component

Description

All component classes must implement the component interface. All functions in the interface must be implemented.

The pre_instantiate function is called before the component is instantiated. The function returns true if the component can be instantiated, or false if not.

The component might need to do some extra work after the component has been instantiated. This should be done when called via the post_instantiate function.

The create_cell function returns true if the configuration system can create a default cell object for the component, or false if not. Both pre_instantiate and create_cell typically return true.

Component has slots. A slot has key and value. The key is the slot name as a string. The value is a conf object, a pre conf object, or None, or nested lists of such types.

Slots are either defined in the component or added after the component has been created. Slots defined in the component are static slots which can not be deleted, but the slot value can be changed. Slots added to the component after creation are dynamic slots and they can be removed when wanted.

The get_slots function returns a dictionary with slot names as dictionary keys and slot values as dictionary values.

The get_slot_objects function returns a list of all conf objects and pre conf objects extracted from all slot values.

The get_slot_value returns the slot value. The slot name is passed as slot argument. A slot value is set using the set_slot_value function. The value argument should be a conf object, pre conf object, or None, or nested lists of such types. The get function returns NULL on failure. The set function does not return anything to indicate failure.

The has_slot function returns true if the slot exists, otherwise false. The slot can either be a static slot or a dynamic slot. The add_slot function adds the slot named slot. Adding a slot can fail if the slot already exist. The added slot will be a dynamic slot. A dynamic slot can be deleted. The del_slot function deletes a dynamic slot. Deleting a slot will fail if the slot does not exist or if the slot is static. Both add_slot and del_slot returns true on success or false on failure.

SIM_INTERFACE(component) {
        bool (*pre_instantiate)(conf_object_t *obj);
        void (*post_instantiate)(conf_object_t *obj);
        bool (*create_cell)(conf_object_t *obj);

        attr_value_t (*get_slots)(conf_object_t *obj);
        attr_value_t (*get_slot_objects)(conf_object_t *obj);

        attr_value_t (*get_slot_value)(conf_object_t *obj,
                                 const char *NOTNULL slot);
        void (*set_slot_value)(conf_object_t *obj,
                         const char *NOTNULL slot,
                         attr_value_t value);

        bool (*has_slot)(conf_object_t *obj,
                         const char *NOTNULL slot);
        bool (*add_slot)(conf_object_t *obj,
                         const char *NOTNULL slot);
        bool (*del_slot)(conf_object_t *obj,
                         const char *NOTNULL slot);
};
#define COMPONENT_INTERFACE "component"

Execution Context

post_instantiate	Global Context
pre_instantiate	Global Context
create_cell	Global Context
get_slots	Cell Context
get_objects	Cell Context
get_slot_value	Global Context
set_slot_value	Global Context
add_slot	Global Context
del_slot	Global Context