如何查看GType节点,以及父子关系。

os posted @ 2013年8月10日 17:08 in GObject , 1179 阅读

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使用glib的gtype/gobject开发的gtk, gstreamer等,都离不开一个gtype, gobject.

 

Glib使用2个数据结构来保存type:

//1,用指针数组,保存基础类型,即一些父类型

static TypeNode		*static_fundamental_type_nodes[(G_TYPE_FUNDAMENTAL_MAX >> G_TYPE_FUNDAMENTAL_SHIFT) + 1] = { NULL, };

//2, 用散列表来保持所有的类型,包括父类型,子类型

static GHashTable       *static_type_nodes_ht = NULL;
static_type_nodes_ht = g_hash_table_new (g_direct_hash, g_direct_equal);

它使用指针作为键值

 

type创建的过程:

 

  1. 定义xxx_yyy_get_type(), 一般是用宏来定义的
  2. Init时,会调用g_type_class_ref(xxx_yyy_get_type())

如:

g_type_class_ref (gst_object_get_type ());

g_type_class_ref (gst_pad_get_type ());

g_type_class_ref (gst_element_factory_get_type ());

g_type_class_ref (gst_element_get_type ());

  1. xxx_yyy_get_type()会进行type的创建,保存到指针数组和hash table中:
  2. g_type_register_static()
  3. type_node_any_new_W() 首先检查该新建的type,是否由父亲;

如果没有的话,保持在static_fundamental_type_nodes;

如果有父类的话,就保持到父类的子类数组中pnode->children[i] = type;

同时把这个新的type 插入到hash table中:

g_hash_table_insert (static_type_nodes_ht,

GUINT_TO_POINTER (node->qname),

(gpointer) type);

 

如果查看type的list, 以及父子关系呢:

参考gobject_query.c

主要是把父子关系清晰的打印出来:

指针数组static_fundamental_type_nodes,存放了无父类的typenode;

所以只要循环这个指针数组,然后对基础typenode, 嵌套循环其子类,就可以了。

/* GObject - GLib Type, Object, Parameter and Signal Library
 * Copyright (C) 1998-1999, 2000-2001 Tim Janik and Red Hat, Inc.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser 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 <stdlib.h>
#include <string.h>

#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#include <fcntl.h>

#include <glib-object.h>
#include <glib/gprintf.h>

static GType root = G_TYPE_OBJECT;

static void
show_nodes (GType        type,
	    GType        sibling,
	    const gchar *indent)
{
	static gchar *indent_inc = NULL;
	static guint spacing = 1;
	static gboolean recursion = TRUE;

#define	O_SPACE	" "
#define	O_ESPACE ""
#define	O_BRANCH "+"
#define	O_VLINE "|"
#define	O_LLEAF	"`"
#define	O_KEY_FILL "_"

	GType   *children;
	guint i;

	if (!type)
		return;

	if (!indent_inc)
	{
		indent_inc = g_new (gchar, strlen (O_SPACE) + 1);
		*indent_inc = 0;
		strcpy (indent_inc, O_SPACE);
	}  
  
	children = g_type_children (type, NULL);

	if (type != root)
		for (i = 0; i < spacing; i++)
			fprintf(stderr, "%s%s\n", indent, O_VLINE);
  
	fprintf(stderr, "%s%s%s%s",
				indent,
				sibling ? O_BRANCH : (type != root ? O_LLEAF : O_SPACE),
				O_ESPACE,
				g_type_name (type));

	for (i = strlen (g_type_name (type)); i <= strlen (indent_inc); i++)
		fputs (O_KEY_FILL, stdout);
	fputc ('\n', stdout);

	if (children && recursion)
	{
		gchar *new_indent;
		GType   *child;

		if (sibling)
			new_indent = g_strconcat (indent, O_VLINE, indent_inc, NULL);
		else
			new_indent = g_strconcat (indent, O_SPACE, indent_inc, NULL);

		for (child = children; *child; child++)
			show_nodes (child[0], child[1], new_indent);

		g_free (new_indent);
	}

	g_free (children);
}

void list_type_node_tree(void)
{
	gint i;
	
  	root = ~0;
	for (i = 0; i <= G_TYPE_FUNDAMENTAL_MAX; i += G_TYPE_MAKE_FUNDAMENTAL (1))
	{
		const gchar *name = g_type_name (i);

		if (name)
			show_nodes (i, 0, "");
	}

}

g_type_init()后的type list, 以及父子关系:


id

|

`GInterface

  |

  `GTypePlugin

|

`gchar

|

`guchar

|

`gboolean

|

`gint

|

`guint

|

`glong

|

`gulong

|

`gint64

|

`guint64

|

`GEnum

|

`GFlags

|

`gfloat

|

`gdouble

|

`gchararray

|

`gpointer

  |

  `GType

|

`GBoxed

  |

  `GValueArray

|

`GParam

  |

  +GParamChar

  |

  +GParamUChar

  |

  +GParamBoolean

  |

  +GParamInt

  |

  +GParamUInt

  |

  +GParamLong

  |

  +GParamULong

  |

  +GParamInt64

  |

  +GParamUInt64

  |

  +GParamUnichar

  |

  +GParamEnum

  |

  +GParamFlags

  |

  +GParamFloat

  |

  +GParamDouble

  |

  +GParamString

  |

  +GParamParam

  |

  +GParamBoxed

  |

  +GParamPointer

  |

  +GParamValueArray

  |

  +GParamObject

  |

  +GParamOverride

  |

  +GParamGType

  |

  `GParamVariant

|

`GObject

|

`GVariant

 

gst_init()后 type/gobject list, 以及object的父子关系:

|

`void

|

`GInterface

  |

  +GTypePlugin

  |

  +GstChildProxy

  |

  `GstURIHandler

|

`gchar

|

`guchar

|

`gboolean

|

`gint

|

`guint

|

`glong

|

`gulong

|

`gint64

|

`guint64

|

`GEnum

  |

  +GstFormat

  |

  +GstPadDirection

  |

  +GstBufferListItem

  |

  +GstBusSyncReply

  |

  +GstClockReturn

  |

  +GstClockEntryType

  |

  +GstClockType

  |

  +GstState

  |

  +GstStateChangeReturn

  |

  +GstStateChange

  |

  +GstCoreError

  |

  +GstLibraryError

  |

  +GstResourceError

  |

  +GstStreamError

  |

  +GstEventType

  |

  +GstSeekType

  |

  +GstQOSType

  |

  +GstIndexCertainty

  |

  +GstIndexEntryType

  |

  +GstIndexLookupMethod

  |

  +GstIndexResolverMethod

  |

  +GstDebugLevel

  |

  +GstDebugColorFlags

  |

  +GstIteratorResult

  |

  +GstIteratorItem

  |

  +GstPadLinkReturn

  |

  +GstFlowReturn

  |

  +GstActivateMode

  |

  +GstPadPresence

  |

  +GstPluginError

  |

  +GstRank

  |

  +GstQueryType

  |

  +GstBufferingMode

  |

  +GstStreamStatusType

  |

  +GstStructureChangeType

  |

  +GstTagMergeMode

  |

  +GstTagFlag

  |

  +GstTaskState

  |

  +GstTypeFindProbability

  |

  +GstURIType

  |

  +GstParseError

  |

  +GstSearchMode

  |

  +GstProgressType

  |

  `GstCapsIntersectMode

|

`GFlags

  |

  +GstObjectFlags

  |

  +GstBinFlags

  |

  +GstBufferFlag

  |

  +GstBufferCopyFlags

  |

  +GstBusFlags

  |

  +GstCapsFlags

  |

  +GstClockFlags

  |

  +GstDebugGraphDetails

  |

  +GstElementFlags

  |

  +GstEventTypeFlags

  |

  +GstSeekFlags

  |

  +GstAssocFlags

  |

  +GstIndexFlags

  |

  +GstMessageType

  |

  +GstMiniObjectFlags

  |

  +GstPadLinkCheck

  |

  +GstPadFlags

  |

  +GstPadTemplateFlags

  |

  +GstPipelineFlags

  |

  +GstPluginFlags

  |

  +GstPluginDependencyFlags

  |

  +GstAllocTraceFlags

  |

  `GstParseFlags

|

`gfloat

|

`gdouble

|

`gchararray

|

`gpointer

  |

  `GType

|

`GBoxed

  |

  +GValueArray

  |

  +GstCaps

  |

  +GstStructure

  |

  +GstDate

  |

  +GstDateTime

  |

  +GDate

  |

  +GstBufferListIterator

  |

  +GstParseContext

  |

  `GError

|

`GParam

  |

  +GParamChar

  |

  +GParamUChar

  |

  +GParamBoolean

  |

  +GParamInt

  |

  +GParamUInt

  |

  +GParamLong

  |

  +GParamULong

  |

  +GParamInt64

  |

  +GParamUInt64

  |

  +GParamUnichar

  |

  +GParamEnum

  |

  +GParamFlags

  |

  +GParamFloat

  |

  +GParamDouble

  |

  +GParamString

  |

  +GParamParam

  |

  +GParamBoxed

  |

  +GParamPointer

  |

  +GParamValueArray

  |

  +GParamObject

  |

  +GParamOverride

  |

  +GParamGType

  |

  +GParamVariant

  |

  `GstParamFraction

|

`GObject

  |

  +GstObject

  | |

  | +GstPad

  | |

  | +GstPadTemplate

  | |

  | +GstPluginFeature

  | | |

  | | +GstElementFactory

  | | |

  | | +GstTypeFindFactory

  | | |

  | | `GstIndexFactory

  | |

  | +GstElement

  | | |

  | | `GstBin

  | |   |

  | |   `GstPipeline

  | |

  | +GstBus

  | |

  | +GstTask

  | |

  | +GstTaskPool

  | |

  | +GstClock

  | |

  | +GstPlugin

  | |

  | `GstRegistry

  |

  `GstSignalObject

|

`GVariant

|

`GstMiniObject

  |

  +GstQuery

  |

  +GstMessage

  |

  +GstBuffer

  |

  +GstEvent

  |

  `GstBufferList

|

`GstFourcc

|

`GstIntRange

|

`GstInt64Range

|

`GstDoubleRange

|

`GstFractionRange

|

`GstValueList

|

`GstValueArray

|

`GstFraction

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