DTP Plug-in Versioning Policy
[3/4/08]: Updated for the new qualifier tag format in the PDE build.
[11/5/07]: This document has been reviewed and approved: it now represents DTP policy.
This document specifies plug-in versioning rules for DTP. That is, a policy for changing plug-in version numbers based on the types of changes made to the plug-in is specified below. We follow generally accepted Eclipse rules in this area, for example the versioning policy for the Eclipse platform, and we deviate only slightly as described below in the "Qualifier Field Format" section. It is important that all DTP committers adhere to this policy so tools (such as Eclipse Update Manager) and DTP users can determine the types of changes present between two versions of a given plug-in.
- A DTP plug-in version number has four fields, separated by a ".": Major.Minor.Service.Qualifier
- A major change indicates breakage in API or significant new/reorganization of functionality.
- A minor change indicates changes visible to users or extenders of DTP.
- A service change indicates bug fixes.
- A qualifier change indicates the plug-in has changed.
As with any specification, there is room for interpretation, and each committer's best judgment is required. When in doubt, ask the DTP team/community by creating a bug or message to the DTP dev mailing list.
Whatever is done to plug-in version numbers following this policy, each update must result in a number that is monotonically increasing. Otherwise, the Eclipse Update Manager will not detect the newer version of the plug-in, and users' DTP installations will be rendered inconsistent. If you believe that the policy expressed herein requires breaking this fundamental constraint, immediately notify the DTP PMC for direction.
- The major, minor, and service fields respectively are to be incremented only once per DTP stream release cycle, depending on the type of change as described above. For example, "1.5.0" can go to "1.5.1" during a release cycle, but not "1.5.2" or higher.
- The qualifier field is to be updated whenever anything delivered in DTP builds for the plug-in is changed.
- The precedence of the fields is major > minor > service. When a higher precedence field is updated, fields of lower precedence should be reset to 0 ("zero"). Note:
- The precedence rules mean that the major field can not be reset to 0.
- The qualifier field is updated separately, and is not simply incremented nor reset to zero (see below).
- If a field is reset to 0, then it may be incremented again during a release cycle.
Qualifier Field Format
The qualifier field must be "vYearMonthDateIteration." Further the value must reflect the date in Shanghai. Since DTP now uses a PDE based system with map files, only source code specified in the map files (by tag) will be used for DTP builds. Thus, when you wish to update a plug-in for the build:
- Commit any changes for the plug-in as usual to CVS HEAD
- Create a Qualifier field date stamp
- Determine the current date in Shanghai. You can use this site to do so.
- Use a "v" followed by the four digit year, two digit month, and two digit date
- Add the iteration count at the end of the Qualifier field. For the first update to a plug-in on a given (Shanghai) calendar day, this value is 1. For each subsequent update to that same plug-in on the same (Shanghai) calendar day, increment the iteration count.
- Create a CVS tag on HEAD for the plug-in using the Qualifier value.
- Update the appropriate map file to use the new CVS tag for that plug-in.
- Commit the changes to the map file.
Suppose the date is March 4, 2008 in Boston, MA (ET). First, I check the time clock to get the date for Shanghai, which happens to be March 5, 2008. So, the format of the Qualifier is:
Next, I take this value and create a tag in CVS HEAD for the updated plug-in. Finally, I check out and update the map file using the exact same Qualifier value for that plug-in.
Suppose I then realize that I forgot to commit one small change. So, I commit the additional change to CVS HEAD, [ http://www.worldtimeserver.com/current_time_in_CN.aspx check the date in Shanghai] -- which turns out to be the same -- and create a new tag in CVS HEAD for the plug-in:
Notice in this case that the final number ("interation") has been incremented. I then update the associated map file for this new value.
Initial Version for New Plug-ins
Plug-ins newly added to a DTP release cycle normally will start with a "1.0.0.Qualifier" version number, unless the plug-in is considered to be a "tech preview" version for that release. Committers adding new plug-ins to a DTP release should confirm the initial version with their project lead.