/*
* QEMU Object Model
*
* Copyright IBM, Corp. 2011
*
* Authors:
* Anthony Liguori <aliguori@us.ibm.com>
*
* This work is licensed under the terms of the GNU GPL, version 2 or later.
* See the COPYING file in the top-level directory.
*
*/
#ifndef QEMU_OBJECT_H
#define QEMU_OBJECT_H
#include "qapi-types.h"
#include "qemu/queue.h"
struct TypeImpl;
typedef struct TypeImpl *Type;
typedef struct ObjectClass ObjectClass;
typedef struct Object Object;
typedef struct TypeInfo TypeInfo;
typedef struct InterfaceClass InterfaceClass;
typedef struct InterfaceInfo InterfaceInfo;
#define TYPE_OBJECT "object"
/**
* SECTION:object.h
* @title:Base Object Type System
* @short_description: interfaces for creating new types and objects
*
* The QEMU Object Model provides a framework for registering user creatable
* types and instantiating objects from those types. QOM provides the following
* features:
*
* - System for dynamically registering types
* - Support for single-inheritance of types
* - Multiple inheritance of stateless interfaces
*
* <example>
* <title>Creating a minimal type</title>
* <programlisting>
* #include "qdev.h"
*
* #define TYPE_MY_DEVICE "my-device"
*
* // No new virtual functions: we can reuse the typedef for the
* // superclass.
* typedef DeviceClass MyDeviceClass;
* typedef struct MyDevice
* {
* DeviceState parent;
*
* int reg0, reg1, reg2;
* } MyDevice;
*
* static const TypeInfo my_device_info = {
* .name = TYPE_MY_DEVICE,
* .parent = TYPE_DEVICE,
* .instance_size = sizeof(MyDevice),
* };
*
* static void my_device_register_types(void)
* {
* type_register_static(&my_device_info);
* }
*
* type_init(my_device_register_types)
* </programlisting>
* </example>
*
* In the above example, we create a simple type that is described by #TypeInfo.
* #TypeInfo describes information about the type including what it inherits
* from, the instance and class size, and constructor/destructor hooks.
*
* Alternatively several static types could be registered using helper macro
* DEFINE_TYPES()
*
* <example>
* <programlisting>
* static const TypeInfo device_types_info[] = {
* {
* .name = TYPE_MY_DEVICE_A,
* .parent = TYPE_DEVICE,
* .instance_size = sizeof(MyDeviceA),
* },
* {
* .name = TYPE_MY_DEVICE_B,
* .parent = TYPE_DEVICE,
* .instance_size = sizeof(MyDeviceB),
* },
* };
*
* DEFINE_TYPES(device_types_info)
* </programlisting>
* </example>
*
* Every type has an #ObjectClass associated with it. #ObjectClass derivatives
* are instantiated dynamically but there is only ever one instance for any
* given type. The #ObjectClass typically holds a table of function pointers
* for the virtual methods implemented by this type.
*
* Using object_new(), a new #Object derivative will be instantiated. You can
* cast an #Object to a subclass (or base-class) type using
* object_dynamic_cast(). You typically want to define macro wrappers around
* OBJECT_CHECK() and OBJECT_CLASS_CHECK() to make it easier to convert to a
* specific type:
*
* <example>
* <title>Typecasting macros</title>
* <programlisting>
* #define MY_DEVICE_GET_CLASS(obj) \
* OBJECT_GET_CLASS(MyDeviceClass, obj, TYPE_MY_DEVICE)
* #define MY_DEVICE_CLASS(klass) \
* OBJECT_CLASS_CHECK(MyDeviceClass, klass, TYPE_MY_DEVICE)
* #define MY_DEVICE(obj) \
* OBJECT_CHECK(MyDevice, obj, TYPE_MY_DEVICE)
* </programlisting>
* </example>
*
* # Class Initialization #
*
* Before an object is initialized, the class for the object must be
* initialized. There is only one class object for all instance objects
* that is created lazily.
*
* Classes are initialized by first initializing any parent classes (if
* necessary). After the parent class object has initialized, it will be
* copied into the current class object and any additional storage in the
* class object is zero filled.
*
* The effect of this is that classes automatically inherit any virtual
* function pointers that the parent class has already initialized. All
* other fields will be zero filled.
*
* Once all of the parent classes have been initialized, #TypeInfo::class_init
* is called to let the class being instantiated provide default initialize for
* its virtual functions. Here is how the above example might be modified
* to introduce an overridden virtual function:
*
* <example>
* <title>Overriding a virtual function</title>
* <programlisting>
* #include "qdev.h"
*
* void my_device_class_init(ObjectClass *klass, void *class_data)
* {
* DeviceClass *dc = DEVICE_CLASS(klass);
* dc->reset = my_device_reset;
* }
*
* static const TypeInfo my_device_info = {
* .name = TYPE_MY_DEVICE,
* .parent = TYPE_DEVICE,
* .instance_size = sizeof(MyDevice),
* .class_init = my_device_class_init,
* };
* </programlisting>
* </example>
*
* Introducing new virtual methods requires a class to define its own
* struct and to add a .class_size member to the #TypeInfo. Each method
* will also have a wrapper function to call it easily:
*
* <example>
* <title>Defining an abstract class</title>
* <programlisting>
* #include "qdev.h"
*
* typedef struct MyDeviceClass
* {
* DeviceClass parent;
*
* void (*frobnicate) (MyDevice *obj);
* } MyDeviceClass;
*
* static const TypeInfo my_device_info = {
* .name = TYPE_MY_DEVICE,
* .parent = TYPE_DEVICE,
* .instance_size = sizeof(MyDevice),
* .abstract = true, // or set a default in my_device_class_init
* .class_size = sizeof(MyDeviceClass),
* };
*
* void my_device_frobnicate(MyDevice *obj)
* {
* MyDeviceClass *klass = MY_DEVICE_GET_CLASS(obj);
*
* klass->frobnicate(obj);
* }
* </programlisting>
* </example>
*
* # Interfaces #
*
* Interfaces allow a limited form of multiple inheritance. Instances are
* similar to normal types except for the fact that are only defined by
* their classes and never carry any state. You can dynamically cast an object
* to one of its #Interface types and vice versa.
*
* # Methods #
*
* A <emphasis>method</emphasis> is a function within the namespace scope of
* a class. It usually operates on the object instance by passing it as a
* strongly-typed first argument.
* If it does not operate on an object instance, it is dubbed
* <emphasis>class method</emphasis>.
*
* Methods cannot be overloaded. That is, the #ObjectClass and method name
* uniquely identity the function to be called; the signature does not vary
* except for trailing varargs.
*
* Methods are always <emphasis>virtual</emphasis>. Overriding a method in
* #TypeInfo.class_init of a subclass leads to any user of the class obtained
* via OBJECT_GET_CLASS() accessing the overridden function.
* The original function is not automatically invoked. It is the responsibility
* of the overriding class to determine whether and when to invoke the method
* being overridden.
*
* To invoke the method being overridden, the preferred solution is to store
* the original value in the overriding class before overriding the method.
* This corresponds to |[ {super,base}.method(...) ]| in Java and C#
* respectively; this frees the overriding class from hardcoding its parent
* class, which someone might choose to change at some point.
*
* <example>
* <title>Overriding a virtual method</title>
* <programlisting>
* typedef struct MyState MyState;
*
* typedef void (*MyDoSomething)(MyState *obj);
*
* typedef struct MyClass {
* ObjectClass parent_class;
*
* MyDoSomething do_something;
* } MyClass;
*
* static void my_do_something(MyState *obj)
* {
* // do something
* }
*
* static void my_class_init(ObjectClass *oc, void *data)
* {
* MyClass *mc = MY_CLASS(oc);
*
* mc->do_something = my_do_something;
* }
*
* static const TypeInfo my_type_info = {
* .name = TYPE_MY,
* .parent = TYPE_OBJECT,
* .instance_size = sizeof(MyState),
* .class_size = sizeof(MyClass),
* .class_init = my_class_init,
* };
*
* typedef struct DerivedClass {
* MyClass parent_class;
*
* MyDoSomething parent_do_something;
* } DerivedClass;
*
* static void derived_do_something(MyState *obj)
* {
* DerivedClass *dc = DERIVED_GET_CLASS(obj);
*
* // do something here
* dc->parent_do_something(obj);
* // do something else here
* }
*
* static void derived_class_init(ObjectClass *oc, void *data)
* {
* MyClass *mc = MY_CLASS(oc);
* DerivedClass *dc = DERIVED_CLASS(oc);
*
* dc->parent_do_something = mc->do_something;
* mc->do_something = derived_do_something;
* }
*
* static const TypeInfo derived_type_info = {
* .name = TYPE_DERIVED,
* .parent = TYPE_MY,
* .class_size = sizeof(DerivedClass),
* .class_init = derived_class_init,
* };
* </programlisting>
* </example>
*
* Alternatively, object_class_by_name() can be used to obtain the class and
* its non-overridden methods for a specific type. This would correspond to
* |[ MyClass::method(...) ]| in C++.
*
* The first example of such a QOM method was #CPUClass.reset,
* another example is #DeviceClass.realize.
*/
/**
* ObjectPropertyAccessor:
* @obj: the object that owns the property
* @v: the visitor that contains the property data
* @name: the name of the property
* @opaque: the object property opaque
* @errp: a pointer to an Error that is filled if getting/setting fails.
*
* Called when trying to get/set a property.
*/
typedef void (ObjectPropertyAccessor)(Object *obj,
Visitor *v,
const char *name,
void *opaque,
Error **errp);
/**
* ObjectPropertyResolve:
* @obj: the object that owns the property
* @opaque: the opaque registered with the property
* @part: the name of the property
*
* Resolves the #Object corresponding to property @part.
*
* The returned object can also be used as a starting point
* to resolve a relative path starting with "@part".
*
* Returns: If @path is the path that led to @obj, the function
* returns the #Object corresponding to "@path/@part".
* If "@path/@part" is not a valid object path, it returns #NULL.
*/
typedef Object *(ObjectPropertyResolve)(Object *obj,
void *opaque,
const char *part);
/**
* ObjectPropertyRelease:
* @obj: the object that owns the property
* @name: the name of the property
* @opaque: the opaque registered with the property
*
* Called when a property is removed from a object.
*/
typedef void (ObjectPropertyRelease)(Object *obj,
const char *name,
void *opaque);
typedef struct ObjectProperty
{
gchar *name;
gchar *type;
gchar *description;
ObjectPropertyAccessor *get;
ObjectPropertyAccessor *set;
ObjectPropertyResolve *resolve;
ObjectPropertyRelease *release;
void *opaque;
} ObjectProperty;
/**
* ObjectUnparent:
* @obj: the object that is being removed from the composition tree
*
* Called when an object is being removed from the QOM composition tree.
* The function should remove any backlinks from children objects to @obj.
*/
typedef void (ObjectUnparent)(Object *obj);
/**
* ObjectFree:
* @obj: the object being freed
*
* Called when an object's last reference is removed.
*/
typedef void (ObjectFree)(void *obj);
#define OBJECT_CLASS_CAST_CACHE 4
/**
* ObjectClass:
*
* The base for all classes. The only thing that #ObjectClass contains is an
* integer type handle.
*/
struct ObjectClass
{
/*< private >*/
Type type;
GSList *interfaces;
const char *object_cast_cache[OBJECT_CLASS_CAST_CACHE];
const char *class_cast_cache[OBJECT_CLASS_CAST_CACHE];
ObjectUnparent *unparent;
GHashTable *properties;
};
/**
* Object:
*
* The base for all objects. The first member of this object is a pointer to
* a #ObjectClass. Since C guarantees that the first member of a structure
* always begins at byte 0 of that structure, as long as any sub-object places
* its parent as the first member, we can cast directly to a #Object.
*
* As a result, #Object contains a reference to the objects type as its
* first member. This allows identification of the real type of the object at
* run time.
*/
struct Object
{
/*< private >*/
ObjectClass *class;
ObjectFree *free;
GHashTable *properties;
uint32_t ref;
Object *parent;
};
/**
* TypeInfo:
* @name: The name of the type.
* @parent: The name of the parent type.
* @instance_size: The size of the object (derivative of #Object). If
* @instance_size is 0, then the size of the object will be the size of the
* parent object.
* @instance_init: This function is called to initialize an object. The parent
* class will have already been initialized so the type is only responsible
* for initializing its own members.
* @instance_post_init: This function is called to finish initialization of
* an object, after all @instance_init functions were called.
* @instance_finalize: This function is called during object destruction. This
* is called before the parent @instance_finalize function has been called.
* An object should only free the members that are unique to its type in this
* function.
* @abstract: If this field is true, then the class is considered abstract and
* cannot be directly instantiated.
* @class_size: The size of the class object (derivative of #ObjectClass)
* for this object. If @class_size is 0, then the size of the class will be
* assumed to be the size of the parent class. This allows a type to avoid
* implementing an explicit class type if they are not adding additional
* virtual functions.
* @class_init: This function is called after all parent class initialization
* has occurred to allow a class to set its default virtual method pointers.
* This is also the function to use to override virtual methods from a parent
* class.
* @class_base_init: This function is called for all base classes after all
* parent class initialization has occurred, but before the class itself
* is initialized. This is the function to use to undo the effects of
* memcpy from the parent class to the descendants.
* @class_finalize: This function is called during class destruction and is
* meant to release and dynamic parameters allocated by @class_init.
* @class_data: Data to pass to the @class_init, @class_base_init and
* @class_finalize functions. This can be useful when building dynamic
* classes.
* @interfaces: The list of interfaces associated with this type. This
* should point to a static array that's terminated with a zero filled
* element.
*/
struct TypeInfo
{
const char *name;
const char *parent;
size_t instance_size;
void (*instance_init)(Object *obj);
void (*instance_post_init)(Object *obj);
void (*instance_finalize)(Object *obj);
bool abstract;
size_t class_size;
void (*class_init)(ObjectClass *klass, void *data);
void (*class_base_init)(ObjectClass *klass, void *data);
void (*class_finalize)(ObjectClass *klass, void *data);
void *class_data;
InterfaceInfo *interfaces;
};
/**
* OBJECT:
* @obj: A derivative of #Object
*
* Converts an object to a #Object. Since all objects are #Objects,
* this function will always succeed.
*/
#define OBJECT(obj) \
((Object *)(obj))
/**
* OBJECT_CLASS:
* @class: A derivative of #ObjectClass.
*
* Converts a class to an #ObjectClass. Since all objects are #Objects,
* this function will always succeed.
*/
#define OBJECT_CLASS(class) \
((ObjectClass *)(class))
/**
* OBJECT_CHECK:
* @type: The C type to use for the return value.
* @obj: A derivative of @type to cast.
* @name: The QOM typename of @type
*
* A type safe version of @object_dynamic_cast_assert. Typically each class
* will define a macro based on this type to perform type safe dynamic_casts to
* this object type.
*
* If an invalid object is passed to this function, a run time assert will be
* generated.
*/
#define OBJECT_CHECK(type, obj, name) \
((type *)object_dynamic_cast_assert(OBJECT(obj), (name), \
__FILE__, __LINE__, __func__))
/**
* OBJECT_CLASS_CHECK:
* @class_type: The C type to use for the return value.
* @class: A derivative class of @class_type to cast.
* @name: the QOM typename of @class_type.
*
* A type safe version of @object_class_dynamic_cast_assert. This macro is
* typically wrapped by each type to perform type safe casts of a class to a
* specific class type.
*/
#define OBJECT_CLASS_CHECK(class_type, class, name) \
((class_type *)object_class_dynamic_cast_assert(OBJECT_CLASS(class), (name), \
__FILE__, __LINE__, __func__))
/**
* OBJECT_GET_CLASS:
* @class: The C type to use for the return value.
* @obj: The object to obtain the class for.
* @name: The QOM typename of @obj.
*
* This function will return a specific class for a given object. Its generally
* used by each type to provide a type safe macro to get a specific class type
* from an object.
*/
#define OBJECT_GET_CLASS(class, obj, name) \
OBJECT_CLASS_CHECK(class, object_get_class(OBJECT(obj)), name)
/**
* InterfaceInfo:
* @type: The name of the interface.
*
* The information associated with an interface.
*/
struct InterfaceInfo {
const char *type;
};
/**
* InterfaceClass:
* @parent_class: the base class
*
* The class for all interfaces. Subclasses of this class should only add
* virtual methods.
*/
struct InterfaceClass
{
ObjectClass parent_class;
/*< private >*/
ObjectClass *concrete_class;
Type interface_type;
};
#define TYPE_INTERFACE "interface"
/**
* INTERFACE_CLASS:
* @klass: class to cast from
* Returns: An #InterfaceClass or raise an error if cast is invalid
*/
#define INTERFACE_CLASS(klass) \
OBJECT_CLASS_CHECK(InterfaceClass, klass, TYPE_INTERFACE)
/**
* INTERFACE_CHECK:
* @interface: the type to return
* @obj: the object to convert to an interface
* @name: the interface type name
*
* Returns: @obj casted to @interface if cast is valid, otherwise raise error.
*/
#define INTERFACE_CHECK(interface, obj, name) \
((interface *)object_dynamic_cast_assert(OBJECT((obj)), (name), \
__FILE__, __LINE__, __func__))
/**
* object_new:
* @typename: The name of the type of the object to instantiate.
*
* This function will initialize a new object using heap allocated memory.
* The returned object has a reference count of 1, and will be freed when
* the last reference is dropped.
*
* Returns: The newly allocated and instantiated object.
*/
Object *object_new(const char *typename);
/**
* object_new_with_props:
* @typename: The name of the type of the object to instantiate.
* @parent: the parent object
* @id: The unique ID of the object
* @errp: pointer to error object
* @...: list of property names and values
*
* This function will initialize a new object using heap allocated memory.
* The returned object has a reference count of 1, and will be freed when
* the last reference is dropped.
*
* The @id parameter will be used when registering the object as a
* child of @parent in the composition tree.
*
* The variadic parameters are a list of pairs of (propname, propvalue)
* strings. The propname of %NULL indicates the end of the property
* list. If the object implements the user creatable interface, the
* object will be marked complete once all the properties have been
* processed.
*
* <example>
* <title>Creating an object with properties</title>
* <programlisting>
* Error *err = NULL;
* Object *obj;
*
* obj = object_new_with_props(TYPE_MEMORY_BACKEND_FILE,
* object_get_objects_root(),
* "hostmem0",
* &err,
* "share", "yes",
* "mem-path", "/dev/shm/somefile",
* "prealloc", "yes",
* "size", "1048576",
* NULL);
*
* if (!obj) {
* g_printerr("Cannot create memory backend: %s\n",
* error_get_pretty(err));
* }
* </programlisting>
* </example>
*
* The returned object will have one stable reference maintained
* for as long as it is present in the object hierarchy.
*
* Returns: The newly allocated, instantiated & initialized object.
*/
Object *object_new_with_props(const char *typename,
Object *parent,
const char *id,
Error **errp,
...) QEMU_SENTINEL;
/**
* object_new_with_propv:
* @typename: The name of the type of the object to instantiate.
* @parent: the parent object
* @id: The unique ID of the object
* @errp: pointer to error object
* @vargs: list of property names and values
*
* See object_new_with_props() for documentation.
*/
Object *object_new_with_propv(const char *typename,
Object *parent,
const char *id,
Error **errp,
va_list vargs);
/**
* object_set_props:
* @obj: the object instance to set properties on
* @errp: pointer to error object
* @...: list of property names and values
*
* This function will set a list of properties on an existing object
* instance.
*
* The variadic parameters are a list of pairs of (propname, propvalue)
* strings. The propname of %NULL indicates the end of the property
* list.
*
* <example>
* <title>Update an object's properties</title>
* <programlisting>
* Error *err = NULL;
* Object *obj = ...get / create object...;
*
* obj = object_set_props(obj,
* &err,
* "share", "yes",
* "mem-path", "/dev/shm/somefile",
* "prealloc", "yes",
* "size", "1048576",
* NULL);
*
* if (!obj) {
* g_printerr("Cannot set properties: %s\n",
* error_get_pretty(err));
* }
* </programlisting>
* </example>
*
* The returned object will have one stable reference maintained
* for as long as it is present in the object hierarchy.
*
* Returns: -1 on error, 0 on success
*/
int object_set_props(Object *obj,
Error **errp,
...) QEMU_SENTINEL;
/**
* object_set_propv:
* @obj: the object instance to set properties on
* @errp: pointer to error object
* @vargs: list of property names and values
*
* See object_set_props() for documentation.
*
* Returns: -1 on error, 0 on success
*/
int object_set_propv(Object *obj,
Error **errp,
va_list vargs);
/**
* object_initialize:
* @obj: A pointer to the memory to be used for the object.
* @size: The maximum size available at @obj for the object.
* @typename: The name of the type of the object to instantiate.
*
* This function will initialize an object. The memory for the object should
* have already been allocated. The returned object has a reference count of 1,
* and will be finalized when the last reference is dropped.
*/
void object_initialize(void *obj, size_t size, const char *typename);
/**
* object_dynamic_cast:
* @obj: The object to cast.
* @typename: The @typename to cast to.
*
* This function will determine if @obj is-a @typename. @obj can refer to an
* object or an interface associated with an object.
*
* Returns: This function returns @obj on success or #NULL on failure.
*/
Object *object_dynamic_cast(Object *obj, const char *typename);
/**
* object_dynamic_cast_assert:
*
* See object_dynamic_cast() for a description of the parameters of this
* function. The only difference in behavior is that this function asserts
* instead of returning #NULL on failure if QOM cast debugging is enabled.
* This function is not meant to be called directly, but only through
* the wrapper macro OBJECT_CHECK.
*/
Object *object_dynamic_cast_assert(Object *obj, const char *typename,
const char *file, int line, const char *func);
/**
* object_get_class:
* @obj: A derivative of #Object
*
* Returns: The #ObjectClass of the type associated with @obj.
*/
ObjectClass *object_get_class(Object *obj);
/**
* object_get_typename:
* @obj: A derivative of #Object.
*
* Returns: The QOM typename of @obj.
*/
const char *object_get_typename(const Object *obj);
/**
* type_register_static:
* @info: The #TypeInfo of the new type.
*
* @info and all of the strings it points to should exist for the life time
* that the type is registered.
*
* Returns: the new #Type.
*/
Type type_register_static(const TypeInfo *info);
/**
* type_register:
* @info: The #TypeInfo of the new type
*
* Unlike type_register_static(), this call does not require @info or its
* string members to continue to exist after the call returns.
*
* Returns: the new #Type.
*/
Type type_register(const TypeInfo *info);
/**
* type_register_static_array:
* @infos: The array of the new type #TypeInfo structures.
* @nr_infos: number of entries in @infos
*
* @infos and all of the strings it points to should exist for the life time
* that the type is registered.
*/
void type_register_static_array(const TypeInfo *infos, int nr_infos);
/**
* DEFINE_TYPES:
* @type_array: The array containing #TypeInfo structures to register
*
* @type_array should be static constant that exists for the life time
* that the type is registered.
*/
#define DEFINE_TYPES(type_array) \
static void do_qemu_init_ ## type_array(void) \
{ \
type_register_static_array(type_array, ARRAY_SIZE(type_array)); \
} \
type_init(do_qemu_init_ ## type_array)
/**
* object_class_dynamic_cast_assert:
* @klass: The #ObjectClass to attempt to cast.
* @typename: The QOM typename of the class to cast to.
*
* See object_class_dynamic_cast() for a description of the parameters
* of this function. The only difference in behavior is that this function
* asserts instead of returning #NULL on failure if QOM cast debugging is
* enabled. This function is not meant to be called directly, but only through
* the wrapper macros OBJECT_CLASS_CHECK and INTERFACE_CHECK.
*/
ObjectClass *object_class_dynamic_cast_assert(ObjectClass *klass,
const char *typename,
const char *file, int line,
const char *func);
/**
* object_class_dynamic_cast:
* @klass: The #ObjectClass to attempt to cast.
* @typename: The QOM typename of the class to cast to.
*
* Returns: If @typename is a class, this function returns @klass if
* @typename is a subtype of @klass, else returns #NULL.
*
* If @typename is an interface, this function returns the interface
* definition for @klass if @klass implements it unambiguously; #NULL
* is returned if @klass does not implement the interface or if multiple
* classes or interfaces on the hierarchy leading to @klass implement
* it. (FIXME: perhaps this can be detected at type definition time?)
*/
ObjectClass *object_class_dynamic_cast(ObjectClass *klass,
const char *typename);
/**
* object_class_get_parent:
* @klass: The class to obtain the parent for.
*
* Returns: The parent for @klass or %NULL if none.
*/
ObjectClass *object_class_get_parent(ObjectClass *klass);
/**
* object_class_get_name:
* @klass: The class to obtain the QOM typename for.
*
* Returns: The QOM typename for @klass.
*/
const char *object_class_get_name(ObjectClass *klass);
/**
* object_class_is_abstract:
* @klass: The class to obtain the abstractness for.
*
* Returns: %true if @klass is abstract, %false otherwise.
*/
bool object_class_is_abstract(ObjectClass *klass);
/**
* object_class_by_name:
* @typename: The QOM typename to obtain the class for.
*
* Returns: The class for @typename or %NULL if not found.
*/
ObjectClass *object_class_by_name(const char *typename);
void object_class_foreach(void (*fn)(ObjectClass *klass, void *opaque),
const char *implements_type, bool include_abstract,
void *opaque);
/**
* object_class_get_list:
* @implements_type: The type to filter for, including its derivatives.
* @include_abstract: Whether to include abstract classes.
*
* Returns: A singly-linked list of the classes in reverse hashtable order.
*/
GSList *object_class_get_list(const char *implements_type,
bool include_abstract);
/**
* object_ref:
* @obj: the object
*
* Increase the reference count of a object. A object cannot be freed as long
* as its reference count is greater than zero.
*/
void object_ref(Object *obj);
/**
* object_unref:
* @obj: the object
*
* Decrease the reference count of a object. A object cannot be freed as long
* as its reference count is greater than zero.
*/
void object_unref(Object *obj);
/**
* object_property_add:
* @obj: the object to add a property to
* @name: the name of the property. This can contain any character except for
* a forward slash. In general, you should use hyphens '-' instead of
* underscores '_' when naming properties.
* @type: the type name of the property. This namespace is pretty loosely
* defined. Sub namespaces are constructed by using a prefix and then
* to angle brackets. For instance, the type 'virtio-net-pci' in the
* 'link' namespace would be 'link<virtio-net-pci>'.
* @get: The getter to be called to read a property. If this is NULL, then
* the property cannot be read.
* @set: the setter to be called to write a property. If this is NULL,
* then the property cannot be written.
* @release: called when the property is removed from the object. This is
* meant to allow a property to free its opaque upon object
* destruction. This may be NULL.
* @opaque: an opaque pointer to pass to the callbacks for the property
* @errp: returns an error if this function fails
*
* Returns: The #ObjectProperty; this can be used to set the @resolve
* callback for child and link properties.
*/
ObjectProperty *object_property_add(Object *obj, const char *name,
const char *type,
ObjectPropertyAccessor *get,
ObjectPropertyAccessor *set,
ObjectPropertyRelease *release,
void *opaque, Error **errp);
void object_property_del(Object *obj, const char *name, Error **errp);
ObjectProperty *object_class_property_add(ObjectClass *klass, const char *name,
const char *type,
ObjectPropertyAccessor *get,
ObjectPropertyAccessor *set,
ObjectPropertyRelease *release,
void *opaque, Error **errp);
/**
* object_property_find:
* @obj: the object
* @name: the name of the property
* @errp: returns an error if this function fails
*
* Look up a property for an object and return its #ObjectProperty if found.
*/
ObjectProperty *object_property_find(Object *obj, const char *name,
Error **errp);
ObjectProperty *object_class_property_find(ObjectClass *klass, const char *name,
Error **errp);
typedef struct ObjectPropertyIterator {
ObjectClass *nextclass;
GHashTableIter iter;
} ObjectPropertyIterator;
/**
* object_property_iter_init:
* @obj: the object
*
* Initializes an iterator for traversing all properties
* registered against an object instance, its class and all parent classes.
*
* It is forbidden to modify the property list while iterating,
* whether removing or adding properties.
*
* Typical usage pattern would be
*
* <example>
* <title>Using object property iterators</title>
* <programlisting>
* ObjectProperty *prop;
* ObjectPropertyIterator iter;
*
* object_property_iter_init(&iter, obj);
* while ((prop = object_property_iter_next(&iter))) {
* ... do something with prop ...
* }
* </programlisting>
* </example>
*/
void object_property_iter_init(ObjectPropertyIterator *iter,
Object *obj);
/**
* object_property_iter_next:
* @iter: the iterator instance
*
* Return the next available property. If no further properties
* are available, a %NULL value will be returned and the @iter
* pointer should not be used again after this point without
* re-initializing it.
*
* Returns: the next property, or %NULL when all properties
* have been traversed.
*/
ObjectProperty *object_property_iter_next(ObjectPropertyIterator *iter);
void object_unparent(Object *obj);
/**
* object_property_get:
* @obj: the object
* @v: the visitor that will receive the property value. This should be an
* Output visitor and the data will be written with @name as the name.
* @name: the name of the property
* @errp: returns an error if this function fails
*
* Reads a property from a object.
*/
void object_property_get(Object *obj, Visitor *v, const char *name,
Error **errp);
/**
* object_property_set_str:
* @value: the value to be written to the property
* @name: the name of the property
* @errp: returns an error if this function fails
*
* Writes a string value to a property.
*/
void object_property_set_str(Object *obj, const char *value,
const char *name, Error **errp);
/**
* object_property_get_str:
* @obj: the object
* @name: the name of the property
* @errp: returns an error if this function fails
*
* Returns: the value of the property, converted to a C string, or NULL if
* an error occurs (including when the property value is not a string).
* The caller should free the string.
*/
char *object_property_get_str(Object *obj, const char *name,
Error **errp);
/**
* object_property_set_link:
* @value: the value to be written to the property
* @name: the name of the property
* @errp: returns an error if this function fails
*
* Writes an object's canonical path to a property.
*/
void object_property_set_link(Object *obj, Object *value,
const char *name, Error **errp);
/**
* object_property_get_link:
* @obj: the object
* @name: the name of the property
* @errp: returns an error if this function fails
*
* Returns: the value of the property, resolved from a path to an Object,
* or NULL if an error occurs (including when the property value is not a
* string or not a valid object path).
*/
Object *object_property_get_link(Object *obj, const char *name,
Error **errp);
/**
* object_property_set_bool:
* @value: the value to be written to the property
* @name: the name of the property
* @errp: returns an error if this function fails
*
* Writes a bool value to a property.
*/
void object_property_set_bool(Object *obj, bool value,
const char *name, Error **errp);
/**
* object_property_get_bool:
* @obj: the object
* @name: the name of the property
* @errp: returns an error if this function fails
*
* Returns: the value of the property, converted to a boolean, or NULL if
* an error occurs (including when the property value is not a bool).
*/
bool object_property_get_bool(Object *obj, const char *name,
Error **errp);
/**
* object_property_set_int:
* @value: the value to be written to the property
* @name: the name of the property
* @errp: returns an error if this function fails
*
* Writes an integer value to a property.
*/
void object_property_set_int(Object *obj, int64_t value,
const char *name, Error **errp);
/**
* object_property_get_int:
* @obj: the object
* @name: the name of the property
* @errp: returns an error if this function fails
*
* Returns: the value of the property, converted to an integer, or negative if
* an error occurs (including when the property value is not an integer).
*/
int64_t object_property_get_int(Object *obj, const char *name,
Error **errp);
/**
* object_property_set_uint:
* @value: the value to be written to the property
* @name: the name of the property
* @errp: returns an error if this function fails
*
* Writes an unsigned integer value to a property.
*/
void object_property_set_uint(Object *obj, uint64_t value,
const char *name, Error **errp);
/**
* object_property_get_uint:
* @obj: the object
* @name: the name of the property
* @errp: returns an error if this function fails
*
* Returns: the value of the property, converted to an unsigned integer, or 0
* an error occurs (including when the property value is not an integer).
*/
uint64_t object_property_get_uint(Object *obj, const char *name,
Error **errp);
/**
* object_property_get_enum:
* @obj: the object
* @name: the name of the property
* @typename: the name of the enum data type
* @errp: returns an error if this function fails
*
* Returns: the value of the property, converted to an integer, or
* undefined if an error occurs (including when the property value is not
* an enum).
*/
int object_property_get_enum(Object *obj, const char *name,
const char *typename, Error **errp);
/**
* object_property_get_uint16List:
* @obj: the object
* @name: the name of the property
* @list: the returned int list
* @errp: returns an error if this function fails
*
* Returns: the value of the property, converted to integers, or
* undefined if an error occurs (including when the property value is not
* an list of integers).
*/
void object_property_get_uint16List(Object *obj, const char *name,
uint16List **list, Error **errp);
/**
* object_property_set:
* @obj: the object
* @v: the visitor that will be used to write the property value. This should
* be an Input visitor and the data will be first read with @name as the
* name and then written as the property value.
* @name: the name of the property
* @errp: returns an error if this function fails
*
* Writes a property to a object.
*/
void object_property_set(Object *obj, Visitor *v, const char *name,
Error **errp);
/**
* object_property_parse:
* @obj: the object
* @string: the string that will be used to parse the property value.
* @name: the name of the property
* @errp: returns an error if this function fails
*
* Parses a string and writes the result into a property of an object.
*/
void object_property_parse(Object *obj, const char *string,
const char *name, Error **errp);
/**
* object_property_print:
* @obj: the object
* @name: the name of the property
* @human: if true, print for human consumption
* @errp: returns an error if this function fails
*
* Returns a string representation of the value of the property. The
* caller shall free the string.
*/
char *object_property_print(Object *obj, const char *name, bool human,
Error **errp);
/**
* object_property_get_type:
* @obj: the object
* @name: the name of the property
* @errp: returns an error if this function fails
*
* Returns: The type name of the property.
*/
const char *object_property_get_type(Object *obj, const char *name,
Error **errp);
/**
* object_get_root:
*
* Returns: the root object of the composition tree
*/
Object *object_get_root(void);
/**
* object_get_objects_root:
*
* Get the container object that holds user created
* object instances. This is the object at path
* "/objects"
*
* Returns: the user object container
*/
Object *object_get_objects_root(void);
/**
* object_get_internal_root:
*
* Get the container object that holds internally used object
* instances. Any object which is put into this container must not be
* user visible, and it will not be exposed in the QOM tree.
*
* Returns: the internal object container
*/
Object *object_get_internal_root(void);
/**
* object_get_canonical_path_component:
*
* Returns: The final component in the object's canonical path. The canonical
* path is the path within the composition tree starting from the root.
*/
gchar *object_get_canonical_path_component(Object *obj);
/**
* object_get_canonical_path:
*
* Returns: The canonical path for a object. This is the path within the
* composition tree starting from the root.
*/
gchar *object_get_canonical_path(Object *obj);
/**
* object_resolve_path:
* @path: the path to resolve
* @ambiguous: returns true if the path resolution failed because of an
* ambiguous match
*
* There are two types of supported paths--absolute paths and partial paths.
*
* Absolute paths are derived from the root object and can follow child<> or
* link<> properties. Since they can follow link<> properties, they can be
* arbitrarily long. Absolute paths look like absolute filenames and are
* prefixed with a leading slash.
*
* Partial paths look like relative filenames. They do not begin with a
* prefix. The matching rules for partial paths are subtle but designed to make
* specifying objects easy. At each level of the composition tree, the partial
* path is matched as an absolute path. The first match is not returned. At
* least two matches are searched for. A successful result is only returned if
* only one match is found. If more than one match is found, a flag is
* returned to indicate that the match was ambiguous.
*
* Returns: The matched object or NULL on path lookup failure.
*/
Object *object_resolve_path(const char *path, bool *ambiguous);
/**
* object_resolve_path_type:
* @path: the path to resolve
* @typename: the type to look for.
* @ambiguous: returns true if the path resolution failed because of an
* ambiguous match
*
* This is similar to object_resolve_path. However, when looking for a
* partial path only matches that implement the given type are considered.
* This restricts the search and avoids spuriously flagging matches as
* ambiguous.
*
* For both partial and absolute paths, the return value goes through
* a dynamic cast to @typename. This is important if either the link,
* or the typename itself are of interface types.
*
* Returns: The matched object or NULL on path lookup failure.
*/
Object *object_resolve_path_type(const char *path, const char *typename,
bool *ambiguous);
/**
* object_resolve_path_component:
* @parent: the object in which to resolve the path
* @part: the component to resolve.
*
* This is similar to object_resolve_path with an absolute path, but it
* only resolves one element (@part) and takes the others from @parent.
*
* Returns: The resolved object or NULL on path lookup failure.
*/
Object *object_resolve_path_component(Object *parent, const gchar *part);
/**
* object_property_add_child:
* @obj: the object to add a property to
* @name: the name of the property
* @child: the child object
* @errp: if an error occurs, a pointer to an area to store the area
*
* Child properties form the composition tree. All objects need to be a child
* of another object. Objects can only be a child of one object.
*
* There is no way for a child to determine what its parent is. It is not
* a bidirectional relationship. This is by design.
*
* The value of a child property as a C string will be the child object's
* canonical path. It can be retrieved using object_property_get_str().
* The child object itself can be retrieved using object_property_get_link().
*/
void object_property_add_child(Object *obj, const char *name,
Object *child, Error **errp);
typedef enum {
/* Unref the link pointer when the property is deleted */
OBJ_PROP_LINK_UNREF_ON_RELEASE = 0x1,
} ObjectPropertyLinkFlags;
/**
* object_property_allow_set_link:
*
* The default implementation of the object_property_add_link() check()
* callback function. It allows the link property to be set and never returns
* an error.
*/
void object_property_allow_set_link(const Object *, const char *,
Object *, Error **);
/**
* object_property_add_link:
* @obj: the object to add a property to
* @name: the name of the property
* @type: the qobj type of the link
* @child: a pointer to where the link object reference is stored
* @check: callback to veto setting or NULL if the property is read-only
* @flags: additional options for the link
* @errp: if an error occurs, a pointer to an area to store the area
*
* Links establish relationships between objects. Links are unidirectional
* although two links can be combined to form a bidirectional relationship
* between objects.
*
* Links form the graph in the object model.
*
* The <code>@check()</code> callback is invoked when
* object_property_set_link() is called and can raise an error to prevent the
* link being set. If <code>@check</code> is NULL, the property is read-only
* and cannot be set.
*
* Ownership of the pointer that @child points to is transferred to the
* link property. The reference count for <code>*@child</code> is
* managed by the property from after the function returns till the
* property is deleted with object_property_del(). If the
* <code>@flags</code> <code>OBJ_PROP_LINK_UNREF_ON_RELEASE</code> bit is set,
* the reference count is decremented when the property is deleted.
*/
void object_property_add_link(Object *obj, const char *name,
const char *type, Object **child,
void (*check)(const Object *obj, const char *name,
Object *val, Error **errp),
ObjectPropertyLinkFlags flags,
Error **errp);
/**
* object_property_add_str:
* @obj: the object to add a property to
* @name: the name of the property
* @get: the getter or NULL if the property is write-only. This function must
* return a string to be freed by g_free().
* @set: the setter or NULL if the property is read-only
* @errp: if an error occurs, a pointer to an area to store the error
*
* Add a string property using getters/setters. This function will add a
* property of type 'string'.
*/
void object_property_add_str(Object *obj, const char *name,
char *(*get)(Object *, Error **),
void (*set)(Object *, const char *, Error **),
Error **errp);
void object_class_property_add_str(ObjectClass *klass, const char *name,
char *(*get)(Object *, Error **),
void (*set)(Object *, const char *,
Error **),
Error **errp);
/**
* object_property_add_bool:
* @obj: the object to add a property to
* @name: the name of the property
* @get: the getter or NULL if the property is write-only.
* @set: the setter or NULL if the property is read-only
* @errp: if an error occurs, a pointer to an area to store the error
*
* Add a bool property using getters/setters. This function will add a
* property of type 'bool'.
*/
void object_property_add_bool(Object *obj, const char *name,
bool (*get)(Object *, Error **),
void (*set)(Object *, bool, Error **),
Error **errp);
void object_class_property_add_bool(ObjectClass *klass, const char *name,
bool (*get)(Object *, Error **),
void (*set)(Object *, bool, Error **),
Error **errp);
/**
* object_property_add_enum:
* @obj: the object to add a property to
* @name: the name of the property
* @typename: the name of the enum data type
* @get: the getter or %NULL if the property is write-only.
* @set: the setter or %NULL if the property is read-only
* @errp: if an error occurs, a pointer to an area to store the error
*
* Add an enum property using getters/setters. This function will add a
* property of type '@typename'.
*/
void object_property_add_enum(Object *obj, const char *name,
const char *typename,
const QEnumLookup *lookup,
int (*get)(Object *, Error **),
void (*set)(Object *, int, Error **),
Error **errp);
void object_class_property_add_enum(ObjectClass *klass, const char *name,
const char *typename,
const QEnumLookup *lookup,
int (*get)(Object *, Error **),
void (*set)(Object *, int, Error **),
Error **errp);
/**
* object_property_add_tm:
* @obj: the object to add a property to
* @name: the name of the property
* @get: the getter or NULL if the property is write-only.
* @errp: if an error occurs, a pointer to an area to store the error
*
* Add a read-only struct tm valued property using a getter function.
* This function will add a property of type 'struct tm'.
*/
void object_property_add_tm(Object *obj, const char *name,
void (*get)(Object *, struct tm *, Error **),
Error **errp);
void object_class_property_add_tm(ObjectClass *klass, const char *name,
void (*get)(Object *, struct tm *, Error **),
Error **errp);
/**
* object_property_add_uint8_ptr:
* @obj: the object to add a property to
* @name: the name of the property
* @v: pointer to value
* @errp: if an error occurs, a pointer to an area to store the error
*
* Add an integer property in memory. This function will add a
* property of type 'uint8'.
*/
void object_property_add_uint8_ptr(Object *obj, const char *name,
const uint8_t *v, Error **errp);
void object_class_property_add_uint8_ptr(ObjectClass *klass, const char *name,
const uint8_t *v, Error **errp);
/**
* object_property_add_uint16_ptr:
* @obj: the object to add a property to
* @name: the name of the property
* @v: pointer to value
* @errp: if an error occurs, a pointer to an area to store the error
*
* Add an integer property in memory. This function will add a
* property of type 'uint16'.
*/
void object_property_add_uint16_ptr(Object *obj, const char *name,
const uint16_t *v, Error **errp);
void object_class_property_add_uint16_ptr(ObjectClass *klass, const char *name,
const uint16_t *v, Error **errp);
/**
* object_property_add_uint32_ptr:
* @obj: the object to add a property to
* @name: the name of the property
* @v: pointer to value
* @errp: if an error occurs, a pointer to an area to store the error
*
* Add an integer property in memory. This function will add a
* property of type 'uint32'.
*/
void object_property_add_uint32_ptr(Object *obj, const char *name,
const uint32_t *v, Error **errp);
void object_class_property_add_uint32_ptr(ObjectClass *klass, const char *name,
const uint32_t *v, Error **errp);
/**
* object_property_add_uint64_ptr:
* @obj: the object to add a property to
* @name: the name of the property
* @v: pointer to value
* @errp: if an error occurs, a pointer to an area to store the error
*
* Add an integer property in memory. This function will add a
* property of type 'uint64'.
*/
void object_property_add_uint64_ptr(Object *obj, const char *name,
const uint64_t *v, Error **Errp);
void object_class_property_add_uint64_ptr(ObjectClass *klass, const char *name,
const uint64_t *v, Error **Errp);
/**
* object_property_add_alias:
* @obj: the object to add a property to
* @name: the name of the property
* @target_obj: the object to forward property access to
* @target_name: the name of the property on the forwarded object
* @errp: if an error occurs, a pointer to an area to store the error
*
* Add an alias for a property on an object. This function will add a property
* of the same type as the forwarded property.
*
* The caller must ensure that <code>@target_obj</code> stays alive as long as
* this property exists. In the case of a child object or an alias on the same
* object this will be the case. For aliases to other objects the caller is
* responsible for taking a reference.
*/
void object_property_add_alias(Object *obj, const char *name,
Object *target_obj, const char *target_name,
Error **errp);
/**
* object_property_add_const_link:
* @obj: the object to add a property to
* @name: the name of the property
* @target: the object to be referred by the link
* @errp: if an error occurs, a pointer to an area to store the error
*
* Add an unmodifiable link for a property on an object. This function will
* add a property of type link<TYPE> where TYPE is the type of @target.
*
* The caller must ensure that @target stays alive as long as
* this property exists. In the case @target is a child of @obj,
* this will be the case. Otherwise, the caller is responsible for
* taking a reference.
*/
void object_property_add_const_link(Object *obj, const char *name,
Object *target, Error **errp);
/**
* object_property_set_description:
* @obj: the object owning the property
* @name: the name of the property
* @description: the description of the property on the object
* @errp: if an error occurs, a pointer to an area to store the error
*
* Set an object property's description.
*
*/
void object_property_set_description(Object *obj, const char *name,
const char *description, Error **errp);
void object_class_property_set_description(ObjectClass *klass, const char *name,
const char *description,
Error **errp);
/**
* object_child_foreach:
* @obj: the object whose children will be navigated
* @fn: the iterator function to be called
* @opaque: an opaque value that will be passed to the iterator
*
* Call @fn passing each child of @obj and @opaque to it, until @fn returns
* non-zero.
*
* It is forbidden to add or remove children from @obj from the @fn
* callback.
*
* Returns: The last value returned by @fn, or 0 if there is no child.
*/
int object_child_foreach(Object *obj, int (*fn)(Object *child, void *opaque),
void *opaque);
/**
* object_child_foreach_recursive:
* @obj: the object whose children will be navigated
* @fn: the iterator function to be called
* @opaque: an opaque value that will be passed to the iterator
*
* Call @fn passing each child of @obj and @opaque to it, until @fn returns
* non-zero. Calls recursively, all child nodes of @obj will also be passed
* all the way down to the leaf nodes of the tree. Depth first ordering.
*
* It is forbidden to add or remove children from @obj (or its
* child nodes) from the @fn callback.
*
* Returns: The last value returned by @fn, or 0 if there is no child.
*/
int object_child_foreach_recursive(Object *obj,
int (*fn)(Object *child, void *opaque),
void *opaque);
/**
* container_get:
* @root: root of the #path, e.g., object_get_root()
* @path: path to the container
*
* Return a container object whose path is @path. Create more containers
* along the path if necessary.
*
* Returns: the container object.
*/
Object *container_get(Object *root, const char *path);
/**
* object_type_get_instance_size:
* @typename: Name of the Type whose instance_size is required
*
* Returns the instance_size of the given @typename.
*/
size_t object_type_get_instance_size(const char *typename);
#endif
