qemu/include/qom/object.h
Gonglei 8074264203 qom: Add description field in ObjectProperty struct
The descriptions can serve as documentation in the code,
and they can be used to provide better help.

Copy property descriptions when copying alias properties.

Cc: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Gonglei <arei.gonglei@huawei.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Andreas Färber <afaerber@suse.de>
2014-10-15 05:03:15 +02:00

1319 lines
44 KiB
C

/*
* 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 <glib.h>
#include <stdint.h>
#include <stdbool.h>
#include "qemu/queue.h"
#include "qapi/error.h"
struct Visitor;
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.
*
* 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 = my_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
* @opaque: the object property opaque
* @name: the name of the property
* @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,
struct Visitor *v,
void *opaque,
const char *name,
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;
QTAILQ_ENTRY(ObjectProperty) node;
} 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;
};
/**
* 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.
*
* #Object also contains a list of #Interfaces that this object
* implements.
*/
struct Object
{
/*< private >*/
ObjectClass *class;
ObjectFree *free;
QTAILQ_HEAD(, ObjectProperty) 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 descendents.
* @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: The C type to use for the return value.
* @obj: A derivative of @type to cast.
* @name: the QOM typename of @class.
*
* 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, obj, name) \
((class *)object_class_dynamic_cast_assert(OBJECT_CLASS(obj), (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_type:
* @type: 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_with_type(Type type);
/**
* object_initialize_with_type:
* @data: A pointer to the memory to be used for the object.
* @size: The maximum size available at @data for the object.
* @type: 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_with_type(void *data, size_t size, Type type);
/**
* 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(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: 0 on failure, the new #Type on success.
*/
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: 0 on failure, the new #Type on success.
*/
Type type_register(const TypeInfo *info);
/**
* 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);
/**
* qdef_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);
/**
* 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);
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, struct 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 NULL 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_get_enum:
* @obj: the object
* @name: the name of the property
* @strings: strings corresponding to enums
* @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 *strings[], 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, struct 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_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(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)(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);
/**
* 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);
/**
* 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);
/**
* 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);
/**
* 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);
/**
* 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);
/**
* 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_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);
/**
* 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.
*
* 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);
/**
* 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);
#endif