[jbosscache-dev] New collections

[Manik Surtani]

On 5 Aug 2008, at 14:42, Jason T. Greene wrote:

>>>
>>> What I would like to do, provided everyone is ok with this, is  
>>> switch this code to static factory methods like so:
>>>
>>> Immutables.immutableCopy(Map map);
>>> Immutables.immutableCopy(List list);
>>> Immutables.immutableCopy(Set set);
>>>
>>> These will then just call clone and Collections.unmodifiableXXX as  
>>> appropriate. We can then add optimizations later if they become  
>>> available.
>> Would these be more generic, to suit any collection  
>> implementation?  Remember that not all Maps, for example, implement  
>> Cloneable or have a copy constructor.  And wrapping any Map passed  
>> in as a FastCopyHashMap may break correctness, for example, if a  
>> SortedMap were passed in.
>
> Right, they would use instanceof to check all the known map types as  
> a fast-path optimization. After that it would check for cloneable,  
> and use reflection to invoke clone. It would then look for a copy  
> constructor, and failing that it would then create a different  
> collection type. We could for example, in the case of a non-copyable  
> SortedMap, use a TreeMap, and order is maintained.


Right yes, you would need the logic in place to do this.
--
Manik Surtani
Lead, JBoss Cache
manik at jboss.org