RFR: 8247532: Records deserialization is slow

[Chris Hegarty]

> On 17 Jun 2020, at 07:08, Peter Levart <peter.levart at gmail.com> wrote:
> 
> 
> On 6/16/20 5:15 PM, Chris Hegarty wrote:
>> The caching is on a per-stream-field shape basis, which should be consistent in the common case, but of course is not always guaranteed to be the case, hence the need for the cache. I think that this should be fine, since the ObjectStreamClass ( that holds the cache ) is already itself cached as a weak reference. But I did wonder if the size of this new cache should be limited. Probably not worth the complexity unless it is an obvious issue.
> 
> I don't think there will normally be many different shapes of the same class deserialized by a single VM. Each shape means that a different version of that class must have existed to serialize it.

Right.

> There could be deliberate "forged" streams trying to inflate the cache. Are you worried about that?

Yes.

> In that case I can add logic to limit the number of different shapes kept with a simple LRA (Least Recently Added) strategy that would not hurt access performance.

That would be great.

-Chris.