If the new API is completely pull such that the API is again the same as 
the last released version then yes, revert to 1.0. But as long as the API 
is different than the last released version, it should remain 1.1. Putting 
a qualifier of a build date or tag on the package export is wrong. It will 
lead one to believe that importing that package with a qualifier is ok and 
meaningful. But a qualifier of a build date or tag says nothing about API 
backwards compatibility. It is just a form of identity with no meaningful 
ordering.
-- 

BJ Hargrave
Senior Technical Staff Member, IBM
OSGi Fellow and CTO of the OSGi Alliance
[EMAIL PROTECTED]

office: +1 386 848 1781
mobile: +1 386 848 3788





From:
Thomas Watson/Austin/[EMAIL PROTECTED]
To:
Equinox development mailing list <equinox-dev@eclipse.org>
Date:
2008/09/05 12:03 PM
Subject:
Re: [equinox-dev] .qualifier for export package?



Anyone adopting early API (before API freeze) has to be prepared for 
breaking changes. We must have the flexibility to develop our new API and 
increment our versions properly from one final release to the next. 
Imagine the following scenario

foo; version=1.0

The M1 build adds new backwards compatibility API to foo and the version 
becomes:

foo; version=1.1

In the M2 build it is decided that the new API is bad and is pulled out, 
now what do you think foo version should be? back to 1.0 or 1.2 or 2.0? 
removing the API technically is a backwards compatibility change so 
technically the version should become 2.0 when compared to the version of 
foo from the M1 build. I think we must evolve our API versions from the 
last release, not from build to build. In this case the foo package 
contains the exact API as the 1.0 version, making it anything other than 
1.0 is wrong and confusing.

Adding a qualifier will allow clients to depend on a particular version of 
the package from a particular build (or CVS tag) if they really need to. 
But I do not think this is the common case and we should not recommend as 
a best practice to include qualifiers in version ranges used in 
Import-Package or Require-Bundle.

Tom



BJ Hargrave---09/05/2008 09:40:56 AM---But the qualifier is just another 
component of the version to allow ordering among versions. Why is change 
it any different tha


From:

BJ Hargrave/Austin/[EMAIL PROTECTED]

To:

Equinox development mailing list <equinox-dev@eclipse.org>

Date:

09/05/2008 09:40 AM

Subject:

Re: [equinox-dev] .qualifier for export package?




But the qualifier is just another component of the version to allow 
ordering among versions. Why is change it any different than changing any 
other component of the version? (Other than semantic we place on the 
version components.) 

Changing any part of the version during development is only interesting if 
someone will change their import to depend upon that "higher" version. And 
if someone becomes dependent upon that new version, then making backwards 
incompatible API changes during development is in trouble. Backing out API 
changes made during dev does not mean you can simply revert the version 
number since there may have been changes in other areas of the package 
which are not affected by the back out. 

Original: 1.2 
Make change A: 1.2.0.qual1 
Make change B: 1.2.0.qual2 
Backout change A: 1.2.0.qual1 is not right since change B is still there. 

-- 

BJ Hargrave
Senior Technical Staff Member, IBM
OSGi Fellow and CTO of the OSGi Alliance
[EMAIL PROTECTED] 

office: +1 386 848 1781
mobile: +1 386 848 3788




From: 
Thomas Watson/Austin/[EMAIL PROTECTED] 
To: 
Equinox development mailing list <equinox-dev@eclipse.org> 
Date: 
2008/09/05 10:11 AM 
Subject: 
Re: [equinox-dev] .qualifier for export package?




If we decided to back out an API then we revert the version back and have 
to make the necessary announcements to the community to prepare them for 
the version decrease in mid development cycle. From release to release our 
version have to follow our version rules at 
http://wiki.eclipse.org/index.php/Version_Numbering

I do not think we should change the minor number each time API is added 
for each I-Build or milestone. That should only be done once each release. 
What Jeff would like is the ability to pick a particular build of a 
package from a development. If this is important then the qualifier 
approach is likely the most simple approach. Another approach could be to 
have exporters add a matching attribute that indicates new API. But this 
does not scale well. For example:

Export-Package: foo; version="2.1"; bar=true

This would be used when some new bar feature was added to the foo package, 
then

Export-Package: foo; version="2.1"; bar=true; baz=true

This would be used when both the bar and baz features are added to the foo 
package. This is possible but is hard to manage and is just ugly. Is this 
a serious enough issue that we must address it? It seems like it is just a 
temporary issue that goes away once the final release is done.

Tom



BJ Hargrave---09/05/2008 07:50:25 AM---If I understand #2 correctly, then 
you want a controlled version practice during the development cycle. This 
is challenging sin 

From: 

BJ Hargrave/Austin/[EMAIL PROTECTED] 

To: 

Equinox development mailing list <equinox-dev@eclipse.org> 

Date: 

09/05/2008 07:50 AM 

Subject: 

Re: [equinox-dev] .qualifier for export package?





If I understand #2 correctly, then you want a controlled version practice 
during the development cycle. This is challenging since you may want to 
change your mind and break from a previous API change made during the same 
dev cycle. 

For example: 

1.2 is the last shipped version of a package (let's say thats in 
Ganymede). 

So during the dev cycle you change to 1.3 because you add new API. Soon 
you add more API. 1.3.1 or 1.4? Then you decide to pull some of those API 
changes because we learned they did not work as expected. What version 
then? 2.0? Because of the breaking change? I think this is a fairly 
impossible situation during the dev cycle because we are free to change 
our mind about new API until API freeze. 

I think the odd/even versioning could be useful. But it still does not 
easily handle the removal of new API previously added during the dev 
cycle. It only seems to work well if the API only "grows" but does not 
shrink. 

-- 

BJ Hargrave
Senior Technical Staff Member, IBM
OSGi Fellow and CTO of the OSGi Alliance
[EMAIL PROTECTED] 

office: +1 386 848 1781
mobile: +1 386 848 3788



From: 
Jeff McAffer <[EMAIL PROTECTED]> 
To: 
Equinox development mailing list <equinox-dev@eclipse.org> 
Date: 
2008/09/05 04:32 AM 
Subject: 
Re: [equinox-dev] .qualifier for export package?





I'm certainly sympathetic to you thinking here. Having qualifiers in 
import statements is ugly at best. The challenge is that in the dev cycle 
the API of something may change many many times. This would lead to quite 
visible changes in unreasonable ways. For example, say we introduce some 
API and then "break" it several times as we refine in the dev cycle. Then 
the first release of the API might have version 42.23.27 or some such. 
Trying to manage API semantics during the dev/release cycle seems like 
overkill. Clearly that is an over done example but you get the point I 
hope.

Lets step back for a second. Some goals in decreasing order of 
priority/importance.

Goal #1: ensure that at least all API packages have version numbers on the 
exports.
Goal #2: be able to eat our own dog food wrt provisioning and version 
management during the dev cycle.

Good news is that #1 is likely agreed to and *all* we have to do is put 
the initial version numbers on the current packages and then have the 
tooling help people manage them according to the current versioning model.

The proposal for using .qualifier was actually one possible implementation 
of goal #2. #2 is interesting because eating our own dog food seems to 
greatly increase the likelihood of our technology being good/useful. 
Without some sort of increasing version number on the packages, p2 for 
example, will have a hard time figuring out what to give you cause 
everything will look the same to it.
Can anyone think of another way of enabling #2? Of the top of my head I'm 
thinking that something like the odd/even version pattern might help...

Jeff
BJ Hargrave wrote: 

If you change API during dev cycle, that is the proper time to also change 
the major or minor version. That is the whole point. I would assume that 
API tooling will complain until you do so. Just changing the qualifier is 
insufficient to capture an API change. Also, I think that last thing we 
want to see are bundles using qualifiers in import package statements! So 
if you use qualifier to denote API change during dev, then other bundles 
will need to import using qualifiers to ensure they wire to the desire API 
if they use it. UGLY! 

Qualifiers are useful to capture implementation changes. But API is a 
specified thing that changes deliberately and (hopefully) slowly and its 
version is not subject to implementation. 
-- 

BJ Hargrave
Senior Technical Staff Member, IBM
OSGi Fellow and CTO of the OSGi Alliance
[EMAIL PROTECTED] 

office: +1 386 848 1781
mobile: +1 386 848 3788



From: 
Jeff McAffer <[EMAIL PROTECTED]> 
To: 
Equinox development mailing list <equinox-dev@eclipse.org> 
Date: 
2008/09/03 06:16 AM 
Subject: 
Re: [equinox-dev] .qualifier for export package?



I understand your hestiation and actually agree with you from the 
"released code" point of view. However, we spend a lot of time dealing 
with code and API that is in development. If we are to have any hope of 
provisioning and managing that, we need to know the difference between the 
various iterations of the packages. For example, when someone adds an API 
during the dev cycle and you want use it, you need to import the right 
version of the package to ensure you get it. Changing the first three 
segments version number of the package for every change done in the dev 
cycle feels too disruptive.

To a certain extent this could be handled in the provisioning system but 
that would force the situation of bundles in a particular context (e.g., a 
build "lineup"). That is, bundles would no longer be completely/accurately 
self-describing.

Jeff

BJ Hargrave wrote: 

I would be extremely cautious about using qualifier on package versions. I 
must say that I have never seen it done. 

It seems an over specification. I think that having build tools to advise 
you to increment the micro is more than sufficient. 
-- 

BJ Hargrave
Senior Technical Staff Member, IBM
OSGi Fellow and CTO of the OSGi Alliance
[EMAIL PROTECTED] 

office: +1 386 848 1781
mobile: +1 386 848 3788



From: 
Thomas Watson/Austin/[EMAIL PROTECTED] 
To: 
Equinox development mailing list <equinox-dev@eclipse.org> 
Date: 
2008/09/02 10:45 AM 
Subject: 
Re: [equinox-dev] .qualifier for export package?



Before recommending every package uses a qualifier I have the following 
concerns:

1) In Eclipse we have loads of packages. We better make sure all identical 
qualifier Strings are shared (interned etc.) for performance reasons. 
Today when loading from a cached state we share identical Version objects. 
Because package versions are managed independently we will end up with 
lots of different versions that have the same qualifier exported by a 
bundle. We also will limit the ability to share Version objects across 
bundles because each will use a different qualifier (unless we happen to 
use the same CVS tag).

2) The qualifier will change even in cases where no code was touched in 
the package. I'm not sure this is a valid concern. The code got recompiled 
so perhaps changing the version qualifier is warranted. But we need to 
think about the consequences. For example, I can see API tooling start to 
complain that the micro version of a package should be increased to 
indicate a bug "fix" when comparing the package versions with a base line. 
It will notice that the qualifier changed from a previous release but the 
micro version was not increased.

3) What about versions of packages which we do not maintain the API for at 
Eclipse. Things like org.osgi.* and orbit bundles. Shouldn't we use the 
version the producers of the API have defined? Adding a qualifier here 
does not seem right, especially if a qualifier is already defined by the 
producers.

On the surface this sounds like a fine idea, and I am not completely 
against it. But I would like to take the first step of versioning the 
Eclipse API packages first to see what all the issues are with independent 
package versioning. I'm sure we will run into other hurdles along the way. 
For example, how does a developer maintain the version of a split package 
across all the bundles the package is split?

Tom



"Chris Aniszczyk" ---08/31/2008 02:46:34 PM---On Sun, Aug 31, 2008 at 5:53 
AM, Jeff McAffer < [EMAIL PROTECTED] 

From: 

"Chris Aniszczyk" <[EMAIL PROTECTED]> 

To: 

"Equinox development mailing list" <equinox-dev@eclipse.org> 

Date: 

08/31/2008 02:46 PM 

Subject: 

Re: [equinox-dev] .qualifier for export package?







On Sun, Aug 31, 2008 at 5:53 AM, Jeff McAffer <[EMAIL PROTECTED]> wrote: 
As version numbers on packages become more prevalent does it start making 
sense to use .qualifier on them in addition to bundle version numbers? The 
logic here is the same as for bundles. we rev the version number of the 
bundle to match the most extreme change for that release. in between if 
hte provisioning system is going to do its job, it needs to have different 
version numbers. Teh .qualifier allows for the auto-qualification of 
bundle version numbers. The same is true for folks using import/export 
package. 

+1

In PDE, I plan on releasing some builder logic to flag exported packages 
without versions with a warning in M2. API Tooling also has items in plan 
that deal with package versioning, but that will be post M2 

Thoughts for how/if this should be introduced? 

I say before M2, we formulate a plan across the Eclipse proper projects to 
deal with versions on package exports. We can than look at pushing that 
plan to other Eclipse.org projects as a best practice once we get the hang 
of it.

-- 
Cheers,

~ Chris Aniszczyk_______________________________________________
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