PPC: Fix rldcl
[qemu/agraf.git] / include / qom / object.h
blobd0f99c5782c517af5d514dc029c0744ffb062d38
1 /*
2 * QEMU Object Model
4 * Copyright IBM, Corp. 2011
6 * Authors:
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.
14 #ifndef QEMU_OBJECT_H
15 #define QEMU_OBJECT_H
17 #include <glib.h>
18 #include <stdint.h>
19 #include <stdbool.h>
20 #include "qemu/queue.h"
22 struct Visitor;
23 struct Error;
25 struct TypeImpl;
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"
38 /**
39 * SECTION:object.h
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
45 * features:
47 * - System for dynamically registering types
48 * - Support for single-inheritance of types
49 * - Multiple inheritance of stateless interfaces
51 * <example>
52 * <title>Creating a minimal type</title>
53 * <programlisting>
54 * #include "qdev.h"
56 * #define TYPE_MY_DEVICE "my-device"
58 * // No new virtual functions: we can reuse the typedef for the
59 * // superclass.
60 * typedef DeviceClass MyDeviceClass;
61 * typedef struct MyDevice
62 * {
63 * DeviceState parent;
65 * int reg0, reg1, reg2;
66 * } MyDevice;
68 * static const TypeInfo my_device_info = {
69 * .name = TYPE_MY_DEVICE,
70 * .parent = TYPE_DEVICE,
71 * .instance_size = sizeof(MyDevice),
72 * };
74 * static void my_device_register_types(void)
75 * {
76 * type_register_static(&my_device_info);
77 * }
79 * type_init(my_device_register_types)
80 * </programlisting>
81 * </example>
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
96 * specific type:
98 * <example>
99 * <title>Typecasting macros</title>
100 * <programlisting>
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)
107 * </programlisting>
108 * </example>
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:
130 * <example>
131 * <title>Overriding a virtual function</title>
132 * <programlisting>
133 * #include "qdev.h"
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,
146 * };
147 * </programlisting>
148 * </example>
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:
154 * <example>
155 * <title>Defining an abstract class</title>
156 * <programlisting>
157 * #include "qdev.h"
159 * typedef struct MyDeviceClass
161 * DeviceClass parent;
163 * void (*frobnicate) (MyDevice *obj);
164 * } MyDeviceClass;
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),
172 * };
174 * void my_device_frobnicate(MyDevice *obj)
176 * MyDeviceClass *klass = MY_DEVICE_GET_CLASS(obj);
178 * klass->frobnicate(obj);
180 * </programlisting>
181 * </example>
183 * # Interfaces #
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.
190 * # Methods #
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
207 * being overridden.
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.
215 * <example>
216 * <title>Overriding a virtual method</title>
217 * <programlisting>
218 * typedef struct MyState MyState;
220 * typedef void (*MyDoSomething)(MyState *obj);
222 * typedef struct MyClass {
223 * ObjectClass parent_class;
225 * MyDoSomething do_something;
226 * } MyClass;
228 * static void my_do_something(MyState *obj)
230 * // do something
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 = {
241 * .name = TYPE_MY,
242 * .parent = TYPE_OBJECT,
243 * .instance_size = sizeof(MyState),
244 * .class_size = sizeof(MyClass),
245 * .class_init = my_class_init,
246 * };
248 * typedef struct DerivedClass {
249 * MyClass parent_class;
251 * MyDoSomething parent_do_something;
252 * } MyClass;
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,
274 * .parent = TYPE_MY,
275 * .class_size = sizeof(DerivedClass),
276 * .class_init = my_class_init,
277 * };
278 * </programlisting>
279 * </example>
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,
301 struct Visitor *v,
302 void *opaque,
303 const char *name,
304 struct Error **errp);
307 * ObjectPropertyRelease:
308 * @obj: the object that owns the property
309 * @name: the name of the property
310 * @opaque: the opaque registered with the property
312 * Called when a property is removed from a object.
314 typedef void (ObjectPropertyRelease)(Object *obj,
315 const char *name,
316 void *opaque);
318 typedef struct ObjectProperty
320 gchar *name;
321 gchar *type;
322 ObjectPropertyAccessor *get;
323 ObjectPropertyAccessor *set;
324 ObjectPropertyRelease *release;
325 void *opaque;
327 QTAILQ_ENTRY(ObjectProperty) node;
328 } ObjectProperty;
331 * ObjectUnparent:
332 * @obj: the object that is being removed from the composition tree
334 * Called when an object is being removed from the QOM composition tree.
335 * The function should remove any backlinks from children objects to @obj.
337 typedef void (ObjectUnparent)(Object *obj);
340 * ObjectFree:
341 * @obj: the object being freed
343 * Called when an object's last reference is removed.
345 typedef void (ObjectFree)(void *obj);
348 * ObjectClass:
350 * The base for all classes. The only thing that #ObjectClass contains is an
351 * integer type handle.
353 struct ObjectClass
355 /*< private >*/
356 Type type;
357 GSList *interfaces;
359 ObjectUnparent *unparent;
363 * Object:
365 * The base for all objects. The first member of this object is a pointer to
366 * a #ObjectClass. Since C guarantees that the first member of a structure
367 * always begins at byte 0 of that structure, as long as any sub-object places
368 * its parent as the first member, we can cast directly to a #Object.
370 * As a result, #Object contains a reference to the objects type as its
371 * first member. This allows identification of the real type of the object at
372 * run time.
374 * #Object also contains a list of #Interfaces that this object
375 * implements.
377 struct Object
379 /*< private >*/
380 ObjectClass *class;
381 ObjectFree *free;
382 QTAILQ_HEAD(, ObjectProperty) properties;
383 uint32_t ref;
384 Object *parent;
388 * TypeInfo:
389 * @name: The name of the type.
390 * @parent: The name of the parent type.
391 * @instance_size: The size of the object (derivative of #Object). If
392 * @instance_size is 0, then the size of the object will be the size of the
393 * parent object.
394 * @instance_init: This function is called to initialize an object. The parent
395 * class will have already been initialized so the type is only responsible
396 * for initializing its own members.
397 * @instance_finalize: This function is called during object destruction. This
398 * is called before the parent @instance_finalize function has been called.
399 * An object should only free the members that are unique to its type in this
400 * function.
401 * @abstract: If this field is true, then the class is considered abstract and
402 * cannot be directly instantiated.
403 * @class_size: The size of the class object (derivative of #ObjectClass)
404 * for this object. If @class_size is 0, then the size of the class will be
405 * assumed to be the size of the parent class. This allows a type to avoid
406 * implementing an explicit class type if they are not adding additional
407 * virtual functions.
408 * @class_init: This function is called after all parent class initialization
409 * has occurred to allow a class to set its default virtual method pointers.
410 * This is also the function to use to override virtual methods from a parent
411 * class.
412 * @class_base_init: This function is called for all base classes after all
413 * parent class initialization has occurred, but before the class itself
414 * is initialized. This is the function to use to undo the effects of
415 * memcpy from the parent class to the descendents.
416 * @class_finalize: This function is called during class destruction and is
417 * meant to release and dynamic parameters allocated by @class_init.
418 * @class_data: Data to pass to the @class_init, @class_base_init and
419 * @class_finalize functions. This can be useful when building dynamic
420 * classes.
421 * @interfaces: The list of interfaces associated with this type. This
422 * should point to a static array that's terminated with a zero filled
423 * element.
425 struct TypeInfo
427 const char *name;
428 const char *parent;
430 size_t instance_size;
431 void (*instance_init)(Object *obj);
432 void (*instance_finalize)(Object *obj);
434 bool abstract;
435 size_t class_size;
437 void (*class_init)(ObjectClass *klass, void *data);
438 void (*class_base_init)(ObjectClass *klass, void *data);
439 void (*class_finalize)(ObjectClass *klass, void *data);
440 void *class_data;
442 InterfaceInfo *interfaces;
446 * OBJECT:
447 * @obj: A derivative of #Object
449 * Converts an object to a #Object. Since all objects are #Objects,
450 * this function will always succeed.
452 #define OBJECT(obj) \
453 ((Object *)(obj))
456 * OBJECT_CLASS:
457 * @class: A derivative of #ObjectClass.
459 * Converts a class to an #ObjectClass. Since all objects are #Objects,
460 * this function will always succeed.
462 #define OBJECT_CLASS(class) \
463 ((ObjectClass *)(class))
466 * OBJECT_CHECK:
467 * @type: The C type to use for the return value.
468 * @obj: A derivative of @type to cast.
469 * @name: The QOM typename of @type
471 * A type safe version of @object_dynamic_cast_assert. Typically each class
472 * will define a macro based on this type to perform type safe dynamic_casts to
473 * this object type.
475 * If an invalid object is passed to this function, a run time assert will be
476 * generated.
478 #define OBJECT_CHECK(type, obj, name) \
479 ((type *)object_dynamic_cast_assert(OBJECT(obj), (name)))
482 * OBJECT_CLASS_CHECK:
483 * @class: The C type to use for the return value.
484 * @obj: A derivative of @type to cast.
485 * @name: the QOM typename of @class.
487 * A type safe version of @object_class_dynamic_cast_assert. This macro is
488 * typically wrapped by each type to perform type safe casts of a class to a
489 * specific class type.
491 #define OBJECT_CLASS_CHECK(class, obj, name) \
492 ((class *)object_class_dynamic_cast_assert(OBJECT_CLASS(obj), (name)))
495 * OBJECT_GET_CLASS:
496 * @class: The C type to use for the return value.
497 * @obj: The object to obtain the class for.
498 * @name: The QOM typename of @obj.
500 * This function will return a specific class for a given object. Its generally
501 * used by each type to provide a type safe macro to get a specific class type
502 * from an object.
504 #define OBJECT_GET_CLASS(class, obj, name) \
505 OBJECT_CLASS_CHECK(class, object_get_class(OBJECT(obj)), name)
508 * InterfaceInfo:
509 * @type: The name of the interface.
511 * The information associated with an interface.
513 struct InterfaceInfo {
514 const char *type;
518 * InterfaceClass:
519 * @parent_class: the base class
521 * The class for all interfaces. Subclasses of this class should only add
522 * virtual methods.
524 struct InterfaceClass
526 ObjectClass parent_class;
527 /*< private >*/
528 ObjectClass *concrete_class;
531 #define TYPE_INTERFACE "interface"
534 * INTERFACE_CLASS:
535 * @klass: class to cast from
536 * Returns: An #InterfaceClass or raise an error if cast is invalid
538 #define INTERFACE_CLASS(klass) \
539 OBJECT_CLASS_CHECK(InterfaceClass, klass, TYPE_INTERFACE)
542 * INTERFACE_CHECK:
543 * @interface: the type to return
544 * @obj: the object to convert to an interface
545 * @name: the interface type name
547 * Returns: @obj casted to @interface if cast is valid, otherwise raise error.
549 #define INTERFACE_CHECK(interface, obj, name) \
550 ((interface *)object_dynamic_cast_assert(OBJECT((obj)), (name)))
553 * object_new:
554 * @typename: The name of the type of the object to instantiate.
556 * This function will initialize a new object using heap allocated memory.
557 * The returned object has a reference count of 1, and will be freed when
558 * the last reference is dropped.
560 * Returns: The newly allocated and instantiated object.
562 Object *object_new(const char *typename);
565 * object_new_with_type:
566 * @type: The type of the object to instantiate.
568 * This function will initialize a new object using heap allocated memory.
569 * The returned object has a reference count of 1, and will be freed when
570 * the last reference is dropped.
572 * Returns: The newly allocated and instantiated object.
574 Object *object_new_with_type(Type type);
577 * object_initialize_with_type:
578 * @obj: A pointer to the memory to be used for the object.
579 * @type: The type of the object to instantiate.
581 * This function will initialize an object. The memory for the object should
582 * have already been allocated. The returned object has a reference count of 1,
583 * and will be finalized when the last reference is dropped.
585 void object_initialize_with_type(void *data, Type type);
588 * object_initialize:
589 * @obj: A pointer to the memory to be used for the object.
590 * @typename: The name of the type of the object to instantiate.
592 * This function will initialize an object. The memory for the object should
593 * have already been allocated. The returned object has a reference count of 1,
594 * and will be finalized when the last reference is dropped.
596 void object_initialize(void *obj, const char *typename);
599 * object_dynamic_cast:
600 * @obj: The object to cast.
601 * @typename: The @typename to cast to.
603 * This function will determine if @obj is-a @typename. @obj can refer to an
604 * object or an interface associated with an object.
606 * Returns: This function returns @obj on success or #NULL on failure.
608 Object *object_dynamic_cast(Object *obj, const char *typename);
611 * object_dynamic_cast_assert:
613 * See object_dynamic_cast() for a description of the parameters of this
614 * function. The only difference in behavior is that this function asserts
615 * instead of returning #NULL on failure.
617 Object *object_dynamic_cast_assert(Object *obj, const char *typename);
620 * object_get_class:
621 * @obj: A derivative of #Object
623 * Returns: The #ObjectClass of the type associated with @obj.
625 ObjectClass *object_get_class(Object *obj);
628 * object_get_typename:
629 * @obj: A derivative of #Object.
631 * Returns: The QOM typename of @obj.
633 const char *object_get_typename(Object *obj);
636 * type_register_static:
637 * @info: The #TypeInfo of the new type.
639 * @info and all of the strings it points to should exist for the life time
640 * that the type is registered.
642 * Returns: 0 on failure, the new #Type on success.
644 Type type_register_static(const TypeInfo *info);
647 * type_register:
648 * @info: The #TypeInfo of the new type
650 * Unlike type_register_static(), this call does not require @info or its
651 * string members to continue to exist after the call returns.
653 * Returns: 0 on failure, the new #Type on success.
655 Type type_register(const TypeInfo *info);
658 * object_class_dynamic_cast_assert:
659 * @klass: The #ObjectClass to attempt to cast.
660 * @typename: The QOM typename of the class to cast to.
662 * Returns: This function always returns @klass and asserts on failure.
664 ObjectClass *object_class_dynamic_cast_assert(ObjectClass *klass,
665 const char *typename);
667 ObjectClass *object_class_dynamic_cast(ObjectClass *klass,
668 const char *typename);
671 * object_class_get_parent:
672 * @klass: The class to obtain the parent for.
674 * Returns: The parent for @klass or %NULL if none.
676 ObjectClass *object_class_get_parent(ObjectClass *klass);
679 * object_class_get_name:
680 * @klass: The class to obtain the QOM typename for.
682 * Returns: The QOM typename for @klass.
684 const char *object_class_get_name(ObjectClass *klass);
687 * object_class_is_abstract:
688 * @klass: The class to obtain the abstractness for.
690 * Returns: %true if @klass is abstract, %false otherwise.
692 bool object_class_is_abstract(ObjectClass *klass);
695 * object_class_by_name:
696 * @typename: The QOM typename to obtain the class for.
698 * Returns: The class for @typename or %NULL if not found.
700 ObjectClass *object_class_by_name(const char *typename);
702 void object_class_foreach(void (*fn)(ObjectClass *klass, void *opaque),
703 const char *implements_type, bool include_abstract,
704 void *opaque);
707 * object_class_get_list:
708 * @implements_type: The type to filter for, including its derivatives.
709 * @include_abstract: Whether to include abstract classes.
711 * Returns: A singly-linked list of the classes in reverse hashtable order.
713 GSList *object_class_get_list(const char *implements_type,
714 bool include_abstract);
717 * object_ref:
718 * @obj: the object
720 * Increase the reference count of a object. A object cannot be freed as long
721 * as its reference count is greater than zero.
723 void object_ref(Object *obj);
726 * qdef_unref:
727 * @obj: the object
729 * Decrease the reference count of a object. A object cannot be freed as long
730 * as its reference count is greater than zero.
732 void object_unref(Object *obj);
735 * object_property_add:
736 * @obj: the object to add a property to
737 * @name: the name of the property. This can contain any character except for
738 * a forward slash. In general, you should use hyphens '-' instead of
739 * underscores '_' when naming properties.
740 * @type: the type name of the property. This namespace is pretty loosely
741 * defined. Sub namespaces are constructed by using a prefix and then
742 * to angle brackets. For instance, the type 'virtio-net-pci' in the
743 * 'link' namespace would be 'link<virtio-net-pci>'.
744 * @get: The getter to be called to read a property. If this is NULL, then
745 * the property cannot be read.
746 * @set: the setter to be called to write a property. If this is NULL,
747 * then the property cannot be written.
748 * @release: called when the property is removed from the object. This is
749 * meant to allow a property to free its opaque upon object
750 * destruction. This may be NULL.
751 * @opaque: an opaque pointer to pass to the callbacks for the property
752 * @errp: returns an error if this function fails
754 void object_property_add(Object *obj, const char *name, const char *type,
755 ObjectPropertyAccessor *get,
756 ObjectPropertyAccessor *set,
757 ObjectPropertyRelease *release,
758 void *opaque, struct Error **errp);
760 void object_property_del(Object *obj, const char *name, struct Error **errp);
763 * object_property_find:
764 * @obj: the object
765 * @name: the name of the property
766 * @errp: returns an error if this function fails
768 * Look up a property for an object and return its #ObjectProperty if found.
770 ObjectProperty *object_property_find(Object *obj, const char *name,
771 struct Error **errp);
773 void object_unparent(Object *obj);
776 * object_property_get:
777 * @obj: the object
778 * @v: the visitor that will receive the property value. This should be an
779 * Output visitor and the data will be written with @name as the name.
780 * @name: the name of the property
781 * @errp: returns an error if this function fails
783 * Reads a property from a object.
785 void object_property_get(Object *obj, struct Visitor *v, const char *name,
786 struct Error **errp);
789 * object_property_set_str:
790 * @value: the value to be written to the property
791 * @name: the name of the property
792 * @errp: returns an error if this function fails
794 * Writes a string value to a property.
796 void object_property_set_str(Object *obj, const char *value,
797 const char *name, struct Error **errp);
800 * object_property_get_str:
801 * @obj: the object
802 * @name: the name of the property
803 * @errp: returns an error if this function fails
805 * Returns: the value of the property, converted to a C string, or NULL if
806 * an error occurs (including when the property value is not a string).
807 * The caller should free the string.
809 char *object_property_get_str(Object *obj, const char *name,
810 struct Error **errp);
813 * object_property_set_link:
814 * @value: the value to be written to the property
815 * @name: the name of the property
816 * @errp: returns an error if this function fails
818 * Writes an object's canonical path to a property.
820 void object_property_set_link(Object *obj, Object *value,
821 const char *name, struct Error **errp);
824 * object_property_get_link:
825 * @obj: the object
826 * @name: the name of the property
827 * @errp: returns an error if this function fails
829 * Returns: the value of the property, resolved from a path to an Object,
830 * or NULL if an error occurs (including when the property value is not a
831 * string or not a valid object path).
833 Object *object_property_get_link(Object *obj, const char *name,
834 struct Error **errp);
837 * object_property_set_bool:
838 * @value: the value to be written to the property
839 * @name: the name of the property
840 * @errp: returns an error if this function fails
842 * Writes a bool value to a property.
844 void object_property_set_bool(Object *obj, bool value,
845 const char *name, struct Error **errp);
848 * object_property_get_bool:
849 * @obj: the object
850 * @name: the name of the property
851 * @errp: returns an error if this function fails
853 * Returns: the value of the property, converted to a boolean, or NULL if
854 * an error occurs (including when the property value is not a bool).
856 bool object_property_get_bool(Object *obj, const char *name,
857 struct Error **errp);
860 * object_property_set_int:
861 * @value: the value to be written to the property
862 * @name: the name of the property
863 * @errp: returns an error if this function fails
865 * Writes an integer value to a property.
867 void object_property_set_int(Object *obj, int64_t value,
868 const char *name, struct Error **errp);
871 * object_property_get_int:
872 * @obj: the object
873 * @name: the name of the property
874 * @errp: returns an error if this function fails
876 * Returns: the value of the property, converted to an integer, or NULL if
877 * an error occurs (including when the property value is not an integer).
879 int64_t object_property_get_int(Object *obj, const char *name,
880 struct Error **errp);
883 * object_property_set:
884 * @obj: the object
885 * @v: the visitor that will be used to write the property value. This should
886 * be an Input visitor and the data will be first read with @name as the
887 * name and then written as the property value.
888 * @name: the name of the property
889 * @errp: returns an error if this function fails
891 * Writes a property to a object.
893 void object_property_set(Object *obj, struct Visitor *v, const char *name,
894 struct Error **errp);
897 * object_property_parse:
898 * @obj: the object
899 * @string: the string that will be used to parse the property value.
900 * @name: the name of the property
901 * @errp: returns an error if this function fails
903 * Parses a string and writes the result into a property of an object.
905 void object_property_parse(Object *obj, const char *string,
906 const char *name, struct Error **errp);
909 * object_property_print:
910 * @obj: the object
911 * @name: the name of the property
912 * @errp: returns an error if this function fails
914 * Returns a string representation of the value of the property. The
915 * caller shall free the string.
917 char *object_property_print(Object *obj, const char *name,
918 struct Error **errp);
921 * object_property_get_type:
922 * @obj: the object
923 * @name: the name of the property
924 * @errp: returns an error if this function fails
926 * Returns: The type name of the property.
928 const char *object_property_get_type(Object *obj, const char *name,
929 struct Error **errp);
932 * object_get_root:
934 * Returns: the root object of the composition tree
936 Object *object_get_root(void);
939 * object_get_canonical_path:
941 * Returns: The canonical path for a object. This is the path within the
942 * composition tree starting from the root.
944 gchar *object_get_canonical_path(Object *obj);
947 * object_resolve_path:
948 * @path: the path to resolve
949 * @ambiguous: returns true if the path resolution failed because of an
950 * ambiguous match
952 * There are two types of supported paths--absolute paths and partial paths.
954 * Absolute paths are derived from the root object and can follow child<> or
955 * link<> properties. Since they can follow link<> properties, they can be
956 * arbitrarily long. Absolute paths look like absolute filenames and are
957 * prefixed with a leading slash.
959 * Partial paths look like relative filenames. They do not begin with a
960 * prefix. The matching rules for partial paths are subtle but designed to make
961 * specifying objects easy. At each level of the composition tree, the partial
962 * path is matched as an absolute path. The first match is not returned. At
963 * least two matches are searched for. A successful result is only returned if
964 * only one match is found. If more than one match is found, a flag is
965 * returned to indicate that the match was ambiguous.
967 * Returns: The matched object or NULL on path lookup failure.
969 Object *object_resolve_path(const char *path, bool *ambiguous);
972 * object_resolve_path_type:
973 * @path: the path to resolve
974 * @typename: the type to look for.
975 * @ambiguous: returns true if the path resolution failed because of an
976 * ambiguous match
978 * This is similar to object_resolve_path. However, when looking for a
979 * partial path only matches that implement the given type are considered.
980 * This restricts the search and avoids spuriously flagging matches as
981 * ambiguous.
983 * For both partial and absolute paths, the return value goes through
984 * a dynamic cast to @typename. This is important if either the link,
985 * or the typename itself are of interface types.
987 * Returns: The matched object or NULL on path lookup failure.
989 Object *object_resolve_path_type(const char *path, const char *typename,
990 bool *ambiguous);
993 * object_resolve_path_component:
994 * @parent: the object in which to resolve the path
995 * @part: the component to resolve.
997 * This is similar to object_resolve_path with an absolute path, but it
998 * only resolves one element (@part) and takes the others from @parent.
1000 * Returns: The resolved object or NULL on path lookup failure.
1002 Object *object_resolve_path_component(Object *parent, const gchar *part);
1005 * object_property_add_child:
1006 * @obj: the object to add a property to
1007 * @name: the name of the property
1008 * @child: the child object
1009 * @errp: if an error occurs, a pointer to an area to store the area
1011 * Child properties form the composition tree. All objects need to be a child
1012 * of another object. Objects can only be a child of one object.
1014 * There is no way for a child to determine what its parent is. It is not
1015 * a bidirectional relationship. This is by design.
1017 * The value of a child property as a C string will be the child object's
1018 * canonical path. It can be retrieved using object_property_get_str().
1019 * The child object itself can be retrieved using object_property_get_link().
1021 void object_property_add_child(Object *obj, const char *name,
1022 Object *child, struct Error **errp);
1025 * object_property_add_link:
1026 * @obj: the object to add a property to
1027 * @name: the name of the property
1028 * @type: the qobj type of the link
1029 * @child: a pointer to where the link object reference is stored
1030 * @errp: if an error occurs, a pointer to an area to store the area
1032 * Links establish relationships between objects. Links are unidirectional
1033 * although two links can be combined to form a bidirectional relationship
1034 * between objects.
1036 * Links form the graph in the object model.
1038 * Ownership of the pointer that @child points to is transferred to the
1039 * link property. The reference count for <code>*@child</code> is
1040 * managed by the property from after the function returns till the
1041 * property is deleted with object_property_del().
1043 void object_property_add_link(Object *obj, const char *name,
1044 const char *type, Object **child,
1045 struct Error **errp);
1048 * object_property_add_str:
1049 * @obj: the object to add a property to
1050 * @name: the name of the property
1051 * @get: the getter or NULL if the property is write-only. This function must
1052 * return a string to be freed by g_free().
1053 * @set: the setter or NULL if the property is read-only
1054 * @errp: if an error occurs, a pointer to an area to store the error
1056 * Add a string property using getters/setters. This function will add a
1057 * property of type 'string'.
1059 void object_property_add_str(Object *obj, const char *name,
1060 char *(*get)(Object *, struct Error **),
1061 void (*set)(Object *, const char *, struct Error **),
1062 struct Error **errp);
1065 * object_property_add_bool:
1066 * @obj: the object to add a property to
1067 * @name: the name of the property
1068 * @get: the getter or NULL if the property is write-only.
1069 * @set: the setter or NULL if the property is read-only
1070 * @errp: if an error occurs, a pointer to an area to store the error
1072 * Add a bool property using getters/setters. This function will add a
1073 * property of type 'bool'.
1075 void object_property_add_bool(Object *obj, const char *name,
1076 bool (*get)(Object *, struct Error **),
1077 void (*set)(Object *, bool, struct Error **),
1078 struct Error **errp);
1081 * object_child_foreach:
1082 * @obj: the object whose children will be navigated
1083 * @fn: the iterator function to be called
1084 * @opaque: an opaque value that will be passed to the iterator
1086 * Call @fn passing each child of @obj and @opaque to it, until @fn returns
1087 * non-zero.
1089 * Returns: The last value returned by @fn, or 0 if there is no child.
1091 int object_child_foreach(Object *obj, int (*fn)(Object *child, void *opaque),
1092 void *opaque);
1095 * container_get:
1096 * @root: root of the #path, e.g., object_get_root()
1097 * @path: path to the container
1099 * Return a container object whose path is @path. Create more containers
1100 * along the path if necessary.
1102 * Returns: the container object.
1104 Object *container_get(Object *root, const char *path);
1107 #endif