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31 lines
692 B
31 lines
692 B
local bit32 = require("bit32")
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local uuid = {}
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function uuid.next()
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-- e.g. 3c44c8a9-0613-46a2-ad33-97b6ba2e9d9a
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-- 8-4-4-4-12 (halved sizes because bytes make hex pairs)
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local sets = {4, 2, 2, 2, 6}
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local result = ""
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local pos = 0
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for _,set in ipairs(sets) do
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if result:len() > 0 then
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result = result .. "-"
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end
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for _ = 1,set do
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local byte = math.random(0, 255)
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if pos == 6 then
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byte = bit32.bor(bit32.band(byte, 0x0F), 0x40)
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elseif pos == 8 then
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byte = bit32.bor(bit32.band(byte, 0x3F), 0x80)
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end
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result = result .. string.format("%02x", byte)
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pos = pos + 1
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end
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end
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return result
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end
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return uuid
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