[fdo-internals] RE: FDO RFC 61 ready for review

[Sam Wang]

Hi Dan,

I think this can be maintained internally. Once user rolls back to a specific save point, all the save points defined after it will be invalid. Thus for example, if we rolls back to save point #3, and later user rolls back to #4, an FDO exception should be thrown to indicate that save point #4 is no longer valid due to the rollback of save point #3.  

If we are to provide an API to get the list of available save points, I propose that we add an API prototype like:
virtual FdoStringCollection* GetAvailableSavePoints() = 0; 

However my opinion is that users of this API should be aware of the order of save point definition and will not roll back to an invalid save point. So I think this API is more likely to utilize user(even if they had this utility method, they still can pass an invalid save point to rollback method), and I would regard it more like an option than necessary.

Thanks,
Sam

-----Original Message-----
From: fdo-internals-bounces at lists.osgeo.org [mailto:fdo-internals-bounces at lists.osgeo.org] On Behalf Of Dan Stoica
Sent: Wednesday, May 25, 2011 10:07 AM
To: FDO Internals Mail List
Subject: [fdo-internals] RE: FDO RFC 61 ready for review 

Hi Sam,

My point is that the proposed API alllows for an a arbitrary number of save points. Meaning the user needs to keep track of them. And no, "release save point" is not necessary since I assume RollBack() is doing this.

Please let me understand: a collection of save points is actually a stack, right? If so then once the user rolls back to the save point #N (where N is the index in the stack) then all the save points with a higher number are dissolved. Therefore I believe a method to get the remaining save points is necessary. 

Thanks,
Dan.
________________________________________
From: fdo-internals-bounces at lists.osgeo.org [fdo-internals-bounces at lists.osgeo.org] on behalf of Sam Wang [Sam.Wang at autodesk.com]
Sent: Tuesday, May 24, 2011 6:44 PM
To: FDO Internals Mail List
Subject: [fdo-internals] RE: FDO RFC 61 ready for review

Hi Dan,

If you look into the RFC you will find that there is already an API proposed to roll back to a save point : FdoITransaction::RollBack(FdoString* savePointName). Do you mean that should be additional API to do something like "release save point" ?

Thanks,
Sam

From: fdo-internals-bounces at lists.osgeo.org [mailto:fdo-internals-bounces at lists.osgeo.org] On Behalf Of Dan Stoica
Sent: Tuesday, May 24, 2011 10:59 PM
To: FDO Internals Mail List
Subject: [fdo-internals] RE: FDO RFC 61 ready for review

Hi,

Shouldn't the API include a method to get back all the added save points? This would allow to programmatically rollback to a save point, I think.

Thanks,
Dan.

From: fdo-internals-bounces at lists.osgeo.org [mailto:fdo-internals-bounces at lists.osgeo.org] On Behalf Of Sam Wang
Sent: Sunday, May 22, 2011 9:42 PM
To: fdo-internals at lists.osgeo.org
Subject: [fdo-internals] FDO RFC 61 ready for review

Hi experts,

FDO RFC 61 is now ready for review. You can find it at http://trac.osgeo.org/fdo/wiki/FDORfc61

Thanks,
Sam
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