Personally I prefer:
[] Require the jdo implementation to return a read-only copy of the
underlying Set of groups as it exists at the time of the call.
But anything else is also acceptable, except:
[ ] Require the jdo implementation to return a read-only reference to the
underlying implementation that will continue to track modifications made to the
Set of groups.
which makes things complicated for implementations (like ObjectDB) that do not
use a standard Java Collection to maintain the set of fetch groups internally.
Ilan
----- Original Message -----
From: Craig L Russell
To: JDO Expert Group ; Apache JDO project
Sent: Sunday, July 30, 2006 9:58 PM
Subject: [VOTE]: Should FetchPlan.getGroups return a copy or a reference?
Javadogs,
During testing of FetchPlan, Ilan Kirsh discovered that the jdo specification
doesn't specify whether getGroups returns a read-only copy of the set of fetch
groups or can return a read-only reference to the actual set of fetch groups.
[The specification does require returning a read-only Set.]
The TCK as it was written requires a read-only reference, not a copy.
This can result in non-portable behavior, if the application code expects a
"live" reference instead of a copy. The TCK currently has the following code,
which depends on the jdo implementation returning a "live" reference:
public void checkRemoveGroup() {
Set expectedGroups = new HashSet();
FetchPlan fp = getPM().getFetchPlan();
Collection groups = fp.getGroups(); // this assumes that groups is
updated by the following line
fp.removeGroup("default");
if (!setEquals(expectedGroups, groups)) {
failCompare(
"checkRemoveGroup(): wrong getGroups() " +
"after removeGroup.",
expectedGroups, groups);
}
cleanupPM();
}
Please advise:
[ ] Leave it alone.
[ ] Update the specification to note that getGroups returns a Set that might
change if the underlying Set of groups changes (via addGroup, addGroups,
removeGroup, removeGroups, clearGroups).
[ ] Require the jdo implementation to return a read-only reference to the
underlying implementation that will continue to track modifications made to the
Set of groups.
[ ] Require the jdo implementation to return a read-only copy of the
underlying Set of groups as it exists at the time of the call.
Thanks,
Craig
Craig Russell
Architect, Sun Java Enterprise System http://java.sun.com/products/jdo
408 276-5638 mailto:[EMAIL PROTECTED]
P.S. A good JDO? O, Gasp!
