is a control freak! ;-)

If you do need to make further changes to the model concomitant to the
changes observed, that is exactly the purpose of the commands returned
by a pre-commit listener. Why would you want to make additional changes
in a new transaction, rather than piggy-backing on the one that is
committing?

Cheers,

Christian

On Fri, 2008-06-20 at 14:02 +0100, Alan wrote:

> =EF=BB=BF=20
>=20
> Hi,
> =20
> Is there a way to react to changes only once the transaction has
> committed ?
> transactionAboutToCommit is before it commits obviously.
> Also if this can be done will I still be able to write to model. (i.e.
> non-read-only transaction) ?
> =20
> thanks
> =20
> =20
> "Christian W. Damus" <cdamus@zeligsoft.com> wrote in message
> news:1213812277.6416.29.camel@cwdlappy...
> =20
> Hi, Alan,
> =20
> That is exactly the purpose of the ResourceSetListener
> interface. Have a look at its documentation in Javadoc and
> the EMF Model Transaction Developer Guide in the SDK's on-line
> help.
> =20
> An additional benefit of this transactional style of listening
> is that you won't be notified of any changes in the event that
> they are rolled back by the transaction.
> =20
> HTH,
> =20
> Christian
> =20
> =20
> On Wed, 2008-06-18 at 18:55 +0100, Alan wrote:=20
> =20
> > Hello all,
> >=20
> > I am having a problem with notifications in EMF.
> > Basically I have a situation where all the objects in a model m=
ay be being=20
> > listened to by any number of others objects.
> > I have a transaction where I delete a number of these objects.
> > A notification is sent every time I delete an individual object=
but this is=20
> > causing a performance problem.
> > What I was wondering is if there is a way to only send these no=
tifications=20
> > when this transaction is committed ?
> >=20
> > thanks.=20
> >=20
> >=20

--=-CG1EhRtlw+cCDlNX2egk
Content-Type: text/html; charset=utf-8

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 TRANSITIONAL//EN">
<HTML>
<HEAD>
<META HTTP-EQUIV="Content-Type" CONTENT="text/html; CHARSET=UTF-8">
<META NAME="GENERATOR" CONTENT="GtkHTML/3.16.0">
</HEAD>
<BODY BGCOLOR="#ffffff">
Hi, Alan, 
 
What you need is the resourceSetChanged() method of the ResourceSetListener.  It is triggered after changes have been successfully committed by a transaction. 
 
All listener call-backs are performed in a read-only transaction.  This ensures that no surprising new changes will occur during the processing of change notifications, ensuring that all listeners get the same view of the data.  The transaction is a control freak!  ;-) 
 
If you do need to make further changes to the model concomitant to the changes observed, that is exactly the purpose of the commands returned by a pre-commit listener.  Why would you want to make additional changes in a new transaction, rather than piggy-backing on the one that is committing? 
 
Cheers, 
 
Christian 
 
 
On Fri, 2008-06-20 at 14:02 +0100, Alan wrote: 
<BLOCKQUOTE TYPE=CITE>
 
</BLOCKQUOTE>
<BLOCKQUOTE TYPE=CITE>
Hi,
</BLOCKQUOTE>
<BLOCKQUOTE TYPE=CITE>
 
</BLOCKQUOTE>
<BLOCKQUOTE TYPE=CITE>
Is there a way to react to changes only once the transaction has committed ?
</BLOCKQUOTE>
<BLOCKQUOTE TYPE=CITE>
transactionAboutToCommit is before it commits obviously.
</BLOCKQUOTE>
<BLOCKQUOTE TYPE=CITE>
Also if this can be done will I still be able to write to model. (i.e. non-read-only transaction) ?
</BLOCKQUOTE>
<BLOCKQUOTE TYPE=CITE>
 
</BLOCKQUOTE>
<BLOCKQUOTE TYPE=CITE>
thanks
</BLOCKQUOTE>
<BLOCKQUOTE TYPE=CITE>
 
</BLOCKQUOTE>
<BLOCKQUOTE TYPE=CITE>
 
</BLOCKQUOTE>
<BLOCKQUOTE TYPE=CITE>
<BLOCKQUOTE>
"Christian W. Damus" <<A HREF="mailto:cdamus@zeligsoft.com">cdamus@zeligsoft.com</A>> wrote in message <A HREF="news:1213812277.6416.29.camel@cwdlappy">news:1213812277.6416.29.camel@cwdlappy</A>...
</BLOCKQUOTE>
</BLOCKQUOTE>
<BLOCKQUOTE TYPE=CITE>
<BLOCKQUOTE>
Hi, Alan, 
 
That is exactly the purpose of the ResourceSetListener interface.  Have a look at its documentation in Javadoc and the EMF Model Transaction Developer Guide in the SDK's on-line help. 
 
An additional benefit of this transactional style of listening is that you won't be notified of any changes in the event that they are rolled back by the transaction. 
 
HTH, 
 
Christian 
 
 
On Wed, 2008-06-18 at 18:55 +0100, Alan wrote: 
<BLOCKQUOTE TYPE=CITE>
<PRE>
Hello all,

I am having a problem with notifications in EMF.
Basically I have a situation where all the objects in a model may be being 
listened to by any number of others objects.
I have a transaction where I delete a number of these objects.
A notification is sent every time I delete an individual object but this is 
causing a performance problem.
What I was wondering is if there is a way to only send these notifications 
when this transaction is committed ?

thanks. 

</PRE>
</BLOCKQUOTE>
</BLOCKQUOTE>
</BLOCKQUOTE>
</BODY>
</HTML>

--=-CG1EhRtlw+cCDlNX2egk--

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Re: eAdapter Notifications Batched ? [message #420191 is a reply to message #420182]

Fri, 20 June 2008 15:40

Alan

Messages: 44
Registered: July 2009

Member

This is a multi-part message in MIME format.

------=_NextPart_000_0013_01C8D2F4.69C85910
Content-Type: text/plain;
charset="UTF-8"
Content-Transfer-Encoding: quoted-printable

Hi Christian,

Basically changes to the shared model cause other models to react to the =
changes.
Maybe my motivation is performance. I don't want my action slowed up by =
other models reacting to the changes from it.
But perhaps there are other ways to solve this such as jobs, asynch =
threads etc ?

thanks
"Christian W. Damus" <cdamus@zeligsoft.com> wrote in message =
news:1213967822.6358.24.camel@cwdlappy...
Hi, Alan,

What you need is the resourceSetChanged() method of the =
ResourceSetListener. It is triggered after changes have been =
successfully committed by a transaction.

All listener call-backs are performed in a read-only transaction. =
This ensures that no surprising new changes will occur during the =
processing of change notifications, ensuring that all listeners get the =
same view of the data. The transaction is a control freak! ;-)

If you do need to make further changes to the model concomitant to the =
changes observed, that is exactly the purpose of the commands returned =
by a pre-commit listener. Why would you want to make additional changes =
in a new transaction, rather than piggy-backing on the one that is =
committing?

Cheers,

Christian

On Fri, 2008-06-20 at 14:02 +0100, Alan wrote:

=EF=BB=BF=20
Hi,=20
=20
Is there a way to react to changes only once the transaction has =
committed ?=20
transactionAboutToCommit is before it commits obviously.=20
Also if this can be done will I still be able to write to model. =
(i.e. non-read-only transaction) ?=20
=20
thanks=20
=20
=20
"Christian W. Damus" <cdamus@zeligsoft.com> wrote in message =
news:1213812277.6416.29.camel@cwdlappy...=20
Hi, Alan,

That is exactly the purpose of the ResourceSetListener interface. =
Have a look at its documentation in Javadoc and the EMF Model =
Transaction Developer Guide in the SDK's on-line help.

An additional benefit of this transactional style of listening is =
that you won't be notified of any changes in the event that they are =
rolled back by the transaction.

HTH,

Christian

On Wed, 2008-06-18 at 18:55 +0100, Alan wrote:=20
Hello all,

I am having a problem with notifications in EMF.
Basically I have a situation where all the objects in a model may be =
being=20
listened to by any number of others objects.
I have a transaction where I delete a number of these objects.
A notification is sent every time I delete an individual object but this =
is=20
causing a performance problem.
What I was wondering is if there is a way to only send these =
notifications=20
when this transaction is committed ?

thanks.=20

------=_NextPart_000_0013_01C8D2F4.69C85910
Content-Type: text/html;
charset="UTF-8"
Content-Transfer-Encoding: quoted-printable

=EF=BB=BF<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML><HEAD>
<META http-equiv=3DContent-Type content=3D"text/html; CHARSET=3DUTF-8">
<META content=3D"MSHTML 6.00.6000.16640" name=3DGENERATOR>
<STYLE></STYLE>
</HEAD>
<BODY bgColor=3D#ffffff>
<DIV>Hi Christian,</DIV>
<DIV> </DIV>
<DIV>Basically changes to the shared model =
cause other=20
models to react to the changes.</DIV>
<DIV>Maybe my motivation is performance. I =
don't want my=20
action slowed up by other models reacting to the changes from =
it.</DIV>
<DIV>But perhaps there are other ways to =
solve this such=20
as jobs, asynch threads etc ?</DIV>
<DIV> </DIV>
<DIV>thanks</DIV>
<BLOCKQUOTE dir=3Dltr=20
style=3D"PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; =
BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px">
<DIV>"Christian W. Damus" <<A=20
href=3D"mailto:cdamus@zeligsoft.com">cdamus@zeligsoft.com</A>> =
wrote in=20
message <A=20
=
href=3D"news:1213967822.6358.24.camel@cwdlappy">news:1213967822.6358.24.c=
amel@cwdlappy</A>...</DIV>Hi,=20
Alan, What you need is the resourceSetChanged() method of the=20
ResourceSetListener.  It is triggered after changes have been=20
successfully committed by a transaction. All listener =
call-backs are=20
performed in a read-only transaction.  This ensures that no =
surprising=20
new changes will occur during the processing of change notifications, =
ensuring=20
that all listeners get the same view of the data.  The =
transaction is a=20
control freak!  ;-) If you do need to make further changes =
to the=20
model concomitant to the changes observed, that is exactly the purpose =
of the=20
commands returned by a pre-commit listener.  Why would you want =
to make=20
additional changes in a new transaction, rather than piggy-backing on =
the one=20
that is committing? Cheers, Christian On Fri, =

2008-06-20 at 14:02 +0100, Alan wrote: 
<BLOCKQUOTE TYPE=3D"CITE">=EF=BB=BF =
</BLOCKQUOTE>
<BLOCKQUOTE TYPE=3D"CITE">Hi,=20
</BLOCKQUOTE>
<BLOCKQUOTE TYPE=3D"CITE"> </BLOCKQUOTE>
<BLOCKQUOTE TYPE=3D"CITE">Is =
there a way to=20
react to changes only once the transaction has committed =
?=20
</BLOCKQUOTE>
<BLOCKQUOTE TYPE=3D"CITE"><FONT=20
color=3D#000000>transactionAboutToCommit is before it commits=20
obviously. </BLOCKQUOTE>
<BLOCKQUOTE TYPE=3D"CITE">Also if =
this can be=20
done will I still be able to write to model. (i.e. non-read-only=20
transaction) ? </BLOCKQUOTE>
<BLOCKQUOTE TYPE=3D"CITE"> </BLOCKQUOTE>
<BLOCKQUOTE TYPE=3D"CITE"><FONT=20
color=3D#000000>thanks </BLOCKQUOTE>
<BLOCKQUOTE TYPE=3D"CITE"> </BLOCKQUOTE>
<BLOCKQUOTE TYPE=3D"CITE"> </BLOCKQUOTE>
<BLOCKQUOTE TYPE=3D"CITE">
<BLOCKQUOTE>"Christian W. Damus" <<A=20
href=3D"mailto:cdamus@zeligsoft.com">cdamus@zeligsoft.com</A>> =
wrote in=20
message <A=20
=
href=3D"news:1213812277.6416.29.camel@cwdlappy">news:1213812277.6416.29.c=
amel@cwdlappy</A>...=20
</BLOCKQUOTE></BLOCKQUOTE>
<BLOCKQUOTE TYPE=3D"CITE">
<BLOCKQUOTE>Hi, Alan, <FONT=20
color=3D#000000>That is exactly the purpose of the =
ResourceSetListener=20
interface.  Have a look at its documentation in Javadoc and =
the EMF=20
Model Transaction Developer Guide in the SDK's on-line=20
help. An additional benefit of =
this=20
transactional style of listening is that you won't be notified of =
any=20
changes in the event that they are rolled back by the=20
transaction. HTH, <FONT=20
color=3D#000000>Christian On Wed,=20
2008-06-18 at 18:55 +0100, Alan wrote: 
<BLOCKQUOTE TYPE=3D"CITE"><PRE>Hello =
all,

I am having a problem with notifications in =
EMF.
Basically I have a situation where all the objects =
in a model may be being 
listened to by any number of others =
objects.
I have a transaction where I delete a number of =
these objects.
A notification is sent every time I delete an =
individual object but this is 
causing a performance problem.
What I was wondering is if there is a way to only =
send these notifications 
when this transaction is committed ?

thanks. 

</PRE></BLOCKQUOTE></BLOCKQUOTE></BLOCKQUOTE></BLOCKQUOTE ></BODY></HTML>

------=_NextPart_000_0013_01C8D2F4.69C85910--

Report message to a moderator

Re: eAdapter Notifications Batched ? [message #420207 is a reply to message #420191]

Sun, 22 June 2008 02:03

Eclipse User

Originally posted by: cdamus.zeligsoft.com

--=-d7GjS77wSHig/exICjLQ
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: quoted-printable

Hi, Alan,

I guess the performance will depend on just how many changes your action
is performing in the one model, and how many concomitant changes it will
trigger in how many other models. And, of course, these other models
could be remote ... I don't know your situation. If you want to trigger
changes from the post-commit listener, then you will have to do it
asynchronously, because the listener is called in a read-only
transaction and simply will not be able to perform any changes
synchronously.

However, I would be worried about undo/redo. Pre-commit commands are
automatically captured by the transaction for undo/redo. In your case,
though, you will have to rely on undo of the original action triggering
compensating changes in the other models. The problem is how to manage
the undo history. You don't want to asynchronously execute a command on
the stack because it should not appear as a distinct command that can be
undone (I expect this would surprise your users). However, if the other
models are editable, then their undo/redo histories would be corrupted
if these listener-changes are not captured on the command stack, because
subsequent changes will depend on them.

cW

On Fri, 2008-06-20 at 16:40 +0100, Alan wrote:

> =EF=BB=BF=20
>=20
> Hi Christian,
> =20
> Basically changes to the shared model cause other models to react to
> the changes.
> Maybe my motivation is performance. I don't want my action slowed up
> by other models reacting to the changes from it.
> But perhaps there are other ways to solve this such as jobs, asynch
> threads etc ?
> =20
> thanks
> "Christian W. Damus" <cdamus@zeligsoft.com> wrote in message
> news:1213967822.6358.24.camel@cwdlappy...
> =20
> Hi, Alan,
> =20
> What you need is the resourceSetChanged() method of the
> ResourceSetListener. It is triggered after changes have been
> successfully committed by a transaction.
> =20
> All listener call-backs are performed in a read-only
> transaction. This ensures that no surprising new changes will
> occur during the processing of change notifications, ensuring
> that all listeners get the same view of the data. The
> transaction is a control freak! ;-)
> =20
> If you do need to make further changes to the model
> concomitant to the changes observed, that is exactly the
> purpose of the commands returned by a pre-commit listener.
> Why would you want to make additional changes in a new
> transaction, rather than piggy-backing on the one that is
> committing?
> =20
> Cheers,
> =20
> Christian
> =20
> =20
> On Fri, 2008-06-20 at 14:02 +0100, Alan wrote:
> =20
> > =EF=BB=BF=20
> > Hi,=20
> > Is there a way to react to changes only once the transaction
> > has committed ?=20
> > transactionAboutToCommit is before it commits obviously.=20
> > Also if this can be done will I still be able to write to
> > model. (i.e. non-read-only transaction) ?=20
> > thanks=20
> >=20
> > "Christian W. Damus" <cdamus@zeligsoft.com> wrote in
> > message news:1213812277.6416.29.camel@cwdlappy...=20
> > Hi, Alan,
> > =20
> > That is exactly the purpose of the
> > ResourceSetListener interface. Have a look at its
> > documentation in Javadoc and the EMF Model
> > Transaction Developer Guide in the SDK's on-line
> > help.
> > =20
> > An additional benefit of this transactional style of
> > listening is that you won't be notified of any
> > changes in the event that they are rolled back by
> > the transaction.
> > =20
> > HTH,
> > =20
> > Christian
> > =20
> > =20
> > On Wed, 2008-06-18 at 18:55 +0100, Alan wrote:=20
> > =20
> > > Hello all,
> > >=20
> > > I am having a problem with notifications in EMF.
> > > Basically I have a situation where all the objects in=
a model may be being=20
> > > listened to by any number of others objects.
> > > I have a transaction where I delete a number of these=
objects.
> > > A notification is sent every time I delete an individ=
ual object but this is=20
> > > causing a performance problem.
> > > What I was wondering is if there is a way to only sen=
d these notifications=20
> > > when this transaction is committed ?
> > >=20
> > > thanks.=20
> > >=20
> > >=20

--=-d7GjS77wSHig/exICjLQ
Content-Type: text/html; charset=utf-8

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 TRANSITIONAL//EN">
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<META HTTP-EQUIV="Content-Type" CONTENT="text/html; CHARSET=UTF-8">
<META NAME="GENERATOR" CONTENT="GtkHTML/3.16.0">
</HEAD>
<BODY BGCOLOR="#ffffff">
Hi, Alan, 
 
I guess the performance will depend on just how many changes your action is performing in the one model, and how many concomitant changes it will trigger in how many other models.  And, of course, these other models could be remote ... I don't know your situation.  If you want to trigger changes from the post-commit listener, then you will have to do it asynchronously, because the listener is called in a read-only transaction and simply will not be able to perform any changes synchronously. 
 
However, I would be worried about undo/redo.  Pre-commit commands are automatically captured by the transaction for undo/redo.  In your case, though, you will have to rely on undo of the original action triggering compensating changes in the other models.  The problem is how to manage the undo history.  You don't want to asynchronously execute a command on the stack because it should not appear as a distinct command that can be undone (I expect this would surprise your users).  However, if the other models are editable, then their undo/redo histories would be corrupted if these listener-changes are not captured on the command stack, because subsequent changes will depend on them. 
 
cW 
 
 
On Fri, 2008-06-20 at 16:40 +0100, Alan wrote: 
<BLOCKQUOTE TYPE=CITE>
 
</BLOCKQUOTE>
<BLOCKQUOTE TYPE=CITE>
Hi Christian,
</BLOCKQUOTE>
<BLOCKQUOTE TYPE=CITE>
 
</BLOCKQUOTE>
<BLOCKQUOTE TYPE=CITE>
Basically changes to the shared model cause other models to react to the changes.
</BLOCKQUOTE>
<BLOCKQUOTE TYPE=CITE>
Maybe my motivation is performance. I don't want my action slowed up by other models reacting to the changes from it.
</BLOCKQUOTE>
<BLOCKQUOTE TYPE=CITE>
But perhaps there are other ways to solve this such as jobs, asynch threads etc ?
</BLOCKQUOTE>
<BLOCKQUOTE TYPE=CITE>
 
</BLOCKQUOTE>
<BLOCKQUOTE TYPE=CITE>
thanks
</BLOCKQUOTE>
<BLOCKQUOTE TYPE=CITE>
<BLOCKQUOTE>
"Christian W. Damus" <<A HREF="mailto:cdamus@zeligsoft.com">cdamus@zeligsoft.com</A>> wrote in message <A HREF="news:1213967822.6358.24.camel@cwdlappy">news:1213967822.6358.24.camel@cwdlappy</A>...
</BLOCKQUOTE>
</BLOCKQUOTE>
<BLOCKQUOTE TYPE=CITE>
<BLOCKQUOTE>
Hi, Alan, 
 
What you need is the resourceSetChanged() method of the ResourceSetListener.  It is triggered after changes have been successfully committed by a transaction. 
 
All listener call-backs are performed in a read-only transaction.  This ensures that no surprising new changes will occur during the processing of change notifications, ensuring that all listeners get the same view of the data.  The transaction is a control freak!  ;-) 
 
If you do need to make further changes to the model concomitant to the changes observed, that is exactly the purpose of the commands returned by a pre-commit listener.  Why would you want to make additional changes in a new transaction, rather than piggy-backing on the one that is committing? 
 
Cheers, 
 
Christian 
 
 
On Fri, 2008-06-20 at 14:02 +0100, Alan wrote: 
<BLOCKQUOTE TYPE=CITE>
 
Hi, 
Is there a way to react to changes only once the transaction has committed ? 
transactionAboutToCommit is before it commits obviously. 
Also if this can be done will I still be able to write to model. (i.e. non-read-only transaction) ? 
thanks 
<BLOCKQUOTE>
"Christian W. Damus" <<A HREF="mailto:cdamus@zeligsoft.com">cdamus@zeligsoft.com</A>> wrote in message <A HREF="news:1213812277.6416.29.camel@cwdlappy">news:1213812277.6416.29.camel@cwdlappy</A>... 
Hi, Alan, 
 
That is exactly the purpose of the ResourceSetListener interface.  Have a look at its documentation in Javadoc and the EMF Model Transaction Developer Guide in the SDK's on-line help. 
 
An additional benefit of this transactional style of listening is that you won't be notified of any changes in the event that they are rolled back by the transaction. 
 
HTH, 
 
Christian 
 
 
On Wed, 2008-06-18 at 18:55 +0100, Alan wrote: 
<BLOCKQUOTE TYPE=CITE>
<PRE>
Hello all,

I am having a problem with notifications in EMF.
Basically I have a situation where all the objects in a model may be being 
listened to by any number of others objects.
I have a transaction where I delete a number of these objects.
A notification is sent every time I delete an individual object but this is 
causing a performance problem.
What I was wondering is if there is a way to only send these notifications 
when this transaction is committed ?

thanks. 

</PRE>
</BLOCKQUOTE>
</BLOCKQUOTE>
</BLOCKQUOTE>
</BLOCKQUOTE>
</BLOCKQUOTE>
</BODY>
</HTML>

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