Misc cleanup -- Get rid of ExprEvalInterface

[ktf]

Discussed with @ianna over coffee. Given we have only one evaluator we can simply get rid of the abstract base class and clean up the code.

[cmsbuild]

A new Pull Request was created by @ktf (Giulio Eulisse) for CMSSW_7_0_X.

Misc cleanup -- Get rid of ExprEvalInterface

It involves the following packages:

DetectorDescription/Core
DetectorDescription/Parser
DetectorDescription/RegressionTest
DetectorDescription/ExprAlgo

@civanch, @Dr15Jones, @ianna, @mdhildreth, @nclopezo, @ktf can you please review it and eventually sign? Thanks.
You can sign-off by replying to this message having '+1' in the first line of your reply.
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@ktf you are the release manager for this.

[cmsbuild]

Pull request #870 was updated. @civanch, @Dr15Jones, @ianna, @mdhildreth, @nclopezo, @ktf can you please check and sign again.

[cmsbuild]

Pull request #870 was updated. @civanch, @Dr15Jones, @ianna, @mdhildreth, @nclopezo, @ktf can you please check and sign again.

[ianna]

@ktf I wonder why would you like to do this instead of using ExprEval::instance() directly?

[ktf]

Because this way all the accesses to ExprEvalEvaluator go through a instance method of the DDLElementRegistry which is already percolated to the deepest level it is needed (the various DDXMLElements or whatever they are called). This allows me to remove all the references to ExprEvalEvaluator::instance apart from this one and making it just a property of DDLElementRegistry will do the trick of getting rid of the ExprEvalEvaluator singleton.

[ianna]

sounds good to me.

[ianna]

I run the following test:
cmsRun $CMSSW_RELEASE_BASE/src/GeometryReaders/XMLIdealGeometryESSource/test/readIdealAndDump.py

The before and after results are:

< TimeReport> JobTime=1.37958e+09 JobCPU=1.43778
---
> TimeReport> JobTime=1.37958e+09 JobCPU=1.77973


< TimeReport> Time report complete in 36.2799 seconds
---
> TimeReport> Time report complete in 39.5412 seconds

[ianna]

+1

[cmsbuild]

This pull request is fully signed and it will be integrated in one of the next IBs unless changes or unless it breaks tests. @ktf can you please take care of it?

[ktf]

As discussed with @ianna the variance on the measurement is actually larger than the difference reported. Approving this for the time being. We'll keep it in mind if we see a big regression WRT pre4 at the end of the clean up. All the produced files are equal.