root/gst/gstminiobject.c
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DEFINITIONS
This source file includes following definitions.
- gst_mini_object_get_type
- gst_mini_object_base_init
- gst_mini_object_base_finalize
- gst_mini_object_class_init
- gst_mini_object_init
- gst_mini_object_copy_default
- gst_mini_object_finalize
- gst_mini_object_new
- gst_mini_object_copy
- gst_mini_object_is_writable
- gst_mini_object_make_writable
- gst_mini_object_ref
- gst_mini_object_free
- gst_mini_object_unref
- gst_mini_object_replace
- gst_value_mini_object_init
- gst_value_mini_object_free
- gst_value_mini_object_copy
- gst_value_mini_object_peek_pointer
- gst_value_mini_object_collect
- gst_value_mini_object_lcopy
- gst_value_set_mini_object
- gst_value_take_mini_object
- gst_value_get_mini_object
- gst_value_dup_mini_object
- param_mini_object_init
- param_mini_object_set_default
- param_mini_object_validate
- param_mini_object_values_cmp
- gst_param_spec_mini_object_get_type
- gst_param_spec_mini_object
/* GStreamer
* Copyright (C) 2005 David Schleef <ds@schleef.org>
*
* gstminiobject.h: Header for GstMiniObject
*
* 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.
*/
/**
* SECTION:gstminiobject
* @short_description: Lightweight base class for the GStreamer object hierarchy
*
* #GstMiniObject is a baseclass like #GObject, but has been stripped down of
* features to be fast and small.
* It offers sub-classing and ref-counting in the same way as #GObject does.
* It has no properties and no signal-support though.
*
* Last reviewed on 2005-11-23 (0.9.5)
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include "gst/gst_private.h"
#include "gst/gstminiobject.h"
#include "gst/gstinfo.h"
#include <gobject/gvaluecollector.h>
#ifndef GST_DISABLE_TRACE
#include "gsttrace.h"
static GstAllocTrace *_gst_mini_object_trace;
#endif
#define DEBUG_REFCOUNT
#if 0
static void gst_mini_object_base_init (gpointer g_class);
static void gst_mini_object_base_finalize (gpointer g_class);
#endif
static void gst_mini_object_class_init (gpointer g_class, gpointer class_data);
static void gst_mini_object_init (GTypeInstance * instance, gpointer klass);
static void gst_value_mini_object_init (GValue * value);
static void gst_value_mini_object_free (GValue * value);
static void gst_value_mini_object_copy (const GValue * src_value,
GValue * dest_value);
static gpointer gst_value_mini_object_peek_pointer (const GValue * value);
static gchar *gst_value_mini_object_collect (GValue * value,
guint n_collect_values, GTypeCValue * collect_values, guint collect_flags);
static gchar *gst_value_mini_object_lcopy (const GValue * value,
guint n_collect_values, GTypeCValue * collect_values, guint collect_flags);
static GstMiniObject *gst_mini_object_copy_default (const GstMiniObject * obj);
static void gst_mini_object_finalize (GstMiniObject * obj);
GType
gst_mini_object_get_type (void)
{
static GType _gst_mini_object_type = 0;
if (G_UNLIKELY (_gst_mini_object_type == 0)) {
static const GTypeValueTable value_table = {
gst_value_mini_object_init,
gst_value_mini_object_free,
gst_value_mini_object_copy,
gst_value_mini_object_peek_pointer,
(char *) "p",
gst_value_mini_object_collect,
(char *) "p",
gst_value_mini_object_lcopy
};
static const GTypeInfo mini_object_info = {
sizeof (GstMiniObjectClass),
#if 0
gst_mini_object_base_init,
gst_mini_object_base_finalize,
#else
NULL, NULL,
#endif
gst_mini_object_class_init,
NULL,
NULL,
sizeof (GstMiniObject),
0,
(GInstanceInitFunc) gst_mini_object_init,
&value_table
};
static const GTypeFundamentalInfo mini_object_fundamental_info = {
(G_TYPE_FLAG_CLASSED | G_TYPE_FLAG_INSTANTIATABLE |
G_TYPE_FLAG_DERIVABLE | G_TYPE_FLAG_DEEP_DERIVABLE)
};
_gst_mini_object_type = g_type_fundamental_next ();
g_type_register_fundamental (_gst_mini_object_type, "GstMiniObject",
&mini_object_info, &mini_object_fundamental_info, G_TYPE_FLAG_ABSTRACT);
#ifndef GST_DISABLE_TRACE
_gst_mini_object_trace =
gst_alloc_trace_register (g_type_name (_gst_mini_object_type));
#endif
}
return _gst_mini_object_type;
}
#if 0
static void
gst_mini_object_base_init (gpointer g_class)
{
/* do nothing */
}
static void
gst_mini_object_base_finalize (gpointer g_class)
{
/* do nothing */
}
#endif
static void
gst_mini_object_class_init (gpointer g_class, gpointer class_data)
{
GstMiniObjectClass *mo_class = GST_MINI_OBJECT_CLASS (g_class);
mo_class->copy = gst_mini_object_copy_default;
mo_class->finalize = gst_mini_object_finalize;
}
static void
gst_mini_object_init (GTypeInstance * instance, gpointer klass)
{
GstMiniObject *mini_object = GST_MINI_OBJECT_CAST (instance);
mini_object->refcount = 1;
}
static GstMiniObject *
gst_mini_object_copy_default (const GstMiniObject * obj)
{
g_warning ("GstMiniObject classes must implement GstMiniObject::copy");
return NULL;
}
static void
gst_mini_object_finalize (GstMiniObject * obj)
{
/* do nothing */
/* WARNING: if anything is ever put in this method, make sure that the
* following sub-classes' finalize method chains up to this one:
* gstbuffer
* gstevent
* gstmessage
* gstquery
*/
}
/**
* gst_mini_object_new:
* @type: the #GType of the mini-object to create
*
* Creates a new mini-object of the desired type.
*
* MT safe
*
* Returns: the new mini-object.
*/
GstMiniObject *
gst_mini_object_new (GType type)
{
GstMiniObject *mini_object;
/* we don't support dynamic types because they really aren't useful,
* and could cause refcount problems */
mini_object = (GstMiniObject *) g_type_create_instance (type);
#ifndef GST_DISABLE_TRACE
gst_alloc_trace_new (_gst_mini_object_trace, mini_object);
#endif
return mini_object;
}
/* FIXME 0.11: Current way of doing the copy makes it impossible
* to currectly chain to the parent classes and do a copy in a
* subclass without knowing all internals of the parent classes.
*
* For 0.11 we should do something like the following:
* - The GstMiniObjectClass::copy() implementation of GstMiniObject
* should call g_type_create_instance() with the type of the source
* object.
* - All GstMiniObjectClass::copy() implementations should as first
* thing chain up to the parent class and then do whatever they need
* to do to copy their type specific data. Note that this way the
* instance_init() functions are called!
*/
/**
* gst_mini_object_copy:
* @mini_object: the mini-object to copy
*
* Creates a copy of the mini-object.
*
* MT safe
*
* Returns: the new mini-object.
*/
GstMiniObject *
gst_mini_object_copy (const GstMiniObject * mini_object)
{
GstMiniObjectClass *mo_class;
g_return_val_if_fail (mini_object != NULL, NULL);
mo_class = GST_MINI_OBJECT_GET_CLASS (mini_object);
return mo_class->copy (mini_object);
}
/**
* gst_mini_object_is_writable:
* @mini_object: the mini-object to check
*
* Checks if a mini-object is writable. A mini-object is writable
* if the reference count is one and the #GST_MINI_OBJECT_FLAG_READONLY
* flag is not set. Modification of a mini-object should only be
* done after verifying that it is writable.
*
* MT safe
*
* Returns: TRUE if the object is writable.
*/
gboolean
gst_mini_object_is_writable (const GstMiniObject * mini_object)
{
g_return_val_if_fail (mini_object != NULL, FALSE);
return (GST_MINI_OBJECT_REFCOUNT_VALUE (mini_object) == 1) &&
((mini_object->flags & GST_MINI_OBJECT_FLAG_READONLY) == 0);
}
/**
* gst_mini_object_make_writable:
* @mini_object: the mini-object to make writable
*
* Checks if a mini-object is writable. If not, a writable copy is made and
* returned. This gives away the reference to the original mini object,
* and returns a reference to the new object.
*
* MT safe
*
* Returns: a mini-object (possibly the same pointer) that is writable.
*/
GstMiniObject *
gst_mini_object_make_writable (GstMiniObject * mini_object)
{
GstMiniObject *ret;
g_return_val_if_fail (mini_object != NULL, NULL);
if (gst_mini_object_is_writable (mini_object)) {
ret = mini_object;
} else {
GST_CAT_DEBUG (GST_CAT_PERFORMANCE, "copy %s miniobject",
g_type_name (G_TYPE_FROM_INSTANCE (mini_object)));
ret = gst_mini_object_copy (mini_object);
gst_mini_object_unref (mini_object);
}
return ret;
}
/**
* gst_mini_object_ref:
* @mini_object: the mini-object
*
* Increase the reference count of the mini-object.
*
* Note that the refcount affects the writeability
* of @mini-object, see gst_mini_object_is_writable(). It is
* important to note that keeping additional references to
* GstMiniObject instances can potentially increase the number
* of memcpy operations in a pipeline, especially if the miniobject
* is a #GstBuffer.
*
* Returns: the mini-object.
*/
GstMiniObject *
gst_mini_object_ref (GstMiniObject * mini_object)
{
g_return_val_if_fail (mini_object != NULL, NULL);
/* we can't assert that the refcount > 0 since the _free functions
* increments the refcount from 0 to 1 again to allow resurecting
* the object
g_return_val_if_fail (mini_object->refcount > 0, NULL);
*/
#ifdef DEBUG_REFCOUNT
g_return_val_if_fail (GST_IS_MINI_OBJECT (mini_object), NULL);
GST_CAT_TRACE (GST_CAT_REFCOUNTING, "%p ref %d->%d", mini_object,
GST_MINI_OBJECT_REFCOUNT_VALUE (mini_object),
GST_MINI_OBJECT_REFCOUNT_VALUE (mini_object) + 1);
#endif
g_atomic_int_inc (&mini_object->refcount);
return mini_object;
}
static void
gst_mini_object_free (GstMiniObject * mini_object)
{
GstMiniObjectClass *mo_class;
/* At this point, the refcount of the object is 0. We increase the refcount
* here because if a subclass recycles the object and gives out a new
* reference we don't want to free the instance anymore. */
gst_mini_object_ref (mini_object);
mo_class = GST_MINI_OBJECT_GET_CLASS (mini_object);
mo_class->finalize (mini_object);
/* decrement the refcount again, if the subclass recycled the object we don't
* want to free the instance anymore */
if (G_LIKELY (g_atomic_int_dec_and_test (&mini_object->refcount))) {
#ifndef GST_DISABLE_TRACE
gst_alloc_trace_free (_gst_mini_object_trace, mini_object);
#endif
g_type_free_instance ((GTypeInstance *) mini_object);
}
}
/**
* gst_mini_object_unref:
* @mini_object: the mini-object
*
* Decreases the reference count of the mini-object, possibly freeing
* the mini-object.
*/
void
gst_mini_object_unref (GstMiniObject * mini_object)
{
g_return_if_fail (mini_object != NULL);
g_return_if_fail (mini_object->refcount > 0);
#ifdef DEBUG_REFCOUNT
g_return_if_fail (GST_IS_MINI_OBJECT (mini_object));
GST_CAT_TRACE (GST_CAT_REFCOUNTING, "%p unref %d->%d",
mini_object,
GST_MINI_OBJECT_REFCOUNT_VALUE (mini_object),
GST_MINI_OBJECT_REFCOUNT_VALUE (mini_object) - 1);
#endif
if (G_UNLIKELY (g_atomic_int_dec_and_test (&mini_object->refcount))) {
gst_mini_object_free (mini_object);
}
}
/**
* gst_mini_object_replace:
* @olddata: pointer to a pointer to a mini-object to be replaced
* @newdata: pointer to new mini-object
*
* Modifies a pointer to point to a new mini-object. The modification
* is done atomically, and the reference counts are updated correctly.
* Either @newdata and the value pointed to by @olddata may be NULL.
*/
void
gst_mini_object_replace (GstMiniObject ** olddata, GstMiniObject * newdata)
{
GstMiniObject *olddata_val;
g_return_if_fail (olddata != NULL);
#ifdef DEBUG_REFCOUNT
GST_CAT_TRACE (GST_CAT_REFCOUNTING, "replace %p (%d) with %p (%d)",
*olddata, *olddata ? (*olddata)->refcount : 0,
newdata, newdata ? newdata->refcount : 0);
#endif
olddata_val = g_atomic_pointer_get ((gpointer *) olddata);
if (olddata_val == newdata)
return;
if (newdata)
gst_mini_object_ref (newdata);
while (!g_atomic_pointer_compare_and_exchange ((gpointer *) olddata,
olddata_val, newdata)) {
olddata_val = g_atomic_pointer_get ((gpointer *) olddata);
}
if (olddata_val)
gst_mini_object_unref (olddata_val);
}
static void
gst_value_mini_object_init (GValue * value)
{
value->data[0].v_pointer = NULL;
}
static void
gst_value_mini_object_free (GValue * value)
{
if (value->data[0].v_pointer) {
gst_mini_object_unref (GST_MINI_OBJECT_CAST (value->data[0].v_pointer));
}
}
static void
gst_value_mini_object_copy (const GValue * src_value, GValue * dest_value)
{
if (src_value->data[0].v_pointer) {
dest_value->data[0].v_pointer =
gst_mini_object_ref (GST_MINI_OBJECT_CAST (src_value->data[0].
v_pointer));
} else {
dest_value->data[0].v_pointer = NULL;
}
}
static gpointer
gst_value_mini_object_peek_pointer (const GValue * value)
{
return value->data[0].v_pointer;
}
static gchar *
gst_value_mini_object_collect (GValue * value, guint n_collect_values,
GTypeCValue * collect_values, guint collect_flags)
{
if (collect_values[0].v_pointer) {
value->data[0].v_pointer =
gst_mini_object_ref (collect_values[0].v_pointer);
} else {
value->data[0].v_pointer = NULL;
}
return NULL;
}
static gchar *
gst_value_mini_object_lcopy (const GValue * value, guint n_collect_values,
GTypeCValue * collect_values, guint collect_flags)
{
gpointer *mini_object_p = collect_values[0].v_pointer;
if (!mini_object_p) {
return g_strdup_printf ("value location for '%s' passed as NULL",
G_VALUE_TYPE_NAME (value));
}
if (!value->data[0].v_pointer)
*mini_object_p = NULL;
else if (collect_flags & G_VALUE_NOCOPY_CONTENTS)
*mini_object_p = value->data[0].v_pointer;
else
*mini_object_p = gst_mini_object_ref (value->data[0].v_pointer);
return NULL;
}
/**
* gst_value_set_mini_object:
* @value: a valid #GValue of %GST_TYPE_MINI_OBJECT derived type
* @mini_object: mini object value to set
*
* Set the contents of a %GST_TYPE_MINI_OBJECT derived #GValue to
* @mini_object.
* The caller retains ownership of the reference.
*/
void
gst_value_set_mini_object (GValue * value, GstMiniObject * mini_object)
{
gpointer *pointer_p;
g_return_if_fail (GST_VALUE_HOLDS_MINI_OBJECT (value));
g_return_if_fail (mini_object == NULL || GST_IS_MINI_OBJECT (mini_object));
pointer_p = &value->data[0].v_pointer;
gst_mini_object_replace ((GstMiniObject **) pointer_p, mini_object);
}
/**
* gst_value_take_mini_object:
* @value: a valid #GValue of %GST_TYPE_MINI_OBJECT derived type
* @mini_object: mini object value to take
*
* Set the contents of a %GST_TYPE_MINI_OBJECT derived #GValue to
* @mini_object.
* Takes over the ownership of the caller's reference to @mini_object;
* the caller doesn't have to unref it any more.
*/
void
gst_value_take_mini_object (GValue * value, GstMiniObject * mini_object)
{
gpointer *pointer_p;
g_return_if_fail (GST_VALUE_HOLDS_MINI_OBJECT (value));
g_return_if_fail (mini_object == NULL || GST_IS_MINI_OBJECT (mini_object));
pointer_p = &value->data[0].v_pointer;
/* takes additional refcount */
gst_mini_object_replace ((GstMiniObject **) pointer_p, mini_object);
/* remove additional refcount */
if (mini_object)
gst_mini_object_unref (mini_object);
}
/**
* gst_value_get_mini_object:
* @value: a valid #GValue of %GST_TYPE_MINI_OBJECT derived type
*
* Get the contents of a %GST_TYPE_MINI_OBJECT derived #GValue.
* Does not increase the refcount of the returned object.
*
* Returns: mini object contents of @value
*/
GstMiniObject *
gst_value_get_mini_object (const GValue * value)
{
g_return_val_if_fail (GST_VALUE_HOLDS_MINI_OBJECT (value), NULL);
return value->data[0].v_pointer;
}
/**
* gst_value_dup_mini_object:
* @value: a valid #GValue of %GST_TYPE_MINI_OBJECT derived type
*
* Get the contents of a %GST_TYPE_MINI_OBJECT derived #GValue,
* increasing its reference count.
*
* Returns: mini object contents of @value
*
* Since: 0.10.20
*/
GstMiniObject *
gst_value_dup_mini_object (const GValue * value)
{
g_return_val_if_fail (GST_VALUE_HOLDS_MINI_OBJECT (value), NULL);
return gst_mini_object_ref (value->data[0].v_pointer);
}
/* param spec */
static void
param_mini_object_init (GParamSpec * pspec)
{
/* GParamSpecMiniObject *ospec = G_PARAM_SPEC_MINI_OBJECT (pspec); */
}
static void
param_mini_object_set_default (GParamSpec * pspec, GValue * value)
{
value->data[0].v_pointer = NULL;
}
static gboolean
param_mini_object_validate (GParamSpec * pspec, GValue * value)
{
GstMiniObject *mini_object = value->data[0].v_pointer;
gboolean changed = FALSE;
if (mini_object
&& !g_value_type_compatible (G_OBJECT_TYPE (mini_object),
pspec->value_type)) {
gst_mini_object_unref (mini_object);
value->data[0].v_pointer = NULL;
changed = TRUE;
}
return changed;
}
static gint
param_mini_object_values_cmp (GParamSpec * pspec,
const GValue * value1, const GValue * value2)
{
guint8 *p1 = value1->data[0].v_pointer;
guint8 *p2 = value2->data[0].v_pointer;
/* not much to compare here, try to at least provide stable lesser/greater result */
return p1 < p2 ? -1 : p1 > p2;
}
GType
gst_param_spec_mini_object_get_type (void)
{
static GType type;
if (G_UNLIKELY (type) == 0) {
static const GParamSpecTypeInfo pspec_info = {
sizeof (GstParamSpecMiniObject), /* instance_size */
16, /* n_preallocs */
param_mini_object_init, /* instance_init */
G_TYPE_OBJECT, /* value_type */
NULL, /* finalize */
param_mini_object_set_default, /* value_set_default */
param_mini_object_validate, /* value_validate */
param_mini_object_values_cmp, /* values_cmp */
};
/* FIXME 0.11: Should really be GstParamSpecMiniObject */
type = g_param_type_register_static ("GParamSpecMiniObject", &pspec_info);
}
return type;
}
/**
* gst_param_spec_mini_object:
* @name: the canonical name of the property
* @nick: the nickname of the property
* @blurb: a short description of the property
* @object_type: the #GstMiniObject #GType for the property
* @flags: a combination of #GParamFlags
*
* Creates a new #GParamSpec instance that hold #GstMiniObject references.
*
* Returns: a newly allocated #GParamSpec instance
*/
GParamSpec *
gst_param_spec_mini_object (const char *name, const char *nick,
const char *blurb, GType object_type, GParamFlags flags)
{
GstParamSpecMiniObject *ospec;
g_return_val_if_fail (g_type_is_a (object_type, GST_TYPE_MINI_OBJECT), NULL);
ospec = g_param_spec_internal (GST_TYPE_PARAM_MINI_OBJECT,
name, nick, blurb, flags);
G_PARAM_SPEC (ospec)->value_type = object_type;
return G_PARAM_SPEC (ospec);
}