/* GStreamer

 * Copyright (C) 2009 Axis Communications <dev-gstreamer at axis dot com>

 * @author Jonas Holmberg <jonas dot holmberg at axis dot com>

 * Copyright (C) 2014 Tim-Philipp Müller <tim at centricular dot com>

 *

 * gstbufferlist.c: Buffer list

 *

 * This library is free software; you can redistribute it and/or

 * modify it under the terms of the GNU Library General Public

 * License as published by the Free Software Foundation; either

 * version 2 of the License, or (at your option) any later version.

 *

 * This library is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

 * Library General Public License for more details.

 *

 * You should have received a copy of the GNU Library General Public

 * License along with this library; if not, write to the

 * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,

 * Boston, MA 02110-1301, USA.

 */

/**

 * SECTION:gstbufferlist

 * @title: GstBufferList

 * @short_description: Lists of buffers for data-passing

 * @see_also: #GstPad, #GstMiniObject

 *

 * Buffer lists are an object containing a list of buffers.

 *

 * Buffer lists are created with gst_buffer_list_new() and filled with data

 * using gst_buffer_list_insert().

 *

 * Buffer lists can be pushed on a srcpad with gst_pad_push_list(). This is

 * interesting when multiple buffers need to be pushed in one go because it

 * can reduce the amount of overhead for pushing each buffer individually.

 */

#define GST_DISABLE_MINIOBJECT_INLINE_FUNCTIONS

#include "gst_private.h"

#include "gstbuffer.h"

#include "gstbufferlist.h"

#include "gstutils.h"

#define GST_CAT_DEFAULT GST_CAT_BUFFER_LIST

#define GST_BUFFER_LIST_IS_USING_DYNAMIC_ARRAY(list) \

    ((list)->buffers != &(list)->arr[0])

/**

 * GstBufferList:

 *

 * Opaque list of grouped buffers.

 */

struct _GstBufferList

{

  GstMiniObject mini_object;

  GstBuffer **buffers;

  guint n_buffers;

  guint n_allocated;

  /* one-item array, in reality more items are pre-allocated

   * as part of the GstBufferList structure, and that

   * pre-allocated array extends beyond the declared struct */

  GstBuffer *arr[1];

};

GType _gst_buffer_list_type = 0;

GST_DEFINE_MINI_OBJECT_TYPE (GstBufferList, gst_buffer_list);

void

_priv_gst_buffer_list_initialize (void)

{

  _gst_buffer_list_type = gst_buffer_list_get_type ();

}

static GstBufferList *

_gst_buffer_list_copy (GstBufferList * list)

{

  GstBufferList *copy;

  guint i, len;

  len = list->n_buffers;

  copy = gst_buffer_list_new_sized (list->n_allocated);

  /* add and ref all buffers in the array */

  for (i = 0; i < len; i++) {

    copy->buffers[i] = gst_buffer_ref (list->buffers[i]);

    gst_mini_object_add_parent (GST_MINI_OBJECT_CAST (copy->buffers[i]),

        GST_MINI_OBJECT_CAST (copy));

  }

  copy->n_buffers = len;

  return copy;

}

static void

_gst_buffer_list_free (GstBufferList * list)

{

  guint i, len;

  GST_LOG ("free %p", list);

  /* unrefs all buffers too */

  len = list->n_buffers;

  for (i = 0; i < len; i++) {

    gst_mini_object_remove_parent (GST_MINI_OBJECT_CAST (list->buffers[i]),

        GST_MINI_OBJECT_CAST (list));

    gst_buffer_unref (list->buffers[i]);

  }

  if (GST_BUFFER_LIST_IS_USING_DYNAMIC_ARRAY (list))

    g_free (list->buffers);

#ifdef USE_POISONING

  memset (list, 0xff, sizeof (GstBufferList));

#endif

  g_free (list);

}

static void

gst_buffer_list_init (GstBufferList * list, guint n_allocated)

{

  gst_mini_object_init (GST_MINI_OBJECT_CAST (list), 0, _gst_buffer_list_type,

      (GstMiniObjectCopyFunction) _gst_buffer_list_copy, NULL,

      (GstMiniObjectFreeFunction) _gst_buffer_list_free);

  list->buffers = &list->arr[0];

  list->n_buffers = 0;

  list->n_allocated = n_allocated;

  GST_LOG ("init %p", list);

}

/**

 * gst_buffer_list_new_sized:

 * @size: an initial reserved size

 *

 * Creates a new, empty #GstBufferList. The list will have @size space

 * preallocated so that memory reallocations can be avoided.

 *

 * Returns: (transfer full): the new #GstBufferList.

 */

GstBufferList *

gst_buffer_list_new_sized (guint size)

{

  GstBufferList *list;

  gsize slice_size;

  guint n_allocated;

  if (size == 0)

    size = 1;

  n_allocated = GST_ROUND_UP_16 (size);

  slice_size = sizeof (GstBufferList) + (n_allocated - 1) * sizeof (gpointer);

  list = g_malloc0 (slice_size);

  GST_LOG ("new %p", list);

  gst_buffer_list_init (list, n_allocated);

  return list;

}

/**

 * gst_buffer_list_new:

 *

 * Creates a new, empty #GstBufferList.

 *

 * Returns: (transfer full): the new #GstBufferList.

 */

GstBufferList *

gst_buffer_list_new (void)

{

  return gst_buffer_list_new_sized (8);

}

/**

 * gst_buffer_list_length:

 * @list: a #GstBufferList

 *

 * Returns the number of buffers in @list.

 *

 * Returns: the number of buffers in the buffer list

 */

guint

gst_buffer_list_length (GstBufferList * list)

{

  g_return_val_if_fail (GST_IS_BUFFER_LIST (list), 0);

  return list->n_buffers;

}

static inline void

gst_buffer_list_remove_range_internal (GstBufferList * list, guint idx,

    guint length, gboolean unref_old)

{

  guint i;

  if (unref_old) {

    for (i = idx; i < idx + length; ++i) {

      gst_mini_object_remove_parent (GST_MINI_OBJECT_CAST (list->buffers[i]),

          GST_MINI_OBJECT_CAST (list));

      gst_buffer_unref (list->buffers[i]);

    }

  }

  if (idx + length != list->n_buffers) {

    memmove (&list->buffers[idx], &list->buffers[idx + length],

        (list->n_buffers - (idx + length)) * sizeof (void *));

  }

  list->n_buffers -= length;

}

/**

 * gst_buffer_list_foreach:

 * @list: a #GstBufferList

 * @func: (scope call) (closure user_data): a #GstBufferListFunc to call

 * @user_data: user data passed to @func

 *

 * Calls @func with @data for each buffer in @list.

 *

 * @func can modify the passed buffer pointer or its contents. The return value

 * of @func defines if this function returns or if the remaining buffers in

 * the list should be skipped.

 *

 * Returns: %TRUE when @func returned %TRUE for each buffer in @list or when

 * @list is empty.

 */

gboolean

gst_buffer_list_foreach (GstBufferList * list, GstBufferListFunc func,

    gpointer user_data)

{

  guint i, len;

  gboolean ret = TRUE;

  gboolean list_was_writable, first_warning = TRUE;

  g_return_val_if_fail (GST_IS_BUFFER_LIST (list), FALSE);

  g_return_val_if_fail (func != NULL, FALSE);

  list_was_writable = gst_buffer_list_is_writable (list);

  len = list->n_buffers;

  for (i = 0; i < len;) {

    GstBuffer *buf, *buf_ret;

    gboolean was_writable;

    buf = buf_ret = list->buffers[i];

    /* If the buffer is writable, we remove us as parent for now to

     * allow the callback to destroy the buffer. If we get the buffer

     * back, we add ourselves as parent again.

     *

     * Non-writable buffers just get another reference as they were not

     * writable to begin with, and they would possibly become writable

     * by removing ourselves as parent

     */

    was_writable = list_was_writable && gst_buffer_is_writable (buf);

    if (was_writable)

      gst_mini_object_remove_parent (GST_MINI_OBJECT_CAST (buf),

          GST_MINI_OBJECT_CAST (list));

    else

      gst_buffer_ref (buf);

    ret = func (&buf_ret, i, user_data);

    /* Check if the function changed the buffer */

    if (buf != buf_ret) {

      /* If the list was not writable but the callback was actually changing

       * our buffer, then it wouldn't have been allowed to do so.

       *

       * Fortunately we still have a reference to the old buffer in that case

       * and just not modify the list, unref the new buffer (if any) and warn

       * about this */

      if (!list_was_writable) {

        if (first_warning) {

          g_critical

              ("gst_buffer_list_foreach: non-writable list %p was changed from callback",

              list);

          first_warning = FALSE;

        }

        if (buf_ret)

          gst_buffer_unref (buf_ret);

      } else if (buf_ret == NULL) {

        gst_buffer_list_remove_range_internal (list, i, 1, !was_writable);

        --len;

      } else {

        if (!was_writable) {

          gst_mini_object_remove_parent (GST_MINI_OBJECT_CAST (buf),

              GST_MINI_OBJECT_CAST (list));

          gst_buffer_unref (buf);

        }

        list->buffers[i] = buf_ret;

        gst_mini_object_add_parent (GST_MINI_OBJECT_CAST (buf_ret),

            GST_MINI_OBJECT_CAST (list));

      }

    } else {

      if (was_writable)

        gst_mini_object_add_parent (GST_MINI_OBJECT_CAST (buf),

            GST_MINI_OBJECT_CAST (list));

      else

        gst_buffer_unref (buf);

    }

    if (!ret)

      break;

    /* If the buffer was not removed by func go to the next buffer */

    if (buf_ret != NULL)

      i++;

  }

  return ret;

}

/**

 * gst_buffer_list_get:

 * @list: a #GstBufferList

 * @idx: the index

 *

 * Gets the buffer at @idx.

 *

 * You must make sure that @idx does not exceed the number of

 * buffers available.

 *

 * Returns: (transfer none): the buffer at @idx in @group.

 *     The returned buffer remains valid as long as @list is valid and

 *     buffer is not removed from the list.

 */

GstBuffer *

gst_buffer_list_get (GstBufferList * list, guint idx)

{

  g_return_val_if_fail (GST_IS_BUFFER_LIST (list), NULL);

  g_return_val_if_fail (idx < list->n_buffers, NULL);

  return list->buffers[idx];

}

/**

 * gst_buffer_list_get_writable:

 * @list: a (writable) #GstBufferList

 * @idx: the index

 *

 * Gets the buffer at @idx, ensuring it is a writable buffer.

 *

 * You must make sure that @idx does not exceed the number of

 * buffers available.

 *

 * Returns: (transfer none): the buffer at @idx in @group.

 *     The returned buffer remains valid as long as @list is valid and

 *     the buffer is not removed from the list.

 *

 * Since: 1.14

 */

GstBuffer *

gst_buffer_list_get_writable (GstBufferList * list, guint idx)

{

  GstBuffer *new_buf;

  g_return_val_if_fail (GST_IS_BUFFER_LIST (list), NULL);

  g_return_val_if_fail (gst_buffer_list_is_writable (list), NULL);

  g_return_val_if_fail (idx < list->n_buffers, NULL);

  /* We have to implement this manually here to correctly add/remove the

   * parent */

  if (gst_buffer_is_writable (list->buffers[idx]))

    return list->buffers[idx];

  gst_mini_object_remove_parent (GST_MINI_OBJECT_CAST (list->buffers[idx]),

      GST_MINI_OBJECT_CAST (list));

  new_buf = gst_buffer_copy (list->buffers[idx]);

  gst_mini_object_add_parent (GST_MINI_OBJECT_CAST (new_buf),

      GST_MINI_OBJECT_CAST (list));

  gst_buffer_unref (list->buffers[idx]);

  list->buffers[idx] = new_buf;

  return new_buf;

}

/**

 * gst_buffer_list_add:

 * @l: a #GstBufferList

 * @b: a #GstBuffer

 *

 * Append @b at the end of @l.

 */

/**

 * gst_buffer_list_insert:

 * @list: a #GstBufferList

 * @idx: the index

 * @buffer: (transfer full): a #GstBuffer

 *

 * Inserts @buffer at @idx in @list. Other buffers are moved to make room for

 * this new buffer.

 *

 * A -1 value for @idx will append the buffer at the end.

 */

void

gst_buffer_list_insert (GstBufferList * list, gint idx, GstBuffer * buffer)

{

  guint want_alloc;

  g_return_if_fail (GST_IS_BUFFER_LIST (list));

  g_return_if_fail (buffer != NULL);

  g_return_if_fail (gst_buffer_list_is_writable (list));

  if (idx == -1 && list->n_buffers < list->n_allocated) {

    gst_mini_object_add_parent (GST_MINI_OBJECT_CAST (buffer),

        GST_MINI_OBJECT_CAST (list));

    list->buffers[list->n_buffers++] = buffer;

    return;

  }

  if (idx == -1 || idx > list->n_buffers)

    idx = list->n_buffers;

  want_alloc = list->n_buffers + 1;

  if (want_alloc > list->n_allocated) {

    if (G_UNLIKELY (list->n_allocated > (G_MAXUINT / 2)))

      g_error ("Growing GstBufferList would result in overflow");

    want_alloc = MAX (GST_ROUND_UP_16 (want_alloc), list->n_allocated * 2);

    if (GST_BUFFER_LIST_IS_USING_DYNAMIC_ARRAY (list)) {

      list->buffers = g_renew (GstBuffer *, list->buffers, want_alloc);

    } else {

      list->buffers = g_new0 (GstBuffer *, want_alloc);

      memcpy (list->buffers, &list->arr[0], list->n_buffers * sizeof (void *));

      GST_CAT_LOG (GST_CAT_PERFORMANCE, "exceeding pre-alloced array");

    }

    list->n_allocated = want_alloc;

  }

  if (idx < list->n_buffers) {

    memmove (&list->buffers[idx + 1], &list->buffers[idx],

        (list->n_buffers - idx) * sizeof (void *));

  }

  ++list->n_buffers;

  list->buffers[idx] = buffer;

  gst_mini_object_add_parent (GST_MINI_OBJECT_CAST (buffer),

      GST_MINI_OBJECT_CAST (list));

}

/**

 * gst_buffer_list_remove:

 * @list: a #GstBufferList

 * @idx: the index

 * @length: the amount to remove

 *

 * Removes @length buffers starting from @idx in @list. The following buffers

 * are moved to close the gap.

 */

void

gst_buffer_list_remove (GstBufferList * list, guint idx, guint length)

{

  g_return_if_fail (GST_IS_BUFFER_LIST (list));

  g_return_if_fail (idx < list->n_buffers);

  g_return_if_fail (idx + length <= list->n_buffers);

  g_return_if_fail (gst_buffer_list_is_writable (list));

  gst_buffer_list_remove_range_internal (list, idx, length, TRUE);

}

/**

 * gst_buffer_list_copy_deep:

 * @list: a #GstBufferList

 *

 * Creates a copy of the given buffer list. This will make a newly allocated

 * copy of the buffers that the source buffer list contains.

 *

 * Returns: (transfer full): a new copy of @list.

 *

 * Since: 1.6

 */

GstBufferList *

gst_buffer_list_copy_deep (const GstBufferList * list)

{

  guint i, len;

  GstBufferList *result = NULL;

  g_return_val_if_fail (GST_IS_BUFFER_LIST (list), NULL);

  result = gst_buffer_list_new ();

  len = list->n_buffers;

  for (i = 0; i < len; i++) {

    GstBuffer *old = list->buffers[i];

    GstBuffer *new = gst_buffer_copy_deep (old);

    if (G_LIKELY (new)) {

      gst_buffer_list_insert (result, i, new);

    } else {

      g_warning

          ("Failed to deep copy buffer %p while deep "

          "copying buffer list %p. Buffer list copy "

          "will be incomplete", old, list);

    }

  }

  return result;

}

/**

 * gst_buffer_list_calculate_size:

 * @list: a #GstBufferList

 *

 * Calculates the size of the data contained in @list by adding the

 * size of all buffers.

 *

 * Returns: the size of the data contained in @list in bytes.

 *

 * Since: 1.14

 */

gsize

gst_buffer_list_calculate_size (GstBufferList * list)

{

  GstBuffer **buffers;

  gsize size = 0;

  guint i, n;

  g_return_val_if_fail (GST_IS_BUFFER_LIST (list), 0);

  n = list->n_buffers;

  buffers = list->buffers;

  for (i = 0; i < n; ++i)

    size += gst_buffer_get_size (buffers[i]);

  return size;

}

/**

 * gst_buffer_list_ref: (skip)

 * @list: a #GstBufferList

 *

 * Increases the refcount of the given buffer list by one.

 *

 * Note that the refcount affects the writability of @list and its data, see

 * gst_buffer_list_make_writable(). It is important to note that keeping

 * additional references to GstBufferList instances can potentially increase

 * the number of memcpy operations in a pipeline.

 *

 * Returns: (transfer full): @list

 */

GstBufferList *

gst_buffer_list_ref (GstBufferList * list)

{

  return

      GST_BUFFER_LIST_CAST (gst_mini_object_ref (GST_MINI_OBJECT_CAST (list)));

}

/**

 * gst_buffer_list_unref: (skip)

 * @list: (transfer full): a #GstBufferList

 *

 * Decreases the refcount of the buffer list. If the refcount reaches 0, the

 * buffer list will be freed.

 */

void

gst_buffer_list_unref (GstBufferList * list)

{

  gst_mini_object_unref (GST_MINI_OBJECT_CAST (list));

}

/**

 * gst_clear_buffer_list: (skip)

 * @list_ptr: a pointer to a #GstBufferList reference

 *

 * Clears a reference to a #GstBufferList.

 *

 * @list_ptr must not be %NULL.

 *

 * If the reference is %NULL then this function does nothing. Otherwise, the

 * reference count of the list is decreased and the pointer is set to %NULL.

 *

 * Since: 1.16

 */

void

gst_clear_buffer_list (GstBufferList ** list_ptr)

{

  gst_clear_mini_object ((GstMiniObject **) list_ptr);

}

/**

 * gst_buffer_list_copy: (skip)

 * @list: a #GstBufferList

 *

 * Creates a shallow copy of the given buffer list. This will make a newly

 * allocated copy of the source list with copies of buffer pointers. The

 * refcount of buffers pointed to will be increased by one.

 *

 * Returns: (transfer full): a new copy of @list.

 */

GstBufferList *

gst_buffer_list_copy (const GstBufferList * list)

{

  return

      GST_BUFFER_LIST_CAST (gst_mini_object_copy (GST_MINI_OBJECT_CONST_CAST

          (list)));

}

/**

 * gst_buffer_list_replace:

 * @old_list: (inout) (transfer full) (nullable): pointer to a pointer to a

 *     #GstBufferList to be replaced.

 * @new_list: (transfer none) (allow-none): pointer to a #GstBufferList that

 *     will replace the buffer list pointed to by @old_list.

 *

 * Modifies a pointer to a #GstBufferList to point to a different

 * #GstBufferList. The modification is done atomically (so this is useful for

 * ensuring thread safety in some cases), and the reference counts are updated

 * appropriately (the old buffer list is unreffed, the new is reffed).

 *

 * Either @new_list or the #GstBufferList pointed to by @old_list may be %NULL.

 *

 * Returns: %TRUE if @new_list was different from @old_list

 *

 * Since: 1.16

 */

gboolean

gst_buffer_list_replace (GstBufferList ** old_list, GstBufferList * new_list)

{

  return gst_mini_object_replace ((GstMiniObject **) old_list,

      (GstMiniObject *) new_list);

}

/**

 * gst_buffer_list_take:

 * @old_list: (inout) (transfer full): pointer to a pointer to a #GstBufferList

 *     to be replaced.

 * @new_list: (transfer full) (allow-none): pointer to a #GstBufferList

 *     that will replace the bufferlist pointed to by @old_list.

 *

 * Modifies a pointer to a #GstBufferList to point to a different

 * #GstBufferList. This function is similar to gst_buffer_list_replace() except

 * that it takes ownership of @new_list.

 *

 * Returns: %TRUE if @new_list was different from @old_list

 *

 * Since: 1.16

 */

gboolean

gst_buffer_list_take (GstBufferList ** old_list, GstBufferList * new_list)

{

  return gst_mini_object_take ((GstMiniObject **) old_list,

      (GstMiniObject *) new_list);

}

/**

 * gst_buffer_list_steal: (skip)

 * @old_list: (inout) (transfer full) (nullable): pointer to a

 *     pointer to a #GstBufferList to be stolen.

 *

 * Atomically replace the #GstBufferList pointed to by @old_list with %NULL and

 * return the original buffer list.

 * Since: 1.28

 */

GstBufferList *

gst_buffer_list_steal (GstBufferList ** old_list)

{

  return GST_BUFFER_LIST_CAST (gst_mini_object_steal ((GstMiniObject **)

          old_list));

}

/**

 * gst_buffer_list_is_writable:

 * @list: a #GstEvent

 *

 * Tests if you can safely modify @list. It is only safe to modify buffer list when

 * there is only one owner of the buffer list - ie, the object is writable.

 */

gboolean

gst_buffer_list_is_writable (const GstBufferList * list)

{

  return gst_mini_object_is_writable (GST_MINI_OBJECT_CONST_CAST (list));

}

/**

 * gst_buffer_list_make_writable:

 * @list: (transfer full): a #GstBufferList

 *

 * Returns a writable copy of @list.

 *

 * If there is only one reference count on @list, the caller must be the owner,

 * and so this function will return the buffer list object unchanged. If on the other

 * hand there is more than one reference on the object, a new buffer list object will

 * be returned. The caller's reference on @list will be removed, and instead the

 * caller will own a reference to the returned object.

 *

 * In short, this function unrefs the buffer_list in the argument and refs the buffer list

 * that it returns. Don't access the argument after calling this function. See

 * also: gst_buffer_list_ref().

 *

 * Returns: (transfer full): a writable buffer list which may or may not be the

 *     same as @buffer list

 */

GstBufferList *

gst_buffer_list_make_writable (GstBufferList * list)

{

  return

      GST_BUFFER_LIST_CAST (gst_mini_object_make_writable (GST_MINI_OBJECT_CAST

          (list)));

}