So Help Me God, You Will Understand Git's Model, Even If It Kills Me

Transcript

1. Go drink. Presentation starts at 6pm.
2. 1 2 3 4 6 7 8 9 11 15 16 10 12 14 5 13 Trunk Branches Merges Tags Discontinued development branch
3. Everyone Has A Fork • Offline • No server necessary • Frequent branching and merging
5. So Help Me God, You Will Understand Git’s Model Even If It Kills Me
6. SHA1 $ echo 'HELLO TWU' | shasum 7068de75a45caca38a6d772d4b0f371bda003256 -
7. Git Object Model •K: SHA(data) •V: data
8. Objects •Type •Size •Content
9. Blobs Trees Commits Refs Tags
10. Blobs $ git cat-file -p 1377554ebea6f98a2c748183bc5a96852af12ac2 *.swp
11. Trees $ git ls-tree eebc19d60284277eba86620ec828d73d0cdf822a 100644 blob 1377554ebea6f98a2c748183bc5a96852af12ac2 .gitignore 100644 blob ac1bfdc65a699792310498fc0ba003e61eddf1d0 bad.lua 100644 blob b2f5ce962808f4edd04336eb803b6445b843e052 boom.lua 100644 blob 6b1c0b8946e40ff393f73d80a885fdd39fba93dd bullet.lua 100644 blob 268a04ca259b566c7340d8ba8dab8ce0590e8352 main.lua 100644 blob 67638336f18030013b0bcc7533987a6ba892ba46 rail.lua 040000 tree 415ee50b6cf27815df2750de33b0eac1df8ad814 resources 100644 blob c1a79a49a98c0b3868e33270465121cf40dc622e ship.lua 100644 blob d77c7f1d5fecfc6c998e2eec628495075ba27ec1 wave.lua
12. Commit •Tree •Parent(s) •Author and Committer •Message
13. Commit $ git cat-file -p eea6bd6db666365b33496b9fc4c2d55c7af8fdcd tree eebc19d60284277eba86620ec828d73d0cdf822a parent bfe1204bb4d8eaa00b7a20c47e6e421e9be25322 author Sam Gibson <sam@ifdown.net> 1327417487 +0530 committer Sam Gibson <sam@ifdown.net> 1327417487 +0530 Bounds -> Box
14. Tags •Annotated •Lightweight
15. Annotated Tag •Object SHA1 •Type •Tagger •Message
16. Refs (lightweight tags) •Branches (local and remote) •Heads •Tags
17. INCOMING COPYRIGHT VIOLATION
18. In Summary http://book.git-scm.com/1_the_git_object_model.html
19. Let’s Play A Game “What Happens?”
20. What Happens? $ git init Initialized empty Git repository in /.git/
21. Yes, that was a warm up $ find ./.git . ./.git ./.git/config ./.git/description ./.git/HEAD ./.git/hooks ... ./.git/info/exclude ./.git/objects/info ./.git/objects/pack ./.git/refs/heads ./.git/refs/tags
22. What Happens? $ touch xyzzy $ git add xyzzy $ git status # On branch master # # Initial commit # # Changes to be committed: # (use "git rm --cached <file>..." to unstage) # # new file: xyzzy #
23. The Index •Cache •Staging •Whitelist?!
24. You Delete A File And Then Commit It? $ rm xyzzy $ git commit -m 'What happens?'
25. You Can’t Explain That! $ ls $ git status # On branch master # Changes not staged for commit: # (use "git add/rm <file>..." to update what will be committed) # (use "git checkout -- <file>..." to discard changes in working directory) # # deleted: xyzzy # no changes added to commit (use "git add" and/or "git commit -a") $ git checkout -- xyzzy $ ls xyzzy
26. Reflogs $ git reflog add17aa HEAD@{0}: commit: NO a1b7f8d HEAD@{1}: commit (initial): What happens?
27. Practical Examples whereupon mayhap we conversate
28. Fetch Imports remote refs and their associated objects
29. 3-Way Merge • "your" commit • "their" commit • their most recent ancestor
30. Rebase • "your" commit • "their" base commit • their most recent ancestor • Replays each of “your” differences upon “their” base
31. Stash Working Directory Index HEAD
32. fin
33. Git Community Book http://book.git-scm.com