/* * 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. * * 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 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_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_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_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_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); 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_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_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); 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 char * const *strings, 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 char * const *strings, 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