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Liviu Tudor commented on SANDBOX-341: ------------------------------------- Hi Simone, Thanks for the feedback -- my first commit, so I expected a lot of things to go wrong. Since my code was initially committed to {{commons.lang}}, I didn't have access to the classes you mentioned, so I will have a look and use them. Secondly, regarding the Apache header, am I correct in assuming that simply copying and pasting it from an existing class in the repository should be enough? Point taken about the {{@author}} tag, that was generated automatically by my Eclipse (note to self: adjust my _Eclipse_ templates to remove that and a few other things!). I didn't spend too much time on unit testing purely because I wasn't sure still if this was the right place to commit this component, now that I am on the right track I will spend some time to implement those properly. Last but not least, {{org.apache.commons.functor.summarizer.TimedSummarizer#MAIN_TIMER}} is static in order to avoid creating a new one for each instance -- but you are right, it can create a memory leak. I will actually spend some time on it and probably provide a factory for creating instances of the {{TimedSummarizer}} class which will allow for the instance to use it's own {{Timer}} or a shared one; this is so "power users" can use the shared one and minimize the memory and threading footprint, while still allowing for Joe Average to avoid the memory leakage by using a per-instance {{Timer}}. Do you think that would be a good idea? > [functor] New components: summarize and aggregate > ------------------------------------------------- > > Key: SANDBOX-341 > URL: https://issues.apache.org/jira/browse/SANDBOX-341 > Project: Commons Sandbox > Issue Type: Improvement > Components: Functor > Environment: JDK 1.6.0_25 but should work with any JDK 5+ (possibly > 1.4 though I haven't tested). > Reporter: Liviu Tudor > Priority: Minor > Labels: features > Attachments: commons-functor-aggregate+summarizer.zip > > > This is the next step from https://issues.apache.org/jira/browse/SANDBOX-340 > -- as instructed I'm finally hoping to get the code in the right place and > hopefully this is something that the functor component could do with. > Whereas initially I just started with the summarizer component, I have added > now the second one, the "aggregator" as they are somehow related. If this > code proves to be useful to functor in any way, it would actually be good to > get some feedback on these 2 to see if the class hierarchy can in fact be > changed to share some common functionality as I feel (probably due to the > similar needs that lead to writing/using these components) that somehow they > should share a common base. > In brief, the 2 components: > * aggregator: this just allows for data to be aggregated in a user defined > way (e.g. stored in a list for the purpose of averaging, computing the > arithmetic median etc). The classes provided actually offer the > implementation for storing data in a list and computing the above-mentioned > values or summing up everything. > * timed summarizer: this is another variation of the aggreator, however, it > adds the idea of regular "flushes", so based on a timer it will reset the > value and start summing/aggregating the data again. Rather than using an > aggregator which would store the whole data series (possibly for applying > more complex formulas), this component just computes on the fly on each > request the formula and stores the result of it. (Which does mean things like > computing arithmetic mean, median etc would be difficult to compute without > knowing upfront how many calls will be received -- i.e. how many elements we > will be required to summarize/aggregate.) So the memory footprint of running > this is much smaller -- even though, as I said, it achieves similar results. > I have only provided a summarizer which operates on integers, but obviously > others for float, double etc can be created if we go ahead with this design. > Hopefully the above make sense; this code has resulted from finding myself > writing similar components to these a few times and because it's always been > either one type (e.g. aggregator) or another (summarizer) I haven't given > quite possibly enough thought to the class design to join these 2. Also, > unfortunately, the time I sat down to make these components a bit more > general and submitted issue 340 was nearly 3 months ago so I'm trying to > remember myself all the ideas I had at a time so bear with me please if these > are still a bit fuzzy :) However, if you can make use of these I'm quite > happy to elaborate on areas that are unclear and obviously put some effort > into getting these components to the standards required to put these into a > release. -- This message is automatically generated by JIRA. For more information on JIRA, see: http://www.atlassian.com/software/jira