From 1d0bda8005066f481ff5b243dccb983306023410 Mon Sep 17 00:00:00 2001
From: Edward Hervey <edward@centricular.com>
Date: Fri, 17 Apr 2020 17:12:10 +0200
Subject: [PATCH] caps: Unify common checks for intersections

Regardless of the intersect method chosen, migrate the same checks
up into the calling function. Same result, just less code.

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/455>
---
 gst/gstcaps.c | 46 ++++++++++++++++------------------------------
 1 file changed, 16 insertions(+), 30 deletions(-)

diff --git a/gst/gstcaps.c b/gst/gstcaps.c
index aa4a34d900..2bbb5ff7fa 100644
--- a/gst/gstcaps.c
+++ b/gst/gstcaps.c
@@ -1620,21 +1620,6 @@ gst_caps_intersect_zig_zag (GstCaps * caps1, GstCaps * caps2)
   GstCaps *dest;
   GstStructure *istruct;
 
-  /* caps are exactly the same pointers, just copy one caps */
-  if (G_UNLIKELY (caps1 == caps2))
-    return gst_caps_ref (caps1);
-
-  /* empty caps on either side, return empty */
-  if (G_UNLIKELY (CAPS_IS_EMPTY (caps1) || CAPS_IS_EMPTY (caps2)))
-    return gst_caps_ref (GST_CAPS_NONE);
-
-  /* one of the caps is any, just copy the other caps */
-  if (G_UNLIKELY (CAPS_IS_ANY (caps1)))
-    return gst_caps_ref (caps2);
-
-  if (G_UNLIKELY (CAPS_IS_ANY (caps2)))
-    return gst_caps_ref (caps1);
-
   dest = gst_caps_new_empty ();
   /* run zigzag on top line then right line, this preserves the caps order
    * much better than a simple loop.
@@ -1719,21 +1704,6 @@ gst_caps_intersect_first (GstCaps * caps1, GstCaps * caps2)
   GstCaps *dest;
   GstStructure *istruct;
 
-  /* caps are exactly the same pointers, just copy one caps */
-  if (G_UNLIKELY (caps1 == caps2))
-    return gst_caps_ref (caps1);
-
-  /* empty caps on either side, return empty */
-  if (G_UNLIKELY (CAPS_IS_EMPTY (caps1) || CAPS_IS_EMPTY (caps2)))
-    return gst_caps_ref (GST_CAPS_NONE);
-
-  /* one of the caps is any, just copy the other caps */
-  if (G_UNLIKELY (CAPS_IS_ANY (caps1)))
-    return gst_caps_ref (caps2);
-
-  if (G_UNLIKELY (CAPS_IS_ANY (caps2)))
-    return gst_caps_ref (caps1);
-
   dest = gst_caps_new_empty ();
   len1 = GST_CAPS_LEN (caps1);
   len2 = GST_CAPS_LEN (caps2);
@@ -1785,6 +1755,22 @@ gst_caps_intersect_full (GstCaps * caps1, GstCaps * caps2,
   g_return_val_if_fail (GST_IS_CAPS (caps1), NULL);
   g_return_val_if_fail (GST_IS_CAPS (caps2), NULL);
 
+  /* Common fast-path */
+  /* caps are exactly the same pointers, just copy one caps */
+  if (G_UNLIKELY (caps1 == caps2))
+    return gst_caps_ref (caps1);
+
+  /* empty caps on either side, return empty */
+  if (G_UNLIKELY (CAPS_IS_EMPTY (caps1) || CAPS_IS_EMPTY (caps2)))
+    return gst_caps_ref (GST_CAPS_NONE);
+
+  /* one of the caps is any, just copy the other caps */
+  if (G_UNLIKELY (CAPS_IS_ANY (caps1)))
+    return gst_caps_ref (caps2);
+
+  if (G_UNLIKELY (CAPS_IS_ANY (caps2)))
+    return gst_caps_ref (caps1);
+
   switch (mode) {
     case GST_CAPS_INTERSECT_FIRST:
       return gst_caps_intersect_first (caps1, caps2);