Re: [cdi-dev] Mutable annotation literals
The problem is an AnnotationLiteral could theoretically be mutable as well. Thus the
AnnotationLiteral class must not make such assumptions imo.
I the case of an empty value-methods list we could btw also improve the equals method.
In the case where you have value-methods, you already need to implement the interface
manually. It would be no problem to just add the 2 lines for caching the hashCode in case
the values do not change.
LieGrue,
strub
----- Original Message -----
From: Pete Muir <pmuir(a)redhat.com>
To: Mark Struberg <struberg(a)yahoo.de>
Cc: cdi-dev <cdi-dev(a)lists.jboss.org>
Sent: Thursday, August 16, 2012 2:20 PM
Subject: Re: [cdi-dev] Mutable annotation literals
I guess what Marko/I am proposing is that we provide a utility for the common
case of an immutable annotation literal with member values...
On 16 Aug 2012, at 13:18, Mark Struberg wrote:
> Imo we don't need to cache the hashCode in the AnnotationLiteral
itself. We just need to cache if there are value methods or not. If not, then we
can immediately return 0. If there are value methods present, then you need to
extend the AnnotationLiteral class anyway and can add an own hashCode which
delegates to super.hashCode() and caches the result if the values will not be
changed.
>
> LieGrue,
> strub
>
>
>
>
> ----- Original Message -----
>> From: Pete Muir <pmuir(a)redhat.com>
>> To: cdi-dev <cdi-dev(a)lists.jboss.org>
>> Cc:
>> Sent: Thursday, August 16, 2012 1:43 PM
>> Subject: [cdi-dev] Mutable annotation literals
>>
>> All
>>
>> Marko has added caching for the hashcode value on AnnotationLiteral,
which is
>> based on the premise that an AnnotationLiteral is not mutable.
>>
>>
https://github.com/luksa/cdi/commit/f3c200fcdf8ca8681c194c921567aedcce375102
>>
>> This is a reasonable thing to require (as real annotations are normally
>> immutable!) and a very good optimisation, however it is not backwards
>> compatible, as we have not previously required AnnotationLiteral to be
>> immutable.
>>
>> An alternative option is to introduce the ImmutableAnnotationLiteral
subclass,
>> which would require any concrete instances to be immutable and could
use this
>> optimisation. We could "deprecate" AnnotationLiteral (as
described in
>> java.net/projects/javaee-spec/pages/CompatibilityRequirements).
>>
>> Note that regardless, we can apply the minor optimisation suggested by
Mark,
>> that we return 0 if the annotation has no members.
>>
>> Pete
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