1 files changed, 77 insertions, 0 deletions
diff --git a/lain/widgets/cpu.lua b/lain/widgets/cpu.lua
new file mode 100644
index 0000000..7c1ecb0
--- /dev/null
+++ b/lain/widgets/cpu.lua
@@ -0,0 +1,77 @@
+
+--[[
+                                                  
+     Licensed under GNU General Public License v2 
+      * (c) 2013,      Luke Bonham                
+      * (c) 2010-2012, Peter Hofmann              
+                                                  
+--]]
+
+local first_line   = require("lain.helpers").first_line
+local newtimer     = require("lain.helpers").newtimer
+
+local wibox        = require("wibox")
+
+local math         = { ceil   = math.ceil }
+local string       = { format = string.format,
+                       gmatch = string.gmatch }
+local tostring     = tostring
+
+local setmetatable = setmetatable
+
+-- CPU usage
+-- lain.widgets.cpu
+local cpu = {
+    last_total = 0,
+    last_active = 0
+}
+
+local function worker(args)
+    local args     = args or {}
+    local timeout  = args.timeout or 5
+    local settings = args.settings or function() end
+
+    cpu.widget = wibox.widget.textbox('')
+
+    function 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.
+        local times = first_line("/proc/stat")
+        local at = 1
+        local idle = 0
+        local total = 0
+        for field in string.gmatch(times, "[%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
+
+        -- Read current data and calculate relative values.
+        local dactive = active - cpu.last_active
+        local dtotal = total - cpu.last_total
+
+        cpu_now = {}
+        cpu_now.usage = tostring(math.ceil((dactive / dtotal) * 100))
+
+        widget = cpu.widget
+        settings()
+
+        -- Save current data for the next run.
+        cpu.last_active = active
+        cpu.last_total = total
+    end
+
+    newtimer("cpu", timeout, update)
+
+    return cpu.widget
+end
+
+return setmetatable(cpu, { __call = function(_, ...) return worker(...) end })