elements: improve buffer flags to string utility function

Avoid relocations and refactor so that we don't calculate
the fixed and known at compile time maximum string size
every time. Also skip the mini object flags which we are
not going to print anyway.

diff --git a/plugins/elements/gstelements_private.c b/plugins/elements/gstelements_private.c
index 2364741d402d1ae7489bc5aca1ec6d2a4e5726c6..f539a8554a13d1d853f8bab6743cdc97d7a7d10b 100644 (file)
--- a/plugins/elements/gstelements_private.c
+++ b/plugins/elements/gstelements_private.c
@@ -29,29 +29,33 @@
 #include "gst/gst.h"
 #include "gstelements_private.h"
 
+#define BUFFER_FLAG_SHIFT 4
+
+G_STATIC_ASSERT ((1 << BUFFER_FLAG_SHIFT) == GST_MINI_OBJECT_FLAG_LAST);
+
 /* Returns a newly allocated string describing the flags on this buffer */
 char *
 gst_buffer_get_flags_string (GstBuffer * buffer)
 {
-  static const char *const flag_list[] = {
-    "", "", "", "", "live", "decode-only", "discont", "resync", "corrupted",
-    "marker", "header", "gap", "droppable", "delta-unit", "tag-memory",
-    "FIXME"
+  static const char flag_strings[] =
+      "\000\000\000\000live\000decode-only\000discont\000resync\000corrupted\000"
+      "marker\000header\000gap\000droppable\000delta-unit\000tag-memory\000"
+      "FIXME";
+  static const guint8 flag_idx[] = { 0, 1, 2, 3, 4, 9, 21, 29, 36, 46, 53,
+    60, 64, 74, 85, 96
   };
   int i, max_bytes;
   char *flag_str, *end;
 
-  max_bytes = 1;                /* NUL */
-  for (i = 0; i < G_N_ELEMENTS (flag_list); i++) {
-    max_bytes += strlen (flag_list[i]) + 1;     /* string and space */
-  }
+  /* max size is all flag strings plus a space or terminator after each one */
+  max_bytes = sizeof (flag_strings);
   flag_str = g_malloc (max_bytes);
 
   end = flag_str;
   end[0] = '\0';
-  for (i = 0; i < G_N_ELEMENTS (flag_list); i++) {
+  for (i = BUFFER_FLAG_SHIFT; i < G_N_ELEMENTS (flag_idx); i++) {
     if (GST_MINI_OBJECT_CAST (buffer)->flags & (1 << i)) {
-      strcpy (end, flag_list[i]);
+      strcpy (end, flag_strings + flag_idx[i]);
       end += strlen (end);
       end[0] = ' ';
       end[1] = '\0';