EGit Synchronize ChangeSet – a small step ahead

This is  actually a really small step, because I only manage to display list of commits between two selected branches/tags (as you can see on this screen shot):

<img class="aligncenter size-medium wp-image-629" title="egit-synchronize-change-set" src="https://luksza More×1.trans.gif” data-lazy-src=”×300.jpg” alt=”” width=”223″ height=”300″ srcset=”×300.jpg 223w, 382w” sizes=”(max-width: 223px) 100vw, 223px” />But for me it is a great success, after more then a week of fighting with Team Framework API, with was actually designed for centralized version control system.

Actually this list isn’t even sorted properly, listed commits doesn’t contains any data/child  … but I think that right now things should goes faster then it was before, because I think that I’ve got idea of change set’s.

What should be done? All commit’s should be assigned to root node with should represent repository (this is in  case if someone will be synchronizing multiple repositories at a same time). Commit’s should contains list of changes with proper path representation: project (if it is included in this repository), folder (and java packages if it is a java project) and finally files that was changed in this particular commit.

EGit synchornization – the next step

First step of providing synchronization feature into  EGit was, display set of changes between two branches, and this works quite well (if there is applied my latest patch for common ancestor).

The next step of integration would be to make it more “git” way. In this case all changes should be spited into proper commits, because in Git we track changes on repository level (not on file level) and every commit leads us from one consistent state to another. In this case, synchronize view should show list of commits (first 4-6 characters of each SHA-1 and first line from commit message), then as a child of particular commit we should see resources that was changed by this commit. Generally all changes in particular commit should have one direction incoming or outgoing (despite conflicts that can appears on file or container level inside commit). Also merge operation should be available only on commit level.

OK, so this is how things should be handled and how they should look like … but how to achieve it?

This is quite tricky question. Thanks of bug 317934 that was made by Benjamin Muskalla I’ve started for looking information about ‘change set’ in eclipse.This leads me to ‘Team Logical Model Integration‘. According to this documentation I should almost rewrite all project … change base class of GitSynchronizationParticipant, provides implementation of IResourceMapping, ISynchornizationContext, IResourceMappingManager, etc …

The other thing that I’ve spot some time ago, is that Mercurial plug-in for Eclipse has functionally that is somehow similar with those that I’ve want to implement (they split changes into two groups: incoming and outgoing); thank god that it is open sourced ;). With base knowledge about ‘Eclipse Logical Model’ I’ve downloaded MercurialEclipse sources … of course using hg 😉 BTW. to download sources I was forced to create an account on … this is next account that I used only once … no comments for that …

When I finally get sources I’ve started inspecting how they implement change sets … and realize that they also use ‘Logical Model Integration’ … but according to comment for MercurialSynchronizeParticipant they don’t really know why they use ModelSynchronizeParticipant 😉 … why bother with that, so it is working ;).

So my plan for next few days is:

  • migrate actual implementation of synchronization on ‘Logical Model’
  • implement change sets

This looks like there will be next 1 or 2 kloc patch set o integrate into EGit …

Wish me luck 😉 … or suggest better/easier solution 😉

Any suggestions are strongly required 😉

GSoC10 midterm and EGit common ancestor

I don’t know exactly when we hit a Google Summer of Code 2010 midterm date … time runs so fast, few weeks ago I was writing that I’ve got accepted in this year’s program edition, and now we hit a midterm evaluations. This is a quite good time to sum up this short period of time.

Starting from the begging … estimating a project; now I know that initially I was very, very (and even more very, very ;)) optimistic about project time line. According to my initial estimation I should now start working on stashing support in JGit … but for now I’m “stuck” in synchronize view. Even more because now I see that I’ll need two or more weeks to make it ready for 0.9.0 release, now it has two major issues that I would like to solve before upcoming release. I even  don’t want to think where I would be right now if Remy didn’t made initial contribution …

OK, so what is project current status? Well we had an synchronize action and it works quite well. It shows upcoming, outgoing and conflicting changes … but there are few issues in current implementation. First of all common ancestor isn’t calculated properly (according to bug: 317371). Next issue is that we always use HEAD as a ‘local’ in three-way-compare, to be honest this seams to be an Team Framework limitation because ‘local’ is always instance of IResource .. btw. I should raise an issue for this ;). Last thing (for now) that in my humble opinion should be included in 0.9.0 is support for change set’s (bug: 3318473) because Git works on repository state changes not on file changes. Additionally there is one small feature that also should be included in 0.9.0: merging support from synchronization view, but (for now) it seams to be a simple thing to achieve.

What are my plans? Fix for bug 317371 currently wait for approvement in Gerrit, so I thing that this is rather a closed thing. For now I’ll focus on change set support. In case of popper handling of source branch setup I’ll wait for any hints on eclipse forum thread, then I thin that I’ll try to implement it somehow. If I fail in this task, I thing that we should disable source branch selecting and set it by default to HEAD.

Some statistics and numbers:

In my humble opinion this is quite good result for around 7 weeks of work 😉

EGit preliminary synchronization view support merged!

Yesterday  patch “Add preliminary synchronization support within Eclipse for branches” (to be honest it also supports synchronization with tags) was merged into master. What it means ? This mean that every one who want to play with current Synchronization view support in EGit can easily download it from EGit’s nightly build repository.

Quick description what is supported you can find in my previous post. Of course you can play with other new features like reimplemented Git Repositories view, colorize diff and others … detailed description can be found here 😉

Please be aware that this is only a “preliminary synchronization support“. This means that there are some things to work on and to be added in nearest feature. In case of any bugs or feature request please fill a bug report for EGit go right here.

Preview of EGit integration with Synchronization View

Since of May 16 I’m officially working on integration EGit with Synchronization View. Right now I know that this task is more complicated then I was thinking before GSoC. But thanks Remy Suen and his initial contribution to EGit which gave me some foundation this isn’t so scary as it could be ;). Here is a very quick overview of current situation.

Currently there are three way to launch synchronization:

  1. From synchronize wizard
    Second step of wizard requires some work, it has some usability issues …
  2. From branch context menu in Repositories View
    In this case we are synchronizing current HEAD (active branch), with selected branch; locally made uncommited changes are excluded in this comparison.
  3. From project’s context menu by selecting Team -> Synchronize
    After this we would see above dialog:
    Where we can select source and target branch or tag (both are supported) and declare does we want include local changes in this comparison

No matter with way will you use, you always will see something similar to this:

When you will use EGit Synchronization view there are few important things that you have in mind:

  1. Synchronization always occur on repository level. What it means ? It means that you cannot synchronize a single folder or file (for “file synchronization” there is a Compare With -> HEAD Revision / Git index). If you have more then one project in repository (eg. two or more maven modules), synchronize action will compare all of them.
  2. Changes are organized in commits and can’t be extracted or moved between them. You can only merge entire commit.

This two things distinguish Git from CVS/SVN.

This isn’t end of my work with synchronization view. There are lots of things that should be improved, implemented and fixed 😉 eg.:

  • showing proper files in Compare view (currently compare view always compares local file with remote, in some cases it should compare file that is in selected branch instead of current local)
  • splitting changes into commits when we will presenting it in Synchronize view (this is important because after it would be implemented we can start thinking of implementing merging from synchronize view)
  • performance improvements
  • usability improvements
  • (and of course) bug fixes 😉