MySQL Bugs: #40242: NDBAPI : All NDBAPI objects should provide accessors for their 'parents'

Bug #40242	NDBAPI : All NDBAPI objects should provide accessors for their 'parents'
Submitted:	22 Oct 2008 12:03	Modified:	12 Nov 2008 21:03
Reporter:	Frazer Clement	Email Updates:
Status:	Closed	Impact on me:	None
Category:	MySQL Server: Documentation	Severity:	S3 (Non-critical)
Version:	5.1-telco-6.2+	OS:	Any
Assigned to:	Jon Stephens	CPU Architecture:	Any

Description:
To simplify client error handling code, and code in NDBAPI wrapper frameworks, it should be easier to navigate up the hierarchy of NDBAPI objects, for example : 

NdbBlob -> Ndb(Scan)Operation -> NdbTransaction
 

How to repeat:
Look at NdbBlob.hpp - no way to obtain 'parent' Transaction or Operation object pointers.

Suggested fix:
Add new accessor methods to NdbBlob and other Apis

Proposed patch adding accessors to NDBAPI objects

Attachment: bug40242.patch (text/x-patch), 3.37 KiB.

Cleaned up patch originally proposed for Bug#31775.

const NdbOperation* is returned as :
 1) Don't want to return non-const NdbOperation* to NdbRecord operation
 2) Don't want to have runtime checks of operation type to avoid returning null non-const NdbOperation* for NdbRecord ops. 
 3) Expect that navigating up from Blob to operation would be done as part of error handling post-execution rather than before, when users might try to modify the operation before it's executed.

As a side-effect, the NdbOperation::getNdbErrorLine() method is modified to be const so that it can be used with a const NdbOperation*

A patch for this bug has been committed. After review, it may
be pushed to the relevant source trees for release in the next
version. You can access the patch from:

  http://lists.mysql.com/commits/57996

2718 Frazer Clement	2008-11-06
      Bug# 40242 NDBAPI : All NDBAPI objects should provide accessors for their 'parents'
      
      This patch adds :
       - getNdbOperation() method to NdbBlob to get const operation*
       - getNdbTransaction() method to NdbScanOperation and NdbOperation to get NdbTransaction*
       - const variant of getNdbErrorLine() to NdbOperation to allow error handling with
         a const*.

A patch for this bug has been committed. After review, it may
be pushed to the relevant source trees for release in the next
version. You can access the patch from:

  http://lists.mysql.com/commits/58251

2723 Frazer Clement	2008-11-08
            Bug# 40242 NDBAPI : All NDBAPI objects should provide accessors for their 'parents'
            
            This patch adds :
             - getNdbOperation() method to NdbBlob to get const operation*
             - getNdbTransaction() method to NdbScanOperation and NdbOperation to get NdbTransaction*
             - const variant of getNdbErrorLine() to NdbOperation to allow error handling with
               a const*.

Pushed into 5.1.29-ndb-6.4.0  (revid:frazer@mysql.com-20081108204015-izsn1r9ac1eqrwbs) (version source revid:frazer@mysql.com-20081108214303-z8nr2z5c1yccxac8) (pib:5)

Pushed into 5.1.29-ndb-6.2.17  (revid:frazer@mysql.com-20081108204015-izsn1r9ac1eqrwbs) (version source revid:frazer@mysql.com-20081108204015-izsn1r9ac1eqrwbs) (pib:5)

Pushed into 5.1.29-ndb-6.3.19  (revid:frazer@mysql.com-20081108204015-izsn1r9ac1eqrwbs) (version source revid:frazer@mysql.com-20081108212257-xppq7h6xmg3wduzp) (pib:5)

Documented bugfix in the ndb-6.2.17 and ndb-6.3.19 changelogs as follows:

        It was not always possible to access parent objects directly
        from NdbBlob, NdbOperation, and NdbScanOperation objects. To fix
        this problem, a new getNdbOperation() method has been added to
        NdbBlob and new getNdbTransaction() method has been added to
        NdbOperation and NdbScanOperation. In addition, a const variant
        of NdbOperation::getErrorLine() is now also available.

Changing this to a Docs bug and assigning to myself so I won't forget to document the new API methods after lunch. :)

NDBAPI docs updated, commit is here: http://lists.mysql.com/commits/58584

Pushed into 6.0.9-alpha  (revid:frazer@mysql.com-20081108204015-izsn1r9ac1eqrwbs) (version source revid:tomas.ulin@sun.com-20081209185954-9svcixh2p5hsfi6w) (pib:5)