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util/human/units.lua @ 12386:2d3080d02960
net.websocket.frames: Replace bit fiddling code with util.struct
Fallback code for not having either the string.pack and string.unpack
functions available in Lua 5.4 or the struct lib is no longer needed
since the struct lib was imported as util.struct in 3ce3633527af
author | Kim Alvefur <zash@zash.se> |
---|---|
date | Sun, 06 Mar 2022 15:13:50 +0100 |
parent | 10903:c5f26f9adb31 |
child | 12573:0f4feaf9ca64 |
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local math_abs = math.abs; local math_ceil = math.ceil; local math_floor = math.floor; local math_log = math.log; local math_max = math.max; local math_min = math.min; local unpack = table.unpack or unpack; --luacheck: ignore 113 if math_log(10, 10) ~= 1 then -- Lua 5.1 COMPAT local log10 = math.log10; function math_log(n, base) return log10(n) / log10(base); end end local large = { "k", 1000, "M", 1000000, "G", 1000000000, "T", 1000000000000, "P", 1000000000000000, "E", 1000000000000000000, "Z", 1000000000000000000000, "Y", 1000000000000000000000000, } local small = { "m", 0.001, "μ", 0.000001, "n", 0.000000001, "p", 0.000000000001, "f", 0.000000000000001, "a", 0.000000000000000001, "z", 0.000000000000000000001, "y", 0.000000000000000000000001, } local binary = { "Ki", 2^10, "Mi", 2^20, "Gi", 2^30, "Ti", 2^40, "Pi", 2^50, "Ei", 2^60, "Zi", 2^70, "Yi", 2^80, } local function adjusted_unit(n, b) local round = math_floor; local prefixes = large; local logbase = 1000; if b == 'b' then prefixes = binary; logbase = 1024; elseif n < 1 then prefixes = small; round = math_ceil; end local m = math_max(0, math_min(8, round(math_abs(math_log(math_abs(n), logbase))))); local prefix, multiplier = unpack(prefixes, m * 2-1, m*2); return multiplier or 1, prefix; end -- n: number, the number to format -- unit: string, the base unit -- b: optional enum 'b', thousands base local function format(n, unit, b) --> string local fmt = "%.3g %s%s"; if n == 0 then return fmt:format(n, "", unit); end local multiplier, prefix = adjusted_unit(n, b); return fmt:format(n / multiplier, prefix or "", unit); end return { adjust = adjusted_unit; format = format; };