gstreamer/gst/gstbuffer.c
Erik Walthinsen c7c1192ab3 fixed stupid bug in buffer_span()
Original commit message from CVS:
fixed stupid bug in buffer_span()
2001-08-11 22:04:48 +00:00

428 lines
11 KiB
C

/* GStreamer
* Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>
* 2000 Wim Taymans <wtay@chello.be>
*
* gstbuffer.c: Buffer operations
*
* 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.
*/
/* this file makes too much noise for most debugging sessions */
#define GST_DEBUG_FORCE_DISABLE
#include "gst_private.h"
#include "gstbuffer.h"
static GMemChunk *_gst_buffer_chunk;
static GMutex *_gst_buffer_chunk_lock;
void
_gst_buffer_initialize (void)
{
int buffersize = sizeof(GstBuffer);
// round up to the nearest 32 bytes for cache-line and other efficiencies
buffersize = (((buffersize-1) / 32) + 1) * 32;
_gst_buffer_chunk = g_mem_chunk_new ("GstBuffer", buffersize,
buffersize * 32, G_ALLOC_AND_FREE);
_gst_buffer_chunk_lock = g_mutex_new ();
}
/**
* gst_buffer_new:
*
* Create a new buffer.
*
* Returns: new buffer
*/
GstBuffer*
gst_buffer_new(void)
{
GstBuffer *buffer;
g_mutex_lock (_gst_buffer_chunk_lock);
buffer = g_mem_chunk_alloc (_gst_buffer_chunk);
g_mutex_unlock (_gst_buffer_chunk_lock);
GST_INFO (GST_CAT_BUFFER,"creating new buffer %p",buffer);
buffer->lock = g_mutex_new ();
#ifdef HAVE_ATOMIC_H
atomic_set (&buffer->refcount, 1);
#else
buffer->refcount = 1;
#endif
buffer->flags = 0;
buffer->data = NULL;
buffer->size = 0;
buffer->maxsize = 0;
buffer->offset = -1;
buffer->timestamp = 0;
buffer->parent = NULL;
buffer->pool = NULL;
buffer->free = NULL;
buffer->copy = NULL;
return buffer;
}
/**
* gst_buffer_new_from_pool:
* @pool: the buffer pool to use
*
* Create a new buffer using the specified bufferpool.
*
* Returns: new buffer
*/
GstBuffer*
gst_buffer_new_from_pool (GstBufferPool *pool)
{
return gst_buffer_pool_new_buffer (pool);
}
/**
* gst_buffer_create_sub:
* @parent: parent buffer
* @offset: offset into parent buffer
* @size: size of new subbuffer
*
* Creates a sub-buffer from the parent at a given offset.
*
* Returns: new buffer
*/
GstBuffer*
gst_buffer_create_sub (GstBuffer *parent,
guint32 offset,
guint32 size)
{
GstBuffer *buffer;
g_return_val_if_fail (parent != NULL, NULL);
g_return_val_if_fail (size > 0, NULL);
g_return_val_if_fail ((offset+size) <= parent->size, NULL);
g_mutex_lock (_gst_buffer_chunk_lock);
buffer = g_mem_chunk_alloc (_gst_buffer_chunk);
g_mutex_unlock (_gst_buffer_chunk_lock);
GST_INFO (GST_CAT_BUFFER,"creating new subbuffer %p from parent %p", buffer, parent);
buffer->lock = g_mutex_new ();
#ifdef HAVE_ATOMIC_H
atomic_set (&buffer->refcount, 1);
#else
buffer->refcount = 1;
#endif
// copy flags and type from parent, for lack of better
buffer->flags = parent->flags;
// set the data pointer, size, offset, and maxsize
buffer->data = parent->data + offset;
buffer->size = size;
buffer->maxsize = parent->size - offset;
// deal with bogus/unknown offsets
if (parent->offset != -1)
buffer->offset = parent->offset + offset;
else
buffer->offset = -1;
// again, for lack of better, copy parent's timestamp
buffer->timestamp = parent->timestamp;
buffer->maxage = parent->maxage;
// if the parent buffer is a subbuffer itself, use its parent, a real buffer
if (parent->parent != NULL)
parent = parent->parent;
// set parentage and reference the parent
buffer->parent = parent;
gst_buffer_ref (parent);
buffer->pool = NULL;
// return the new subbuffer
return buffer;
}
// FIXME FIXME: how does this overlap with the newly-added gst_buffer_span() ???
/**
* gst_buffer_append:
* @buffer: a buffer
* @append: the buffer to append
*
* Creates a new buffer by appending the data of append to the
* existing data of buffer.
*
* Returns: new buffer
*/
GstBuffer*
gst_buffer_append (GstBuffer *buffer,
GstBuffer *append)
{
guint size;
GstBuffer *newbuf;
g_return_val_if_fail (buffer != NULL, NULL);
g_return_val_if_fail (append != NULL, NULL);
g_return_val_if_fail (buffer->pool == NULL, NULL);
GST_INFO (GST_CAT_BUFFER,"appending buffers %p and %p",buffer,append);
GST_BUFFER_LOCK (buffer);
// the buffer is not used by anyone else
if (GST_BUFFER_REFCOUNT (buffer) == 1 && buffer->parent == NULL
&& !GST_BUFFER_FLAG_IS_SET (buffer, GST_BUFFER_DONTFREE)) {
// save the old size
size = buffer->size;
buffer->size += append->size;
buffer->data = g_realloc (buffer->data, buffer->size);
memcpy(buffer->data + size, append->data, append->size);
GST_BUFFER_UNLOCK (buffer);
}
// the buffer is used, create a new one
else {
newbuf = gst_buffer_new ();
newbuf->size = buffer->size+append->size;
newbuf->data = g_malloc (newbuf->size);
memcpy (newbuf->data, buffer->data, buffer->size);
memcpy (newbuf->data+buffer->size, append->data, append->size);
GST_BUFFER_UNLOCK (buffer);
gst_buffer_unref (buffer);
buffer = newbuf;
}
return buffer;
}
/**
* gst_buffer_destroy:
* @buffer: the GstBuffer to destroy
*
* destroy the buffer
*/
void gst_buffer_destroy (GstBuffer *buffer)
{
g_return_if_fail (buffer != NULL);
GST_INFO (GST_CAT_BUFFER,"freeing %sbuffer %p", (buffer->parent?"sub":""),buffer);
// free the data only if there is some, DONTFREE isn't set, and not sub
if (GST_BUFFER_DATA (buffer) &&
!GST_BUFFER_FLAG_IS_SET (buffer, GST_BUFFER_DONTFREE) &&
(buffer->parent == NULL)) {
// if there's a free function, use it
if (buffer->free != NULL) {
(buffer->free)(buffer);
} else {
g_free (GST_BUFFER_DATA (buffer));
}
}
// unreference the parent if there is one
if (buffer->parent != NULL)
gst_buffer_unref (buffer->parent);
g_mutex_free (buffer->lock);
//g_print("freed mutex\n");
// remove it entirely from memory
g_mutex_lock (_gst_buffer_chunk_lock);
g_mem_chunk_free (_gst_buffer_chunk,buffer);
g_mutex_unlock (_gst_buffer_chunk_lock);
}
/**
* gst_buffer_ref:
* @buffer: the GstBuffer to reference
*
* Increment the refcount of this buffer.
*/
void
gst_buffer_ref (GstBuffer *buffer)
{
g_return_if_fail (buffer != NULL);
GST_DEBUG (0,"referencing buffer %p\n", buffer);
#ifdef HAVE_ATOMIC_H
//g_return_if_fail(atomic_read(&(buffer->refcount)) > 0);
atomic_inc (&(buffer->refcount));
#else
g_return_if_fail (buffer->refcount > 0);
GST_BUFFER_LOCK (buffer);
buffer->refcount++;
GST_BUFFER_UNLOCK (buffer);
#endif
}
/**
* gst_buffer_ref_by_count:
* @buffer: the GstBuffer to reference
* @count: a number
*
* Increment the refcount of this buffer by the given number.
*/
void
gst_buffer_ref_by_count (GstBuffer *buffer, int count)
{
g_return_if_fail (buffer != NULL);
g_return_if_fail (count > 0);
#ifdef HAVE_ATOMIC_H
g_return_if_fail (atomic_read (&(buffer->refcount)) > 0);
atomic_add (count, &(buffer->refcount));
#else
g_return_if_fail (buffer->refcount > 0);
GST_BUFFER_LOCK (buffer);
buffer->refcount += count;
GST_BUFFER_UNLOCK (buffer);
#endif
}
/**
* gst_buffer_unref:
* @buffer: the GstBuffer to unref
*
* Decrement the refcount of this buffer. If the refcount is
* zero, the buffer will be destroyed.
*/
void
gst_buffer_unref (GstBuffer *buffer)
{
gint zero;
g_return_if_fail (buffer != NULL);
GST_DEBUG (0,"unreferencing buffer %p\n", buffer);
#ifdef HAVE_ATOMIC_H
g_return_if_fail (atomic_read (&(buffer->refcount)) > 0);
zero = atomic_dec_and_test (&(buffer->refcount));
#else
g_return_if_fail (buffer->refcount > 0);
GST_BUFFER_LOCK (buffer);
buffer->refcount--;
zero = (buffer->refcount == 0);
GST_BUFFER_UNLOCK (buffer);
#endif
/* if we ended up with the refcount at zero, destroy the buffer */
if (zero) {
// if it came from a pool, give it back
if (buffer->pool != NULL) {
gst_buffer_pool_destroy_buffer (buffer->pool, buffer);
return;
}
else {
gst_buffer_destroy (buffer);
}
}
}
/**
* gst_buffer_copy:
* @buffer: the orignal GstBuffer to make a copy of
*
* Make a full copy of the give buffer, data and all.
*
* Returns: new buffer
*/
GstBuffer *
gst_buffer_copy (GstBuffer *buffer)
{
GstBuffer *newbuf;
// allocate a new buffer
newbuf = gst_buffer_new();
// if a copy function exists, use it, else copy the bytes
if (buffer->copy != NULL) {
(buffer->copy)(buffer,newbuf);
} else {
// copy the absolute size
newbuf->size = buffer->size;
// allocate space for the copy
newbuf->data = (guchar *)g_malloc (buffer->size);
// copy the data straight across
memcpy(newbuf->data,buffer->data,buffer->size);
// the new maxsize is the same as the size, since we just malloc'd it
newbuf->maxsize = newbuf->size;
}
newbuf->offset = buffer->offset;
newbuf->timestamp = buffer->timestamp;
newbuf->maxage = buffer->maxage;
// since we just created a new buffer, so we have no ties to old stuff
newbuf->parent = NULL;
newbuf->pool = NULL;
return newbuf;
}
GstBuffer *
gst_buffer_span (GstBuffer *buf1, guint32 offset, GstBuffer *buf2, guint32 len)
{
GstBuffer *newbuf;
// make sure buf1 has a lower address than buf2
if (buf1->data > buf2->data) {
GstBuffer *tmp = buf1;
buf1 = buf2;
buf2 = tmp;
}
// if the two buffers have the same parent and are adjacent
if ((buf1->parent == buf2->parent) &&
((buf1->data + buf1->size) == buf2->data)) {
// we simply create a subbuffer of the common parent
return gst_buffer_create_sub(buf1->parent, buf1->data - (buf1->parent->data) + offset, len);
}
// otherwise we simply have to brute-force copy the buffers
newbuf = gst_buffer_new();
// put in new size
newbuf->size = len;
// allocate space for the copy
newbuf->data = (guchar *)g_malloc(len);
// copy the first buffer's data across
memcpy(newbuf->data, buf1->data + offset, buf1->size - offset);
// copy the second buffer's data across
memcpy(newbuf->data + offset, buf2->data, len - (buf1->size - offset));
if (newbuf->offset != -1)
newbuf->offset = buf1->offset + offset;
newbuf->timestamp = buf1->timestamp;
if (buf2->maxage > buf1->maxage) newbuf->maxage = buf2->maxage;
else newbuf->maxage = buf1->maxage;
newbuf->parent = NULL;
newbuf->pool = NULL;
return newbuf;
}
GstBuffer *
gst_buffer_merge (GstBuffer *buf1, GstBuffer *buf2)
{
// we're just a specific case of the more general gst_buffer_span()
return gst_buffer_span(buf1, 0, buf2, buf1->size + buf2->size);
}