モジュールの深さについて / depth of module

Transcript

1. Ϟδϡʔϧͷਂ͞ʹ͍ͭͯ CAEC MeetUP #4

2. Me • தඌ ྋ (@nakabonne) • தԝେֶ঎ֶ෦3೥ • AWAϚΠΫϩαʔϏε •

   Go, Envoy, etc…

3. My tasks https://www.redhat.com/cms/managed-files/service-mesh-1680.png

4. My tasks https://github.com/DataDog/dd-py-tracing-workshop

5. Agenda • ྑ͍Ϟδϡʔϧͱ͸ • deep moduleͱ͸

6. ྑ͍Ϟδϡʔϧͱ͸

7. খ͍͞Ϟδϡʔϧʁ

8. –The Unix Philosophy “Small is beautiful”

9. ԿނϞδϡʔϧΛ࡞Δͷ͔

10. ؔ࿈ੑͷߴ͍ཁૉ͕ू·Δ →࣮૷ͷෳࡶ͞ΛԼ͛Δ

11. Open a file in Java FileInputStream fileStream = new FileInputStream(fileName);

    BufferedInputStream bufferedStream = new BufferedInputStream(fileStream); ObjectInputStream objectStream = new ObjectInputStream(bufferedStream);

12. Open a file in Java FileInputStream fileStream = new FileInputStream(fileName);

    BufferedInputStream bufferedStream = new BufferedInputStream(fileStream); ObjectInputStream objectStream = new ObjectInputStream(bufferedStream); ॳาతͳI/O

13. Open a file in Java FileInputStream fileStream = new FileInputStream(fileName);

    BufferedInputStream bufferedStream = new BufferedInputStream(fileStream); ObjectInputStream objectStream = new ObjectInputStream(bufferedStream); όοϑΝϦϯά

14. Open a file in Java FileInputStream fileStream = new FileInputStream(fileName);

    BufferedInputStream bufferedStream = new BufferedInputStream(fileStream); ObjectInputStream objectStream = new ObjectInputStream(bufferedStream); read/write

15. ࣮૷ͷෳࡶ͕͞࿙ΕͯΔ…

16. • খ͍͞ͱ͍͏͜ͱ͸ɺ࣋ͬͯΔ৘ใྔ͕গͳ͍ • ࣋ͬͯΔ৘ใྔ͕গͳ͍ͱɺ࣮૷ͷෳࡶ͕͞࿙ Ε΍͍͢ • ࣮૷ͷෳࡶ͕͞࿙Ε͍ͯΔͱɺ࣮૷มߋ͕पΓ ʹӨڹΛ༩͑΍͘͢ͳΔ

17. খ͞͞Λҙࣝ͗͢͠Δ

18. খ͞͞Λҙࣝ͗͢͠Δ

19. ߴڽूʁૄ݁߹ʁ

20. ߴڽूʁૄ݁߹ʁ

21. ߴڽूʁૄ݁߹ʁ ྑ͍ΠϯλʔϑΣʔε͕ඞཁ

22. ྑ͍ΠϯλʔϑΣʔεͱ͸

23. Bad interface

24. Bad interface

25. Bad interface

26. ͔͠͠ιϑτ΢ΣΞ͸มߋ͞ΕΔ →͜ͷໃ६ͷதͰ΋่Εͳ͍͜ͱ͕ٻΊΒΕΔ

27. Good interface ෆมʢ௥ՃҎ֎ͷมߋΛڐ͞ͳ͍ʣ

28. And

29. ࢖͍΍͋͘͢Δ΂͖

30. –Rich Hickey “Easy is relative”

31. Կ͕ศར͔͸ϢʔβʔʹΑΔ

32. Use case Edge case General case

33. Use case Edge case General case

34. Ұൠతͳέʔεʹߜͬͯ ࢖͍΍͢͞Λ௥ٻ͢Δ

35. ෳࡶԽͷཧ༝ FileInputStream fileStream = new FileInputStream(fileName); BufferedInputStream bufferedStream = new

    BufferedInputStream(fileStream); ObjectInputStream objectStream = new ObjectInputStream(bufferedStream); όοϑΝϦϯά͠ͳ͍ͱ͍͏ ΤοδέʔεΛڐ༰͍ͯ͠Δ

36. Good module ؔ࿈ੑͷߴ͍ͨ͘͞ΜͷཁૉΛӅ࣋ͪ͠ɺ ҰൠతͳέʔεͰ࢖͍΍͘͢ෆมͳΠϯλʔ ϑΣʔεʹΑͬͯڧྗͳػೳΛఏڙ͢Δ

37. ߟ͑Δ͜ͱଟ͗͢ʂ

38. ຊ୊

39. deep module

40. A Philosophy of Software Design • ஶऀ͸ελϯϑΥʔυେֶ John Ousterhoutڭत •

    ઐ໳͸෼ࢄγεςϜ΍OS ͳͲଟذʹ౉Δ

41. deep module γϯϓϧͳΠϯλʔϑΣʔεͰ ڧྗͳػೳΛఏڙ͢Δ

42. deep vs shallow modules

43. deep vs shallow modules

44. ΠϯλʔϑΣʔεͷෳࡶ͞͸ίετͰ ػೳͷڧྗ͞͸རӹ

45. ࢹ఺ • ػೳ͸ڧྗ͚ͩͲɺͦΕҎ্ʹΠϯλʔ ϑΣʔε͕ෳࡶʹͳͬͯͳ͍͔ʁ • ΠϯλʔϑΣʔε͸؆୯͚ͩͲɺػೳ ͸ශऑͰ͸ͳ͍͔ʁ

46. ྫɿUnix ϑΝΠϧI/O • open() • read() • write() • close()

    • lseek() ←ෆม

47. Χʔωϧ ϢʔβΞϓϦέʔγϣϯΛ҆ఆͯ͠ ಈ࡞ͤ͞ΔͨΊʹઃܭ͞Ε͍ͯΔ →ࢀߟʹͳΔ

48. ·ͱΊ

49. ·ͱΊ • ྑ͍Ϟδϡʔϧͱ͸ʮؔ࿈ੑͷߴ͍ͨ͘͞ΜͷཁૉΛӅ࣋ͪ͠ɺҰൠత ͳέʔεͰ࢖͍΍͘͢ෆมͳΠϯλʔϑΣʔεʹΑͬͯڧྗͳػೳΛఏ ڙ͢Δ΋ͷʯ • ࣮ݱ͢ΔͨΊʹʮϞδϡʔϧͷਂ͞ʯΛҙࣝ͢Δ • ͋͘·ͰҰͭͷߟ͑ํͰ͋ΔͨΊɺ൓࿦΢ΣϧΧϜ

50. ͋Γ͕ͱ͏͍͟͝·ͨ͠