}
/**
+ * gst_adapter_take_buffer_fast:
+ * @adapter: a #GstAdapter
+ * @nbytes: the number of bytes to take
+ *
+ * Returns a #GstBuffer containing the first @nbytes of the @adapter.
+ * The returned bytes will be flushed from the adapter. This function
+ * is potentially more performant than gst_adapter_take_buffer() since
+ * it can reuse the memory in pushed buffers by subbuffering or
+ * merging. Unlike gst_adapter_take_buffer(), the returned buffer may
+ * be composed of multiple non-contiguous #GstMemory objects, no
+ * copies are made.
+ *
+ * Note that no assumptions should be made as to whether certain buffer
+ * flags such as the DISCONT flag are set on the returned buffer, or not.
+ * The caller needs to explicitly set or unset flags that should be set or
+ * unset.
+ *
+ * This function can return buffer up to the return value of
+ * gst_adapter_available() without making copies if possible.
+ *
+ * Caller owns a reference to the returned buffer. gst_buffer_unref() after
+ * usage.
+ *
+ * Free-function: gst_buffer_unref
+ *
+ * Returns: (transfer full): a #GstBuffer containing the first @nbytes of
+ * the adapter, or #NULL if @nbytes bytes are not available.
+ * gst_buffer_unref() when no longer needed.
+ *
+ * Since: 1.2
+ */
+
+GstBuffer *
+gst_adapter_take_buffer_fast (GstAdapter * adapter, gsize nbytes)
+{
+ GstBuffer *buffer = NULL;
+ GstBuffer *cur;
+ GSList *item;
+ gsize skip;
+ gsize left = nbytes;
+
+ g_return_val_if_fail (GST_IS_ADAPTER (adapter), NULL);
+ g_return_val_if_fail (nbytes > 0, NULL);
+
+ GST_LOG_OBJECT (adapter, "taking buffer of %" G_GSIZE_FORMAT " bytes",
+ nbytes);
+
+ /* we don't have enough data, return NULL. This is unlikely
+ * as one usually does an _available() first instead of grabbing a
+ * random size. */
+ if (G_UNLIKELY (nbytes > adapter->size))
+ return NULL;
+
+ skip = adapter->skip;
+ cur = adapter->buflist->data;
+
+ if (skip == 0 && gst_buffer_get_size (cur) == nbytes) {
+ GST_LOG_OBJECT (adapter, "providing buffer of %" G_GSIZE_FORMAT " bytes"
+ " as head buffer", nbytes);
+ buffer = gst_buffer_ref (cur);
+ goto done;
+ }
+
+ for (item = adapter->buflist; item && left > 0; item = item->next) {
+ gsize size;
+
+ cur = item->data;
+ size = MIN (gst_buffer_get_size (cur), left);
+
+ GST_LOG_OBJECT (adapter, "appending %" G_GSIZE_FORMAT " bytes"
+ " via region copy", size);
+ if (buffer)
+ gst_buffer_copy_into (buffer, cur, GST_BUFFER_COPY_MEMORY, 0, size);
+ else
+ buffer = gst_buffer_copy_region (cur, GST_BUFFER_COPY_ALL, skip, size);
+ skip = 0;
+ left -= size;
+ }
+
+done:
+ gst_adapter_flush_unchecked (adapter, nbytes);
+
+ return buffer;
+}
+
+/**
* gst_adapter_take_buffer:
* @adapter: a #GstAdapter
* @nbytes: the number of bytes to take
*
* Returns a #GstBuffer containing the first @nbytes bytes of the
* @adapter. The returned bytes will be flushed from the adapter.
- * This function is potentially more performant than gst_adapter_take()
- * since it can reuse the memory in pushed buffers by subbuffering
- * or merging.
+ * This function is potentially more performant than
+ * gst_adapter_take() since it can reuse the memory in pushed buffers
+ * by subbuffering or merging. This function will always return a
+ * buffer with a single memory region.
*
* Note that no assumptions should be made as to whether certain buffer
* flags such as the DISCONT flag are set on the returned buffer, or not.
GST_END_TEST;
+GST_START_TEST (test_take_buffer_fast)
+{
+ GstAdapter *adapter;
+ GstBuffer *buffer;
+
+ adapter = gst_adapter_new ();
+ fail_if (adapter == NULL);
+
+ buffer = gst_buffer_new_and_alloc (5);
+ fail_if (buffer == NULL);
+ gst_adapter_push (adapter, buffer);
+
+ buffer = gst_buffer_new_and_alloc (10);
+ fail_if (buffer == NULL);
+ gst_adapter_push (adapter, buffer);
+
+ buffer = gst_buffer_new_and_alloc (15);
+ fail_if (buffer == NULL);
+ gst_adapter_push (adapter, buffer);
+
+ fail_unless (gst_adapter_available (adapter) == 30);
+
+ buffer = gst_adapter_take_buffer_fast (adapter, 30);
+ fail_unless (gst_adapter_available (adapter) == 0);
+
+ fail_unless (gst_buffer_n_memory (buffer) == 3);
+ fail_unless (gst_buffer_get_sizes_range (buffer, 0, 1, NULL, NULL) == 5);
+ fail_unless (gst_buffer_get_sizes_range (buffer, 1, 1, NULL, NULL) == 10);
+ fail_unless (gst_buffer_get_sizes_range (buffer, 2, 1, NULL, NULL) == 15);
+
+ gst_buffer_unref (buffer);
+ g_object_unref (adapter);
+}
+
+GST_END_TEST;
+
static Suite *
gst_adapter_suite (void)
{
tcase_add_test (tc_chain, test_scan);
tcase_add_test (tc_chain, test_take_list);
tcase_add_test (tc_chain, test_merge);
+ tcase_add_test (tc_chain, test_take_buffer_fast);
return s;
}
projects / platform / upstream / gstreamer.git / commitdiff