src/plugin.[ch]: Implement plugin_dispatch_multivalue().

diff --git a/src/plugin.c b/src/plugin.c
index 6c7aa05..5f1ca55 100644 (file)
--- a/src/plugin.c
+++ b/src/plugin.c
@@ -1,6 +1,6 @@
 /**
  * collectd - src/plugin.c
- * Copyright (C) 2005-2013  Florian octo Forster
+ * Copyright (C) 2005-2014  Florian octo Forster
  *
  * This program is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License as published by the
@@ -2089,6 +2089,65 @@ int plugin_dispatch_values (value_list_t const *vl)
        return (0);
 }
 
+__attribute__((sentinel))
+int plugin_dispatch_multivalue (value_list_t const *template, /* {{{ */
+               _Bool store_percentage, ...)
+{
+       value_list_t *vl;
+       int failed = 0;
+       gauge_t sum = 0.0;
+       va_list ap;
+
+       assert (template->values_len == 1);
+
+       va_start (ap, store_percentage);
+       while (42)
+       {
+               char const *name;
+               gauge_t value;
+
+               name = va_arg (ap, char const *);
+               if (name == NULL)
+                       break;
+
+               value = va_arg (ap, gauge_t);
+               if (!isnan (value))
+                       sum += value;
+       }
+       va_end (ap);
+
+       vl = plugin_value_list_clone (template);
+       /* plugin_value_list_clone makes sure vl->time is set to non-zero. */
+       if (store_percentage)
+               sstrncpy (vl->type, "percent", sizeof (vl->type));
+
+       va_start (ap, store_percentage);
+       while (42)
+       {
+               char const *name;
+               int status;
+
+               /* Set the type instance. */
+               name = va_arg (ap, char const *);
+               if (name == NULL)
+                       break;
+               sstrncpy (vl->type_instance, name, sizeof (vl->type_instance));
+
+               /* Set the value. */
+               vl->values[0].gauge = va_arg (ap, gauge_t);
+               if (store_percentage)
+                       vl->values[0].gauge *= 100.0 / sum;
+
+               status = plugin_write_enqueue (vl);
+               if (status != 0)
+                       failed++;
+       }
+       va_end (ap);
+
+       plugin_value_list_free (vl);
+       return (failed);
+} /* }}} int plugin_dispatch_multivalue */
+
 int plugin_dispatch_notification (const notification_t *notif)
 {
        llentry_t *le;

diff --git a/src/plugin.h b/src/plugin.h
index 8f0c6d8..924c842 100644 (file)
--- a/src/plugin.h
+++ b/src/plugin.h
@@ -2,7 +2,7 @@
 #define PLUGIN_H
 /**
  * collectd - src/plugin.h
- * Copyright (C) 2005-2011  Florian octo Forster
+ * Copyright (C) 2005-2014  Florian octo Forster
  *
  * This program is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License as published by the
@@ -328,6 +328,35 @@ int plugin_unregister_notification (const char *name);
  *              function.
  */
 int plugin_dispatch_values (value_list_t const *vl);
+
+/*
+ * NAME
+ *  plugin_dispatch_multivalue
+ *
+ * SYNOPSIS
+ *  plugin_dispatch_multivalue (vl, 1,
+ *                              "free", 42.0,
+ *                              "used", 58.0,
+ *                              NULL);
+ *
+ * DESCRIPTION
+ *  Takes a list of type instances and values and dispatches that in a batch,
+ *  making sure that all values have the same time stamp. If "store_percentage"
+ *  is set to true, the "type" is set to "percent" and a percentage is
+ *  calculated and dispatched, rather than the absolute values. Values that are
+ *  NaN are dispatched as NaN and will not influence the total.
+ *
+ *  The variadic arguments is a list of type_instance / gauge pairs, that are
+ *  interpreted as type "char const *" and "gauge_t". The last argument must be
+ *  a NULL pointer to signal end-of-list.
+ *
+ * RETURNS
+ *  The number of values it failed to dispatch (zero on success).
+ */
+__attribute__((sentinel))
+int plugin_dispatch_multivalue (value_list_t const *vl,
+               _Bool store_percentage, ...);
+
 int plugin_dispatch_missing (const value_list_t *vl);
 
 int plugin_dispatch_notification (const notification_t *notif);