git-inside

.git の中身を見るという内々勉強会用の資料です
(画像などは入っていないので後日差し替え予定)

Transcript

1. ࣮ߦ͠ͳ͕ΒΈΔ .gitͷத਎
2. ໨త • gitͷΦϒδΣΫτ؅ཧͷ࢓૊ΈΛཧղ͢Δ • ίϛοτ͔ΒͭΒͳΔάϥϑߏ଄ • branch/tagͳͲͷϦϑΝϨϯεߏ଄ • ߏ଄ΛΘ্͔ͬͨͰίϚϯυΛݟΔ͜ͱͰཧղ͕ਂ·Δ • Կ͕͓͖͍ͯΔ͔Θ͔Δ͔Βɺݩʹ໭͢ํ๏΋Θ͔Δ
3. git init ΛΈΔ
4. git init௚ޙͷ.git $ git init $ ls -p .git/ HEAD config description hooks/ info/ objects/ refs/ $ find .git/objects .git/objects .git/objects/info .git/objects/pack
5. git add & commitΛΈΔ $ echo 'Hello world!' > hello_world.txt $ git add hello_world.txt $ git commit -m 'First Commit' [master (root-commit) 27baa2b] First Commit 1 file changed, 1 insertion(+) create mode 100644 hello_world.txt
6. .git/objectsͷத $ find .git/objects .git/objects .git/objects/27 .git/objects/27/baa2b9da21b4485966c2a97268876b189331e9 .git/objects/9b .git/objects/9b/e385e79f8f3e0870e48474809dab293843aece .git/objects/cd .git/objects/cd/0875583aabe89ee197ea133980a9085d08e497 .git/objects/info .git/objects/pack 3ͭϑΝΠϧ͕૿Ճ
7. 3ͭϑΝΠϧ͕૿͑ͨ • 1ͭ͸͓ͦΒ͘ςΩετϑΝΠϧ • ࢒Γͷ2ϑΝΠϧʹ͸Կ͕?
8. Ͱ͸ݟ͍͖ͯ·͢
9. # ίϛοτޙͷϝοηʔδ [master (root-commit) 27baa2b] First Commit ~~~~~~~ 1 file changed, 1 insertion(+) create mode 100644 hello_world.txt # .gitҎԼͷϑΝΠϧ .git/objects/27/baa2b9da21b4485966c2a97268876b189331e9 ~~~~~~~~ SHA-1͕Ұக͍ͯ͠Δ
10. 27baa2b(ུ)ͷத਎ΛݟͯΈΔ $ git cat-file -t 27baa2b9da21b4485966c2a97268876b189331e9 commit ͜ͷϑΝΠϧͷλΠϓ͸commit
11. 27baa2b(ུ)ͷத਎ΛݟͯΈΔ தʹ͸͜Μͳ৘ใ͕อଘ͞Ε͍ͯΔ $ git cat-file -p 27baa2b9da21b4485966c2a97268876b189331e9 tree 9be385e79f8f3e0870e48474809dab293843aece author chiastolite <chiastolite.1980@gmail.com> 1494611014 +0900 committer chiastolite <chiastolite.1980@gmail.com> 1494611014 +0900 First Commit
12. 27baa2b(ུ)ͷத਎ΛݟͯΈΔ • author ͱ λΠϜελϯϓ • commiter ͱ λΠϜελϯϓ • ίϛοτϝοηʔδ • tree?
13. # commitΦϒδΣΫτͷத਎ tree 9be385e79f8f3e0870e48474809dab293843aece # .gitҎԼͷϑΝΠϧ .git/objects/9b/e385e79f8f3e0870e48474809dab293843aece ·ͨ΋SHA-1͕Ұக͍ͯ͠Δ
14. 9be385e(ུ)ͷத਎ΛݟͯΈΔ $ git cat-file -t 9be385e79f8f3e0870e48474809dab293843aece tree ͜ͷϑΝΠϧͷλΠϓ͸tree
15. 9be385e(ུ)ͷத਎ΛݟͯΈΔ $ git cat-file -p 9be385e79f8f3e0870e48474809dab293843aece 100644 blob cd0875583aabe89ee197ea133980a9085d08e497 hello_world.txt
16. 9be385e(ུ)ͷத਎ΛݟͯΈΔ • mode • ύʔϛογϣϯͱ͔ͦ͏͍͏ͷ • ϑΝΠϧ໊ • SHA-1 • blob?
17. # treeΦϒδΣΫτͷத਎ 100644 blob cd0875583aabe89ee197ea133980a9085d08e497 hello_world.txt # .gitҎԼͷϑΝΠϧ .git/objects/cd/0875583aabe89ee197ea133980a9085d08e497 ·ͨ΋SHA-1͕Ұக͍ͯ͠Δ
18. cd08755(ུ)ͷத਎ΛݟͯΈΔ $ git cat-file -t cd0875583aabe89ee197ea133980a9085d08e497 blob ͜ͷϑΝΠϧͷλΠϓ͸blob
19. cd08755(ུ)ͷத਎ΛݟͯΈΔ $ git cat-file -p cd0875583aabe89ee197ea133980a9085d08e497 Hello world! Α͏΍͘த਎ʹḷΓ͍ͭͨ
20. ͜͜·Ͱͷ·ͱΊ git ͸ • 3छྨͷλΠϓͷΦϒδΣΫτͰ؅ཧͯ͠Δ • commmit • tree • blob • ֤ΦϒδΣΫτ͸SHA-1Ͱ؅ཧ͞Ε͍ͯͯΦϒδΣΫτಉ࢜Λ ࢀর͍ͯ͠Δ
21. ਤʹ͢Δͱ͜Μͳײ͡
22. ࣍ʹ # ϑΝΠϧΛαϒσΟϨΫτϦʹίϐʔ $ mkdir subdir $ cp hello_world.txt subdir/sample.txt $ git add subdir/sample.txt # ݩϑΝΠϧΛॻ͖׵͑ $ echo 'Hello world!!' > hello_world.txt $ git add -u hello_world.txt $ git commit -m'update'
23. ࠓͷঢ়ଶ !"" hello_world.txt #=> Hello world!! #"" subdir #"" sample.txt #=> Hello world!
24. commitͷத਎ $ git cat-file -p HEAD tree 95aaf923a1c8171c9ec05225a3911a0dbeb53d6f parent 27baa2b9da21b4485966c2a97268876b189331e9 author chiastolite <chiastolite.1980@gmail.com> 1494611946 +0900 committer chiastolite <chiastolite.1980@gmail.com> 1494611946 +0900 update • parent͕௥Ճ͞Ε͍ͯΔ • 1ͭલͷcommitͷSHA-1
25. treeͷத਎ git cat-file -p 95aaf923a1c8171c9ec05225a3911a0dbeb53d6f 100644 blob b297683f36d0557a8ef83506beda7b80e233723d hello_world.txt 040000 tree 601df7ed8aabbd875614ba3a301fe344e5c45ae2 subdir • த਎͕มΘͬͨhello_world.txtͷSHA-1͕มԽ • treeͷதʹtree͕
26. αϒπϦʔͷத਎ git cat-file -p 601df7ed8aabbd875614ba3a301fe344e5c45ae2 100644 blob cd0875583aabe89ee197ea133980a9085d08e497 sample.txt • sample.txt͸࠷ॳͷίϛοτͷhello_world.txtͱಉ͡SHA-1
27. ͜͜·Ͱ • commitΛ͢Δͱݩcommit΁ͷࢀর͕͓͖Δ • 1όΠτϑΝΠϧ͕มΘΕ͹SHA1͕มΘΔ • SHA1͕Ͱ͖Δͱ͍͏͜ͱ͸ΦϒδΣΫτ͕1ͭੜ੒͞Ε͍ͯ Δ • gitͰ͸ࠩ෼Ͱ͸؅ཧ͕͞Ε͍ͯͳ͍ • ϑΝΠϧ໊͕มΘͬͯ΋த਎͕ҰॹͳΒ͹SHA1͸มΘΒͳ͍
28. ਤʹ͢Δͱ͜Μͳײ͡
29. SHA-1ͷ͖·Γ͔ͨ • த਎(+ΦϒδΣΫτͷtype)͔Β Ұҙʹ ܾ·͍ͬͯΔ • ͩΕ͕ͲͷλΠϛϯάͰHello world!ͯ͠΋SHA-1͸ cd0875583aabe89ee197ea133980a9085d08e497 $ git hash-object -t blob <(echo 'Hello world!') cd0875583aabe89ee197ea133980a9085d08e497 ৄ͘͠͸ Git͸sha1ͷܭࢉΛͲͷΑ͏ʹ΍͍ͬͯΔͷ͔ · DQNEO ىۀ೔ه ͕ৄ͍͠
30. refs
31. refs • master • branch • tag • HEAD(=@) • ORIG_HEAD ͳͲͳͲ
32. .git/HEAD ݱࡏࢀর͍ͯ͠Δͱ͜Ζ $ cat .git/HEAD ref: refs/heads/master ࠓ͸masterϒϥϯνΛݟ͍ͯΔΆ͍
33. $ cat .git/refs/heads/master 2e7a843cd5706b128e13f06cf7572cda27afa0a7 $ git log commit 2e7a843cd5706b128e13f06cf7572cda27afa0a7 (HEAD -> master) • Ұக • masterϒϥϯν͕ͲͷίϛοτΛࢦ͍ͯ͠Δ͔ܾΊ͍ͯΔ
34. ͨΊ͠ʹ $ mv .git/refs/heads/{master, hogehoge} $ cat 'ref: refs/heads/hogehoge' > .git/HEAD ͱ΍Δͱ git branch -m hogehoge͕Ͱ͖Δ
35. branch $ git branch test_branch $ cat .git/refs/heads/test_branch 2e7a843cd5706b128e13f06cf7572cda27afa0a7 • ϒϥϯνΛ੾͚ͬͨͩͩͱSHA-1͸͔ΘΒͳ͍ • ͜ͷ࣌఺Ͱ͸masterͱԿ΋ҧ͍͕ͳ͍ • ϒϥϯν͸ͲͪΒ͔ͱ͍͏ͱϙΠϯλʔ΍ϥϕϧతײ֮ • ݴ͏΄ͲࢬΆ͘͸ͳ͍
36. branchΛࢀর͍ͯ͠Δঢ়ଶͰίϛοτΛͯ͠ΈΔ $ git checkout test_branch Switched to branch 'test_branch' $ git rm -r subdir rm 'subdir/sample.txt' $ git commit -m'Remove sub dir'
37. $ cat .git/refs/heads/test_branch 508b59bff7ae9af5b516d873eea32c9446540c09 $ git cat-file -p 686bcfe77bf1c43eb8d4e2aa75075e6d6e7e961e tree 19e6ae1b6538047780cd1d44a10fdb0685f15705 parent 2e7a843cd5706b128e13f06cf7572cda27afa0a7 author chiastolite <chiastolite.1980@gmail.com> 1494613438 +0900 committer chiastolite <chiastolite.1980@gmail.com> 1494613438 +0900 Remove sub dir ίϛοτ͢Δref͕มߋ͞ΕΔ
38. mergeͯ͠ΈΔ $ git checkout test_branch $ git merge test_branch --no-ff Removing subdir/sample.txt Merge made by the 'recursive' strategy. subdir/sample.txt | 1 - 1 file changed, 1 deletion(-) delete mode 100644 subdir/sample.txt
39. $ git cat-file -p master tree 19e6ae1b6538047780cd1d44a10fdb0685f15705 parent 2e7a843cd5706b128e13f06cf7572cda27afa0a7 parent 508b59bff7ae9af5b516d873eea32c9446540c09 author chiastolite <chiastolite.1980@gmail.com> 1494613595 +0900 committer chiastolite <chiastolite.1980@gmail.com> 1494613595 +0900 Merge branch 'test_branch' • parent͕2ͭ • masterͩͬͨͱ͜Ζ • test_branch
40. ਤ
41. rebaseͯ͠ΈΔ (͜ͷ··ͩͱ্ख͍͔͘ͳ͍ͷͰmasterΛmergeલʹ໭ͯ͠ί ϛοτΛ௥Ճ͓ͯ͘͠)
42. $ git rebase master First, rewinding head to replay your work on top of it... Applying: Remove sub dir $ cat .git/refs/heads/test_branch 0957492b728dbf7854f46c30be6670fcf29b61a6 ৽͍͠SHA-1
43. rebaseલͷίϛοτ͸? $ git log 508b59bff7ae9af5b516d873eea32c9446540c09 commit 508b59bff7ae9af5b516d873eea32c9446540c09 Author: chiastolite <chiastolite.1980@gmail.com> Date: Sat May 13 03:23:58 2017 +0900 Remove sub dir ී௨ʹΞΫηεͰ͖Δ rebaseͯ͠΋ίϛοτ͕ফ͑ͨΓ͸͠ͳ͍
44. ਤ
45. ͓͖͍֮͑ͯͨ͜ͱ • gitͰίϛοτ͕ফ͑Δ͜ͱ͸ͳ͍ • (ྫ֎తʹ)git gcίϚϯυͷΈ • ͳͷͰؾܰʹrebase΍mergeͯ͠΍͹͔ͬͨΒ໭ͦ͏
46. ϦϞʔτͷѻ͍ • gitͰϦϞʔτϦϙδτϦͷૢ࡞Λग़དྷΔͷ͸ҎԼͷίϚϯυͷ Έ (set-remote ͸ઃఆ͢Δ͚ͩͳͷͰૢ࡞͸Ͱ͖ͳ͍) • fetch • push • pull͸಺෦Ͱfetch + (merge or rebase) ΛݺΜͰ͍Δ
47. • fetch • ϦϞʔτϦϙδτϦͷঢ়ଶΛϩʔΧϧʹ࣋ͬͯ͘Δ • push • ϩʔΧϧͷ಺༰Λࢦఆͨ͠ϒϥϯνʹૹΔ
48. git remote ײ֮తʹϨΠϠʔߏ଄ͱࣅͯΔؾ͕ͯ͠Δ • ϩʔΧϧͱϦϞʔτͱ͍͏ϨΠϠʔ • fetch͢Δ͜ͱͰϩʔΧϧͷϦϙδτϦϨΠϠʔʹϦϞʔτͷ ಺༰Λ൓ө͢ΔΈ͍ͨͳ • ౷߹͡Όͳ͍ͷ͕ҧ͏ͱ͜Ζ
49. ਤʹ͢Δͱ͜Μͳײ͡?
50. origin/masterͱorigin masterͷҧ͍ • origin master • originʹઃఆͨ͠ϦϞʔτϦϙδτϦͷmasterϒϥϯν • ϦϞʔτͷ࿩ • origin/master • originʹઃఆͨ͠ϦϞʔτϦϙδτϦͷmasterϒϥϯνͷref Λखݩʹίϐʔͨ͠΋ͷ • ϩʔΧϧͷ࿩
51. • origin/master͸࠷ޙʹfetchͨ͠ͱ͖ͷ origin ͷ masterͷঢ়ଶ ͳͷͰϦϞʔτͷ࠷৽ͱ͸ݶΒͳ͍ • ϦϞʔτʹ௥ै͠Α͏ͱ rebase origin/master͢Δ৔߹͸ ࣄ લʹfetchͨ͠΄͏͕Α͍
52. Α͘࢖͏Φϓγϣϯ • add • -u • -p • commit • --ammend • -C • -v
53. Α͘࢖͏Φϓγϣϯ • stash • --keep-index • push • --force-with-lease • rebase • -i • --autosquash(git commit --fixupલఏ)
54. Conditional configuration(>= Git 2.13) $ cat ~/.gitconfig [includeIf "gitdir:~/work/"] path = .gitconfig-work [includeIf "gitdir:~/play/"] path = .gitconfig-play $ cat ~/.gitconfig-work [user] name = Hiroyuki Morita email = hiroyuki.morita@hogehoge.co.jp $ cat ~/.gitconfig-play [user] name = chiastolite email = chiastolite.1980@gmail.com ࢓ࣄͱϓϥΠϕʔτɺ࢓ࣄͱOSSͷઃఆΛ෼͚ΒΕΔ