memory: make writability check into a method

Use a method to check for writability instead of a macro so that we can change
the implementation more easily.

gst/gstbuffer.c

@@ -652,7 +652,7 @@ _get_memory (GstBuffer * buffer, guint idx, gboolean write)
 
   mem = GST_BUFFER_MEM_PTR (buffer, idx);
 
-  if (G_UNLIKELY (write && !GST_MEMORY_IS_WRITABLE (mem))) {
+  if (G_UNLIKELY (write && !gst_memory_is_writable (mem))) {
     GstMemory *copy;
     GST_CAT_LOG (GST_CAT_BUFFER,
         "making writable copy of memory %p in buffer %p", mem, buffer);
@@ -868,7 +868,7 @@ gst_buffer_resize (GstBuffer * buffer, gssize offset, gssize size)
 
     if (offset != 0 || left != bsize) {
       /* we need to clip something */
-      if (GST_MEMORY_IS_WRITABLE (mem)) {
+      if (gst_memory_is_writable (mem)) {
         gst_memory_resize (mem, offset, left);
       } else {
         GstMemory *tmp;
@@ -968,7 +968,7 @@ gst_buffer_map (GstBuffer * buffer, gsize * size, gsize * maxsize,
     }
   }
 
-  if (G_UNLIKELY (write && !GST_MEMORY_IS_WRITABLE (mem))) {
+  if (G_UNLIKELY (write && !gst_memory_is_writable (mem))) {
     GstMemory *copy;
     /* replace with a writable copy */
     copy = gst_memory_copy (mem, 0, -1);

gst/gstmemory.c

@@ -460,11 +460,29 @@ void
 gst_memory_resize (GstMemory * mem, gssize offset, gsize size)
 {
   g_return_if_fail (mem != NULL);
-  g_return_if_fail (GST_MEMORY_IS_WRITABLE (mem));
+  g_return_if_fail (gst_memory_is_writable (mem));
 
   mem->allocator->info.resize (mem, offset, size);
 }
 
+/**
+ * gst_memory_is_writable:
+ * @mem: a #GstMemory
+ *
+ * Check if @mem is writable.
+ *
+ * Returns: %TRUE is @mem is writable.
+ */
+gboolean
+gst_memory_is_writable (GstMemory * mem)
+{
+  g_return_val_if_fail (mem != NULL, FALSE);
+
+  return (mem->refcount == 1) &&
+      ((mem->parent == NULL) || (mem->parent->refcount == 1)) &&
+      ((mem->flags & GST_MEMORY_FLAG_READONLY) == 0);
+}
+
 /**
  * gst_memory_map:
  * @mem: a #GstMemory
@@ -489,7 +507,7 @@ gst_memory_map (GstMemory * mem, gsize * size, gsize * maxsize,
   g_return_val_if_fail (mem != NULL, NULL);
   access_mode = flags & 3;
   g_return_val_if_fail (!(access_mode & GST_MAP_WRITE)
-      || GST_MEMORY_IS_WRITABLE (mem), NULL);
+      || gst_memory_is_writable (mem), NULL);
 
   do {
     state = g_atomic_int_get (&mem->state);

gst/gstmemory.h

@@ -55,16 +55,6 @@ typedef enum {
   GST_MEMORY_FLAG_LAST     = (1 << 16)
 } GstMemoryFlags;
 
-/**
- * GST_MEMORY_IS_WRITABLE:
- * @mem: a #GstMemory
- *
- * Check if @mem is writable.
- */
-#define GST_MEMORY_IS_WRITABLE(mem) (((mem)->refcount == 1) && \
-    (((mem)->parent == NULL) || ((mem)->parent->refcount == 1)) && \
-    (((mem)->flags & GST_MEMORY_FLAG_READONLY) == 0))
-
 /**
  * GstMemory:
  * @allocator: pointer to the #GstAllocator
@@ -289,24 +279,26 @@ GstMemory * gst_memory_new_wrapped     (GstMemoryFlags flags, gpointer data, GFr
                                         gsize maxsize, gsize offset, gsize size);
 
 /* refcounting */
-GstMemory * gst_memory_ref        (GstMemory *mem);
+GstMemory * gst_memory_ref         (GstMemory *mem);
-void        gst_memory_unref      (GstMemory *mem);
+void        gst_memory_unref       (GstMemory *mem);
 
 /* getting/setting memory properties */
-gsize       gst_memory_get_sizes  (GstMemory *mem, gsize *offset, gsize *maxsize);
+gsize       gst_memory_get_sizes   (GstMemory *mem, gsize *offset, gsize *maxsize);
-void        gst_memory_resize     (GstMemory *mem, gssize offset, gsize size);
+void        gst_memory_resize      (GstMemory *mem, gssize offset, gsize size);
 
 /* retrieving data */
-gpointer    gst_memory_map        (GstMemory *mem, gsize *size, gsize *maxsize,
+gboolean    gst_memory_is_writable (GstMemory *mem);
-                                   GstMapFlags flags);
+
-gboolean    gst_memory_unmap      (GstMemory *mem, gpointer data, gssize size);
+gpointer    gst_memory_map         (GstMemory *mem, gsize *size, gsize *maxsize,
+                                    GstMapFlags flags);
+gboolean    gst_memory_unmap       (GstMemory *mem, gpointer data, gssize size);
 
 /* copy and subregions */
-GstMemory * gst_memory_copy       (GstMemory *mem, gssize offset, gssize size);
+GstMemory * gst_memory_copy        (GstMemory *mem, gssize offset, gssize size);
-GstMemory * gst_memory_share      (GstMemory *mem, gssize offset, gssize size);
+GstMemory * gst_memory_share       (GstMemory *mem, gssize offset, gssize size);
 
 /* span memory */
-gboolean    gst_memory_is_span    (GstMemory *mem1, GstMemory *mem2, gsize *offset);
+gboolean    gst_memory_is_span     (GstMemory *mem1, GstMemory *mem2, gsize *offset);
 
 G_END_DECLS
 

tests/check/gst/gstmemory.c

@@ -134,7 +134,7 @@ create_read_only_memory (void)
   /* assign some read-only data to the new memory */
   mem = gst_memory_new_wrapped (GST_MEMORY_FLAG_READONLY,
       (gpointer) ro_memory, NULL, sizeof (ro_memory), 0, sizeof (ro_memory));
-  fail_if (GST_MEMORY_IS_WRITABLE (mem));
+  fail_if (gst_memory_is_writable (mem));
 
   return mem;
 }
@@ -149,11 +149,11 @@ GST_START_TEST (test_writable)
   mem = create_read_only_memory ();
 
   ASSERT_CRITICAL (gst_memory_map (mem, &size, NULL, GST_MAP_WRITE));
-  fail_if (GST_MEMORY_IS_WRITABLE (mem));
+  fail_if (gst_memory_is_writable (mem));
 
   mem2 = gst_memory_copy (mem, 0, -1);
-  fail_if (GST_MEMORY_IS_WRITABLE (mem));
+  fail_if (gst_memory_is_writable (mem));
-  fail_unless (GST_MEMORY_IS_WRITABLE (mem2));
+  fail_unless (gst_memory_is_writable (mem2));
 
   data = gst_memory_map (mem2, &size, NULL, GST_MAP_WRITE);
   data[4] = 'a';
@@ -183,7 +183,7 @@ GST_START_TEST (test_submemory_writable)
   mem = create_read_only_memory ();
 
   sub_mem = gst_memory_share (mem, 0, 8);
-  fail_if (GST_MEMORY_IS_WRITABLE (sub_mem));
+  fail_if (gst_memory_is_writable (sub_mem));
 
   ASSERT_CRITICAL (gst_memory_map (mem, &size, NULL, GST_MAP_WRITE));
   ASSERT_CRITICAL (gst_memory_map (sub_mem, &size, NULL, GST_MAP_WRITE));