On Tue, 18 Oct 2022 17:47:38 GMT, Michael Strauß <mstra...@openjdk.org> wrote:
>> I'd respectfully disagree: in a large application, there might be hundreds >> (a thousand?) Nodes, and only a handful (10-20?) Nodes with this property >> (2%), so it's a waste of RAM. One may think it's only 8Kb on a 64 bit >> machine, but it does add up quickly. Even the access pattern is basically >> 'get it once to establish the fluent pipeline', with no more calls to the >> Node accessor (unlike MiscProperties constituents, some of which get >> accessed rather frequently). > >> I'd respectfully disagree: in a large application, there might be hundreds >> (a thousand?) Nodes, and only a handful (10-20?) Nodes with this property >> (2%), so it's a waste of RAM. One may think it's only 8Kb on a 64 bit >> machine, but it does add up quickly. Even the access pattern is basically >> 'get it once to establish the fluent pipeline', with no more calls to the >> Node accessor (unlike MiscProperties constituents, some of which get >> accessed rather frequently). > > I understand your point, but I don't think that this is sufficient reason to > introduce a new way of storing property instances in an ad-hoc manner. If > memory consumption is a concern, I would rather analyze the issue in a > separate enhancement proposal, think it through in terms of API, and then > transition all relevant property instances to the new storage mechanism. Part > of that proposal should also be an evaluation of the trade-offs between > memory consumption and performance in terms of cache locality and lookup > speed. `getProperties()` isn't the place for this. After looking at the grouping of properties, there might be merit to reevaluate the distribution of properties into their helper classes in the case that a single use of a common property will create many other unused ones. As for RAM usage, Hotspot can compress pointers on a 64bit machine. I don't think that the change in memory here will be more significant than in other areas in `Node` that can be addressed. ------------- PR: https://git.openjdk.org/jfx/pull/830
