Hi Lee, Thanks for such a cogent response. All of that makes a lot of sense to me.
I’m not at all considering making improvements, rather I’m merely wanting to use CppSketch within a Flink job as state. Making the class final adds a little friction to doing so, but not an overwhelming amount. Ron > On Apr 24, 2020, at 3:12 PM, leerho <lee...@gmail.com> wrote: > > Hi Ron, > > Our mission is to develop a robust sketch library product that can be used in > production systems in many different environments and be high performing and > binary compatible across languages and systems. > To be able to achieve this mission with our very limited resources, we have > to be careful about making the surface area of what we have to support too > large. Making classes final and/or private are some of the ways to reduce > the size of the support surface area. > We have found that robust sketch software that is usable in production > environments can be very tricky and even though we have been doing this for a > number of years, we continue to discover new ways that these probabilistic > algorithms can behave in totally unexpected ways. Also, testing and > validating these probabilistic algorithms can be very tricky. Making what > appears to be a simple change to a class can have major impact on its > testability or stability. Making a class final is one way to communicate > that the code and its testing counterparts is more complex than you might > think. > We have had experience with a number of folks that have tried to "improve" > these sketches on their own, but with disastrous results. Making a class > final is one way to communicate that we do not recommend users to attempt to > extend these clases on their own. > Making a class final (or private) also gives us, as developers, additional > degrees of freedom in terms of making necessary changes and improvements to > the internals of the class because we know that there are no other classes > that depend on it. > From a owner-developer's point of view, making a class final is conservative. > We can always remove the restriction in the future if the need arises. But > once a class is no longer final, it can never be put back-in-the-box, so to > speak. > We are not in a position to support any external changes to our code that we > release, nor can we support extensions to our code that are not part of our > library. Making classes final is one way of communicating that we do not > encourage modifications or arbitrary extensions to our code base. > > The DataSketches library is an active open source Apache project. We > encourage users to make suggestions and submit pull requests and contribute > to the library to make it a better product for everyone. We believe we are > very social and open to new ideas. We have a growing community of interested > users, developers and scientists that want to use our library and make it > even better. We actively monitor our communication channels and respond to > sincere requests for help as promptly as we can. > > If you have ideas about added capabilities that you feel would be valuable > extensions to the library, please engage with us through our community > <https://datasketches.apache.org/docs/Community/index.html> mailing lists or > Slack, we would like to hear from you. > > As open source, you are always free to fork the library and do whatever you > want with the code subject to the Apache license. But then, you are on your > own :) > > Cheers, > > Lee. > > > > > > > > > > > > On Thu, Apr 23, 2020 at 4:27 PM Ron Crocker <rcroc...@newrelic.com > <mailto:rcroc...@newrelic.com>> wrote: > It seems anti-social to make these classes, particularly CpcSketch, final. Is > there a good reason for that? > > Ron
