Hi, Sorry for this late reply, I was busy for past few days. On Fri, Mar 14, 2014 at 12:34 PM, Jeff King <peff@xxxxxxxx> wrote: > On Wed, Mar 12, 2014 at 04:19:23PM +0800, Yuxuan Shui wrote: > >> I'm Yuxuan Shui, a undergraduate student from China. I'm applying for >> GSoC 2014, and here is my proposal: >> >> I found this idea on the ideas page, and did some research about it. >> The pack bitmap patchset add a new .bitmap file for every pack file >> which contains the reachability information of selected commits. This >> information is used to speed up git fetching and cloning, and produce >> a very convincing results. >> >> The goal of my project is to port the pack bitmap implementation in >> core git to libgit2, so users of libgit2 could benefit from this >> optimization as well. >> >> Please let me know if my proposal makes sense, thanks. > > You'd want to flesh it out a bit more to show how you're thinking about > tackling the problem: > > - What are the areas of libgit2 that you will need to touch? Be > specific. What's the current state of the packing code? What > files and functions will you need to touch? Firstly I will need to implement bitmap creation in libgit2's git_packbuilder_* functions (probably also git_odb_write_pack), so libgit2 could support bitmap creation. Then I will need to change git_revwalk_* functions to make them use bitmap. Since the operations that can benefit from bitmap is, if my understanding is correct, all using the git_revwalk_* functions, having bitmap support in revwalk functions should be enough. Files I need to touch probably are: revwalk.c pack-objects.c If I need to change the API of packbuilder or revwalk functions I will have to change the callers as well: push.c fetch.c and transport/smart_protocol.c I haven't read all the code to put together a list of functions I need to change, but I think the list will be long. > > - What are the challenges you expect to encounter in porting the code? The architecture differences between git and libgit2 will probably be a challenge. > > - Can you give a detailed schedule of the summer's work? What will you > work on in each week? What milestones do you expect to hit, and > when? I don't really have a plan, but I'll try to provide a rough schedule. I'll read the code and try to understand the code, to the point where I can start to add new code. This will probably take a week. For next three or four weeks I should be implementing bitmap creation in packbuilder. Then for the rest of time I will be optimizing revwalk using bitmap. > > -Peff -- Regards Yuxuan Shui -- To unsubscribe from this list: send the line "unsubscribe git" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html