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gotandajs-11-nodejs-recursive-readdir
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Araya
May 10, 2019
Programming
2
490
gotandajs-11-nodejs-recursive-readdir
Gotanda.js #11 in MobileFactory (
https://gotandajs.connpass.com/event/127779/
) での発表資料です。
Araya
May 10, 2019
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Transcript
Node.jsͰͷrecursive readdirΛߟ͑Δ ͋Β @arayaryoma Gotanda.js #11 in Mobile Factory
ࣗݾհ ͋Β / Ѩ෦ ྇ຏ @arayaryoma @arayaryoma https://araya.dev גࣜձࣾϔϚλΠτ /
෭ۀϑϦʔϥϯε JavaScript/TypeScript/Go/Kotlin Angular/React/ReactNative/Next.js/Nest.js
͔͜͜Βࠇํ໘ʹ10͘Β͍า͍ͨͱ͜ΖʹΦϑΟε͕͋ΔձࣾͰಇ͍͍ͯ·͢ ޒాͷ͖ͳ͓ళϗοτεϓʔϯͰ͢
ୡ͍ͨ͜͠ͱ ͜ͷΑ͏ͳσΟϨΫτϦͰ filesΑΓԼʹ͋ΔશͯͷϑΝΠϧͷϦετΛऔಘ͍ͨ͠
·ͣߟ͑Δ͜ͱ fs.readdirʹΦϓγϣϯΛ͢ͱɺ͔͍͍ͯ͠͠ײ͡ʹऔΕΔͷͰͳ͍͔
·ͣߟ͑Δ͜ͱ વͦΜͳநతͳͷͳ͍
ੈͷதʹస͕͍ͬͯΔղܾࡦ • https://github.com/jergason/recursive-readdir • https://stackoverflow.com/questions/5827612/node-js-fs-readdir-recursive-directory-search • https://gist.github.com/kethinov/6658166 ͳͲ… GoogleͰʮnode.js
recursive readdirʯͱݕࡧ͢Δͱɺ ͍͔ͭ͘ղܾࡦϥΠϒϥϦ͕ݟ͔ͭΔ
ੈͷதʹస͕͍ͬͯΔղܾࡦ ͜ΕΒͷ࣮ྫͰɺ͓͓·͔ʹ 1. fs.readdirͰσΟϨΫτϦԼͷϑΝΠϧͷϦετΛऔಘ͢Δ 2. 1ͷ݁ՌΛϧʔϓΠςϨʔλͰճ͠ɺ֤ϑΝΠϧͷύεΛfs.statؔʹ͠ɺ fs.StatsΦϒδΣΫτΛಘΔ 3. fs.StatsΦϒδΣΫτʹisDirectory()ϝιου͕͋Γɺ͜ΕͰରͷϑΝΠϧ͕ σΟϨΫτϦ͔Ͳ͏͔ఆ͢Δ
4. 3ͷ݁ՌɺσΟϨΫτϦͩͬͨ߹ͦͷσΟϨΫτϦʹ͍ͭͯɺ1~3Λߦ͏ 3ͷ݁ՌɺϑΝΠϧͩͬͨ߹ྻfilesʹՃ͢Δ 5. ϧʔϓ͕ऴΘͬͨΒྻfilesΛฦ͢ ͱ͍͏ํ๏͕ͱΒΕ͍ͯΔɻ
ੈͷதʹస͕͍ͬͯΔղܾࡦ ΤϥʔϋϯυϦϯάແࢹͨ͠࠷খݶͷ࣮ྫ ಡΈ͢͞ͷͨΊʹಉظ࣮ߦ͞ΕΔؔΛ༻
ੈͷதʹస͕͍ͬͯΔղܾࡦ ݱࡏͷσΟϨΫτϦԼͷϑΝΠϧҰཡΛऔಘ
ੈͷதʹస͕͍ͬͯΔղܾࡦ fs.statSync()Ͱfs.StatsΦϒδΣΫτΛऔಘ͠ɺ σΟϨΫτϦ͔Ͳ͏͔ఆɻ ϑΝΠϧͩͬͨ߹ϑΝΠϧϦετʹՃɻ
ੈͷதʹస͕͍ͬͯΔղܾࡦ ࢠσΟϨΫτϦͷϦετΛϧʔϓͰճ͠ɺ ֤ࢠσΟϨΫτϦʹରͯؔ͠Λ࠶ؼݺͼग़͢͠Δɻ
ੈͷதʹస͕͍ͬͯΔղܾࡦ ϑΝΠϧͷϦετΛฦ͢
ੈͷதʹస͕͍ͬͯΔղܾࡦ ࣮ߦ݁Ռ
Node.js v10.10Ҏ߱Ͱfs.statΛΘͣʹॻ͚Δ fs.readdir()ʹ{withFileTypes: true}Λ͢ͱɺfilesfs.DirentΦϒδΣΫτͷྻʹͳΔ
Node.js v10.10Ҏ߱Ͱfs.statΛΘͣʹॻ͚Δ fs.DirentΦϒδΣΫτʹisDirectory() isFile()ͳͲͷϝιου͕࣮͞Ε͍ͯΔ ϑΝΠϧ໊.nameͰऔಘͰ͖Δ -> ϑΝΠϧγεςϜίʔϧΛ1σΟϨΫτϦʹ͖ͭ 1Ͱࡁ·͢͜ͱ͕Ͱ͖Δ https://github.com/nodejs/node/pull/22020
fs.Dirent ΦϒδΣΫτΛ࣮ͬͨྫ
fs.Dirent ΦϒδΣΫτΛ࣮ͬͨྫ {withFileTypes: true}Λࢦఆͯ͠ fs.DirentΦϒδΣΫτΛಘΔ dirent.isDirectoryͰ σΟϨΫτϦ͔Ͳ͏͔ఆ 1֊ʹ͖ͭ1ͷϑΝΠϧγεςϜίʔϧ
fs.Dirent ΦϒδΣΫτΛ࣮ͬͨྫ {withFileTypes: true}Λࢦఆͯ͠ fs.DirentΦϒδΣΫτΛಘΔ dirent.isDirectoryͰ σΟϨΫτϦ͔Ͳ͏͔ఆ 1֊ʹ͖ͭ1ͷϑΝΠϧγεςϜίʔϧ
ඇಉظʹ͢Δ fs.readdir()ʹίʔϧόοΫؔΛͯ݁͠ՌΛॲཧ͍͍͕ͯ͠ɺ Node.js v10 ͰɺExperimental͕ͩfs Promises API͕ఏڙ͞Ε͍ͯΔ (v12Ͱstable)
fs Promises API
fs Promises APIΛͬͯॻ͖͢
·ͱΊ •ϥΠϒϥϦΛΘͳͯ͘ɺͦ͜·Ͱଟ͘ͳ͍هड़ྔͰrecursive readdir࣮ݱͰ͖Δɻ •Node.js v10.10Ҏ͕߱͑Δ߹fs.DirentΦϒδΣΫτΛ׆༻ͯ͠ ϑΝΠϧγεςϜίʔϧͷճΛݮΒ͢͜ͱ͕Ͱ͖Δɻ •fs Promises APIΛ༻͍Δ͜ͱͰɺϑΝΠϧγεςϜૢ࡞͕PromiseϕʔεͰॻ͚Δɻ •Node.jsminor
version updateͰศརͳAPI͕Ճ͞ΕΔ͜ͱ͕͋ΔͨΊɺ LTSͷ࠷৽Λ͍ଓ͚Δબࢶ͕औΕΔͱྑ͍ɻ
ิ: direntͱ͍͏֓೦ʹ͍ͭͯ direntLinux Programmingʹ͓͍ͯɺϑΝΠϧͷใΛ࣋ͭߏମɻ readdirؔ͜ͷߏମΛฦ͢ɻ manϖʔδ( http://man7.org/linux/man-pages/man3/readdir.3.html )ΑΓɺglibcͰͷ࣮