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Swift warm up NSUUID
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Johnlin
September 04, 2018
Programming
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Swift warm up NSUUID
Johnlin
September 04, 2018
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Transcript
Swift ఔࣜখ NSUUID John Lin
ॄኄੋ UUID • ௨༻།Ұࣝผᛰ(Universally Unique Identifier) • 550e8400-e29b-41d4-a716-446655440000 • 32
ݸ16 ਐҐᏐ= 16byte = 128 bitɼ༗ 3.4 * 10 ^ 38 छ߹
UUID ֨ࣜ • xxxxxxxx-xxxx-Mxxx-Nxxx-xxxxxxxxxxxx • ࣈᏐత֨ࣜੋ 8-4-4-4-12 • ଖதၷݸํੋ༻ိදࣔ൛ຊతɻ
UUID ൛ຊ • લ༗ޒݸ൛ຊɼၷछᏓᱪɻ • ࠷ৗ༻తੋ 1 4
UUID1 • timestamp (60 bit) + clock_seq(14bit) + version(6bit) +
MAC address(48bit) = 128bit • ࣌ؒੋኺ 1582/10/15T00:00 ։࢝ࢉʢެ㑕։࢝)ɼ 㑌100 ns ࢉҰݸᄸҐ
UUID 䉰 • timestamp (60 bit) + clock_seq(14bit) + version(6bit)
+ MAC address(48bit) = 128bit • ࡏಉҰػث্ɼ100 ಸඵ㚎ᬋػతൣᅴ༗ 14 bit ༗త࣌ީ။㗞ੜҰᒬతUUIDɼҝ䉰
ੜዬ • Ұݸ൝্༗ࡾेݸਓɼ༗ࢸগၷݸਓಉҰఱੜతػ ੋଟগ䏆ʁ • (1/365)^30 ?
ੜዬ • Ұݸ൝্༗ࡾेݸਓɼ༗ࢸগၷݸਓಉҰఱੜతػ ੋଟগ䏆ʁ • ਖ਼֬తࢉ๏ੋ༻ 1 ݮᎃશᔒ༗ॏෳతػɻब ੋ •
ࡏ 30 ݸਓతگԼେੋ 70 %
UUID1 䉰 • timestamp (60 bit) + clock_seq(14bit) + version(6bit)
+ MAC address(48bit) = 128bit • ࡏಉҰػث্ɼ100 ಸඵ㚎ᬋػతൣᅴ༗ 14 bit ༗త࣌ީ။㗞ੜҰᒬతUUIDɼҝ䉰 • ༻ੜዬɼ100 ಸඵ㚎㗞ੜ 18 ݸ UUID ब༗ 1 % తػ။䉰ɼෆଠద߹շ༻
UUID4 • Swift 㚎ݐత NSUUID & UUID ༗ UUID4 •
random (122 bit) + version (6bit) = 128 bit • 䉰తػখଟ • 㗞ੜ 103 ஹݸ UUID4 ။༗ 10ԯ೭Ұతػ။䉰
NSUUID
UUID • ޭೳ NSUUID Ұᒬɼෆաੋ Struct ൛తɻ • ݐٞ༻Ṝݸൺֱ҆શɻ
݁ • UUID 4 䉰తػᕝత • ༗धཁᘐಛ ID త࣌ީब༻㠧ɼൺࣗݾrandom ؆
ᄸɻ
Q&A
፮ᐔػ • http://slot.miario.com/machines/150067