Commit 588cdcd3 authored by Edward Hervey's avatar Edward Hervey 🤘 Committed by Edward Hervey

libs: New growing-only queue.

This is a queue which has the same API as GQueue, except that:
* It uses an array, instead of a doubled-linked-list
* The array can only grow.

This code is not-threadsafe. It is up to the owner to make sure the
proper locking is taken before calling this API.
parent 49ea16e0
......@@ -13,7 +13,8 @@ libgstbase_@GST_API_VERSION@_la_SOURCES = \
gstbytewriter.c \
gstcollectpads.c \
gstpushsrc.c \
gsttypefindhelper.c
gsttypefindhelper.c \
gstqueuearray.c
libgstbase_@GST_API_VERSION@_la_CFLAGS = $(GST_OBJ_CFLAGS)
libgstbase_@GST_API_VERSION@_la_LIBADD = $(GST_OBJ_LIBS)
......@@ -33,7 +34,8 @@ libgstbase_@GST_API_VERSION@include_HEADERS = \
gstbytewriter.h \
gstcollectpads.h \
gstpushsrc.h \
gsttypefindhelper.h
gsttypefindhelper.h \
gstqueuearray.h
noinst_HEADERS = \
gstbytereader-docs.h \
......
/* GStreamer
* Copyright (C) 2009 Edward Hervey <bilboed@bilboed.com>
*
* gstqueuearray.c:
*
* 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., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*/
#include <string.h>
#include <gst/gst.h>
#include "gstqueuearray.h"
GstQueueArray *
gst_queue_array_new (guint initial_size)
{
GstQueueArray *array = g_malloc (sizeof (GstQueueArray));
array->size = initial_size;
array->array = g_new0 (gpointer, initial_size);
array->head = 0;
array->tail = 0;
array->length = 0;
return array;
}
gpointer
gst_queue_array_pop_head (GstQueueArray * array)
{
gpointer ret;
/* empty array */
if (G_UNLIKELY (array->length == 0))
return NULL;
ret = array->array[array->head];
array->head++;
array->head %= array->size;
array->length--;
return ret;
}
void
gst_queue_array_push_tail (GstQueueArray * array, gpointer data)
{
/* Check if we need to make room */
if (G_UNLIKELY (array->length == array->size)) {
/* newsize is 50% bigger */
guint newsize = (3 * array->size) / 2;
/* copy over 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->size;
array->length++;
}
gboolean
gst_queue_array_is_empty (GstQueueArray * array)
{
return (array->length == 0);
}
void
gst_queue_array_free (GstQueueArray * array)
{
g_free (array->array);
g_free (array);
}
void
gst_queue_array_drop_element (GstQueueArray * array, guint idx)
{
if (idx == array->head) {
/* just move the head */
array->head++;
array->head %= array->size;
return;
}
if (idx == array->tail - 1) {
/* just move the tail */
array->tail = (array->tail - 1 + array->size) % array->size;
return;
}
/* drop the element #idx... and readjust the array */
if (array->head < array->tail) {
/* Make sure it's within the boundaries */
g_assert (array->head < idx && idx <= array->tail);
/* ends not wrapped */
/* move head-idx to head+1 */
memcpy (&array->array[array->head + 1],
&array->array[array->head], (idx - array->head) * sizeof (gpointer));
array->tail--;
} else {
/* ends are wrapped */
if (idx < array->tail) {
/* move idx-tail backwards one */
memcpy (&array->array[idx - 1],
&array->array[idx], (array->tail - idx) * sizeof (gpointer));
array->tail--;
} else if (idx >= array->head) {
/* move head-idx forwards one */
memcpy (&array->array[array->head],
&array->array[array->head + 1],
(idx - array->head) * sizeof (gpointer));
array->head++;
} else
g_assert_not_reached ();
}
}
guint
gst_queue_array_find (GstQueueArray * array, GCompareFunc func, gpointer data)
{
guint i;
/* Scan from head to tail */
for (i = array->head; i < array->length; i = (i + 1) % array->size)
if (func (array->array[i], data) == 0)
return i;
return -1;
}
/* GStreamer
* Copyright (C) 2009-2010 Edward Hervey <bilboed@bilboed.com>
*
* gstqueuearray.h:
*
* 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., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*/
#include <glib.h>
#ifndef __GST_QUEUE_ARRAY_H__
#define __GST_QUEUE_ARRAY_H__
typedef struct _GstQueueArray GstQueueArray;
struct _GstQueueArray
{
gpointer *array;
guint size;
guint head;
guint tail;
guint length;
};
GstQueueArray *gst_queue_array_new (guint initial_size);
gpointer gst_queue_array_pop_head (GstQueueArray * array);
void gst_queue_array_push_tail (GstQueueArray * array, gpointer data);
gboolean gst_queue_array_is_empty (GstQueueArray * array);
void gst_queue_array_free (GstQueueArray * array);
void gst_queue_array_drop_element (GstQueueArray * array, guint idx);
guint gst_queue_array_find (GstQueueArray * array, GCompareFunc func,
gpointer data);
#endif
......@@ -237,6 +237,11 @@ EXPORTS
gst_collect_pads_stop
gst_collect_pads_take_buffer
gst_push_src_get_type
gst_queue_array_free
gst_queue_array_is_empty
gst_queue_array_new
gst_queue_array_pop_head
gst_queue_array_push_tail
gst_type_find_helper
gst_type_find_helper_for_buffer
gst_type_find_helper_for_data
......
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