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EGit Iteractive Adding

So what is “interactive adding” in git? Imagine situation when you change two or three lines in file (this could be also two or three blocks/methods), then you realize that you will want to commit those changes in two (three or more) separate commits.

Here is Al Blue’s description how interactive adding works in native git: Git Tip of the Week: Interactive Adding

What about EGit? Honestly this is currently supported … but it isn’t really straight forward to access. You need to select a file then choose from context menu Team > Compare With > Git Index and then you can easily move changes around, finally when you are happy with both versions (left is working tree and right is one that will be staged/added to index) just save compare editor contents. Version from right hand side will be added to index as it is in this editor.

OK, so now you can easily stage and unstage partial changes … maybe you would also like to partial replace staged changes by version in HEAD? Currently in version 1.1 you can compare version from git index with HEAD version using context menu Team > Compare With > Git Index with HEAD, but you cannot overwrite anything … yet, because (hopefully) in 1.2 such option will be available. Here is patch that adds this functionality (to be honest this is a side effect…).

And what about (my favorite) Synchronize View? Unfortunately EGit 1.1 don’t allow to move any changes in compare editors launched from Synchronize View … but with change mentioned above and with this one both features would be available from Git Commits model (before it was named as Git Change Set model)

Here is a short screen cast that shows how this work:

 

End of Google Summer of Code 2011

Officially coding period in Google Summer of Code was closed last Monday (August 22nd) , so this is good time to sum up last three months of my work on EGit project.

During that time I’ve manage to contribute 32 commits (29 of them are already merged into master, rest is pending for review). I have also two not finished changes in my local git repository. First is about supporting non-workspace files in Workspace presentation model in sync-view, second is refactoring of current Git Change Set implementation.

Here is detailed list of things that was done during GSoC and are available in current nightly build:

  • improved synchronize wizard
  • Workspace presentation model will refresh after repository change
  • pushing from sync view to multiple repositories is now possible
  • Git Change Set presentation model will be refreshed after workspace change
  • context menu in synchronize view was cleaned up and git actions are shown for multiple selections
  • synchronization on folder level is now possible and it will narrow results just for selected folder (when synchronization is launched for project then results will show changes in whole repository)
  • local changes can be drag and dropped between <working tree> and <staged changes> nodes in Git Change Set presentation model

Performance improvements for Workspace presentation model are still awaiting for review in Gerrit. Some part of performance and memory usage improvements for Git Change Set are also pending in Gerri, I’m currently working on rest of required refactoring in Git Change Set presentation model.

I want to thank my mentor Matthias Sohn for his commitment in GSoC, for reviewing my patches and his feedback. It was a great pleasure working  with him! 😉

Progress on non-workspace files in Workspace presentation model

For last three weeks I was working on including non-workspace files in Workspace presentation model in Synchronize View. This idea can sounds weird since the Workspace presentation model was designed to show only changed files that are in Eclipse workspace … but there are some use cases in which such behavior seams to be reasonable (eg. EGit and JGit projects doesn’t import repository root into workspace only projects are imported and files like master pom.xml, README, LICENCE and so on are left outside workspace).

If you don’t import all data into Eclipse workspace you won’t see any incoming nor outgoing changes. Even more, after merge/rebase actions changes in non-workspace files will magically appear in those resources and can even brake something (eg. massed up in master pom.xml file).

So, what is current status ? First of all I want to point that I’m describing here current situation in my working copy, described here changes currently are not available in public. After hours of debugging, code analysis and rewriting my code I’ve manage to show some indication in synchornize view that there are some non-workspace chagnes. The next step will be to show what particular file was changed and then enable all operations like overwrite, mark as merged, etc.

Here is a screenshot showing current status:

Non-workspace files in Workspace presenation model
As you can see there is home folder in sync results. It even have expand indicator (but after expanding it there is nothing inside). I suppose that on windows this folder will correspond to drive letter, but I’m not sure here.  Now I only need to tell Team Framework that there are some files inside home node …

This seams to be quite easy task, since parent folder is already included in view … but this isn’t that easy. First of all Workspace model is based on IResource‘s with are manageable by Eclipse platform. Of course I can create such resource using IWorkspaceRoot.getFolder() and IWorkspaceRoot.getFile(). Unfortunately non-workspace resources created by those two methods will return theirs first segment (on unix system it will be usually /home) as theirs project. Of course such project doesn’t exist in workspace therefore this node is empty.

Honestly speaking I currently don’t have any good ides how to move things forward … as usually I’ll dive into debugging and code analysis …

Any hints and ideas from the community are kindly welcome!

Huge performance boost for EGit sync-view

For last few days I was working on EGit Synchronize View performance, especially on Workspace presentation model (the Git Change Set is next on my list ;)). My starting point was 1m 40s to compare two linux kernel versions, v2.6.36 versus v2.6.38-rc2. Such result seams to be very good, but you need to know that it was achived on SSD hard drive and comparing to regular HDD it would be much worst (maybe more then 3 or 4 minutes).

What can be improved ? Fist of all, current implementation whenever it is asked for members of particular folder it opens repository* and read data directly from it. Of course there is a cashing mechanism, but it is only on single resource level. Therefore when you are launching synchronization on repository that have about 300 folders, current implementation will create and configure 300 connections* to repository to read data and then will cache it.

So, my idea was to create only one connection*, read all data at once and put them into global cache. This cache will be used whenever any list of members for given folder will be required. This approach gives about 2.5x performance boost to synchronization (from 1m 40s down to 40s). This result looks much better and maybe on HDD this action will take less then 2 minutes … but this isn’t over 😉

Reading members of folder is one thing, but getting information about particular file (it is changed, added or removed and does this change is incoming, outgoing or conflicting) is another. Currently we are reusing default implementation of SyncInfo class from Team Framework. This is really good implementation … when you cannot obtain such information from version control system. In Git  we have SHA-1 for each file and folder version and we didn’t have to compare file contents to check they are similar or not, comparing SHA-1 is sufficient. This should save lots of CPU time, disk IO’s and developer time waiting for synchronization to finish ;).

Now when I already have cache that contains list of all changed resources it was natural thing to add information about change type to it. Then whenever Team Framework need to know change type it can be easily obtained from this cache … no IO’s are needed, no comparison just read from in-memory-cache and return proper value.

I’m sure that you are wondering how fast synchronization can be now … I can only that it is REALLY fast … as you can remember my stating point was 1m 40s, now same comparison will finish in less than 7s!! This means that now synchronization will be 14 times faster then before! What this means for a regular user? Well, it meas that you will get results of ‘Synchronize Workspace‘ action almost instantly.

Unfortunately, mentioned above changes are sill awaiting for review in gerrit, you can grab them from change #3891 and build it locally. I hope this will be included in 1.1 release …

* jgit uses concept of walks (with filters) through repository, but I’ve used more commonly recognized terminology here