開発期間数年のサービスの完成間際にcontext対応をぶち込む / introduce context.Context into long term project

kamakura.go #5 @ 鎌倉

Transcript

1. ࣮࿥ʂ։ൃظؒ਺೥ͷ
   αʔϏεͷ׬੒ؒࡍʹ
   DPOUFYUରԠΛͿͪࠐΉ
   LBNBLVSBHP
   
   !BDJEMFNPOɹ@
   

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2. ͜Μʹͪ͸ʙ
   w ໘ന๏ਓΧϠοΫιʔγϟϧήʔϜࣄۀ෦

   ήʔϜٕݚϦʔμʔ

   ֤ϓϩδΣΫτΛԣஅͰαϙʔτ͢ΔνʔϜ
   
   w ීஈ͸ओʹ(Pॻ͍ͨΓ1FSMॻ͍ͨΓ

   ௚ۙ͸$Λॻ͍͍ͯΔ 6OJUZ
   

   &NBDT೿͚ͩͬͨͲ࠷ۙ74$PEF࢖ͬͯΔ
   w ח૔ࡏॅ Ո͔Β͜ͷձ৔·Ͱెา෼
   
   !BDJEMFNPO
   

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3. ࣄͷ࢝·Γ
   w ͋Β͢͡
   w ɹɹɹΑ͍ͭ͠΋ͷΑ͏ʹෛՙࢼݧ͢Δͧ
   w ɹɹɹ"8493BZͰ෼ࢄτϨʔγϯάͩ
   ਺೥͔͚ͯ։ൃͨ͠(PͷαʔόϓϩάϥϜ͕ͦΖͦΖ

   αʔϏεΠϯ͢Δ͜ͱʹΊͰ͍ͨͰ͢Ͷʙ
   

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4. 93BZͰ෼ࢄτϨʔγϯά
   w ૊௕ !GVKJXBSB
   ͷ:"1$5PLZPͷൃදͳͲͰ͓ͳ͡Έ
   IUUQTTQFBLFSEFDLDPNGVKJXBSBZBQDUPLZP
   
   w ΧϠοΫͰ͸ࡢ೥͔Βෛՙࢼݧ΍ຊ൪؀ڥͷௐࠪʹ"8493BZΛ
   ར༻͍ͯ͠Δ
   w ૊௕͕࠷ॳʹೖΕͨࣄྫ͸1FSM͕ͩͬͨɺࠓճ͸(PϓϩμΫτ

   (PͳΒ"84͕4%,Λग़͍ͯ͠ΔͷͰࣗલͰϥΠϒϥϦ࡞ΔΈ͍ͨ
   ͳ͜ͱ͠ͳͯ͘΋େৎ෉͜Ε͸উͬͨͳʜʜ ϑϥάͷཱͭԻ
   
   

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5. 93BZ͸ԿΛ͢Δ͔
   w 8FCαʔϏεʹ͓͚Δ͔͔࣌ؒΔཁૉͷՄࢹԽ
   w جຊతʹ֎෦*0 σʔλϕʔεɺ,74ɺ)551ͳͲʜ
   ͕͔࣌ؒ
   ͔Δॲཧ
   w ηάϝϯτΛ࡞ͬͯ։࢝࣌ؒͱ

   ऴྃ࣌ؒɺΤϥʔͳͲΛه࿥ͯ͠ૹΔ
   w "84͞ΜʹૹΓ͚ͭΔͱ͍͍ײ͡ʹ

   ՄࢹԽͯ͘͠ΕΔˠ͜Μͳײ͡ˠ
   

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6. 93BZ4%,GPS(Pͷ৔߹
   DPOUFYUͷҾ͖ճ͠Ͱ࣮ݱ
   

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7. ͜Μͳײ͡
   w YSBZ$BQUVSFʹDUYͱ࣮ߦ͍ͨ͠ॲཧΛแΜͩؔ਺Λ౉͢ͱɺ
   $BQUVSF͕։࢝࣌ࠁͱऴྃ࣌ࠁΛDUYʹه࿥ͯ͘͠ΕΔ

   93BZ)551ΫϥΠΞϯτͳͲ͸಺෦Ͱ͜ΕΛ΍͍ͬͯΔ
   
   func criticalSection(ctx context.Context) {
   //this is an example of a subsegment
   xray.Capture(ctx, "GameModel.saveGame", func(ctx1 context.Context) error {
   var err error
   section.Lock()
   result := someLockedResource.Go()
   section.Unlock()
   xray.AddMetadata(ctx1, "ResourceResult", result)
   })
   }
   IUUQTEPDTBXTBNB[PODPNKB@KQYSBZMBUFTUEFWHVJEFYSBZTELHPTVCTFHNFOUTIUNM
   

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8. ͳΔ΄Ͳʜ
   w 93BZ4%,GPS(PΛ࢖͏ʹ͸DPOUFYU$POUFYU͕ඞཁ
   w ͜ͷϓϩδΣΫτ͸DPOUFYUᴈ໌ظʹ։ൃ͕ελʔτͨ͠ͷͰɺ%#
   ΞΫηε΍3FEJTૢ࡞ͷ෦෼ʹDPOUFYUΛར༻͍ͯ͠ͳ͍
   w ϦϑΝΫλϦϯάͯ͠DPOUFYUΛҾ͖ճ͍ͯ͘͠ඞཁ͕͋Δͳʜ
   

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9. DPOUFYUҾ͖ճ͠ϦϑΝΫλ
   w 3FEJT
   w SFEJHPΛར༻͍ͯͯ͠ɺࣗલͷ3FEJT$MJFOUͰXSBQ͍ͯͨ͠
   ͷͰͦͷҾ਺ʹDPOUFYU$POUFYUΛ௥Ճ

   SFEJHP͸3FEJT$MVTUFSඇରԠͳͷͰޙʹHPSFEJTʹೖΕସ͑ͨ
   
   w 3FEJTͷ13—
   w 'MVFOU-PHHFS
   w ͜Ε΋ࣗલͰXSBQͯͨ͠ͷͰҾ਺ʹDPOUFYU$POUFYUΛ௥Ճ
   w 'MVFOU-PHHFSͷ13—
   

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10. ͦͷ΄͔
    w )551ϦΫΤετ
    w ֎෦಺෦ؔ܎ͳ͘93BZ4%,ͷ)551$MJFOUʹࠩ͠ସ͑
    w "84ͷ֤छαʔϏε
    w 4244$MPVE4FBSDIͳͲͳͲ͸93BZ4%,ͰXSBQ
    ͯ͠ద༻Ͱ͖ΔΑ͏ʹͳ͍ͬͯΔ
    w ͜ͷลΛϞϩϞϩద༻ͯ͠—
    

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11. ͜͜·Ͱ͸!LPOCPJͷ࢓ࣄ
    ϝϧϖΠʹస৬͍ͯͬͯ͠͠·ͬͨʜ
    
    

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12. Ұ൪෺ྔ͋Γͦ͏ͳ
    %#ΞΫηεͷͱ͜Ζ͕
    ·ͩ࢒͍ͬͯΔ
    

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13. ਓൈ͚ͯϓϩδΣΫτଆ͸େ๩͠
    Θͨ͠ͷग़൪ͩ@
    

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14. %#ΞΫηεͷDPOUFYUରԠ
    w HPSN HJUIVCDPNKJO[IVHPSN
    Λར༻ͯͨ͠
    w ͦ΋ͦ΋HPSN͕DPOUFYUରԠ͍ͯ͠ͳ͍
    w W@EFWϒϥϯνͰDPOUFYUରԠ։ൃͯ͠Δ͚Ͳఀ଺த
    w ʜͱ͸͍͑93BZ࢖͏ͷʹ%#ΞΫηεݟΒΕͳ͍ͷ͸ࠔΔ
    w ͍Ζ͍Ζௐࠪͯ͠Έͨ
    

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15. 93BZ4%,͕༻ҙͯ͠Δ΋ͷ
    w 42-ͷτϨʔεʹ͍ͭͯͷυΩϡϝϯτ͕৴͡ΒΕͳ͍͘Β͍ബ͍
    w ΄Μͱʹ͜Ε͔͠ॻ͍ͯͳ͍
    

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16. 93BZ4%,͕༻ҙͯ͠Δ΋ͷ
    w ॻ͍ͯ͋Δ͜ͱʮ͓·͑ΒͨͿΜsql.OpenͰ%#ϓʔϧ࡞ͬͯΔ
    Αͳ ͦΕΛxray.SQLʹ͢Ε͹͍͍͚ͩͩͥʯ
    w ͳΔ΄Ͳ΍ͬͯΈͨˠίϯύΠϧΤϥʔ
    w γάωνϟΛ֬ೝˠ໭Γ஋TRM%#͡Όͳͯ͘YSBZ%#ͩʜ
    package xray
    func SQL(driver, dsn string) (*DB, error)
    

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17. YSBZ%#ͩ
    w HPSN͸42-$PNNPOͱ͍͏TRM%#ͷίϯςΩετͳ͠ϝιο
    υΛΠϯλϑΣʔεԽ͍ͯ͠Δ
    w YSBZ%#͸શ෦DUY෇͖ͰTRM%#ͷDUYϝιουΛ࣮૷͍ͯ͠Δ
    w ͭ·ΓΠϯλϑΣʔε͕ద߹͠ͳ͍ʜ
    type SQLCommon interface {
    Exec(query string, args ...interface{}) (sql.Result, error)
    Prepare(query string) (*sql.Stmt, error)
    Query(query string, args ...interface{}) (*sql.Rows, error)
    QueryRow(query string, args ...interface{}) *sql.Row
    }
    package xray
    func (db *DB) Exec(ctx context.Context, query string, args ...interface{}) (sql.Result, error)
    func (db *DB) Prepare(ctx context.Context, query string) (*Stmt, error)
    func (db *DB) Query(ctx context.Context, query string, args ...interface{}) (*sql.Rows, error)
    func (db *DB) QueryRow(ctx context.Context, query string, args ...interface{}) *sql.Row
    HPSN
    YSBZ
    

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18. ཧ૝ͱݱ࣮
    w HPSNʹ౉͢TRM%#తͳԿ͔ʹࡉ޻Λͯ͠ɺHPSNΛXSBQͨ͠ϓ
    ϩδΣΫτͷ%#ΞΫηεΦϒδΣΫτ͔ΒͦͷDUYΛ஫ೖ͍ͨ͠
    w ͱʹ͔͍͘Ζ͍Ζ΍ͬͯΈ·͕ͨ͠ɺͰ͖·ͤΜͰͨ͠

    HPSN͕DPOUFYUରԠͯ͠ͳ͍ͷͰҾ͖ճ͕͠HPSNͰ෼அ͞Εͯ
    ͠·ͬͯ౉ͤͳ͍ʜΧελϜύϥϝʔλΛ౉͢ํ๏΋༻ҙ͞Εͯͳ͍

    &YFD2VFSZͷBSHTͷ࠷ॳʹDUY౉ͯ͠ϥούʔ͕෼཭͢Δࠇຐ๏Έ͍ͨͳ΍ͭ΋ࢼ͚ͨ͠Ͳͪΐͬͱແཧ͕͋ͬͨ

    ͋ͱɺTUSVDUͷϝϯόʹDUY࣋ͨͤΔํࣜ͸TRM%#΍HPSN͕දݱ͢Δ΋ͷ͸ίωΫγϣϯϓʔϧͰ͋ͬͯίωΫγϣϯ
    Ͱ͸ͳ͍ʜͱ͍͏͜ͱ͔ΒHPSPVUJOFTBGFʹͳΒͳ͍ͷͰ΍ͬͯ͸͍͚ͳ͍Ϡπ
    

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19. ଥڠͨ͠ํ਑
    w %#ΞΫηε෦෼͕DPOUFYUରԠͯ͠ྫ͑͹EFBEMJOFͱ͔DBODFM
    ͰΫΤϦதஅͰ͖ΔΑ͏ʹ͢Δͷ͸ʜఘΊΔ
    w HPSNΛXSBQͨ͠΋ͷΛ࡞ͬͯDUY͕౉ΔΑ͏ʹͯ͠ɺ93BZͷ
    $BQUVSF͚ͩ͸ͪΌΜͱ͢Δ
    

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20. (PSNͷϥούΛ࡞ͬͯ࢓ࠐΉ
    w ಋೖखॱͱͯ͠͸͜Μͳ͔Μ͡
    HPSN%#ͷϝιουͷ͏ͪ࢖ͬͯΔ΍ͭΛશ෦ಉ͡γάωνϟ
    Ͱఆٛͯ͠ɺ·ͣ͸ίϯύΠϧΛ௨͢ த਎͸HPSNΛݺͿ͚ͩ
    
    ࣍ʹϥούͷୈҰҾ਺ʹશ෦ctx context.ContextΛ௥Ճ͢Δ
    (PSNΛݺͼग़ͯ͠Δ෦෼Ͱຊ౰ʹେྔͷίϯύΠϧΤϥʔ͕Ͱ
    ΔͷͰɺͦΕΛશ෦௚͢
    93BZͷ$BQUVSFΛϥούʔʹ࢓ࠐΉ
    w ͱʹ͔͕͘େมͳ΍ͭͰ͢
    

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21. ࣮ࡍͷ࡞ۀ
    

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22. ࣗಈੜ੒ܥͷରԠ
    w ϦϦʔε௚લͷ͍·DUYೖΕͳ͔ͬͨΒ͍ΘΏΔٕज़తෛ࠴͕υΧʔϯͱͳ
    ΔΑͶʜΈ͍ͨͳ͜ͱΛ13ίϝϯτʹॻ͍͍ͯͨ
    w ࣗಈੜ੒ܥ͸େͨۤ͠࿑ͯ͠ͳ͍͚ͲɺEJGG͸ —
    

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23. ࢒Γͷ࡞ۀ
    w ͱʹ͔͘%#ݺͼग़͕͠େྔʹ͋ΔͷͰςΩετஔ׵ͳͲ΋ۦ࢖ͭͭ͠
    ͣͬͱϦϑΝΫλϦϯάͯ͠ςετΛճ͍ͯͨ͠
    w ౰࣌ͷϝϞʹΑΔͱɺ$SFBUF%FMFUF&YFD'JOE'JSTU
    3BX4BWFͷछͷϝιου͕߹ܭՕॴͰݺ͹Ε͍ͯΔ
    w Օॴશ෦खͰ௚ͯ͠ɺ͞Βʹݺͼग़͠ݩ͕DUY࣋ͬͯͳ͔ͬͨ
    Βͦ͜·ͰDUYΛҾ͖ճͨ͢Ίʹݺͼग़͠ݩΛ૎ͬͯDUY͕ग़ͯ͘Δ·
    ͰୈҰҾ਺ʹDUY௥Ճ͢Δ࡞ۀ
    w ͞Βʹɺςετ΋શ෦context.Background()ͯ͠౉͢࡞ۀ͕ඞཁ
    

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24. ్தܦաͷ༷ࢠ
    w ҙ֎ͱͭΒ͘ͳͦ͞͏ʹݟ͑Δͷ͸ɺࣗ෼͕ϦϑΝΫλϦϯάେ޷͖
    ਓ͔ؒͩΒ ๨೥ձ͔Βؼ͖ͬͯͯਲͬ෷͍ͳ͕ΒϦϑΝΫλϦϯά͢Δఔ౓ʹ͸େ޷͖
    
    

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25. िؒ൒͔͔ͬͯແࣄ׬ྃ
    w HPSNΛXSBQ͢Δ࡞ۀͷຊਞϒϥϯν͸ —
    w ͜ΕͰҰ൪͕͔͔࣌ؒΔͱ͜Ζ͸͓ΘͬͨͷͰɺ93BZͷ$BQUVSF
    Λ࢓ࠐΜͰ͍͘
    

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26. ϥούʔʹ$BQUVSFΛ௥Ճ
    w 93BZͷ$BQUVSFΛͦΕͧΕͷϝιουͰ΍Δ
    w ͜ͷํࣜͰ͸HPSN͕࣮ࡍʹ࣮ߦ͢Δ42-ΛऔΓग़ͤͳ͍ͨΊɺ୅ΘΓ
    ʹݺͼग़͠ͷҾ਺ͱίʔϧελοΫΛه࿥
    // Exec ͩΑ
    func (g *GormDB) Exec(ctx context.Context, sql string, values ...interface{}) *GormDB {
    if seg := xray.GetSegment(ctx); seg == nil {
    return g.wrap(g.db.Exec(sql, values...))
    }
    var res *GormDB
    tmp := []interface{}{sql}
    tmp = append(tmp, values...)
    caller := traceCaller("Exec", tmp...)
    xray.Capture(ctx, g.name, func(ctx context.Context) error {
    g.recordSQL(ctx, caller)
    res = g.wrap(g.db.Exec(sql, values...))
    return res.Error
    })
    return res
    }
    93BZະ࢖༻࣌
    93BZ࢖༻࣌
    

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27. த਎
    w ίʔϧελοΫͱ42-ͷBSHTΛه࿥
    w ه࿥෦෼͸93BZ4%,ͷxray.DB.populate()Λࢀߟʹ
    func traceCaller(name string, args ...interface{}) string {
    pc, _, line, _ := runtime.Caller(2)
    f := runtime.FuncForPC(pc)
    return fmt.Sprintf("from %s(Line %d): %s(%s) ", f.Name(), line, name, argsString(args...))
    }
    func (g *GormDB) recordSQL(ctx context.Context, info string) {
    seg := xray.GetSegment(ctx)
    typ := "master"
    if g.slave {
    typ = "slave"
    }
    seg.Lock()
    seg.Namespace = "remote"
    seg.GetSQL().ConnectionString = g.name
    seg.GetSQL().DatabaseType = typ
    seg.GetSQL().SanitizedQuery = info
    seg.Unlock()
    }
    

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28. ແࣄ93BZରԠ׬ྃ
    w 93BZ4%,GPS(PͷYSBZ42-Λ࢖ͬͨͱ͖ͷΑ͏ʹ͸ߦ͔ͳ
    ͔͕ͬͨɺ࠷௿ݶ͔͔ͬͨ࣌ؒͱݺͼग़͍ͯ͠Δ৔ॴ಺༰͸Έ͑Δ
    Α͏ʹͳͬͨɻ͜ͷ13—
    w ࠓ΋ແࣄຊ൪؀ڥͰ93BZͷτϨʔε͕ಈ͍͍ͯ·͢
    

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29. DPOUFYUʹ͍ͭͯ
    ͦͷଞͷ࿩୊
    

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30. ΫϥΠΞϯτ੾அʹΑΔDBODFM
    w ΫϥΠΞϯτཁҼͳͷͰཧ༝͸Θ͔Βͳ͍͚ͲɺεϚϗΞϓϦͰ͸ͨ
    ·ʹඵͱ͔ͰϦΫΤετΛΩϟϯηϧ͢ΔΫϥΠΞϯτ͕͍Δ
    w %#ίϛοτޙͷϩάॻ͍ͯΔͱ͖ʹΫϥΠΞϯτཁҼͷDPOUFYU
    DBODFM͕ൃੜ͢Δ͜ͱ͕͋ͬͯɺࠔΔ
    w IUUQ4FSWFS͔ΒΩϟϯηϧ͞Εͳ͍΄͏͕͏Ε͍͠
    

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31. ΫϥΠΞϯτ੾அʹΑΔDBODFM
    w ͦ΋ͦ΋ႈ౳ͳ࡞Γͷ"1*ʹͳ͍ͬͯΕ͹ɺαʔόʹϦΫΤετ͕དྷ
    ͨΒΫϥΠΞϯτʹؔ܎ͳ͘૸Γ͖ͬͨ΄͏͕Α͍
    w SFRSFR8JUI$POUFYU OFX$UY
    Ͱࠩ͠ସ͑Ͱ͖Δ
    w ϦΫΤετࣗମͷλΠϜΞ΢τ͸ඞཁͳͷͰɺSFRͷDUYΛܧঝͤͣ
    ʹDPOUFYU#BDLHSPVOE
    Ͱ৽͍͠ίϯςΩετΛ࡞ͬͯλΠϜ
    Ξ΢τΛઃఆ͢Δ
    w 4FSWFSΛ(SBDFGVMʹTIVUEPXO͢Δͷ͸ϦΫΤετλΠϜΞ
    ΢τ෼͘Β͍଴ͯ͹৽͍͠ϦΫΤετड͚෇͚ͳ͍ͷͰେৎ෉
    

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32. ·ͱΊ
    

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33. ·ͱΊײ૝
    w ઌԆ͹͍ͯ͠͠Δͱޙ͔ΒϦϑΝΫλϦϯά͢Δίετ͕͍͢͝ࣄʹ
    ͳΔͷͰͬ͞͞ͱDPOUFYUରԠͨ͠΄͏͕Α͍
    w ࠓ͔Β։ൃΛ࢝ΊΔͳΒɺ࢖͍ͬͯΔ%#03.΍3FEJTΞΫηεͳ
    Ͳͷύοέʔδ͸DPOUFYUରԠ͍ͯ͠Δ΋ͷΛબͿ΂͖

    ٕज़બఆͷ༏ઌ౓ͱ͔ͯ͠ͳΓߴ͍ͱ͜ΖʹҐஔ͚ͮΔ΂͖
    
    w ઃܭํ਑ͱͯ͠ɺ ͨͱ͑ͦΕΛ࣮૷͢Δͱ͖͸࢖ͬͯͳͯ͘΋
    ϩ
    δοΫతʹ֎෦ͷ*0͕͋Δ΋ͷ͸DPOUFYUΛ౉͓ͯ͘͠ͱΑ͍

    ͦ͏ͳΔͱ'MVFOUEͰϩάऔΔՄೳੑ͕͋Δͱ͜Ζ͸શ෦౉ͦ͏ʜͱͳΔ͚Ͳͦ͏͍͏΋Μͩ
    
    

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34. ิ଍ ͕࣌ؒ͋Ε͹
    
    

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35. ิ଍
    w YSBZ42-ͱDPOUFYUඇରԠ03.ͷ૬ੑʹ͍ͭͯɺ13ʹϝϞ͕
    ͋ΔͷͰͦΕΛҾ༻
    

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36. ิ଍ ͖ͭͮ
    
    w HPSN͔Β࣮ߦ͢Δੜͷ42-ΛऔΓग़ͯ͠93BZʹه࿥Ͱ͖ͳ͍ཧ༝
    w ิ଍͢ΔͱɺXSBQ͍ͯ͠ΔͷͰHPSNͷ࣮ମΛݺ͹ͳ͍ͱ8)&3&ͷ৚݅Λ૊Έཱ
    ͯͯ͘Εͳ͍ͷͰɺ࣮ମΛݺͿલʹه࿥Ͱ͖ͳ͍

    ࣮ମΛݺΜͩ͋ͱʹ஌Δํ๏͸ίʔϧόοΫͳΜ͚ͩͲͦΕʹDUY౉͢ํ๏͕ͳ͍ʜ
    

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