qom: Add check() argument to object_property_add_link()
[qemu.git] / include / qom / object.h
1 /*
2 * QEMU Object Model
3 *
4 * Copyright IBM, Corp. 2011
5 *
6 * Authors:
7 * Anthony Liguori <aliguori@us.ibm.com>
8 *
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.
11 *
12 */
13
14 #ifndef QEMU_OBJECT_H
15 #define QEMU_OBJECT_H
16
17 #include <glib.h>
18 #include <stdint.h>
19 #include <stdbool.h>
20 #include "qemu/queue.h"
21 #include "qapi/error.h"
22
23 struct Visitor;
24
25 struct TypeImpl;
26 typedef struct TypeImpl *Type;
27
28 typedef struct ObjectClass ObjectClass;
29 typedef struct Object Object;
30
31 typedef struct TypeInfo TypeInfo;
32
33 typedef struct InterfaceClass InterfaceClass;
34 typedef struct InterfaceInfo InterfaceInfo;
35
36 #define TYPE_OBJECT "object"
37
38 /**
39 * SECTION:object.h
40 * @title:Base Object Type System
41 * @short_description: interfaces for creating new types and objects
42 *
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:
46 *
47 * - System for dynamically registering types
48 * - Support for single-inheritance of types
49 * - Multiple inheritance of stateless interfaces
50 *
51 * <example>
52 * <title>Creating a minimal type</title>
53 * <programlisting>
54 * #include "qdev.h"
55 *
56 * #define TYPE_MY_DEVICE "my-device"
57 *
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;
64 *
65 * int reg0, reg1, reg2;
66 * } MyDevice;
67 *
68 * static const TypeInfo my_device_info = {
69 * .name = TYPE_MY_DEVICE,
70 * .parent = TYPE_DEVICE,
71 * .instance_size = sizeof(MyDevice),
72 * };
73 *
74 * static void my_device_register_types(void)
75 * {
76 * type_register_static(&my_device_info);
77 * }
78 *
79 * type_init(my_device_register_types)
80 * </programlisting>
81 * </example>
82 *
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.
86 *
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.
91 *
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:
97 *
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>
109 *
110 * # Class Initialization #
111 *
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.
115 *
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.
120 *
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.
124 *
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:
129 *
130 * <example>
131 * <title>Overriding a virtual function</title>
132 * <programlisting>
133 * #include "qdev.h"
134 *
135 * void my_device_class_init(ObjectClass *klass, void *class_data)
136 * {
137 * DeviceClass *dc = DEVICE_CLASS(klass);
138 * dc->reset = my_device_reset;
139 * }
140 *
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>
149 *
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:
153 *
154 * <example>
155 * <title>Defining an abstract class</title>
156 * <programlisting>
157 * #include "qdev.h"
158 *
159 * typedef struct MyDeviceClass
160 * {
161 * DeviceClass parent;
162 *
163 * void (*frobnicate) (MyDevice *obj);
164 * } MyDeviceClass;
165 *
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 * };
173 *
174 * void my_device_frobnicate(MyDevice *obj)
175 * {
176 * MyDeviceClass *klass = MY_DEVICE_GET_CLASS(obj);
177 *
178 * klass->frobnicate(obj);
179 * }
180 * </programlisting>
181 * </example>
182 *
183 * # Interfaces #
184 *
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.
189 *
190 * # Methods #
191 *
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>.
197 *
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.
201 *
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.
208 *
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.
214 *
215 * <example>
216 * <title>Overriding a virtual method</title>
217 * <programlisting>
218 * typedef struct MyState MyState;
219 *
220 * typedef void (*MyDoSomething)(MyState *obj);
221 *
222 * typedef struct MyClass {
223 * ObjectClass parent_class;
224 *
225 * MyDoSomething do_something;
226 * } MyClass;
227 *
228 * static void my_do_something(MyState *obj)
229 * {
230 * // do something
231 * }
232 *
233 * static void my_class_init(ObjectClass *oc, void *data)
234 * {
235 * MyClass *mc = MY_CLASS(oc);
236 *
237 * mc->do_something = my_do_something;
238 * }
239 *
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 * };
247 *
248 * typedef struct DerivedClass {
249 * MyClass parent_class;
250 *
251 * MyDoSomething parent_do_something;
252 * } DerivedClass;
253 *
254 * static void derived_do_something(MyState *obj)
255 * {
256 * DerivedClass *dc = DERIVED_GET_CLASS(obj);
257 *
258 * // do something here
259 * dc->parent_do_something(obj);
260 * // do something else here
261 * }
262 *
263 * static void derived_class_init(ObjectClass *oc, void *data)
264 * {
265 * MyClass *mc = MY_CLASS(oc);
266 * DerivedClass *dc = DERIVED_CLASS(oc);
267 *
268 * dc->parent_do_something = mc->do_something;
269 * mc->do_something = derived_do_something;
270 * }
271 *
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>
280 *
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++.
284 *
285 * The first example of such a QOM method was #CPUClass.reset,
286 * another example is #DeviceClass.realize.
287 */
288
289
290 /**
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.
297 *
298 * Called when trying to get/set a property.
299 */
300 typedef void (ObjectPropertyAccessor)(Object *obj,
301 struct Visitor *v,
302 void *opaque,
303 const char *name,
304 Error **errp);
305
306 /**
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
311 *
312 * Called when a property is removed from a object.
313 */
314 typedef void (ObjectPropertyRelease)(Object *obj,
315 const char *name,
316 void *opaque);
317
318 typedef struct ObjectProperty
319 {
320 gchar *name;
321 gchar *type;
322 ObjectPropertyAccessor *get;
323 ObjectPropertyAccessor *set;
324 ObjectPropertyRelease *release;
325 void *opaque;
326
327 QTAILQ_ENTRY(ObjectProperty) node;
328 } ObjectProperty;
329
330 /**
331 * ObjectUnparent:
332 * @obj: the object that is being removed from the composition tree
333 *
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.
336 */
337 typedef void (ObjectUnparent)(Object *obj);
338
339 /**
340 * ObjectFree:
341 * @obj: the object being freed
342 *
343 * Called when an object's last reference is removed.
344 */
345 typedef void (ObjectFree)(void *obj);
346
347 #define OBJECT_CLASS_CAST_CACHE 4
348
349 /**
350 * ObjectClass:
351 *
352 * The base for all classes. The only thing that #ObjectClass contains is an
353 * integer type handle.
354 */
355 struct ObjectClass
356 {
357 /*< private >*/
358 Type type;
359 GSList *interfaces;
360
361 const char *object_cast_cache[OBJECT_CLASS_CAST_CACHE];
362 const char *class_cast_cache[OBJECT_CLASS_CAST_CACHE];
363
364 ObjectUnparent *unparent;
365 };
366
367 /**
368 * Object:
369 *
370 * The base for all objects. The first member of this object is a pointer to
371 * a #ObjectClass. Since C guarantees that the first member of a structure
372 * always begins at byte 0 of that structure, as long as any sub-object places
373 * its parent as the first member, we can cast directly to a #Object.
374 *
375 * As a result, #Object contains a reference to the objects type as its
376 * first member. This allows identification of the real type of the object at
377 * run time.
378 *
379 * #Object also contains a list of #Interfaces that this object
380 * implements.
381 */
382 struct Object
383 {
384 /*< private >*/
385 ObjectClass *class;
386 ObjectFree *free;
387 QTAILQ_HEAD(, ObjectProperty) properties;
388 uint32_t ref;
389 Object *parent;
390 };
391
392 /**
393 * TypeInfo:
394 * @name: The name of the type.
395 * @parent: The name of the parent type.
396 * @instance_size: The size of the object (derivative of #Object). If
397 * @instance_size is 0, then the size of the object will be the size of the
398 * parent object.
399 * @instance_init: This function is called to initialize an object. The parent
400 * class will have already been initialized so the type is only responsible
401 * for initializing its own members.
402 * @instance_post_init: This function is called to finish initialization of
403 * an object, after all @instance_init functions were called.
404 * @instance_finalize: This function is called during object destruction. This
405 * is called before the parent @instance_finalize function has been called.
406 * An object should only free the members that are unique to its type in this
407 * function.
408 * @abstract: If this field is true, then the class is considered abstract and
409 * cannot be directly instantiated.
410 * @class_size: The size of the class object (derivative of #ObjectClass)
411 * for this object. If @class_size is 0, then the size of the class will be
412 * assumed to be the size of the parent class. This allows a type to avoid
413 * implementing an explicit class type if they are not adding additional
414 * virtual functions.
415 * @class_init: This function is called after all parent class initialization
416 * has occurred to allow a class to set its default virtual method pointers.
417 * This is also the function to use to override virtual methods from a parent
418 * class.
419 * @class_base_init: This function is called for all base classes after all
420 * parent class initialization has occurred, but before the class itself
421 * is initialized. This is the function to use to undo the effects of
422 * memcpy from the parent class to the descendents.
423 * @class_finalize: This function is called during class destruction and is
424 * meant to release and dynamic parameters allocated by @class_init.
425 * @class_data: Data to pass to the @class_init, @class_base_init and
426 * @class_finalize functions. This can be useful when building dynamic
427 * classes.
428 * @interfaces: The list of interfaces associated with this type. This
429 * should point to a static array that's terminated with a zero filled
430 * element.
431 */
432 struct TypeInfo
433 {
434 const char *name;
435 const char *parent;
436
437 size_t instance_size;
438 void (*instance_init)(Object *obj);
439 void (*instance_post_init)(Object *obj);
440 void (*instance_finalize)(Object *obj);
441
442 bool abstract;
443 size_t class_size;
444
445 void (*class_init)(ObjectClass *klass, void *data);
446 void (*class_base_init)(ObjectClass *klass, void *data);
447 void (*class_finalize)(ObjectClass *klass, void *data);
448 void *class_data;
449
450 InterfaceInfo *interfaces;
451 };
452
453 /**
454 * OBJECT:
455 * @obj: A derivative of #Object
456 *
457 * Converts an object to a #Object. Since all objects are #Objects,
458 * this function will always succeed.
459 */
460 #define OBJECT(obj) \
461 ((Object *)(obj))
462
463 /**
464 * OBJECT_CLASS:
465 * @class: A derivative of #ObjectClass.
466 *
467 * Converts a class to an #ObjectClass. Since all objects are #Objects,
468 * this function will always succeed.
469 */
470 #define OBJECT_CLASS(class) \
471 ((ObjectClass *)(class))
472
473 /**
474 * OBJECT_CHECK:
475 * @type: The C type to use for the return value.
476 * @obj: A derivative of @type to cast.
477 * @name: The QOM typename of @type
478 *
479 * A type safe version of @object_dynamic_cast_assert. Typically each class
480 * will define a macro based on this type to perform type safe dynamic_casts to
481 * this object type.
482 *
483 * If an invalid object is passed to this function, a run time assert will be
484 * generated.
485 */
486 #define OBJECT_CHECK(type, obj, name) \
487 ((type *)object_dynamic_cast_assert(OBJECT(obj), (name), \
488 __FILE__, __LINE__, __func__))
489
490 /**
491 * OBJECT_CLASS_CHECK:
492 * @class: The C type to use for the return value.
493 * @obj: A derivative of @type to cast.
494 * @name: the QOM typename of @class.
495 *
496 * A type safe version of @object_class_dynamic_cast_assert. This macro is
497 * typically wrapped by each type to perform type safe casts of a class to a
498 * specific class type.
499 */
500 #define OBJECT_CLASS_CHECK(class, obj, name) \
501 ((class *)object_class_dynamic_cast_assert(OBJECT_CLASS(obj), (name), \
502 __FILE__, __LINE__, __func__))
503
504 /**
505 * OBJECT_GET_CLASS:
506 * @class: The C type to use for the return value.
507 * @obj: The object to obtain the class for.
508 * @name: The QOM typename of @obj.
509 *
510 * This function will return a specific class for a given object. Its generally
511 * used by each type to provide a type safe macro to get a specific class type
512 * from an object.
513 */
514 #define OBJECT_GET_CLASS(class, obj, name) \
515 OBJECT_CLASS_CHECK(class, object_get_class(OBJECT(obj)), name)
516
517 /**
518 * InterfaceInfo:
519 * @type: The name of the interface.
520 *
521 * The information associated with an interface.
522 */
523 struct InterfaceInfo {
524 const char *type;
525 };
526
527 /**
528 * InterfaceClass:
529 * @parent_class: the base class
530 *
531 * The class for all interfaces. Subclasses of this class should only add
532 * virtual methods.
533 */
534 struct InterfaceClass
535 {
536 ObjectClass parent_class;
537 /*< private >*/
538 ObjectClass *concrete_class;
539 Type interface_type;
540 };
541
542 #define TYPE_INTERFACE "interface"
543
544 /**
545 * INTERFACE_CLASS:
546 * @klass: class to cast from
547 * Returns: An #InterfaceClass or raise an error if cast is invalid
548 */
549 #define INTERFACE_CLASS(klass) \
550 OBJECT_CLASS_CHECK(InterfaceClass, klass, TYPE_INTERFACE)
551
552 /**
553 * INTERFACE_CHECK:
554 * @interface: the type to return
555 * @obj: the object to convert to an interface
556 * @name: the interface type name
557 *
558 * Returns: @obj casted to @interface if cast is valid, otherwise raise error.
559 */
560 #define INTERFACE_CHECK(interface, obj, name) \
561 ((interface *)object_dynamic_cast_assert(OBJECT((obj)), (name), \
562 __FILE__, __LINE__, __func__))
563
564 /**
565 * object_new:
566 * @typename: The name of the type of the object to instantiate.
567 *
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.
571 *
572 * Returns: The newly allocated and instantiated object.
573 */
574 Object *object_new(const char *typename);
575
576 /**
577 * object_new_with_type:
578 * @type: The type of the object to instantiate.
579 *
580 * This function will initialize a new object using heap allocated memory.
581 * The returned object has a reference count of 1, and will be freed when
582 * the last reference is dropped.
583 *
584 * Returns: The newly allocated and instantiated object.
585 */
586 Object *object_new_with_type(Type type);
587
588 /**
589 * object_initialize_with_type:
590 * @data: A pointer to the memory to be used for the object.
591 * @size: The maximum size available at @data for the object.
592 * @type: The type of the object to instantiate.
593 *
594 * This function will initialize an object. The memory for the object should
595 * have already been allocated. The returned object has a reference count of 1,
596 * and will be finalized when the last reference is dropped.
597 */
598 void object_initialize_with_type(void *data, size_t size, Type type);
599
600 /**
601 * object_initialize:
602 * @obj: A pointer to the memory to be used for the object.
603 * @size: The maximum size available at @obj for the object.
604 * @typename: The name of the type of the object to instantiate.
605 *
606 * This function will initialize an object. The memory for the object should
607 * have already been allocated. The returned object has a reference count of 1,
608 * and will be finalized when the last reference is dropped.
609 */
610 void object_initialize(void *obj, size_t size, const char *typename);
611
612 /**
613 * object_dynamic_cast:
614 * @obj: The object to cast.
615 * @typename: The @typename to cast to.
616 *
617 * This function will determine if @obj is-a @typename. @obj can refer to an
618 * object or an interface associated with an object.
619 *
620 * Returns: This function returns @obj on success or #NULL on failure.
621 */
622 Object *object_dynamic_cast(Object *obj, const char *typename);
623
624 /**
625 * object_dynamic_cast_assert:
626 *
627 * See object_dynamic_cast() for a description of the parameters of this
628 * function. The only difference in behavior is that this function asserts
629 * instead of returning #NULL on failure if QOM cast debugging is enabled.
630 * This function is not meant to be called directly, but only through
631 * the wrapper macro OBJECT_CHECK.
632 */
633 Object *object_dynamic_cast_assert(Object *obj, const char *typename,
634 const char *file, int line, const char *func);
635
636 /**
637 * object_get_class:
638 * @obj: A derivative of #Object
639 *
640 * Returns: The #ObjectClass of the type associated with @obj.
641 */
642 ObjectClass *object_get_class(Object *obj);
643
644 /**
645 * object_get_typename:
646 * @obj: A derivative of #Object.
647 *
648 * Returns: The QOM typename of @obj.
649 */
650 const char *object_get_typename(Object *obj);
651
652 /**
653 * type_register_static:
654 * @info: The #TypeInfo of the new type.
655 *
656 * @info and all of the strings it points to should exist for the life time
657 * that the type is registered.
658 *
659 * Returns: 0 on failure, the new #Type on success.
660 */
661 Type type_register_static(const TypeInfo *info);
662
663 /**
664 * type_register:
665 * @info: The #TypeInfo of the new type
666 *
667 * Unlike type_register_static(), this call does not require @info or its
668 * string members to continue to exist after the call returns.
669 *
670 * Returns: 0 on failure, the new #Type on success.
671 */
672 Type type_register(const TypeInfo *info);
673
674 /**
675 * object_class_dynamic_cast_assert:
676 * @klass: The #ObjectClass to attempt to cast.
677 * @typename: The QOM typename of the class to cast to.
678 *
679 * See object_class_dynamic_cast() for a description of the parameters
680 * of this function. The only difference in behavior is that this function
681 * asserts instead of returning #NULL on failure if QOM cast debugging is
682 * enabled. This function is not meant to be called directly, but only through
683 * the wrapper macros OBJECT_CLASS_CHECK and INTERFACE_CHECK.
684 */
685 ObjectClass *object_class_dynamic_cast_assert(ObjectClass *klass,
686 const char *typename,
687 const char *file, int line,
688 const char *func);
689
690 /**
691 * object_class_dynamic_cast:
692 * @klass: The #ObjectClass to attempt to cast.
693 * @typename: The QOM typename of the class to cast to.
694 *
695 * Returns: If @typename is a class, this function returns @klass if
696 * @typename is a subtype of @klass, else returns #NULL.
697 *
698 * If @typename is an interface, this function returns the interface
699 * definition for @klass if @klass implements it unambiguously; #NULL
700 * is returned if @klass does not implement the interface or if multiple
701 * classes or interfaces on the hierarchy leading to @klass implement
702 * it. (FIXME: perhaps this can be detected at type definition time?)
703 */
704 ObjectClass *object_class_dynamic_cast(ObjectClass *klass,
705 const char *typename);
706
707 /**
708 * object_class_get_parent:
709 * @klass: The class to obtain the parent for.
710 *
711 * Returns: The parent for @klass or %NULL if none.
712 */
713 ObjectClass *object_class_get_parent(ObjectClass *klass);
714
715 /**
716 * object_class_get_name:
717 * @klass: The class to obtain the QOM typename for.
718 *
719 * Returns: The QOM typename for @klass.
720 */
721 const char *object_class_get_name(ObjectClass *klass);
722
723 /**
724 * object_class_is_abstract:
725 * @klass: The class to obtain the abstractness for.
726 *
727 * Returns: %true if @klass is abstract, %false otherwise.
728 */
729 bool object_class_is_abstract(ObjectClass *klass);
730
731 /**
732 * object_class_by_name:
733 * @typename: The QOM typename to obtain the class for.
734 *
735 * Returns: The class for @typename or %NULL if not found.
736 */
737 ObjectClass *object_class_by_name(const char *typename);
738
739 void object_class_foreach(void (*fn)(ObjectClass *klass, void *opaque),
740 const char *implements_type, bool include_abstract,
741 void *opaque);
742
743 /**
744 * object_class_get_list:
745 * @implements_type: The type to filter for, including its derivatives.
746 * @include_abstract: Whether to include abstract classes.
747 *
748 * Returns: A singly-linked list of the classes in reverse hashtable order.
749 */
750 GSList *object_class_get_list(const char *implements_type,
751 bool include_abstract);
752
753 /**
754 * object_ref:
755 * @obj: the object
756 *
757 * Increase the reference count of a object. A object cannot be freed as long
758 * as its reference count is greater than zero.
759 */
760 void object_ref(Object *obj);
761
762 /**
763 * qdef_unref:
764 * @obj: the object
765 *
766 * Decrease the reference count of a object. A object cannot be freed as long
767 * as its reference count is greater than zero.
768 */
769 void object_unref(Object *obj);
770
771 /**
772 * object_property_add:
773 * @obj: the object to add a property to
774 * @name: the name of the property. This can contain any character except for
775 * a forward slash. In general, you should use hyphens '-' instead of
776 * underscores '_' when naming properties.
777 * @type: the type name of the property. This namespace is pretty loosely
778 * defined. Sub namespaces are constructed by using a prefix and then
779 * to angle brackets. For instance, the type 'virtio-net-pci' in the
780 * 'link' namespace would be 'link<virtio-net-pci>'.
781 * @get: The getter to be called to read a property. If this is NULL, then
782 * the property cannot be read.
783 * @set: the setter to be called to write a property. If this is NULL,
784 * then the property cannot be written.
785 * @release: called when the property is removed from the object. This is
786 * meant to allow a property to free its opaque upon object
787 * destruction. This may be NULL.
788 * @opaque: an opaque pointer to pass to the callbacks for the property
789 * @errp: returns an error if this function fails
790 */
791 void object_property_add(Object *obj, const char *name, const char *type,
792 ObjectPropertyAccessor *get,
793 ObjectPropertyAccessor *set,
794 ObjectPropertyRelease *release,
795 void *opaque, Error **errp);
796
797 void object_property_del(Object *obj, const char *name, Error **errp);
798
799 /**
800 * object_property_find:
801 * @obj: the object
802 * @name: the name of the property
803 * @errp: returns an error if this function fails
804 *
805 * Look up a property for an object and return its #ObjectProperty if found.
806 */
807 ObjectProperty *object_property_find(Object *obj, const char *name,
808 Error **errp);
809
810 void object_unparent(Object *obj);
811
812 /**
813 * object_property_get:
814 * @obj: the object
815 * @v: the visitor that will receive the property value. This should be an
816 * Output visitor and the data will be written with @name as the name.
817 * @name: the name of the property
818 * @errp: returns an error if this function fails
819 *
820 * Reads a property from a object.
821 */
822 void object_property_get(Object *obj, struct Visitor *v, const char *name,
823 Error **errp);
824
825 /**
826 * object_property_set_str:
827 * @value: the value to be written to the property
828 * @name: the name of the property
829 * @errp: returns an error if this function fails
830 *
831 * Writes a string value to a property.
832 */
833 void object_property_set_str(Object *obj, const char *value,
834 const char *name, Error **errp);
835
836 /**
837 * object_property_get_str:
838 * @obj: the object
839 * @name: the name of the property
840 * @errp: returns an error if this function fails
841 *
842 * Returns: the value of the property, converted to a C string, or NULL if
843 * an error occurs (including when the property value is not a string).
844 * The caller should free the string.
845 */
846 char *object_property_get_str(Object *obj, const char *name,
847 Error **errp);
848
849 /**
850 * object_property_set_link:
851 * @value: the value to be written to the property
852 * @name: the name of the property
853 * @errp: returns an error if this function fails
854 *
855 * Writes an object's canonical path to a property.
856 */
857 void object_property_set_link(Object *obj, Object *value,
858 const char *name, Error **errp);
859
860 /**
861 * object_property_get_link:
862 * @obj: the object
863 * @name: the name of the property
864 * @errp: returns an error if this function fails
865 *
866 * Returns: the value of the property, resolved from a path to an Object,
867 * or NULL if an error occurs (including when the property value is not a
868 * string or not a valid object path).
869 */
870 Object *object_property_get_link(Object *obj, const char *name,
871 Error **errp);
872
873 /**
874 * object_property_set_bool:
875 * @value: the value to be written to the property
876 * @name: the name of the property
877 * @errp: returns an error if this function fails
878 *
879 * Writes a bool value to a property.
880 */
881 void object_property_set_bool(Object *obj, bool value,
882 const char *name, Error **errp);
883
884 /**
885 * object_property_get_bool:
886 * @obj: the object
887 * @name: the name of the property
888 * @errp: returns an error if this function fails
889 *
890 * Returns: the value of the property, converted to a boolean, or NULL if
891 * an error occurs (including when the property value is not a bool).
892 */
893 bool object_property_get_bool(Object *obj, const char *name,
894 Error **errp);
895
896 /**
897 * object_property_set_int:
898 * @value: the value to be written to the property
899 * @name: the name of the property
900 * @errp: returns an error if this function fails
901 *
902 * Writes an integer value to a property.
903 */
904 void object_property_set_int(Object *obj, int64_t value,
905 const char *name, Error **errp);
906
907 /**
908 * object_property_get_int:
909 * @obj: the object
910 * @name: the name of the property
911 * @errp: returns an error if this function fails
912 *
913 * Returns: the value of the property, converted to an integer, or NULL if
914 * an error occurs (including when the property value is not an integer).
915 */
916 int64_t object_property_get_int(Object *obj, const char *name,
917 Error **errp);
918
919 /**
920 * object_property_set:
921 * @obj: the object
922 * @v: the visitor that will be used to write the property value. This should
923 * be an Input visitor and the data will be first read with @name as the
924 * name and then written as the property value.
925 * @name: the name of the property
926 * @errp: returns an error if this function fails
927 *
928 * Writes a property to a object.
929 */
930 void object_property_set(Object *obj, struct Visitor *v, const char *name,
931 Error **errp);
932
933 /**
934 * object_property_parse:
935 * @obj: the object
936 * @string: the string that will be used to parse the property value.
937 * @name: the name of the property
938 * @errp: returns an error if this function fails
939 *
940 * Parses a string and writes the result into a property of an object.
941 */
942 void object_property_parse(Object *obj, const char *string,
943 const char *name, Error **errp);
944
945 /**
946 * object_property_print:
947 * @obj: the object
948 * @name: the name of the property
949 * @human: if true, print for human consumption
950 * @errp: returns an error if this function fails
951 *
952 * Returns a string representation of the value of the property. The
953 * caller shall free the string.
954 */
955 char *object_property_print(Object *obj, const char *name, bool human,
956 Error **errp);
957
958 /**
959 * object_property_get_type:
960 * @obj: the object
961 * @name: the name of the property
962 * @errp: returns an error if this function fails
963 *
964 * Returns: The type name of the property.
965 */
966 const char *object_property_get_type(Object *obj, const char *name,
967 Error **errp);
968
969 /**
970 * object_get_root:
971 *
972 * Returns: the root object of the composition tree
973 */
974 Object *object_get_root(void);
975
976 /**
977 * object_get_canonical_path_component:
978 *
979 * Returns: The final component in the object's canonical path. The canonical
980 * path is the path within the composition tree starting from the root.
981 */
982 gchar *object_get_canonical_path_component(Object *obj);
983
984 /**
985 * object_get_canonical_path:
986 *
987 * Returns: The canonical path for a object. This is the path within the
988 * composition tree starting from the root.
989 */
990 gchar *object_get_canonical_path(Object *obj);
991
992 /**
993 * object_resolve_path:
994 * @path: the path to resolve
995 * @ambiguous: returns true if the path resolution failed because of an
996 * ambiguous match
997 *
998 * There are two types of supported paths--absolute paths and partial paths.
999 *
1000 * Absolute paths are derived from the root object and can follow child<> or
1001 * link<> properties. Since they can follow link<> properties, they can be
1002 * arbitrarily long. Absolute paths look like absolute filenames and are
1003 * prefixed with a leading slash.
1004 *
1005 * Partial paths look like relative filenames. They do not begin with a
1006 * prefix. The matching rules for partial paths are subtle but designed to make
1007 * specifying objects easy. At each level of the composition tree, the partial
1008 * path is matched as an absolute path. The first match is not returned. At
1009 * least two matches are searched for. A successful result is only returned if
1010 * only one match is found. If more than one match is found, a flag is
1011 * returned to indicate that the match was ambiguous.
1012 *
1013 * Returns: The matched object or NULL on path lookup failure.
1014 */
1015 Object *object_resolve_path(const char *path, bool *ambiguous);
1016
1017 /**
1018 * object_resolve_path_type:
1019 * @path: the path to resolve
1020 * @typename: the type to look for.
1021 * @ambiguous: returns true if the path resolution failed because of an
1022 * ambiguous match
1023 *
1024 * This is similar to object_resolve_path. However, when looking for a
1025 * partial path only matches that implement the given type are considered.
1026 * This restricts the search and avoids spuriously flagging matches as
1027 * ambiguous.
1028 *
1029 * For both partial and absolute paths, the return value goes through
1030 * a dynamic cast to @typename. This is important if either the link,
1031 * or the typename itself are of interface types.
1032 *
1033 * Returns: The matched object or NULL on path lookup failure.
1034 */
1035 Object *object_resolve_path_type(const char *path, const char *typename,
1036 bool *ambiguous);
1037
1038 /**
1039 * object_resolve_path_component:
1040 * @parent: the object in which to resolve the path
1041 * @part: the component to resolve.
1042 *
1043 * This is similar to object_resolve_path with an absolute path, but it
1044 * only resolves one element (@part) and takes the others from @parent.
1045 *
1046 * Returns: The resolved object or NULL on path lookup failure.
1047 */
1048 Object *object_resolve_path_component(Object *parent, const gchar *part);
1049
1050 /**
1051 * object_property_add_child:
1052 * @obj: the object to add a property to
1053 * @name: the name of the property
1054 * @child: the child object
1055 * @errp: if an error occurs, a pointer to an area to store the area
1056 *
1057 * Child properties form the composition tree. All objects need to be a child
1058 * of another object. Objects can only be a child of one object.
1059 *
1060 * There is no way for a child to determine what its parent is. It is not
1061 * a bidirectional relationship. This is by design.
1062 *
1063 * The value of a child property as a C string will be the child object's
1064 * canonical path. It can be retrieved using object_property_get_str().
1065 * The child object itself can be retrieved using object_property_get_link().
1066 */
1067 void object_property_add_child(Object *obj, const char *name,
1068 Object *child, Error **errp);
1069
1070 typedef enum {
1071 /* Unref the link pointer when the property is deleted */
1072 OBJ_PROP_LINK_UNREF_ON_RELEASE = 0x1,
1073 } ObjectPropertyLinkFlags;
1074
1075 /**
1076 * object_property_allow_set_link:
1077 *
1078 * The default implementation of the object_property_add_link() check()
1079 * callback function. It allows the link property to be set and never returns
1080 * an error.
1081 */
1082 void object_property_allow_set_link(Object *, const char *,
1083 Object *, Error **);
1084
1085 /**
1086 * object_property_add_link:
1087 * @obj: the object to add a property to
1088 * @name: the name of the property
1089 * @type: the qobj type of the link
1090 * @child: a pointer to where the link object reference is stored
1091 * @check: callback to veto setting or NULL if the property is read-only
1092 * @flags: additional options for the link
1093 * @errp: if an error occurs, a pointer to an area to store the area
1094 *
1095 * Links establish relationships between objects. Links are unidirectional
1096 * although two links can be combined to form a bidirectional relationship
1097 * between objects.
1098 *
1099 * Links form the graph in the object model.
1100 *
1101 * The <code>@check()</code> callback is invoked when
1102 * object_property_set_link() is called and can raise an error to prevent the
1103 * link being set. If <code>@check</code> is NULL, the property is read-only
1104 * and cannot be set.
1105 *
1106 * Ownership of the pointer that @child points to is transferred to the
1107 * link property. The reference count for <code>*@child</code> is
1108 * managed by the property from after the function returns till the
1109 * property is deleted with object_property_del(). If the
1110 * <code>@flags</code> <code>OBJ_PROP_LINK_UNREF_ON_RELEASE</code> bit is set,
1111 * the reference count is decremented when the property is deleted.
1112 */
1113 void object_property_add_link(Object *obj, const char *name,
1114 const char *type, Object **child,
1115 void (*check)(Object *obj, const char *name,
1116 Object *val, Error **errp),
1117 ObjectPropertyLinkFlags flags,
1118 Error **errp);
1119
1120 /**
1121 * object_property_add_str:
1122 * @obj: the object to add a property to
1123 * @name: the name of the property
1124 * @get: the getter or NULL if the property is write-only. This function must
1125 * return a string to be freed by g_free().
1126 * @set: the setter or NULL if the property is read-only
1127 * @errp: if an error occurs, a pointer to an area to store the error
1128 *
1129 * Add a string property using getters/setters. This function will add a
1130 * property of type 'string'.
1131 */
1132 void object_property_add_str(Object *obj, const char *name,
1133 char *(*get)(Object *, Error **),
1134 void (*set)(Object *, const char *, Error **),
1135 Error **errp);
1136
1137 /**
1138 * object_property_add_bool:
1139 * @obj: the object to add a property to
1140 * @name: the name of the property
1141 * @get: the getter or NULL if the property is write-only.
1142 * @set: the setter or NULL if the property is read-only
1143 * @errp: if an error occurs, a pointer to an area to store the error
1144 *
1145 * Add a bool property using getters/setters. This function will add a
1146 * property of type 'bool'.
1147 */
1148 void object_property_add_bool(Object *obj, const char *name,
1149 bool (*get)(Object *, Error **),
1150 void (*set)(Object *, bool, Error **),
1151 Error **errp);
1152
1153 /**
1154 * object_property_add_uint8_ptr:
1155 * @obj: the object to add a property to
1156 * @name: the name of the property
1157 * @v: pointer to value
1158 * @errp: if an error occurs, a pointer to an area to store the error
1159 *
1160 * Add an integer property in memory. This function will add a
1161 * property of type 'uint8'.
1162 */
1163 void object_property_add_uint8_ptr(Object *obj, const char *name,
1164 const uint8_t *v, Error **errp);
1165
1166 /**
1167 * object_property_add_uint16_ptr:
1168 * @obj: the object to add a property to
1169 * @name: the name of the property
1170 * @v: pointer to value
1171 * @errp: if an error occurs, a pointer to an area to store the error
1172 *
1173 * Add an integer property in memory. This function will add a
1174 * property of type 'uint16'.
1175 */
1176 void object_property_add_uint16_ptr(Object *obj, const char *name,
1177 const uint16_t *v, Error **errp);
1178
1179 /**
1180 * object_property_add_uint32_ptr:
1181 * @obj: the object to add a property to
1182 * @name: the name of the property
1183 * @v: pointer to value
1184 * @errp: if an error occurs, a pointer to an area to store the error
1185 *
1186 * Add an integer property in memory. This function will add a
1187 * property of type 'uint32'.
1188 */
1189 void object_property_add_uint32_ptr(Object *obj, const char *name,
1190 const uint32_t *v, Error **errp);
1191
1192 /**
1193 * object_property_add_uint64_ptr:
1194 * @obj: the object to add a property to
1195 * @name: the name of the property
1196 * @v: pointer to value
1197 * @errp: if an error occurs, a pointer to an area to store the error
1198 *
1199 * Add an integer property in memory. This function will add a
1200 * property of type 'uint64'.
1201 */
1202 void object_property_add_uint64_ptr(Object *obj, const char *name,
1203 const uint64_t *v, Error **Errp);
1204
1205 /**
1206 * object_child_foreach:
1207 * @obj: the object whose children will be navigated
1208 * @fn: the iterator function to be called
1209 * @opaque: an opaque value that will be passed to the iterator
1210 *
1211 * Call @fn passing each child of @obj and @opaque to it, until @fn returns
1212 * non-zero.
1213 *
1214 * Returns: The last value returned by @fn, or 0 if there is no child.
1215 */
1216 int object_child_foreach(Object *obj, int (*fn)(Object *child, void *opaque),
1217 void *opaque);
1218
1219 /**
1220 * container_get:
1221 * @root: root of the #path, e.g., object_get_root()
1222 * @path: path to the container
1223 *
1224 * Return a container object whose path is @path. Create more containers
1225 * along the path if necessary.
1226 *
1227 * Returns: the container object.
1228 */
1229 Object *container_get(Object *root, const char *path);
1230
1231
1232 #endif