[zxypoo]

This is an old email... there's been many improvements to both JGit, Java/JVM and other areas of interest.

Shawn and I gave a presentation at the Googleplex not so long ago about JGit [1]. In particular, you may be interested in the 'JGit at Google' section.

There are some cases where JGit is faster than CGit, but the benefits of JGit are that it's easy to embed. There are projects like gitblit and other IDEs that use the library. On top of that, you have crazy folks like NGit [2] who cross compile the library using Sharpen so it can be used by the .NET community...

[1] - https://docs.google.com/present/edit?id=0ATM14GNiXaXfZGZkeHp... [2] - https://github.com/slluis/ngit

[gelliott]

That's really interesting - according to this presentation JGit clone is significantly faster than native git clone (2.3x in the example).

I'd love to hear more about any code changes that lead to this result.

[chubot]

Total speculation... but maybe because C git clone always reads from local disk (?). jgit clone appears to read from Bigtable/GFS, and those systems have in-memory caches, or columns can reside totally in memory. Also you could probably make use of parallelism in I/O with cluster of servers, where as with local disk you are probably limited by there being a single disk head that has to move around.

So I doubt it has anything to with Java, but the underlying storage. If I'm wrong I'd also like to hear about it!