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queuearray: fix gst_queue_array_drop_element()
https://bugzilla.gnome.org/show_bug.cgi?id=692691 Conflicts: libs/gst/base/gstqueuearray.c
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0c643e2cf7
commit
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1 changed files with 60 additions and 36 deletions
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@ -212,52 +212,76 @@ gst_queue_array_is_empty (GstQueueArray * array)
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gpointer
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gst_queue_array_drop_element (GstQueueArray * array, guint idx)
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{
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int first_item_index, last_item_index;
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gpointer element;
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if (idx == array->head) {
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/* just move the head */
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element = array->array[idx];
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g_return_val_if_fail (array->length > 0, NULL);
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g_return_val_if_fail (idx < array->size, NULL);
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first_item_index = array->head;
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/* tail points to the first free spot */
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last_item_index = (array->tail - 1 + array->size) % array->size;
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element = array->array[idx];
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/* simple case idx == first item */
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if (idx == first_item_index) {
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/* move the head plus one */
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array->head++;
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array->head %= array->size;
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array->length--;
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return element;
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}
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if (idx == array->tail - 1) {
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/* just move the tail */
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element = array->array[idx];
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/* simple case idx == last item */
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if (idx == last_item_index) {
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/* move tail minus one, potentially wrapping */
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array->tail = (array->tail - 1 + array->size) % array->size;
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array->length--;
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return element;
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}
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/* drop the element #idx... and readjust the array */
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if (array->head < array->tail) {
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/* Make sure it's within the boundaries */
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g_assert (array->head < idx && idx <= array->tail);
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element = array->array[idx];
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/* ends not wrapped */
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/* move head-idx to head+1 */
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memcpy (&array->array[array->head + 1],
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&array->array[array->head], (idx - array->head) * sizeof (gpointer));
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array->tail--;
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} else {
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/* ends are wrapped */
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if (idx < array->tail) {
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element = array->array[idx];
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/* move idx-tail backwards one */
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memcpy (&array->array[idx - 1],
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&array->array[idx], (array->tail - idx) * sizeof (gpointer));
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array->tail--;
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} else if (idx >= array->head) {
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element = array->array[idx];
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/* move head-idx forwards one */
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memcpy (&array->array[array->head],
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&array->array[array->head + 1],
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(idx - array->head) * sizeof (gpointer));
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array->head++;
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} else {
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g_assert_not_reached ();
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element = NULL;
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}
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/* non-wrapped case */
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if (first_item_index < last_item_index) {
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g_assert (first_item_index < idx && idx < last_item_index);
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/* move everything beyond idx one step towards zero in array */
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memmove (&array->array[idx],
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&array->array[idx + 1], (last_item_index - idx) * sizeof (gpointer));
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/* tail might wrap, ie if tail == 0 (and last_item_index == size) */
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array->tail = (array->tail - 1 + array->size) % array->size;
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array->length--;
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return element;
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}
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return element;
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/* only wrapped cases left */
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g_assert (first_item_index > last_item_index);
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if (idx < last_item_index) {
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/* idx is before last_item_index, move data towards zero */
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memmove (&array->array[idx],
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&array->array[idx + 1], (last_item_index - idx) * sizeof (gpointer));
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/* tail should not wrap in this case! */
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g_assert (array->tail > 0);
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array->tail--;
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array->length--;
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return element;
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}
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if (idx > first_item_index) {
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element = array->array[idx];
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/* idx is after first_item_index, move data to higher indices */
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memmove (&array->array[first_item_index + 1],
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&array->array[first_item_index],
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(idx - first_item_index) * sizeof (gpointer));
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array->head++;
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/* head should not wrap in this case! */
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g_assert (array->head < array->size);
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array->length--;
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return element;
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}
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g_return_val_if_reached (NULL);
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}
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/**
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