atom feed29 messages in org.apache.incubator.sling-devVersion Numbers
FromSent OnAttachments
Felix MeschbergerNov 9, 2009 7:35 am 
Carsten ZiegelerNov 16, 2009 12:23 am 
Bertrand DelacretazNov 16, 2009 1:27 am 
Felix MeschbergerNov 16, 2009 11:34 pm 
Carsten ZiegelerNov 17, 2009 12:24 am 
Bertrand DelacretazNov 17, 2009 12:47 am 
Vidar RamdalNov 17, 2009 12:51 am 
Karl PaulsNov 17, 2009 1:47 am 
Karl PaulsNov 17, 2009 1:54 am 
Felix MeschbergerNov 17, 2009 2:05 am 
Felix MeschbergerNov 17, 2009 2:08 am 
Felix MeschbergerNov 17, 2009 2:11 am 
Alexander KlimetschekNov 17, 2009 2:12 am 
Felix MeschbergerNov 17, 2009 2:17 am 
Carsten ZiegelerNov 17, 2009 2:27 am 
Bertrand DelacretazNov 17, 2009 2:39 am 
Felix MeschbergerNov 17, 2009 4:16 am 
Bertrand DelacretazNov 17, 2009 4:24 am 
Felix MeschbergerNov 17, 2009 4:28 am 
Alexander KlimetschekNov 17, 2009 4:48 am 
Ian BostonNov 17, 2009 6:28 am 
Bertrand DelacretazNov 17, 2009 6:34 am 
Vidar RamdalNov 17, 2009 6:45 am 
Bertrand DelacretazNov 17, 2009 6:50 am 
Felix MeschbergerNov 17, 2009 6:55 am 
Felix MeschbergerNov 17, 2009 12:01 pm 
Bertrand DelacretazNov 17, 2009 12:12 pm 
Felix MeschbergerNov 17, 2009 12:20 pm 
Felix MeschbergerNov 17, 2009 12:22 pm 
Subject:Version Numbers
From:Felix Meschberger (fmes@gmail.com)
Date:Nov 9, 2009 7:35:04 am
List:org.apache.incubator.sling-dev

Hi all,

<warning>lengthy mail</warning>

In comments to SLING-1176 Ian Boston wrote:

"The exports in bundle/api/pom.xml look like they might become problematic from a support point of view, although we probably cant avoid this. [...] [The problem is the] manual maintenance of the version numbers. (not a big problem bit needs to be done)"

I agree, that this is a problem. Let me reasonate on this a bit ;-)

As a reference you might want to read my latest blog post at [1] and also what the Eclipse guys have to say [2] (great read, btw).

So for Sling, we have three kinds of version numbers: (1) Big Sling releases, (2) Sling bundles, and (3) exported packages.

For (1) we have already an ample solution in that we just increase the number from release to release. Just remember that a "big Sling release" is a convenience release of existing released Sling bundles.

For (2) version numbers are just defined as the <version> element of the bundle's POM. The only restriction here is, that we decided to use even numbers for releases and odd numbers for SNAPSHOTs. Whether and when which version part is increased is not codified.

For (3) the situation is more problematic since there are a number of places to set exported package version number: In a packageinfo file inside the package (picked up by the Bundle plugin to set the export version) or explicitly in the <Export-Package> element of the Bundle plugin configuration or by reference to the bundle version number using the ${pom.version} variable.

Upto now, we mostly used the ${pom.version} notation linking the exported package version to the bundle version. This works well for bundles with simple exports. For more complicated bundles, specifically for bundles with multiple exported packages which may evolve independently, this does not work well.

Consider for example the Sling API bundle, which exports 7 packages. Each of which may evolve independently. Now the resource package is enhanced causing a minor version increase. Should the version numbers of the other exports also be increased ? Thus acting as if there was some API change ?

I would say, no. Particularly if some API implementation bundle is restricting the import version of the API implemented. Such an implementation would immediately stop working because the version has been increased. But since there has been no change, the implementation would still be correct.

So, I think, we should evolve the exported package versions independently from each other and possibly even independently from the bundle version.

This places more burden on the developer when deciding on the exported package version - in fact this requires such a decision as compared to have Maven take the decision by just setting the bundle version.

The only problem is: Where shall this be noted ? In the POM or in the packageinfo file ? If we would place the packageinfo file just beneath the class source files, I would say, in the packageinfo file.

But this would require defining the class source locations as resource location in the POM (at least for packageinfo) files.

I am not sure ....

WDYT ?

Regards Felix

[1] http://blog.meschberger.ch/2009/10/on-version-numbers.html [2] http://wiki.eclipse.org/index.php/Version_Numbering