disk plugin: send disk_merged,disk_io_time,pending_operations only when data exists...

[collectd.git] / src / disk.c

diff --git a/src/disk.c b/src/disk.c
index 8f8f370240ba2f99c48dcfdf2d0efe4b77d05521..e3bd76186fab4a3ee6b350a3a83fb10c69e4d4a2 100644 (file)
--- a/src/disk.c
+++ b/src/disk.c
@@ -106,6 +106,10 @@ typedef struct diskstats
        derive_t avg_read_time;
        derive_t avg_write_time;
 
+       _Bool has_merged;
+       _Bool has_in_progress;
+       _Bool has_io_time;
+
        struct diskstats *next;
 } diskstats_t;
 
@@ -681,7 +685,6 @@ static int disk_read (void)
        {
                char *disk_name;
                char *output_name;
-               char *alt_name;
 
                numfields = strsplit (buffer, fields, 32);
 
@@ -819,6 +822,16 @@ static int disk_read (void)
                        ds->read_time = read_time;
                        ds->write_ops = write_ops;
                        ds->write_time = write_time;
+
+                       if (read_merged || write_merged)
+                               ds->has_merged = 1;
+
+                       if (in_progress)
+                               ds->has_in_progress = 1;
+
+                       if (io_time)
+                               ds->has_io_time = 1;
+               
                } /* if (is_disk) */
 
                /* Don't write to the RRDs if we've just started.. */
@@ -841,13 +854,10 @@ static int disk_read (void)
                output_name = disk_name;
 
 #if HAVE_LIBUDEV
-               alt_name = disk_udev_attr_name (handle_udev, disk_name,
-                               conf_udev_name_attr);
-#else
-               alt_name = NULL;
-#endif
+               char *alt_name = disk_udev_attr_name (handle_udev, disk_name, conf_udev_name_attr);
                if (alt_name != NULL)
                        output_name = alt_name;
+#endif
 
                if ((ds->read_bytes != 0) || (ds->write_bytes != 0))
                        disk_submit (output_name, "disk_octets",
@@ -863,14 +873,19 @@ static int disk_read (void)
 
                if (is_disk)
                {
-                       disk_submit (output_name, "disk_merged",
+                       if (ds->has_merged)
+                               disk_submit (output_name, "disk_merged",
                                        read_merged, write_merged);
-                       submit_in_progress (output_name, in_progress);
-                       submit_io_time (output_name, io_time, weighted_time);
+                       if (ds->has_in_progress)
+                               submit_in_progress (output_name, in_progress);
+                       if (ds->has_io_time)
+                               submit_io_time (output_name, io_time, weighted_time);
                } /* if (is_disk) */
 
+#if HAVE_LIBUDEV
                /* release udev-based alternate name, if allocated */
-               free(alt_name);
+               sfree (alt_name);
+#endif
        } /* while (fgets (buffer, sizeof (buffer), fh) != NULL) */
 
 #if HAVE_LIBUDEV