{"thread":{"id":"175","subject":"distributed merge prototype","startedAt":"2005-04-20T17:50:42Z","lastAt":"2005-04-20T17:50:42Z","messageCount":1,"participants":["Matt Mackall"],"isPatch":false,"patchVersion":null,"patchTotal":null},"messages":[{"id":"1014","messageId":"20050420175042.GH21897@waste.org","threadId":"175","inReplyTo":null,"subject":"distributed merge prototype","fromName":"Matt Mackall","fromEmail":"mpm@selenic.com","sentAt":"2005-04-20T17:50:42Z","receivedAt":"2005-04-20T17:50:42Z","isPatch":false,"sender":{"key":"mpm@selenic.com","avatar":null},"body":"I've hacked together a prototype SCM that I think you folks might be\ninterested in. The announcement is here:\n\n http://selenic.com/mercurial/announce.txt\n\nIt's at a very early stage right now and is likely to break if you\nlook at it wrong, but I have sucessfully managed to check in kernel\ntrees, do a local clone/branch, make changes in both trees, and then\ndo a pull/sync which called up tkdiff where appropriate.\n\nI mention it here because I've got a fairly simple implementation of\ndistributed merge ala Monotone or BK with the necessary graph smarts.\nIt also should perform decently - I've paid a lot of attention to the\nscalability of the core algorithms. The core of the merge code is less\nthan 100 lines so even people who aren't familiar with Python may be\nable to wrap their head around it and leverage it for git.\n\nI'd also like to encourage more attention to back-end storage.\nMercurial can check in all 495 versions of linux/Makefile from bkcvs\nto compressed delta store in about 5 seconds on my laptop and the\nresult is about 80K (bkcvs takes 254K). Adding and retrieving\nrevisions is O(1).\n\nThe same directory individually compressed by gzip (ie what git does)\ntakes a comparable amount of time and 5.1M of disk space. This is\nadmittedly a worst case for git as most of the deltas are small, but I\nneeded a test file with lots of revisions.\n\nNow back to our regularly scheduled programming..\n\n-- \nMathematics is the supreme nostalgia of our time.\n"}]}