Commit 6ffba69d authored by Wim Taymans's avatar Wim Taymans
Browse files

buffer: small optimizations

shortcut heavy work when buffer_resize does nothing.
Avoid an extra _ref when mapping a buffer.
Add some G_LIKELY.
parent ebd4863d
......@@ -173,7 +173,7 @@ _span_memory (GstBuffer * buffer, gsize offset, gsize size, gboolean writable)
}
static GstMemory *
_get_merged_memory (GstBuffer * buffer)
_get_merged_memory (GstBuffer * buffer, gboolean * merged)
{
guint len;
GstMemory *mem;
......@@ -187,9 +187,11 @@ _get_merged_memory (GstBuffer * buffer)
/* we can take the first one */
mem = GST_BUFFER_MEM_PTR (buffer, 0);
gst_memory_ref (mem);
*merged = FALSE;
} else {
/* we need to span memory */
mem = _span_memory (buffer, 0, -1, FALSE);
*merged = TRUE;
}
return mem;
}
......@@ -722,13 +724,14 @@ GstMemory *
gst_buffer_get_memory (GstBuffer * buffer, gint idx)
{
GstMemory *mem;
gboolean merged;
g_return_val_if_fail (GST_IS_BUFFER (buffer), NULL);
g_return_val_if_fail (idx == -1 ||
(idx >= 0 && idx <= GST_BUFFER_MEM_LEN (buffer)), NULL);
if (idx == -1) {
mem = _get_merged_memory (buffer);
mem = _get_merged_memory (buffer, &merged);
} else if ((mem = GST_BUFFER_MEM_PTR (buffer, idx))) {
gst_memory_ref (mem);
}
......@@ -898,6 +901,10 @@ gst_buffer_resize (GstBuffer * buffer, gssize offset, gssize size)
}
g_return_if_fail (bufmax >= bufoffs + offset + size);
/* no change */
if (offset == 0 && size == bufsize)
return;
len = GST_BUFFER_MEM_LEN (buffer);
/* copy and trim */
......@@ -961,14 +968,16 @@ gst_buffer_resize (GstBuffer * buffer, gssize offset, gssize size)
* When the buffer contains multiple memory blocks, the returned pointer will be
* a concatenation of the memory blocks.
*
* The memory in @info should be unmapped with gst_buffer_unmap() after usage.
*
* Returns: (transfer full): %TRUE if the map succeeded and @info contains valid
* data.
*/
gboolean
gst_buffer_map (GstBuffer * buffer, GstMapInfo * info, GstMapFlags flags)
{
GstMemory *mem;
gboolean write, writable;
GstMemory *mem, *nmem;
gboolean write, writable, merged;
g_return_val_if_fail (GST_IS_BUFFER (buffer), FALSE);
g_return_val_if_fail (info != NULL, FALSE);
......@@ -980,25 +989,28 @@ gst_buffer_map (GstBuffer * buffer, GstMapInfo * info, GstMapFlags flags)
if (G_UNLIKELY (write && !writable))
goto not_writable;
mem = _get_merged_memory (buffer);
mem = _get_merged_memory (buffer, &merged);
if (G_UNLIKELY (mem == NULL))
goto no_memory;
/* now try to map */
mem = gst_memory_make_mapped (mem, info, flags);
if (G_UNLIKELY (mem == NULL))
nmem = gst_memory_make_mapped (mem, info, flags);
if (G_UNLIKELY (nmem == NULL))
goto cannot_map;
/* if the buffer is writable, replace the memory */
if (writable) {
_replace_all_memory (buffer, gst_memory_ref (mem));
} else {
if (GST_BUFFER_MEM_LEN (buffer) > 1) {
GST_CAT_DEBUG (GST_CAT_PERFORMANCE,
"temporary mapping for memory %p in buffer %p", mem, buffer);
/* if we merged or when the map returned a different memory, we try to replace
* the memory in the buffer */
if (G_UNLIKELY (merged || nmem != mem)) {
/* if the buffer is writable, replace the memory */
if (writable) {
_replace_all_memory (buffer, gst_memory_ref (nmem));
} else {
if (GST_BUFFER_MEM_LEN (buffer) > 1) {
GST_CAT_DEBUG (GST_CAT_PERFORMANCE,
"temporary mapping for memory %p in buffer %p", nmem, buffer);
}
}
}
return TRUE;
/* ERROR */
......@@ -1038,7 +1050,9 @@ gst_buffer_unmap (GstBuffer * buffer, GstMapInfo * info)
g_return_if_fail (GST_IS_BUFFER (buffer));
g_return_if_fail (info != NULL);
if (info->memory) {
/* we need to check for NULL, it is possible that we tried to map a buffer
* without memory and we should be able to unmap that fine */
if (G_LIKELY (info->memory)) {
gst_memory_unmap (info->memory, info);
gst_memory_unref (info->memory);
}
......
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