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queuearray: allow storing of structs in addition to pointers

Browse source 
This way we don't have to allocate/free temporary structs
for storing things in the queue array.

API: gst_queue_array_new_for_struct()
API: gst_queue_array_push_tail_struct()
API: gst_queue_array_peek_head_struct()
API: gst_queue_array_pop_head_struct()
API: gst_queue_array_drop_struct()

https://bugzilla.gnome.org/show_bug.cgi?id=750149
This commit is contained in:
Tim-Philipp Müller 2015-05-30 13:07:50 +01:00
parent 5c99d56f62
commit d0f85838ab
4 changed files with 303 additions and 113 deletions
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5
docs/libs/gstreamer-libs-sections.txt
View file

@ -860,6 +860,11 @@ gst_queue_array_push_tail
gst_queue_array_is_empty gst_queue_array_is_empty
gst_queue_array_drop_element gst_queue_array_drop_element
gst_queue_array_find gst_queue_array_find
gst_queue_array_new_for_struct
gst_queue_array_push_tail_struct
gst_queue_array_peek_head_struct
gst_queue_array_pop_head_struct
gst_queue_array_drop_struct
</SECTION> </SECTION>
# net # net

390
libs/gst/base/gstqueuearray.c
View file

@ -1,5 +1,6 @@
/* GStreamer /* GStreamer
* Copyright (C) 2009 Edward Hervey <bilboed@bilboed.com> * Copyright (C) 2009 Edward Hervey <bilboed@bilboed.com>
* Copyright (C) 2015 Tim-Philipp Müller <tim@centricular.com>
* *
* gstqueuearray.c: * gstqueuearray.c:
* *
@ -36,13 +37,45 @@
struct _GstQueueArray struct _GstQueueArray
{ {
/* < private > */ /* < private > */
gpointer *array; guint8 *array;
guint size; guint size;
guint head; guint head;
guint tail; guint tail;
guint length; guint length;
guint elt_size;
gboolean struct_array;
}; };
/**
* gst_queue_array_new_for_struct: (skip)
* @struct_size: Size of each element (e.g. structure) in the array
* @initial_size: Initial size of the new queue
*
* Allocates a new #GstQueueArray object for elements (e.g. structures)
* of size @struct_size, with an initial queue size of @initial_size.
*
* Returns: a new #GstQueueArray object
*
* Since: 1.6
*/
GstQueueArray *
gst_queue_array_new_for_struct (gsize struct_size, guint initial_size)
{
GstQueueArray *array;
g_return_val_if_fail (struct_size > 0, NULL);
array = g_slice_new (GstQueueArray);
array->elt_size = struct_size;
array->size = initial_size;
array->array = g_malloc0 (struct_size * initial_size);
array->head = 0;
array->tail = 0;
array->length = 0;
array->struct_array = TRUE;
return array;
}
/** /**
* gst_queue_array_new: (skip) * gst_queue_array_new: (skip)
* @initial_size: Initial size of the new queue * @initial_size: Initial size of the new queue
@ -59,16 +92,11 @@ gst_queue_array_new (guint initial_size)
{ {
GstQueueArray *array; GstQueueArray *array;
array = g_slice_new (GstQueueArray); array = gst_queue_array_new_for_struct (sizeof (gpointer), initial_size);
array->size = initial_size; array->struct_array = FALSE;
array->array = g_new0 (gpointer, initial_size);
array->head = 0;
array->tail = 0;
array->length = 0;
return array; return array;
} }
/** /**
* gst_queue_array_free: (skip) * gst_queue_array_free: (skip)
* @array: a #GstQueueArray object * @array: a #GstQueueArray object
@ -84,6 +112,36 @@ gst_queue_array_free (GstQueueArray * array)
g_slice_free (GstQueueArray, array); g_slice_free (GstQueueArray, array);
} }
/**
* gst_queue_array_pop_head_struct: (skip)
* @array: a #GstQueueArray object
*
* Returns the head of the queue @array and removes it from the queue.
*
* Returns: pointer to element or struct, or NULL if @array was empty. The
* data pointed to by the returned pointer stays valid only as long as
* the queue array is not modified further!
*
* Since: 1.6
*/
gpointer
gst_queue_array_pop_head_struct (GstQueueArray * array)
{
gpointer p_struct;
/* empty array */
if (G_UNLIKELY (array->length == 0))
return NULL;
p_struct = array->array + (array->elt_size * array->head);
array->head++;
array->head %= array->size;
array->length--;
return p_struct;
}
/** /**
* gst_queue_array_pop_head: (skip) * gst_queue_array_pop_head: (skip)
* @array: a #GstQueueArray object * @array: a #GstQueueArray object
@ -103,18 +161,41 @@ gst_queue_array_pop_head (GstQueueArray * array)
/* empty array */ /* empty array */
if (G_UNLIKELY (array->length == 0)) if (G_UNLIKELY (array->length == 0))
return NULL; return NULL;
ret = array->array[array->head];
ret = *(gpointer *) (array->array + (sizeof (gpointer) * array->head));
array->head++; array->head++;
array->head %= array->size; array->head %= array->size;
array->length--; array->length--;
return ret; return ret;
} }
/**
* gst_queue_array_peek_head_struct: (skip)
* @array: a #GstQueueArray object
*
* Returns the head of the queue @array without removing it from the queue.
*
* Returns: pointer to element or struct, or NULL if @array was empty. The
* data pointed to by the returned pointer stays valid only as long as
* the queue array is not modified further!
*
* Since: 1.6
*/
gpointer
gst_queue_array_peek_head_struct (GstQueueArray * array)
{
/* empty array */
if (G_UNLIKELY (array->length == 0))
return NULL;
return array->array + (array->elt_size * array->head);
}
/** /**
* gst_queue_array_peek_head: (skip) * gst_queue_array_peek_head: (skip)
* @array: a #GstQueueArray object * @array: a #GstQueueArray object
* *
* Returns and head of the queue @array and does not * Returns the head of the queue @array and does not
* remove it from the queue. * remove it from the queue.
* *
* Returns: The head of the queue * Returns: The head of the queue
@ -127,7 +208,77 @@ gst_queue_array_peek_head (GstQueueArray * array)
/* empty array */ /* empty array */
if (G_UNLIKELY (array->length == 0)) if (G_UNLIKELY (array->length == 0))
return NULL; return NULL;
return array->array[array->head];
return *(gpointer *) (array->array + (sizeof (gpointer) * array->head));
}
static void
gst_queue_array_do_expand (GstQueueArray * array)
{
guint elt_size = array->elt_size;
/* newsize is 50% bigger */
guint oldsize = array->size;
guint newsize = MAX ((3 * oldsize) / 2, oldsize + 1);
/* copy over data */
if (array->tail != 0) {
guint8 *array2 = g_malloc0 (elt_size * newsize);
guint t1 = array->head;
guint t2 = oldsize - array->head;
/* [0-----TAIL][HEAD------SIZE]
*
* We want to end up with
* [HEAD------------------TAIL][----FREEDATA------NEWSIZE]
*
* 1) move [HEAD-----SIZE] part to beginning of new array
* 2) move [0-------TAIL] part new array, after previous part
*/
memcpy (array2, array->array + (elt_size * array->head), t2 * elt_size);
memcpy (array2 + t2 * elt_size, array->array, t1 * elt_size);
g_free (array->array);
array->array = array2;
array->head = 0;
} else {
/* Fast path, we just need to grow the array */
array->array = g_realloc (array->array, elt_size * newsize);
memset (array->array + elt_size * oldsize, 0,
elt_size * (newsize - oldsize));
}
array->tail = oldsize;
array->size = newsize;
}
/**
* gst_queue_array_push_element_tail: (skip)
* @array: a #GstQueueArray object
* @p_struct: address of element or structure to push to the tail of the queue
*
* Pushes the element at address @p_struct to the tail of the queue @array
* (Copies the contents of a structure of the struct_size specified when
* creating the queue into the array).
*
* Since: 1.6
*/
void
gst_queue_array_push_tail_struct (GstQueueArray * array, gpointer p_struct)
{
guint elt_size;
g_return_if_fail (p_struct != NULL);
elt_size = array->elt_size;
/* Check if we need to make room */
if (G_UNLIKELY (array->length == array->size))
gst_queue_array_do_expand (array);
memcpy (array->array + elt_size * array->tail, p_struct, elt_size);
array->tail++;
array->tail %= array->size;
array->length++;
} }
/** /**
@ -143,40 +294,10 @@ void
gst_queue_array_push_tail (GstQueueArray * array, gpointer data) gst_queue_array_push_tail (GstQueueArray * array, gpointer data)
{ {
/* Check if we need to make room */ /* Check if we need to make room */
if (G_UNLIKELY (array->length == array->size)) { if (G_UNLIKELY (array->length == array->size))
/* newsize is 50% bigger */ gst_queue_array_do_expand (array);
guint newsize = MAX ((3 * array->size) / 2, array->size + 1);
/* copy over data */ *(gpointer *) (array->array + sizeof (gpointer) * array->tail) = data;
if (array->tail != 0) {
gpointer *array2 = g_new0 (gpointer, newsize);
guint t1 = array->head;
guint t2 = array->size - array->head;
/* [0-----TAIL][HEAD------SIZE]
*
* We want to end up with
* [HEAD------------------TAIL][----FREEDATA------NEWSIZE]
*
* 1) move [HEAD-----SIZE] part to beginning of new array
* 2) move [0-------TAIL] part new array, after previous part
*/
memcpy (array2, &array->array[array->head], t2 * sizeof (gpointer));
memcpy (&array2[t2], array->array, t1 * sizeof (gpointer));
g_free (array->array);
array->array = array2;
array->head = 0;
} else {
/* Fast path, we just need to grow the array */
array->array = g_renew (gpointer, array->array, newsize);
}
array->tail = array->size;
array->size = newsize;
}
array->array[array->tail] = data;
array->tail++; array->tail++;
array->tail %= array->size; array->tail %= array->size;
array->length++; array->length++;
@ -198,6 +319,101 @@ gst_queue_array_is_empty (GstQueueArray * array)
return (array->length == 0); return (array->length == 0);
} }
/**
* gst_queue_array_drop_struct: (skip)
* @array: a #GstQueueArray object
* @idx: index to drop
* @p_struct: address into which to store the data of the dropped structure, or NULL
*
* Drops the queue element at position @idx from queue @array and copies the
* data of the element or structure that was removed into @p_struct if
* @p_struct is set (not NULL).
*
* Returns: TRUE on success, or FALSE on error
*
* Since: 1.6
*/
gboolean
gst_queue_array_drop_struct (GstQueueArray * array, guint idx,
gpointer p_struct)
{
int first_item_index, last_item_index;
guint elt_size;
g_return_val_if_fail (array->length > 0, FALSE);
g_return_val_if_fail (idx < array->size, FALSE);
elt_size = array->elt_size;
first_item_index = array->head;
/* tail points to the first free spot */
last_item_index = (array->tail - 1 + array->size) % array->size;
if (p_struct != NULL)
memcpy (p_struct, array->array + elt_size * idx, elt_size);
/* simple case idx == first item */
if (idx == first_item_index) {
/* move the head plus one */
array->head++;
array->head %= array->size;
array->length--;
return TRUE;
}
/* simple case idx == last item */
if (idx == last_item_index) {
/* move tail minus one, potentially wrapping */
array->tail = (array->tail - 1 + array->size) % array->size;
array->length--;
return TRUE;
}
/* non-wrapped case */
if (first_item_index < last_item_index) {
g_assert (first_item_index < idx && idx < last_item_index);
/* move everything beyond idx one step towards zero in array */
memmove (array->array + elt_size * idx,
array->array + elt_size * (idx + 1),
(last_item_index - idx) * elt_size);
/* tail might wrap, ie if tail == 0 (and last_item_index == size) */
array->tail = (array->tail - 1 + array->size) % array->size;
array->length--;
return TRUE;
}
/* only wrapped cases left */
g_assert (first_item_index > last_item_index);
if (idx < last_item_index) {
/* idx is before last_item_index, move data towards zero */
memmove (array->array + elt_size * idx,
array->array + elt_size * (idx + 1),
(last_item_index - idx) * elt_size);
/* tail should not wrap in this case! */
g_assert (array->tail > 0);
array->tail--;
array->length--;
return TRUE;
}
if (idx > first_item_index) {
/* idx is after first_item_index, move data to higher indices */
memmove (array->array + elt_size * (first_item_index + 1),
array->array + elt_size * first_item_index,
(idx - first_item_index) * elt_size);
array->head++;
/* head should not wrap in this case! */
g_assert (array->head < array->size);
array->length--;
return TRUE;
}
g_return_val_if_reached (FALSE);
}
/** /**
* gst_queue_array_drop_element: (skip) * gst_queue_array_drop_element: (skip)
* @array: a #GstQueueArray object * @array: a #GstQueueArray object
@ -212,75 +428,12 @@ gst_queue_array_is_empty (GstQueueArray * array)
gpointer gpointer
gst_queue_array_drop_element (GstQueueArray * array, guint idx) gst_queue_array_drop_element (GstQueueArray * array, guint idx)
{ {
int first_item_index, last_item_index; gpointer ptr;
gpointer element;
g_return_val_if_fail (array->length > 0, NULL); if (!gst_queue_array_drop_struct (array, idx, &ptr))
g_return_val_if_fail (idx < array->size, NULL); return NULL;
first_item_index = array->head; return ptr;
/* tail points to the first free spot */
last_item_index = (array->tail - 1 + array->size) % array->size;
element = array->array[idx];
/* simple case idx == first item */
if (idx == first_item_index) {
/* move the head plus one */
array->head++;
array->head %= array->size;
array->length--;
return element;
}
/* simple case idx == last item */
if (idx == last_item_index) {
/* move tail minus one, potentially wrapping */
array->tail = (array->tail - 1 + array->size) % array->size;
array->length--;
return element;
}
/* non-wrapped case */
if (first_item_index < last_item_index) {
g_assert (first_item_index < idx && idx < last_item_index);
/* move everything beyond idx one step towards zero in array */
memmove (&array->array[idx],
&array->array[idx + 1], (last_item_index - idx) * sizeof (gpointer));
/* tail might wrap, ie if tail == 0 (and last_item_index == size) */
array->tail = (array->tail - 1 + array->size) % array->size;
array->length--;
return element;
}
/* only wrapped cases left */
g_assert (first_item_index > last_item_index);
if (idx < last_item_index) {
/* idx is before last_item_index, move data towards zero */
memmove (&array->array[idx],
&array->array[idx + 1], (last_item_index - idx) * sizeof (gpointer));
/* tail should not wrap in this case! */
g_assert (array->tail > 0);
array->tail--;
array->length--;
return element;
}
if (idx > first_item_index) {
/* idx is after first_item_index, move data to higher indices */
memmove (&array->array[first_item_index + 1],
&array->array[first_item_index],
(idx - first_item_index) * sizeof (gpointer));
array->head++;
/* head should not wrap in this case! */
g_assert (array->head < array->size);
array->length--;
return element;
}
g_return_val_if_reached (NULL);
} }
/** /**
@ -305,17 +458,28 @@ gst_queue_array_drop_element (GstQueueArray * array, guint idx)
guint guint
gst_queue_array_find (GstQueueArray * array, GCompareFunc func, gpointer data) gst_queue_array_find (GstQueueArray * array, GCompareFunc func, gpointer data)
{ {
gpointer p_element;
guint elt_size;
guint i; guint i;
/* For struct arrays we need to implement this differently so that
* the user gets a pointer to the element data not the dereferenced
* pointer itself */
g_return_val_if_fail (array->struct_array == FALSE, -1);
elt_size = array->elt_size;
if (func != NULL) { if (func != NULL) {
/* Scan from head to tail */ /* Scan from head to tail */
for (i = 0; i < array->length; i++) { for (i = 0; i < array->length; i++) {
if (func (array->array[(i + array->head) % array->size], data) == 0) p_element = array->array + ((i + array->head) % array->size) * elt_size;
if (func (*(gpointer *) p_element, data) == 0)
return (i + array->head) % array->size; return (i + array->head) % array->size;
} }
} else { } else {
for (i = 0; i < array->length; i++) { for (i = 0; i < array->length; i++) {
if (array->array[(i + array->head) % array->size] == data) p_element = array->array + ((i + array->head) % array->size) * elt_size;
if (*(gpointer *) p_element == data)
return (i + array->head) % array->size; return (i + array->head) % array->size;
} }
} }

16
libs/gst/base/gstqueuearray.h
View file

@ -50,4 +50,20 @@ guint gst_queue_array_find (GstQueueArray * array,
guint gst_queue_array_get_length (GstQueueArray * array); guint gst_queue_array_get_length (GstQueueArray * array);
/* Functions for use with structures */
GstQueueArray * gst_queue_array_new_for_struct (gsize struct_size,
guint initial_size);
void gst_queue_array_push_tail_struct (GstQueueArray * array,
gpointer p_struct);
gpointer gst_queue_array_pop_head_struct (GstQueueArray * array);
gpointer gst_queue_array_peek_head_struct (GstQueueArray * array);
gboolean gst_queue_array_drop_struct (GstQueueArray * array,
guint idx,
gpointer p_struct);
#endif #endif

5
win32/common/libgstbase.def
View file

@ -282,14 +282,19 @@ EXPORTS
gst_flow_combiner_update_pad_flow gst_flow_combiner_update_pad_flow
gst_push_src_get_type gst_push_src_get_type
gst_queue_array_drop_element gst_queue_array_drop_element
gst_queue_array_drop_struct
gst_queue_array_find gst_queue_array_find
gst_queue_array_free gst_queue_array_free
gst_queue_array_get_length gst_queue_array_get_length
gst_queue_array_is_empty gst_queue_array_is_empty
gst_queue_array_new gst_queue_array_new
gst_queue_array_new_for_struct
gst_queue_array_peek_head gst_queue_array_peek_head
gst_queue_array_peek_head_struct
gst_queue_array_pop_head gst_queue_array_pop_head
gst_queue_array_pop_head_struct
gst_queue_array_push_tail gst_queue_array_push_tail
gst_queue_array_push_tail_struct
gst_type_find_helper gst_type_find_helper
gst_type_find_helper_for_buffer gst_type_find_helper_for_buffer
gst_type_find_helper_for_data gst_type_find_helper_for_data