1 files changed, 70 insertions, 0 deletions
diff --git a/multiload/src/netspeed.c b/multiload/src/netspeed.c
new file mode 100644
index 00000000..3e889c8f
--- /dev/null
+++ b/multiload/src/netspeed.c
@@ -0,0 +1,70 @@
+#include <config.h>
+#include <glib.h>
+#include <time.h>
+
+#include "netspeed.h"
+
+enum { N_STATES = 4 };
+
+struct _NetSpeed
+{
+    LoadGraph *graph;
+    gulong states[N_STATES];
+    size_t cur;
+};
+
+NetSpeed* netspeed_new(LoadGraph *g)
+{
+    NetSpeed *ns = g_new0(NetSpeed, 1);
+    ns->graph = g;
+    return ns;
+}
+
+void netspeed_delete(NetSpeed *ns)
+{
+    g_free(ns);
+}
+
+void netspeed_add(NetSpeed *ns, gulong tx)
+{
+    ns->cur = (ns->cur + 1) % N_STATES;
+    ns->states[ns->cur] = tx;
+}
+
+/* Something very similar to g_format_size() but for rates.
+ * This should give the same display as in g-s-m */
+static char*
+format_rate_for_display(guint rate)
+{
+    char *bytes;
+    char *text;
+
+    bytes = g_format_size (rate);
+    text = g_strdup_printf (_("%s/s"), bytes);
+    g_free (bytes);
+
+    return text;
+}
+
+char* netspeed_get(NetSpeed *ns)
+{
+    gulong older, newer;
+    guint rate;
+
+    newer = ns->states[ns->cur];
+    older = ns->states[(ns->cur + 1) % N_STATES];
+
+    if ((older != 0) && (newer > older))
+        rate = (newer - older) * 1000 / ((N_STATES - 1) * ns->graph->speed);
+    else
+        /* We end up here if we haven't got enough data yet or the
+        network interface has jumped back (or there has never
+        been any activity on any interface). A value of 0 is
+        likely to be accurate, but if it is wrong it will be
+        clearly wrong. In any event, it should fix itself in a
+        few seconds. */
+        rate = 0;
+
+    return format_rate_for_display(rate);
+}
+