ok, duplicate transformer execution will be resolved by MNG-5667. Of course the performance of signing with an external tool and internal is not a good comparison, but with external tool process was run once and now will be run twice. So I thought about performance in this way that we will do the same job many times.
I see that transformation should be changed, so can we define (if possible) small steps which get us to the goal, but first we need this goal. What I see: - possibility to plug transformations for poms - possibility to plug transformations for other artifacts (do we want?) - possibility to plug transformations for signing/checksumming So never mind we will have transformation in two levels: pom -> signing/consuming each of this level can produce new artefakt or something else which should be attached / installed /deployed When we use transformation like now we need to define all transformation and output items from them before start, because the list of project artifacts which will be installed/deployed is built before the transformation process is started. niedz., 11 paź 2020 o 11:59 Robert Scholte <rfscho...@apache.org> napisał(a): > It is true that for both install and deploy the transformers will be > executed, however in general there is no need to do both, this is how Maven > still works, but should be solved with MNG-5667[1]. > This might be a good reason to give this a higher priority. (and to get > "mvn clean install" out of everybody's system) > > I don't think there's a lot of need for transformers, so I could image > Maven will predefine the available transformation hooks, i.e. pom > transformers and checksum/signature transformers. > > I would like to see numbers of performance differences. (keep in mind it > is probably an unfair comparison, because signing is now done by a third > party program). > To reduce memory consumption the transfomer is using PipedStreams, which > should imply that size doesn't matter anymore. > > thanks, > Robert > > > [1] https://issues.apache.org/jira/browse/MNG-5667 > On 11-10-2020 09:06:11, Slawomir Jaranowski <s.jaranow...@gmail.com> > wrote: > Hi, > > > During a spike on maven-sign-plugin we discovered the chain feature in the > Transformation process will be useful. > > Current transformation solution is dedicated to pom transformation, it will > be also useful to prepare more flexible solutions for another type of > transformation like preparing signatures for artefacts. > > Present implementation of transformers cause of calling the whole > transformation process from beginning for all requests. > > We process it twice - first for install and second for deploy. > So when we add more complicated and more resource demand (like computation > of signature) we can decrease performance in a visible way. > > Now try to build a process with a chined transformer, we will have a > PomTransformer which can produce two kinds of pom. > Next transformer will be for signing SigTransformer, so we will have: > > - pom.xml > -> PomTransformer > - pom.xml FileTransformer > -> SigTransformer > - pom.xml.asc FileTransformer > - pom5.xml FileTransformer > -> SigTransformer > - pom5.xml.asc FileTransformer > > > In this example we can see that in output we need to produce 4 artifacts: > pom.xml, pom5.xml and pom.xml.asc, pom 5.xml.asc so we need 4 final > transformers and transformer from previous level was run twice. > > The biggest problem which I see is that we need results from all > Transformers level. > > I'm afraid that when we start to use transformers for all artifacts we can > decrease performance for projects with big artifacts. > > And the end - summary: > 1. problem of running transformers many times during project build > 2. multilevel / chained transformers - how to reuse output from previous > level > > -- > Sławomir Jaranowski > -- Sławomir Jaranowski
