From Kovarththanan Rajaratnam via bug 3702:

This patch optimizes the data source name processing in add_new_data_source()
by delaying it. We now simply store the constant string and lazily compute the
name when needed. This gives a performance boost because we only need the name
if we have multiple data sources.

svn path=/trunk/; revision=29066

1 files changed, 13 insertions, 6 deletions

diff --git a/epan/packet.c b/epan/packet.c
index 56742448d9..39eefb0b07 100644
--- a/epan/packet.c
+++ b/epan/packet.c
@@ -197,15 +197,22 @@ add_new_data_source(packet_info *pinfo, tvbuff_t *tvb, const char *name)
 
 	src = ep_alloc(sizeof (data_source));
 	src->tvb = tvb;
-	/*
-	 * XXX - if we require this argument to be a string constant,
-	 * we don't need to allocate a buffer for a copy and make a
-	 * copy, and wouldn't need to free the buffer, either.
-	 */
-	src->name = ep_strdup_printf("%s (%u bytes)", name, tvb_length(tvb));
+    src->name_initialized = FALSE;
+	src->name = name;
 	pinfo->data_src = g_slist_append(pinfo->data_src, src);
 }
 
+const char*
+get_data_source_name(data_source *src)
+{
+	if (!src->name_initialized) {
+		src->name = ep_strdup_printf("%s (%u bytes)", src->name, tvb_length(src->tvb));
+		src->name_initialized = TRUE;
+	}
+
+	return src->name;
+}
+
 /*
  * Free up a frame's list of data sources.
  */