1 files changed, 51 insertions, 0 deletions
diff --git a/multiload/src/autoscaler.c b/multiload/src/autoscaler.c
new file mode 100644
index 00000000..735b2713
--- /dev/null
+++ b/multiload/src/autoscaler.c
@@ -0,0 +1,51 @@
+#include <time.h>
+#include <glib.h>
+
+#include "autoscaler.h"
+
+/* i wish i could have used C99 initializers instead of writing this function */
+void autoscaler_init(AutoScaler *that, unsigned interval, unsigned floor)
+{
+    that->update_interval = interval;
+    that->floor = floor;
+    that->max = 0;
+    that->count = 0;
+    that->last_update = 0;
+    that->sum =  0.0f;
+    that->last_average = 0.0f;
+}
+
+
+unsigned autoscaler_get_max(AutoScaler *that, unsigned current)
+{
+    time_t now;
+
+    that->sum += current;
+    that->count++;
+    time(&now);
+
+    if((float)difftime(now, that->last_update) > that->update_interval)
+    {
+        float new_average = that->sum / that->count;
+        float average;
+
+        if(new_average < that->last_average)
+            average = ((that->last_average * 0.5f) + new_average) / 1.5f;
+        else
+            average = new_average;
+
+        that->max = average * 1.2f;
+
+        that->sum = 0.0f;
+        that->count = 0;
+        that->last_update = now;
+        that->last_average = average;
+    }
+
+    that->max = MAX(that->max, current);
+    that->max = MAX(that->max, that->floor);
+#if 0
+    printf("%p max = %u, current = %u, last_average = %f\n", that, that->max, current, that->last_average);
+#endif
+    return that->max;
+}