cpu: calculation and optimization fixes by Joerg

README

@@ -515,3 +515,4 @@ Vicious contributors:
   - Rémy C.                  <shikamaru mandriva.org>
   - Hiltjo Posthuma          <hiltjo codemadness.org>
   - Hagen Schink             <troja84 googlemail.com>
+  - Jörg Thalheim            <jthalheim gmail.com>

widgets/cpu.lua

@@ -42,33 +42,29 @@ local function worker(format)
     end
 
     -- Ensure tables are initialized correctly
-    while #cpu_total < #cpu_lines do
-        table.insert(cpu_total,  0)
-        table.insert(cpu_active, 0)
-        table.insert(cpu_usage,  0)
+    for i = #cpu_total + 1, #cpu_lines do
+        cpu_total[i]  = 0
+        cpu_usage[i]  = 0
+        cpu_active[i] = 0
     end
 
-    local total_new   = {}
-    local active_new  = {}
-    local diff_total  = {}
-    local diff_active = {}
 
     for i, v in ipairs(cpu_lines) do
         -- Calculate totals
-        total_new[i]  = 0
+        local total_new = 0
         for j = 1, #v do
-            total_new[i] = total_new[i] + v[j]
+            total_new = total_new + v[j]
         end
-        active_new[i] = v[1] + v[2] + v[3]
+        local active_new = total_new - (v[4] + v[5])
 
         -- Calculate percentage
-        diff_total[i]  = total_new[i]  - cpu_total[i]
-        diff_active[i] = active_new[i] - cpu_active[i]
-        cpu_usage[i]   = math.floor(diff_active[i] / diff_total[i] * 100)
+        local diff_total  = total_new - cpu_total[i]
+        local diff_active = active_new - cpu_active[i]
+        cpu_usage[i]      = math.floor((diff_active / diff_total) * 100)
 
         -- Store totals
-        cpu_total[i]   = total_new[i]
-        cpu_active[i]  = active_new[i]
+        cpu_total[i]   = total_new
+        cpu_active[i]  = active_new
     end
 
     return cpu_usage