4 * Copyright IBM, Corp. 2011
7 * Anthony Liguori <aliguori@us.ibm.com>
9 * This work is licensed under the terms of the GNU GPL, version 2 or later.
10 * See the COPYING file in the top-level directory.
20 #include "qemu/queue.h"
21 #include "qapi/error.h"
26 typedef struct TypeImpl
*Type
;
28 typedef struct ObjectClass ObjectClass
;
29 typedef struct Object Object
;
31 typedef struct TypeInfo TypeInfo
;
33 typedef struct InterfaceClass InterfaceClass
;
34 typedef struct InterfaceInfo InterfaceInfo
;
36 #define TYPE_OBJECT "object"
40 * @title:Base Object Type System
41 * @short_description: interfaces for creating new types and objects
43 * The QEMU Object Model provides a framework for registering user creatable
44 * types and instantiating objects from those types. QOM provides the following
47 * - System for dynamically registering types
48 * - Support for single-inheritance of types
49 * - Multiple inheritance of stateless interfaces
52 * <title>Creating a minimal type</title>
56 * #define TYPE_MY_DEVICE "my-device"
58 * // No new virtual functions: we can reuse the typedef for the
60 * typedef DeviceClass MyDeviceClass;
61 * typedef struct MyDevice
65 * int reg0, reg1, reg2;
68 * static const TypeInfo my_device_info = {
69 * .name = TYPE_MY_DEVICE,
70 * .parent = TYPE_DEVICE,
71 * .instance_size = sizeof(MyDevice),
74 * static void my_device_register_types(void)
76 * type_register_static(&my_device_info);
79 * type_init(my_device_register_types)
83 * In the above example, we create a simple type that is described by #TypeInfo.
84 * #TypeInfo describes information about the type including what it inherits
85 * from, the instance and class size, and constructor/destructor hooks.
87 * Every type has an #ObjectClass associated with it. #ObjectClass derivatives
88 * are instantiated dynamically but there is only ever one instance for any
89 * given type. The #ObjectClass typically holds a table of function pointers
90 * for the virtual methods implemented by this type.
92 * Using object_new(), a new #Object derivative will be instantiated. You can
93 * cast an #Object to a subclass (or base-class) type using
94 * object_dynamic_cast(). You typically want to define macro wrappers around
95 * OBJECT_CHECK() and OBJECT_CLASS_CHECK() to make it easier to convert to a
99 * <title>Typecasting macros</title>
101 * #define MY_DEVICE_GET_CLASS(obj) \
102 * OBJECT_GET_CLASS(MyDeviceClass, obj, TYPE_MY_DEVICE)
103 * #define MY_DEVICE_CLASS(klass) \
104 * OBJECT_CLASS_CHECK(MyDeviceClass, klass, TYPE_MY_DEVICE)
105 * #define MY_DEVICE(obj) \
106 * OBJECT_CHECK(MyDevice, obj, TYPE_MY_DEVICE)
110 * # Class Initialization #
112 * Before an object is initialized, the class for the object must be
113 * initialized. There is only one class object for all instance objects
114 * that is created lazily.
116 * Classes are initialized by first initializing any parent classes (if
117 * necessary). After the parent class object has initialized, it will be
118 * copied into the current class object and any additional storage in the
119 * class object is zero filled.
121 * The effect of this is that classes automatically inherit any virtual
122 * function pointers that the parent class has already initialized. All
123 * other fields will be zero filled.
125 * Once all of the parent classes have been initialized, #TypeInfo::class_init
126 * is called to let the class being instantiated provide default initialize for
127 * its virtual functions. Here is how the above example might be modified
128 * to introduce an overridden virtual function:
131 * <title>Overriding a virtual function</title>
135 * void my_device_class_init(ObjectClass *klass, void *class_data)
137 * DeviceClass *dc = DEVICE_CLASS(klass);
138 * dc->reset = my_device_reset;
141 * static const TypeInfo my_device_info = {
142 * .name = TYPE_MY_DEVICE,
143 * .parent = TYPE_DEVICE,
144 * .instance_size = sizeof(MyDevice),
145 * .class_init = my_device_class_init,
150 * Introducing new virtual methods requires a class to define its own
151 * struct and to add a .class_size member to the #TypeInfo. Each method
152 * will also have a wrapper function to call it easily:
155 * <title>Defining an abstract class</title>
159 * typedef struct MyDeviceClass
161 * DeviceClass parent;
163 * void (*frobnicate) (MyDevice *obj);
166 * static const TypeInfo my_device_info = {
167 * .name = TYPE_MY_DEVICE,
168 * .parent = TYPE_DEVICE,
169 * .instance_size = sizeof(MyDevice),
170 * .abstract = true, // or set a default in my_device_class_init
171 * .class_size = sizeof(MyDeviceClass),
174 * void my_device_frobnicate(MyDevice *obj)
176 * MyDeviceClass *klass = MY_DEVICE_GET_CLASS(obj);
178 * klass->frobnicate(obj);
185 * Interfaces allow a limited form of multiple inheritance. Instances are
186 * similar to normal types except for the fact that are only defined by
187 * their classes and never carry any state. You can dynamically cast an object
188 * to one of its #Interface types and vice versa.
192 * A <emphasis>method</emphasis> is a function within the namespace scope of
193 * a class. It usually operates on the object instance by passing it as a
194 * strongly-typed first argument.
195 * If it does not operate on an object instance, it is dubbed
196 * <emphasis>class method</emphasis>.
198 * Methods cannot be overloaded. That is, the #ObjectClass and method name
199 * uniquely identity the function to be called; the signature does not vary
200 * except for trailing varargs.
202 * Methods are always <emphasis>virtual</emphasis>. Overriding a method in
203 * #TypeInfo.class_init of a subclass leads to any user of the class obtained
204 * via OBJECT_GET_CLASS() accessing the overridden function.
205 * The original function is not automatically invoked. It is the responsibility
206 * of the overriding class to determine whether and when to invoke the method
209 * To invoke the method being overridden, the preferred solution is to store
210 * the original value in the overriding class before overriding the method.
211 * This corresponds to |[ {super,base}.method(...) ]| in Java and C#
212 * respectively; this frees the overriding class from hardcoding its parent
213 * class, which someone might choose to change at some point.
216 * <title>Overriding a virtual method</title>
218 * typedef struct MyState MyState;
220 * typedef void (*MyDoSomething)(MyState *obj);
222 * typedef struct MyClass {
223 * ObjectClass parent_class;
225 * MyDoSomething do_something;
228 * static void my_do_something(MyState *obj)
233 * static void my_class_init(ObjectClass *oc, void *data)
235 * MyClass *mc = MY_CLASS(oc);
237 * mc->do_something = my_do_something;
240 * static const TypeInfo my_type_info = {
242 * .parent = TYPE_OBJECT,
243 * .instance_size = sizeof(MyState),
244 * .class_size = sizeof(MyClass),
245 * .class_init = my_class_init,
248 * typedef struct DerivedClass {
249 * MyClass parent_class;
251 * MyDoSomething parent_do_something;
254 * static void derived_do_something(MyState *obj)
256 * DerivedClass *dc = DERIVED_GET_CLASS(obj);
258 * // do something here
259 * dc->parent_do_something(obj);
260 * // do something else here
263 * static void derived_class_init(ObjectClass *oc, void *data)
265 * MyClass *mc = MY_CLASS(oc);
266 * DerivedClass *dc = DERIVED_CLASS(oc);
268 * dc->parent_do_something = mc->do_something;
269 * mc->do_something = derived_do_something;
272 * static const TypeInfo derived_type_info = {
273 * .name = TYPE_DERIVED,
275 * .class_size = sizeof(DerivedClass),
276 * .class_init = derived_class_init,
281 * Alternatively, object_class_by_name() can be used to obtain the class and
282 * its non-overridden methods for a specific type. This would correspond to
283 * |[ MyClass::method(...) ]| in C++.
285 * The first example of such a QOM method was #CPUClass.reset,
286 * another example is #DeviceClass.realize.
291 * ObjectPropertyAccessor:
292 * @obj: the object that owns the property
293 * @v: the visitor that contains the property data
294 * @opaque: the object property opaque
295 * @name: the name of the property
296 * @errp: a pointer to an Error that is filled if getting/setting fails.
298 * Called when trying to get/set a property.
300 typedef void (ObjectPropertyAccessor
)(Object
*obj
,
307 * ObjectPropertyResolve:
308 * @obj: the object that owns the property
309 * @opaque: the opaque registered with the property
310 * @part: the name of the property
312 * Resolves the #Object corresponding to property @part.
314 * The returned object can also be used as a starting point
315 * to resolve a relative path starting with "@part".
317 * Returns: If @path is the path that led to @obj, the function
318 * returns the #Object corresponding to "@path/@part".
319 * If "@path/@part" is not a valid object path, it returns #NULL.
321 typedef Object
*(ObjectPropertyResolve
)(Object
*obj
,
326 * ObjectPropertyRelease:
327 * @obj: the object that owns the property
328 * @name: the name of the property
329 * @opaque: the opaque registered with the property
331 * Called when a property is removed from a object.
333 typedef void (ObjectPropertyRelease
)(Object
*obj
,
337 typedef struct ObjectProperty
342 ObjectPropertyAccessor
*get
;
343 ObjectPropertyAccessor
*set
;
344 ObjectPropertyResolve
*resolve
;
345 ObjectPropertyRelease
*release
;
348 QTAILQ_ENTRY(ObjectProperty
) node
;
353 * @obj: the object that is being removed from the composition tree
355 * Called when an object is being removed from the QOM composition tree.
356 * The function should remove any backlinks from children objects to @obj.
358 typedef void (ObjectUnparent
)(Object
*obj
);
362 * @obj: the object being freed
364 * Called when an object's last reference is removed.
366 typedef void (ObjectFree
)(void *obj
);
368 #define OBJECT_CLASS_CAST_CACHE 4
373 * The base for all classes. The only thing that #ObjectClass contains is an
374 * integer type handle.
382 const char *object_cast_cache
[OBJECT_CLASS_CAST_CACHE
];
383 const char *class_cast_cache
[OBJECT_CLASS_CAST_CACHE
];
385 ObjectUnparent
*unparent
;
391 * The base for all objects. The first member of this object is a pointer to
392 * a #ObjectClass. Since C guarantees that the first member of a structure
393 * always begins at byte 0 of that structure, as long as any sub-object places
394 * its parent as the first member, we can cast directly to a #Object.
396 * As a result, #Object contains a reference to the objects type as its
397 * first member. This allows identification of the real type of the object at
400 * #Object also contains a list of #Interfaces that this object
408 QTAILQ_HEAD(, ObjectProperty
) properties
;
415 * @name: The name of the type.
416 * @parent: The name of the parent type.
417 * @instance_size: The size of the object (derivative of #Object). If
418 * @instance_size is 0, then the size of the object will be the size of the
420 * @instance_init: This function is called to initialize an object. The parent
421 * class will have already been initialized so the type is only responsible
422 * for initializing its own members.
423 * @instance_post_init: This function is called to finish initialization of
424 * an object, after all @instance_init functions were called.
425 * @instance_finalize: This function is called during object destruction. This
426 * is called before the parent @instance_finalize function has been called.
427 * An object should only free the members that are unique to its type in this
429 * @abstract: If this field is true, then the class is considered abstract and
430 * cannot be directly instantiated.
431 * @class_size: The size of the class object (derivative of #ObjectClass)
432 * for this object. If @class_size is 0, then the size of the class will be
433 * assumed to be the size of the parent class. This allows a type to avoid
434 * implementing an explicit class type if they are not adding additional
436 * @class_init: This function is called after all parent class initialization
437 * has occurred to allow a class to set its default virtual method pointers.
438 * This is also the function to use to override virtual methods from a parent
440 * @class_base_init: This function is called for all base classes after all
441 * parent class initialization has occurred, but before the class itself
442 * is initialized. This is the function to use to undo the effects of
443 * memcpy from the parent class to the descendents.
444 * @class_finalize: This function is called during class destruction and is
445 * meant to release and dynamic parameters allocated by @class_init.
446 * @class_data: Data to pass to the @class_init, @class_base_init and
447 * @class_finalize functions. This can be useful when building dynamic
449 * @interfaces: The list of interfaces associated with this type. This
450 * should point to a static array that's terminated with a zero filled
458 size_t instance_size
;
459 void (*instance_init
)(Object
*obj
);
460 void (*instance_post_init
)(Object
*obj
);
461 void (*instance_finalize
)(Object
*obj
);
466 void (*class_init
)(ObjectClass
*klass
, void *data
);
467 void (*class_base_init
)(ObjectClass
*klass
, void *data
);
468 void (*class_finalize
)(ObjectClass
*klass
, void *data
);
471 InterfaceInfo
*interfaces
;
476 * @obj: A derivative of #Object
478 * Converts an object to a #Object. Since all objects are #Objects,
479 * this function will always succeed.
481 #define OBJECT(obj) \
486 * @class: A derivative of #ObjectClass.
488 * Converts a class to an #ObjectClass. Since all objects are #Objects,
489 * this function will always succeed.
491 #define OBJECT_CLASS(class) \
492 ((ObjectClass *)(class))
496 * @type: The C type to use for the return value.
497 * @obj: A derivative of @type to cast.
498 * @name: The QOM typename of @type
500 * A type safe version of @object_dynamic_cast_assert. Typically each class
501 * will define a macro based on this type to perform type safe dynamic_casts to
504 * If an invalid object is passed to this function, a run time assert will be
507 #define OBJECT_CHECK(type, obj, name) \
508 ((type *)object_dynamic_cast_assert(OBJECT(obj), (name), \
509 __FILE__, __LINE__, __func__))
512 * OBJECT_CLASS_CHECK:
513 * @class: The C type to use for the return value.
514 * @obj: A derivative of @type to cast.
515 * @name: the QOM typename of @class.
517 * A type safe version of @object_class_dynamic_cast_assert. This macro is
518 * typically wrapped by each type to perform type safe casts of a class to a
519 * specific class type.
521 #define OBJECT_CLASS_CHECK(class, obj, name) \
522 ((class *)object_class_dynamic_cast_assert(OBJECT_CLASS(obj), (name), \
523 __FILE__, __LINE__, __func__))
527 * @class: The C type to use for the return value.
528 * @obj: The object to obtain the class for.
529 * @name: The QOM typename of @obj.
531 * This function will return a specific class for a given object. Its generally
532 * used by each type to provide a type safe macro to get a specific class type
535 #define OBJECT_GET_CLASS(class, obj, name) \
536 OBJECT_CLASS_CHECK(class, object_get_class(OBJECT(obj)), name)
540 * @type: The name of the interface.
542 * The information associated with an interface.
544 struct InterfaceInfo
{
550 * @parent_class: the base class
552 * The class for all interfaces. Subclasses of this class should only add
555 struct InterfaceClass
557 ObjectClass parent_class
;
559 ObjectClass
*concrete_class
;
563 #define TYPE_INTERFACE "interface"
567 * @klass: class to cast from
568 * Returns: An #InterfaceClass or raise an error if cast is invalid
570 #define INTERFACE_CLASS(klass) \
571 OBJECT_CLASS_CHECK(InterfaceClass, klass, TYPE_INTERFACE)
575 * @interface: the type to return
576 * @obj: the object to convert to an interface
577 * @name: the interface type name
579 * Returns: @obj casted to @interface if cast is valid, otherwise raise error.
581 #define INTERFACE_CHECK(interface, obj, name) \
582 ((interface *)object_dynamic_cast_assert(OBJECT((obj)), (name), \
583 __FILE__, __LINE__, __func__))
587 * @typename: The name of the type of the object to instantiate.
589 * This function will initialize a new object using heap allocated memory.
590 * The returned object has a reference count of 1, and will be freed when
591 * the last reference is dropped.
593 * Returns: The newly allocated and instantiated object.
595 Object
*object_new(const char *typename
);
598 * object_new_with_type:
599 * @type: The type of the object to instantiate.
601 * This function will initialize a new object using heap allocated memory.
602 * The returned object has a reference count of 1, and will be freed when
603 * the last reference is dropped.
605 * Returns: The newly allocated and instantiated object.
607 Object
*object_new_with_type(Type type
);
610 * object_initialize_with_type:
611 * @data: A pointer to the memory to be used for the object.
612 * @size: The maximum size available at @data for the object.
613 * @type: The type of the object to instantiate.
615 * This function will initialize an object. The memory for the object should
616 * have already been allocated. The returned object has a reference count of 1,
617 * and will be finalized when the last reference is dropped.
619 void object_initialize_with_type(void *data
, size_t size
, Type type
);
623 * @obj: A pointer to the memory to be used for the object.
624 * @size: The maximum size available at @obj for the object.
625 * @typename: The name of the type of the object to instantiate.
627 * This function will initialize an object. The memory for the object should
628 * have already been allocated. The returned object has a reference count of 1,
629 * and will be finalized when the last reference is dropped.
631 void object_initialize(void *obj
, size_t size
, const char *typename
);
634 * object_dynamic_cast:
635 * @obj: The object to cast.
636 * @typename: The @typename to cast to.
638 * This function will determine if @obj is-a @typename. @obj can refer to an
639 * object or an interface associated with an object.
641 * Returns: This function returns @obj on success or #NULL on failure.
643 Object
*object_dynamic_cast(Object
*obj
, const char *typename
);
646 * object_dynamic_cast_assert:
648 * See object_dynamic_cast() for a description of the parameters of this
649 * function. The only difference in behavior is that this function asserts
650 * instead of returning #NULL on failure if QOM cast debugging is enabled.
651 * This function is not meant to be called directly, but only through
652 * the wrapper macro OBJECT_CHECK.
654 Object
*object_dynamic_cast_assert(Object
*obj
, const char *typename
,
655 const char *file
, int line
, const char *func
);
659 * @obj: A derivative of #Object
661 * Returns: The #ObjectClass of the type associated with @obj.
663 ObjectClass
*object_get_class(Object
*obj
);
666 * object_get_typename:
667 * @obj: A derivative of #Object.
669 * Returns: The QOM typename of @obj.
671 const char *object_get_typename(Object
*obj
);
674 * type_register_static:
675 * @info: The #TypeInfo of the new type.
677 * @info and all of the strings it points to should exist for the life time
678 * that the type is registered.
680 * Returns: 0 on failure, the new #Type on success.
682 Type
type_register_static(const TypeInfo
*info
);
686 * @info: The #TypeInfo of the new type
688 * Unlike type_register_static(), this call does not require @info or its
689 * string members to continue to exist after the call returns.
691 * Returns: 0 on failure, the new #Type on success.
693 Type
type_register(const TypeInfo
*info
);
696 * object_class_dynamic_cast_assert:
697 * @klass: The #ObjectClass to attempt to cast.
698 * @typename: The QOM typename of the class to cast to.
700 * See object_class_dynamic_cast() for a description of the parameters
701 * of this function. The only difference in behavior is that this function
702 * asserts instead of returning #NULL on failure if QOM cast debugging is
703 * enabled. This function is not meant to be called directly, but only through
704 * the wrapper macros OBJECT_CLASS_CHECK and INTERFACE_CHECK.
706 ObjectClass
*object_class_dynamic_cast_assert(ObjectClass
*klass
,
707 const char *typename
,
708 const char *file
, int line
,
712 * object_class_dynamic_cast:
713 * @klass: The #ObjectClass to attempt to cast.
714 * @typename: The QOM typename of the class to cast to.
716 * Returns: If @typename is a class, this function returns @klass if
717 * @typename is a subtype of @klass, else returns #NULL.
719 * If @typename is an interface, this function returns the interface
720 * definition for @klass if @klass implements it unambiguously; #NULL
721 * is returned if @klass does not implement the interface or if multiple
722 * classes or interfaces on the hierarchy leading to @klass implement
723 * it. (FIXME: perhaps this can be detected at type definition time?)
725 ObjectClass
*object_class_dynamic_cast(ObjectClass
*klass
,
726 const char *typename
);
729 * object_class_get_parent:
730 * @klass: The class to obtain the parent for.
732 * Returns: The parent for @klass or %NULL if none.
734 ObjectClass
*object_class_get_parent(ObjectClass
*klass
);
737 * object_class_get_name:
738 * @klass: The class to obtain the QOM typename for.
740 * Returns: The QOM typename for @klass.
742 const char *object_class_get_name(ObjectClass
*klass
);
745 * object_class_is_abstract:
746 * @klass: The class to obtain the abstractness for.
748 * Returns: %true if @klass is abstract, %false otherwise.
750 bool object_class_is_abstract(ObjectClass
*klass
);
753 * object_class_by_name:
754 * @typename: The QOM typename to obtain the class for.
756 * Returns: The class for @typename or %NULL if not found.
758 ObjectClass
*object_class_by_name(const char *typename
);
760 void object_class_foreach(void (*fn
)(ObjectClass
*klass
, void *opaque
),
761 const char *implements_type
, bool include_abstract
,
765 * object_class_get_list:
766 * @implements_type: The type to filter for, including its derivatives.
767 * @include_abstract: Whether to include abstract classes.
769 * Returns: A singly-linked list of the classes in reverse hashtable order.
771 GSList
*object_class_get_list(const char *implements_type
,
772 bool include_abstract
);
778 * Increase the reference count of a object. A object cannot be freed as long
779 * as its reference count is greater than zero.
781 void object_ref(Object
*obj
);
787 * Decrease the reference count of a object. A object cannot be freed as long
788 * as its reference count is greater than zero.
790 void object_unref(Object
*obj
);
793 * object_property_add:
794 * @obj: the object to add a property to
795 * @name: the name of the property. This can contain any character except for
796 * a forward slash. In general, you should use hyphens '-' instead of
797 * underscores '_' when naming properties.
798 * @type: the type name of the property. This namespace is pretty loosely
799 * defined. Sub namespaces are constructed by using a prefix and then
800 * to angle brackets. For instance, the type 'virtio-net-pci' in the
801 * 'link' namespace would be 'link<virtio-net-pci>'.
802 * @get: The getter to be called to read a property. If this is NULL, then
803 * the property cannot be read.
804 * @set: the setter to be called to write a property. If this is NULL,
805 * then the property cannot be written.
806 * @release: called when the property is removed from the object. This is
807 * meant to allow a property to free its opaque upon object
808 * destruction. This may be NULL.
809 * @opaque: an opaque pointer to pass to the callbacks for the property
810 * @errp: returns an error if this function fails
812 * Returns: The #ObjectProperty; this can be used to set the @resolve
813 * callback for child and link properties.
815 ObjectProperty
*object_property_add(Object
*obj
, const char *name
,
817 ObjectPropertyAccessor
*get
,
818 ObjectPropertyAccessor
*set
,
819 ObjectPropertyRelease
*release
,
820 void *opaque
, Error
**errp
);
822 void object_property_del(Object
*obj
, const char *name
, Error
**errp
);
825 * object_property_find:
827 * @name: the name of the property
828 * @errp: returns an error if this function fails
830 * Look up a property for an object and return its #ObjectProperty if found.
832 ObjectProperty
*object_property_find(Object
*obj
, const char *name
,
835 void object_unparent(Object
*obj
);
838 * object_property_get:
840 * @v: the visitor that will receive the property value. This should be an
841 * Output visitor and the data will be written with @name as the name.
842 * @name: the name of the property
843 * @errp: returns an error if this function fails
845 * Reads a property from a object.
847 void object_property_get(Object
*obj
, struct Visitor
*v
, const char *name
,
851 * object_property_set_str:
852 * @value: the value to be written to the property
853 * @name: the name of the property
854 * @errp: returns an error if this function fails
856 * Writes a string value to a property.
858 void object_property_set_str(Object
*obj
, const char *value
,
859 const char *name
, Error
**errp
);
862 * object_property_get_str:
864 * @name: the name of the property
865 * @errp: returns an error if this function fails
867 * Returns: the value of the property, converted to a C string, or NULL if
868 * an error occurs (including when the property value is not a string).
869 * The caller should free the string.
871 char *object_property_get_str(Object
*obj
, const char *name
,
875 * object_property_set_link:
876 * @value: the value to be written to the property
877 * @name: the name of the property
878 * @errp: returns an error if this function fails
880 * Writes an object's canonical path to a property.
882 void object_property_set_link(Object
*obj
, Object
*value
,
883 const char *name
, Error
**errp
);
886 * object_property_get_link:
888 * @name: the name of the property
889 * @errp: returns an error if this function fails
891 * Returns: the value of the property, resolved from a path to an Object,
892 * or NULL if an error occurs (including when the property value is not a
893 * string or not a valid object path).
895 Object
*object_property_get_link(Object
*obj
, const char *name
,
899 * object_property_set_bool:
900 * @value: the value to be written to the property
901 * @name: the name of the property
902 * @errp: returns an error if this function fails
904 * Writes a bool value to a property.
906 void object_property_set_bool(Object
*obj
, bool value
,
907 const char *name
, Error
**errp
);
910 * object_property_get_bool:
912 * @name: the name of the property
913 * @errp: returns an error if this function fails
915 * Returns: the value of the property, converted to a boolean, or NULL if
916 * an error occurs (including when the property value is not a bool).
918 bool object_property_get_bool(Object
*obj
, const char *name
,
922 * object_property_set_int:
923 * @value: the value to be written to the property
924 * @name: the name of the property
925 * @errp: returns an error if this function fails
927 * Writes an integer value to a property.
929 void object_property_set_int(Object
*obj
, int64_t value
,
930 const char *name
, Error
**errp
);
933 * object_property_get_int:
935 * @name: the name of the property
936 * @errp: returns an error if this function fails
938 * Returns: the value of the property, converted to an integer, or NULL if
939 * an error occurs (including when the property value is not an integer).
941 int64_t object_property_get_int(Object
*obj
, const char *name
,
945 * object_property_get_enum:
947 * @name: the name of the property
948 * @strings: strings corresponding to enums
949 * @errp: returns an error if this function fails
951 * Returns: the value of the property, converted to an integer, or
952 * undefined if an error occurs (including when the property value is not
955 int object_property_get_enum(Object
*obj
, const char *name
,
956 const char *strings
[], Error
**errp
);
959 * object_property_get_uint16List:
961 * @name: the name of the property
962 * @list: the returned int list
963 * @errp: returns an error if this function fails
965 * Returns: the value of the property, converted to integers, or
966 * undefined if an error occurs (including when the property value is not
967 * an list of integers).
969 void object_property_get_uint16List(Object
*obj
, const char *name
,
970 uint16List
**list
, Error
**errp
);
973 * object_property_set:
975 * @v: the visitor that will be used to write the property value. This should
976 * be an Input visitor and the data will be first read with @name as the
977 * name and then written as the property value.
978 * @name: the name of the property
979 * @errp: returns an error if this function fails
981 * Writes a property to a object.
983 void object_property_set(Object
*obj
, struct Visitor
*v
, const char *name
,
987 * object_property_parse:
989 * @string: the string that will be used to parse the property value.
990 * @name: the name of the property
991 * @errp: returns an error if this function fails
993 * Parses a string and writes the result into a property of an object.
995 void object_property_parse(Object
*obj
, const char *string
,
996 const char *name
, Error
**errp
);
999 * object_property_print:
1001 * @name: the name of the property
1002 * @human: if true, print for human consumption
1003 * @errp: returns an error if this function fails
1005 * Returns a string representation of the value of the property. The
1006 * caller shall free the string.
1008 char *object_property_print(Object
*obj
, const char *name
, bool human
,
1012 * object_property_get_type:
1014 * @name: the name of the property
1015 * @errp: returns an error if this function fails
1017 * Returns: The type name of the property.
1019 const char *object_property_get_type(Object
*obj
, const char *name
,
1025 * Returns: the root object of the composition tree
1027 Object
*object_get_root(void);
1030 * object_get_canonical_path_component:
1032 * Returns: The final component in the object's canonical path. The canonical
1033 * path is the path within the composition tree starting from the root.
1035 gchar
*object_get_canonical_path_component(Object
*obj
);
1038 * object_get_canonical_path:
1040 * Returns: The canonical path for a object. This is the path within the
1041 * composition tree starting from the root.
1043 gchar
*object_get_canonical_path(Object
*obj
);
1046 * object_resolve_path:
1047 * @path: the path to resolve
1048 * @ambiguous: returns true if the path resolution failed because of an
1051 * There are two types of supported paths--absolute paths and partial paths.
1053 * Absolute paths are derived from the root object and can follow child<> or
1054 * link<> properties. Since they can follow link<> properties, they can be
1055 * arbitrarily long. Absolute paths look like absolute filenames and are
1056 * prefixed with a leading slash.
1058 * Partial paths look like relative filenames. They do not begin with a
1059 * prefix. The matching rules for partial paths are subtle but designed to make
1060 * specifying objects easy. At each level of the composition tree, the partial
1061 * path is matched as an absolute path. The first match is not returned. At
1062 * least two matches are searched for. A successful result is only returned if
1063 * only one match is found. If more than one match is found, a flag is
1064 * returned to indicate that the match was ambiguous.
1066 * Returns: The matched object or NULL on path lookup failure.
1068 Object
*object_resolve_path(const char *path
, bool *ambiguous
);
1071 * object_resolve_path_type:
1072 * @path: the path to resolve
1073 * @typename: the type to look for.
1074 * @ambiguous: returns true if the path resolution failed because of an
1077 * This is similar to object_resolve_path. However, when looking for a
1078 * partial path only matches that implement the given type are considered.
1079 * This restricts the search and avoids spuriously flagging matches as
1082 * For both partial and absolute paths, the return value goes through
1083 * a dynamic cast to @typename. This is important if either the link,
1084 * or the typename itself are of interface types.
1086 * Returns: The matched object or NULL on path lookup failure.
1088 Object
*object_resolve_path_type(const char *path
, const char *typename
,
1092 * object_resolve_path_component:
1093 * @parent: the object in which to resolve the path
1094 * @part: the component to resolve.
1096 * This is similar to object_resolve_path with an absolute path, but it
1097 * only resolves one element (@part) and takes the others from @parent.
1099 * Returns: The resolved object or NULL on path lookup failure.
1101 Object
*object_resolve_path_component(Object
*parent
, const gchar
*part
);
1104 * object_property_add_child:
1105 * @obj: the object to add a property to
1106 * @name: the name of the property
1107 * @child: the child object
1108 * @errp: if an error occurs, a pointer to an area to store the area
1110 * Child properties form the composition tree. All objects need to be a child
1111 * of another object. Objects can only be a child of one object.
1113 * There is no way for a child to determine what its parent is. It is not
1114 * a bidirectional relationship. This is by design.
1116 * The value of a child property as a C string will be the child object's
1117 * canonical path. It can be retrieved using object_property_get_str().
1118 * The child object itself can be retrieved using object_property_get_link().
1120 void object_property_add_child(Object
*obj
, const char *name
,
1121 Object
*child
, Error
**errp
);
1124 /* Unref the link pointer when the property is deleted */
1125 OBJ_PROP_LINK_UNREF_ON_RELEASE
= 0x1,
1126 } ObjectPropertyLinkFlags
;
1129 * object_property_allow_set_link:
1131 * The default implementation of the object_property_add_link() check()
1132 * callback function. It allows the link property to be set and never returns
1135 void object_property_allow_set_link(Object
*, const char *,
1136 Object
*, Error
**);
1139 * object_property_add_link:
1140 * @obj: the object to add a property to
1141 * @name: the name of the property
1142 * @type: the qobj type of the link
1143 * @child: a pointer to where the link object reference is stored
1144 * @check: callback to veto setting or NULL if the property is read-only
1145 * @flags: additional options for the link
1146 * @errp: if an error occurs, a pointer to an area to store the area
1148 * Links establish relationships between objects. Links are unidirectional
1149 * although two links can be combined to form a bidirectional relationship
1152 * Links form the graph in the object model.
1154 * The <code>@check()</code> callback is invoked when
1155 * object_property_set_link() is called and can raise an error to prevent the
1156 * link being set. If <code>@check</code> is NULL, the property is read-only
1157 * and cannot be set.
1159 * Ownership of the pointer that @child points to is transferred to the
1160 * link property. The reference count for <code>*@child</code> is
1161 * managed by the property from after the function returns till the
1162 * property is deleted with object_property_del(). If the
1163 * <code>@flags</code> <code>OBJ_PROP_LINK_UNREF_ON_RELEASE</code> bit is set,
1164 * the reference count is decremented when the property is deleted.
1166 void object_property_add_link(Object
*obj
, const char *name
,
1167 const char *type
, Object
**child
,
1168 void (*check
)(Object
*obj
, const char *name
,
1169 Object
*val
, Error
**errp
),
1170 ObjectPropertyLinkFlags flags
,
1174 * object_property_add_str:
1175 * @obj: the object to add a property to
1176 * @name: the name of the property
1177 * @get: the getter or NULL if the property is write-only. This function must
1178 * return a string to be freed by g_free().
1179 * @set: the setter or NULL if the property is read-only
1180 * @errp: if an error occurs, a pointer to an area to store the error
1182 * Add a string property using getters/setters. This function will add a
1183 * property of type 'string'.
1185 void object_property_add_str(Object
*obj
, const char *name
,
1186 char *(*get
)(Object
*, Error
**),
1187 void (*set
)(Object
*, const char *, Error
**),
1191 * object_property_add_bool:
1192 * @obj: the object to add a property to
1193 * @name: the name of the property
1194 * @get: the getter or NULL if the property is write-only.
1195 * @set: the setter or NULL if the property is read-only
1196 * @errp: if an error occurs, a pointer to an area to store the error
1198 * Add a bool property using getters/setters. This function will add a
1199 * property of type 'bool'.
1201 void object_property_add_bool(Object
*obj
, const char *name
,
1202 bool (*get
)(Object
*, Error
**),
1203 void (*set
)(Object
*, bool, Error
**),
1207 * object_property_add_tm:
1208 * @obj: the object to add a property to
1209 * @name: the name of the property
1210 * @get: the getter or NULL if the property is write-only.
1211 * @errp: if an error occurs, a pointer to an area to store the error
1213 * Add a read-only struct tm valued property using a getter function.
1214 * This function will add a property of type 'struct tm'.
1216 void object_property_add_tm(Object
*obj
, const char *name
,
1217 void (*get
)(Object
*, struct tm
*, Error
**),
1221 * object_property_add_uint8_ptr:
1222 * @obj: the object to add a property to
1223 * @name: the name of the property
1224 * @v: pointer to value
1225 * @errp: if an error occurs, a pointer to an area to store the error
1227 * Add an integer property in memory. This function will add a
1228 * property of type 'uint8'.
1230 void object_property_add_uint8_ptr(Object
*obj
, const char *name
,
1231 const uint8_t *v
, Error
**errp
);
1234 * object_property_add_uint16_ptr:
1235 * @obj: the object to add a property to
1236 * @name: the name of the property
1237 * @v: pointer to value
1238 * @errp: if an error occurs, a pointer to an area to store the error
1240 * Add an integer property in memory. This function will add a
1241 * property of type 'uint16'.
1243 void object_property_add_uint16_ptr(Object
*obj
, const char *name
,
1244 const uint16_t *v
, Error
**errp
);
1247 * object_property_add_uint32_ptr:
1248 * @obj: the object to add a property to
1249 * @name: the name of the property
1250 * @v: pointer to value
1251 * @errp: if an error occurs, a pointer to an area to store the error
1253 * Add an integer property in memory. This function will add a
1254 * property of type 'uint32'.
1256 void object_property_add_uint32_ptr(Object
*obj
, const char *name
,
1257 const uint32_t *v
, Error
**errp
);
1260 * object_property_add_uint64_ptr:
1261 * @obj: the object to add a property to
1262 * @name: the name of the property
1263 * @v: pointer to value
1264 * @errp: if an error occurs, a pointer to an area to store the error
1266 * Add an integer property in memory. This function will add a
1267 * property of type 'uint64'.
1269 void object_property_add_uint64_ptr(Object
*obj
, const char *name
,
1270 const uint64_t *v
, Error
**Errp
);
1273 * object_property_add_alias:
1274 * @obj: the object to add a property to
1275 * @name: the name of the property
1276 * @target_obj: the object to forward property access to
1277 * @target_name: the name of the property on the forwarded object
1278 * @errp: if an error occurs, a pointer to an area to store the error
1280 * Add an alias for a property on an object. This function will add a property
1281 * of the same type as the forwarded property.
1283 * The caller must ensure that <code>@target_obj</code> stays alive as long as
1284 * this property exists. In the case of a child object or an alias on the same
1285 * object this will be the case. For aliases to other objects the caller is
1286 * responsible for taking a reference.
1288 void object_property_add_alias(Object
*obj
, const char *name
,
1289 Object
*target_obj
, const char *target_name
,
1293 * object_property_set_description:
1294 * @obj: the object owning the property
1295 * @name: the name of the property
1296 * @description: the description of the property on the object
1297 * @errp: if an error occurs, a pointer to an area to store the error
1299 * Set an object property's description.
1302 void object_property_set_description(Object
*obj
, const char *name
,
1303 const char *description
, Error
**errp
);
1306 * object_child_foreach:
1307 * @obj: the object whose children will be navigated
1308 * @fn: the iterator function to be called
1309 * @opaque: an opaque value that will be passed to the iterator
1311 * Call @fn passing each child of @obj and @opaque to it, until @fn returns
1314 * Returns: The last value returned by @fn, or 0 if there is no child.
1316 int object_child_foreach(Object
*obj
, int (*fn
)(Object
*child
, void *opaque
),
1321 * @root: root of the #path, e.g., object_get_root()
1322 * @path: path to the container
1324 * Return a container object whose path is @path. Create more containers
1325 * along the path if necessary.
1327 * Returns: the container object.
1329 Object
*container_get(Object
*root
, const char *path
);