Initial commit

lib/lain/widget/cpu.lua

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+--[[
+
+     Licensed under GNU General Public License v2
+      * (c) 2013,      Luca CPZ
+      * (c) 2010-2012, Peter Hofmann
+
+--]]
+
+local helpers = require('lain.helpers')
+local wibox = require('wibox')
+local math = math
+local string = string
+
+-- CPU usage
+-- lain.widget.cpu
+
+local function factory(args)
+	args = args or {}
+
+	local cpu = { core = {}, widget = args.widget or wibox.widget.textbox() }
+	local timeout = args.timeout or 2
+	local settings = args.settings or function() end
+
+	function cpu.update()
+		-- Read the amount of time the CPUs have spent performing
+		-- different kinds of work. Read the first line of /proc/stat
+		-- which is the sum of all CPUs.
+		for index, time in pairs(helpers.lines_match('cpu', '/proc/stat')) do
+			local coreid = index - 1
+			local core = cpu.core[coreid] or { last_active = 0, last_total = 0, usage = 0 }
+			local at = 1
+			local idle = 0
+			local total = 0
+
+			for field in string.gmatch(time, '[%s]+([^%s]+)') do
+				-- 4 = idle, 5 = ioWait. Essentially, the CPUs have done
+				-- nothing during these times.
+				if at == 4 or at == 5 then
+					idle = idle + field
+				end
+				total = total + field
+				at = at + 1
+			end
+
+			local active = total - idle
+
+			if core.last_active ~= active or core.last_total ~= total then
+				-- Read current data and calculate relative values.
+				local dactive = active - core.last_active
+				local dtotal = total - core.last_total
+				local usage = math.ceil(math.abs((dactive / dtotal) * 100))
+
+				core.last_active = active
+				core.last_total = total
+				core.usage = usage
+
+				-- Save current data for the next run.
+				cpu.core[coreid] = core
+			end
+		end
+
+		cpu_now = cpu.core
+		cpu_now.usage = cpu_now[0].usage
+		widget = cpu.widget
+
+		settings()
+	end
+
+	helpers.newtimer('cpu', timeout, cpu.update)
+
+	return cpu
+end
+
+return factory