Dive into .git 日本語版

社内勉強会で使った資料の日本語版です

Transcript

1. %JWF
   JOUP
   HJU 
   ੢ඌହ࿨
2. BCPVU w ͜ͷεϥΠυ͸ࣾ಺ษڧձͰ෼ؒͰ HJUͷத਎ΛݟͯΈΔσϞΛ͢ΔͨΊʹ Ξϯνϣίͱͯ͠࡞ΒΕͨ΋ͷͰ͢ɻ w ϖʔδεϥΠυͰҹ࡮͢ΔͱຕͰ ऩ·ΔͷͰͪΐ͏Ͳ͍͍͔ͱࢥ͍·͢ɻ
3. (JUΑ͘Θ͔ΒΜʁ w ʮ(JUͷ͍ΖΜͳ֓೦͕೉͍͠ʯʁ w ͡Ό͋֓೦͸ஔ͍ͱ͍ͯɺ ʮ෺ཧతʹ͸Ͳ͏ͳͬͯΜͷʁʯ Λ֬ೝͯ͠ΈΑ͏ʂ w (JU͕ͲΜͳ΋ͷ͔Πϝʔδ͠΍͘͢ͳΕ͹޾͍
4. $ mkdir test $ cd test $ ls -a . .. $ git init Initialized empty Git repository in .../test/.git/ 
   HJU
   JOJU
   UFTU
   Ͱ΋0, छ΋࢓ֻ͚΋ͳ͍ͨͩͷ ۭͷσΟϨΫτϦΛ࡞Δ ࣮ݧ༻ͷϦϙδτϦΛ࡞Δ ˡͰ͖ͨʂ
5. $ ls -a . .. .git ϦϙδτϦ͕Ͱ͖ͨʂ
6. த਎ΛݟͯΈΑ͏ $ cd .git $ tree . |-- HEAD |-- config |-- description |-- hooks |-- info | `-- exclude |-- objects | |-- info | `-- pack `-- refs |-- heads `-- tags IPPLTͷத਎͸লུͨ͠
7. $ cd .. $ touch README $ git add README $ git commit -m “initial commit” [master (root-commit) 4dd66d3] initial commit ίϛοτͨ͠Β Կ͕มΘΔʁ
8. PCKFDUT͕૿͑ͨ $ tree .git/objects .git/objects |-- 4d | `-- d66d3a32a66f3578317717ccfb18 |-- 54 | `-- 3b9bebdc6bd5c4b22136034a95dd |-- e6 | `-- 9de29bb2d1d6434b8b29ae775ad8 |-- info `-- pack ௕͍ϑΝΠϧ໊ͷ຤ඌ͸লུͨ͠ ଞʹ΋มΘΔ෦෼͕͋Δ͕ࠓճ͸ׂѪ
9. $ cat > show.py #!/usr/bin/env python import sys import zlib data = file(sys.argv[1], "rb").read() data = zlib.decompress(data) print repr(data) தΛݟͯΈΑ͏ʂ දࣔεΫϦϓτΛ࡞Δ ҎԼͰ͸TIPXQZɻDINPE
   YΛ๨Εͣʹ
10. $PNNJUͷத਎ $ ./show.py .git/objects/4d/d6... 'commit 201\x00 tree 543b...\n author NISHIO Hirokazu <...> 1337655529 +0900\n committer NISHIO Hirokazu <...> 1337655529 +0900\n \n initial commit\n' ద౰ʹվߦΛೖΕͨ USFF
    Cʹ஫໨ ϋογϡ஋͸ίϛοτ࣌ͷϝοηʔδʹදࣔ͞Ε͍ͯΔ
11. 5SFFͷத਎ $ ./show.py 54/3b... 'tree 34\x00 100644 README\x00 \xe6\x9d\xe2\x9b...' ద౰ʹվߦΛೖΕͨ FCʹ஫໨
12. #MPCͷத਎ $ ./show.py e6/9d... 'blob 0\x00' ͜Ε͕3&"%.&ͷத਎ ࠓ͸ۭͳͷͰαΠζ͕ aYͷޙʹԿ΋ͳ͍
13. ϑΝΠϧ໊ $ python -c “import hashlib; hashlib.sha1('blob 0\x00').hexdigest()” 'e69de29b...' ࣮͸த਎ͷ4)"ϋογϡʂ
14. ·ͱΊ w ϦϙδτϦ͸HJUͷதʹೖ͍ͬͯΔ w HJUPCKFDUTʹɺTIBϋογϡΛ໊લʹ͠ɺ ஋Λ[MJCͰѹॖͯ͠ɺ͍Ζ͍Ζೖ͍ͬͯΔ w ʮ͍Ζ͍Ζʯͷதʹ͸DPNNJUΦϒδΣΫτɺ USFFΦϒδΣΫτɺCMPCΦϒδΣΫτ w ࠓճ͸UBH΍SFGTͷ࿩͸ׂѪ ࣍ճʁ
15. ΍ͬͯΈΑ͏ w 3&"%.&Λฤूͯ͠Ͳ͏มΘΔ͔؍࡯͠Α͏ w ৽͍͠DPNNJUΦϒδΣΫτʹ͸ ʮQBSFOU
    ϋογϡ஋ʯͷߦ͕͋Δ w ৽͍͠CMPCʹ͸3&"%.&ͷ಺༰͕ೖ͍ͬͯΔ w ৽͍͠ϑΝΠϧΛ௥Ճͯ͠ΈΑ͏ɻ5SFF͸Ͳ͏ มΘΔʁ w ϑΝΠϧʹ௥هͨ͠ΒʁCMPC͸ࠩ෼ʁશମʁ
17. ͓·͚ w HJU
    TIPX
    GPSNBUSBX͕ͥΜͥΜSBX ͡Όͳͯ͘࢖͍΋ͷʹͳΒͳ͍࿩
18. தΛݟͯΈΑ͏ $ git show --format=raw 4dd6 commit 4dd66d3a32a66f3578317717ccfb1876d43034ea tree 543b9bebdc6bd5c4b22136034a95dd097a57d3dd author NISHIO Hirokazu <...> 1337138246 +0900 committer NISHIO Hirokazu <...> 1337138246 +0900 initial commit diff --git a/README b/README new file mode 100644 index 0000000..e69de29 ϝʔϧΞυϨε͸লུͨ͠
19. 5SFFͷத਎ $ git show --format=raw 543b tree 543b README
20. #MPCͷத਎ Կ΋දࣔ͞Εͳ͍ $ git show --format=raw e69d
21. ͓͔͍͠ ͜Εͷத਎͕FE ͩͱ͍͏৘ใ͸Ͳ͜ʁ $ git show --format=raw 543b tree 543b README ͱ͍͏Θ͚ͰදࣔεΫϦϓτΛ࡞ͬͨ
22. 2" w 2
    εΫϦϓτ࡞Βͳͯ͘΋HVO[JQͱ͔Ͱղౚ͢ Ε͹ྑ͍ͷͰ͸ʁ w "
    [MJCͰѹॖ͞Εͯ͸͍Δ͕ɺ[JQϑΝΠϧͱͯ͠ WBMJEͳϑΥʔϚοτʹ͸ͳ͍ͬͯͳ͍ͷͰղౚͰ ͖ͳ͔ͬͨɻ΋͠΋ͬͱखܰͳํ๏͕͋Ε͹ڭ͑ ͯԼ͍͞ɻ