Deepa Remesh wrote:
>For my DERBY-1002 patch,
>
Thanks Deepa for working to make this code clearer. It had fooled many
developers and burnt you personally a couple of times I know.
> I have added a method DRDAStatement.reuse()
>which resets all fields in this class.
>
> /**
> * Clean up statements and result set for reuse.
> * This method should reset all members of this class except the
> * following which will be set at initial creation or set
>explicitly in the code:
> * database, pkgnamcsn, pkgcnstkn, pkgid, pkgsn
> *
> * @throws SQLException
> */
> protected void reuse() throws SQLException {
> ...
> }
>
>
>
>I was just going through all methods in DRDAStatement and found that
>there is a method called initialize() which does this:
> /**
> * Initialize for reuse
> */
> protected void initialize()
> {
> setTypDefValues();
> }
>where setTypDefValues() does this:
> /**
> * set TypDef values
> *
> */
> protected void setTypDefValues()
> {
> // initialize statement values to current database values
> this.typDefNam = database.typDefNam;
> this.byteOrder = database.byteOrder;
> this.ccsidSBC = database.ccsidSBC;
> this.ccsidDBC = database.ccsidDBC;
> this.ccsidMBC = database.ccsidMBC;
> this.ccsidSBCEncoding = database.ccsidSBCEncoding;
> this.ccsidDBCEncoding = database.ccsidDBCEncoding;
> this.ccsidMBCEncoding = database.ccsidMBCEncoding;
> }
>
>
>I have couple of questions:
>1. I find it confusing to have a initialize and reuse method with
>similar comments. Can initialize be removed since we can call
>setTypDefValues directly at places where it is currently called?
>
>
>
I must say I find every use of initialize() absolutely perplexing except
for the one in parseEXCSQLIMM,
but regardless they all seem to be resetting the defaultDRDAStatement
for reuse, so I think initialize can go away and you can use your new
reuse() method. I think you can have a reuse, with or without a database
parameter.
>2. initialize() is called at called at 5 places in the server code.
>Two of these places (DRDAConnThread methods parseEXCSQLIMM and
>parseEXCSQLSETobjects) have the following comment:
>
>// initialize statement for reuse
>drdaStmt.initialize();
>
>I am not sure about the actual intention of calling initialize() at
>these places - whether it is to just reset the typedef values or does
>it expect all fields to be reset for reuse. Can someone familiar with
>code look at these places to see it is enough to use initialize() at
>these places? If this does not look right, I can open another issue
>for this.
>
>
>
yes. 1
>3. Is my comment for the new reuse method() okay? specifically, the
>comment about fields which should not be reset?
>"This method should reset all members of this class except the
>following which will be set at initial creation or set explicitly in
>the code: database, pkgnamcsn, pkgcnstkn, pkgid, pkgsn"
>
>
>
If these can be reset too that would be good and then get set whereever
the get set just for completeness.
I wonder if reset() is beetter than reuse, but I am the worlds worst namer.
Will there be a reuse() in DRDAResultSet as well?
Will close no longer reset these values and the reuse only called when
the statement is reused?
Even with the rename, I worry a little about the maintainability of
this. Part of that is just that DRDAStatement is way to busy and I
think the ParameterMetadata should be broken out some day..
Thanks again Deepa
