From: Florian Forster <octo@collectd.org>
Date: Wed, 21 Sep 2016 09:32:20 +0000 (+0200)
Subject: src/daemon/plugin.c: Don't copy values twice.
X-Git-Tag: collectd-5.7.0~67^2~1
X-Git-Url: https://git.verplant.org/?a=commitdiff_plain;h=d54dc98aff7fe748d83fc91b0fed685db990e3de;p=collectd.git

src/daemon/plugin.c: Don't copy values twice.

A copy of the values was made in plugin_dispatch_values_internal(). This
code predates the "write queue", which means that each value list (and
its values) are copied anyway and vl->values will always point to heap
memory.
---

diff --git a/src/daemon/plugin.c b/src/daemon/plugin.c
index d9f8da8c..50ab6757 100644
--- a/src/daemon/plugin.c
+++ b/src/daemon/plugin.c
@@ -2081,9 +2081,6 @@ static int plugin_dispatch_values_internal (value_list_t *vl)
 	int status;
 	static c_complain_t no_write_complaint = C_COMPLAIN_INIT_STATIC;
 
-	value_t *saved_values;
-	int      saved_values_len;
-
 	data_set_t *ds;
 
 	_Bool free_meta_data = 0;
@@ -2170,31 +2167,6 @@ static int plugin_dispatch_values_internal (value_list_t *vl)
 	escape_slashes (vl->type, sizeof (vl->type));
 	escape_slashes (vl->type_instance, sizeof (vl->type_instance));
 
-	/* Copy the values. This way, we can assure `targets' that they get
-	 * dynamically allocated values, which they can free and replace if
-	 * they like. */
-	if ((pre_cache_chain != NULL) || (post_cache_chain != NULL))
-	{
-		saved_values     = vl->values;
-		saved_values_len = vl->values_len;
-
-		vl->values = (value_t *) calloc (vl->values_len,
-				sizeof (*vl->values));
-		if (vl->values == NULL)
-		{
-			ERROR ("plugin_dispatch_values: calloc failed.");
-			vl->values = saved_values;
-			return (-1);
-		}
-		memcpy (vl->values, saved_values,
-				vl->values_len * sizeof (*vl->values));
-	}
-	else /* if ((pre == NULL) && (post == NULL)) */
-	{
-		saved_values     = NULL;
-		saved_values_len = 0;
-	}
-
 	if (pre_cache_chain != NULL)
 	{
 		status = fc_process_chain (ds, vl, pre_cache_chain);
@@ -2206,17 +2178,7 @@ static int plugin_dispatch_values_internal (value_list_t *vl)
 					status, status);
 		}
 		else if (status == FC_TARGET_STOP)
-		{
-			/* Restore the state of the value_list so that plugins
-			 * don't get confused.. */
-			if (saved_values != NULL)
-			{
-				sfree (vl->values);
-				vl->values     = saved_values;
-				vl->values_len = saved_values_len;
-			}
 			return (0);
-		}
 	}
 
 	/* Update the value cache */
@@ -2236,15 +2198,6 @@ static int plugin_dispatch_values_internal (value_list_t *vl)
 	else
 		fc_default_action (ds, vl);
 
-	/* Restore the state of the value_list so that plugins don't get
-	 * confused.. */
-	if (saved_values != NULL)
-	{
-		sfree (vl->values);
-		vl->values     = saved_values;
-		vl->values_len = saved_values_len;
-	}
-
 	if ((free_meta_data != 0) && (vl->meta != NULL))
 	{
 		meta_data_destroy (vl->meta);