db-derby-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Knut Anders Hatlen (JIRA)" <j...@apache.org>
Subject [jira] [Updated] (DERBY-6075) Use modern collections in impl/sql/compile
Date Mon, 11 Mar 2013 15:55:13 GMT

     [ https://issues.apache.org/jira/browse/DERBY-6075?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]

Knut Anders Hatlen updated DERBY-6075:
--------------------------------------

    Attachment: d6075-11a-remaining-vectors.diff

The attached 11a patch removes the remaining Vectors and replaces them with ArrayLists. One
exception is the two Vectors storeCostControllers and storeCostConglomIds in CompilerContextImpl.
They were replaced by a single HashMap, as the latter Vector is only used for looking up elements
in the former.

As far as I have been able to see, none of the Vectors are shared between threads, so it should
be safe to replace them with unsynchronized collections.

All regression tests ran cleanly with the patch.
                
> Use modern collections in impl/sql/compile
> ------------------------------------------
>
>                 Key: DERBY-6075
>                 URL: https://issues.apache.org/jira/browse/DERBY-6075
>             Project: Derby
>          Issue Type: Bug
>          Components: SQL
>    Affects Versions: 10.10.0.0
>            Reporter: Knut Anders Hatlen
>            Assignee: Knut Anders Hatlen
>            Priority: Minor
>         Attachments: d6075-10a-aggregate-vectors.diff, d6075-11a-remaining-vectors.diff,
d6075-1a-CollectNodesVisitor.diff, d6075-2a-bindExpression.diff, d6075-3a-javadoc.diff, d6075-4a-parameterList.diff,
d6075-5a-ordering.diff, d6075-6a-DMLModStatementNode.diff, d6075-7a-more-signatures.diff,
d6075-8a-local-hashtables.diff, d6075-9a-hashtable-fields.diff
>
>
> The code in the org.apache.derby.impl.sql.compile package predates the Java Collections
Framework and uses old-style collections like java.util.Vector and java.util.Hashtable. Since
the old-style collection classes are used in many method signatures, it's difficult to use
modern collection classes when adding new code.
> I suggest we switch to using interfaces (like java.util.List and java.util.Map) instead
of specific classes in the signatures, so that we have more flexibility in choosing the right
collection class for the job.
> Only changing the signatures would allow us to continue using Vector and Hashtable, since
they implement the interfaces. However, I think it would be good to switch to ArrayList and
HashMap in a second step. The instances in impl/sql/compile are not shared between threads,
so we don't need the synchronization provided by the old-style classes. Switching to unsynchronized
classes may make compilation slightly faster.

--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators
For more information on JIRA, see: http://www.atlassian.com/software/jira

Mime
View raw message