Functions of class **afb_api** ============================ ## General functions ### afb_api_name ```C /** * Get the name of the 'api'. * * @param api the api whose name is to be returned * * @return the name of the api. * * The returned value must not be changed nor freed. */ const char *afb_api_name( afb_api_t api); ``` ### afb_api_get_userdata ```C /** * Get the "userdata" pointer of the 'api' * * @param api the api whose user's data is to be returned * * @return the user's data pointer of the api. * * @see afb_api_set_userdata */ void *afb_api_get_userdata( afb_api_t api); ``` ### afb_api_set_userdata ```C /** * Set the "userdata" pointer of the 'api' to 'value' * * @param api the api whose user's data is to be set * @param value the data to set * * @see afb_api_get_userdata */ void afb_api_set_userdata( afb_api_t api, void *value); ``` ### afb_api_require_api ```C /** * Check that it requires the API of 'name'. * If 'initialized' is not zero it request the API to be * initialized, implying its initialization if needed. * * Calling this function is only allowed within init. * * A single request allows to require multiple apis. * * @param api the api that requires the other api by its name * @param name a space separated list of required api names * @param initialized if zero, the api is just required to exist. If not zero, * the api is required to exist and to be initialized at return of the call * (initializing it if needed and possible as a side effect of the call). * * @return 0 in case of success or -1 in case of error with errno set appropriately. */ int afb_api_require_api( afb_api_t api, const char *name, int initialized); ``` ## Verbosity functions ### afb_api_wants_log_level ```C /** * Is the log message of 'level (as defined for syslog) required for the api? * * @param api the api to check * @param level the level to check as defined for syslog: * * EMERGENCY 0 System is unusable * ALERT 1 Action must be taken immediately * CRITICAL 2 Critical conditions * ERROR 3 Error conditions * WARNING 4 Warning conditions * NOTICE 5 Normal but significant condition * INFO 6 Informational * DEBUG 7 Debug-level messages * * @return 0 if not required or a value not null if required * * @see syslog */ int afb_api_wants_log_level( afb_api_t api, int level); ``` ### afb_api_vverbose ```C /** * Send to the journal with the logging 'level' a message described * by 'fmt' applied to the va-list 'args'. * * 'file', 'line' and 'func' are indicators of code position in source files * (see macros __FILE__, __LINE__ and __func__). * * 'level' is defined by syslog standard: * * EMERGENCY 0 System is unusable * ALERT 1 Action must be taken immediately * CRITICAL 2 Critical conditions * ERROR 3 Error conditions * WARNING 4 Warning conditions * NOTICE 5 Normal but significant condition * INFO 6 Informational * DEBUG 7 Debug-level messages * * @param api the api that collects the logging message * @param level the level of the message * @param file the source file that logs the messages or NULL * @param line the line in the source file that logs the message * @param func the name of the function in the source file that logs * @param fmt the format of the message as in printf * @param args the arguments to the format string of the message as a va_list * * @see syslog * @see printf */ void afb_api_vverbose( afb_api_t api, int level, const char *file, int line, const char *func, const char *fmt, va_list args); ``` ### afb_api_verbose ```C /** * Send to the journal with the log 'level' a message described * by 'fmt' and following parameters. * * 'file', 'line' and 'func' are indicators of position of the code in source files * (see macros __FILE__, __LINE__ and __func__). * * 'level' is defined by syslog standard: * EMERGENCY 0 System is unusable * ALERT 1 Action must be taken immediately * CRITICAL 2 Critical conditions * ERROR 3 Error conditions * WARNING 4 Warning conditions * NOTICE 5 Normal but significant condition * INFO 6 Informational * DEBUG 7 Debug-level messages * * @param api the api that collects the logging message * @param level the level of the message * @param file the source file that logs the messages or NULL * @param line the line in the source file that logs the message * @param func the name of the function in the source file that logs * @param fmt the format of the message as in printf * @param ... the arguments to the format string of the message * * @see syslog * @see printf */ void afb_api_verbose( afb_api_t api, int level, const char *file, int line, const char *func, const char *fmt, ...); ``` ## Data retrieval functions ### afb_api_rootdir_get_fd ```C /** * Get the root directory file descriptor. This file descriptor can * be used with functions 'openat', 'fstatat', ... * * CAUTION, manipulate this this descriptor with care, in particular, don't close * it. * * This can be used to get the path of the root directory using: * * char buffer[MAX_PATH], proc[100]; * int dirfd = afb_api_rootdir_get_fd(api); * snprintf(proc, sizeof proc, "/proc/self/fd/%d", dirfd); * readlink(proc, buffer, sizeof buffer); * * But note that within AGL this is the value given by the environment variable * AFM_APP_INSTALL_DIR. * * @param api the api that uses the directory file descriptor * * @return the file descriptor of the root directory. * * @see afb_api_rootdir_open_locale */ int afb_api_rootdir_get_fd( afb_api_t api); ``` ### afb_api_rootdir_open_locale ```C /** * Opens 'filename' within the root directory with 'flags' (see function openat) * using the 'locale' definition (example: "jp,en-US") that can be NULL. * * The filename must be relative to the root of the bindings. * * The opening mode must be for read or write but not for O_CREAT. * * The definition of locales and of how files are searched can be checked * here: https://www.w3.org/TR/widgets/#folder-based-localization * and https://tools.ietf.org/html/rfc7231#section-5.3.5 * * @param api the api that queries the file * @param filename the relative path to the file to open * @param flags the flags for opening as for C function 'open' * @param locale string indicating how to search content, can be NULL * * @return the file descriptor or -1 in case of error and errno is set with the * error indication. * * @see open * @see afb_api_rootdir_get_fd */ int afb_api_rootdir_open_locale( afb_api_t api, const char *filename, int flags, const char *locale); ``` ## Calls and job functions ### afb_api_call ```C /** * Calls the 'verb' of the 'api' with the arguments 'args' and 'verb' in the name of the binding. * The result of the call is delivered to the 'callback' function with the 'callback_closure'. * * For convenience, the function calls 'json_object_put' for 'args'. * Thus, in the case where 'args' should remain available after * the function returns, the function 'json_object_get' shall be used. * * The 'callback' receives 5 arguments: * 1. 'closure' the user defined closure pointer 'closure', * 2. 'object' a JSON object returned (can be NULL) * 3. 'error' a string not NULL in case of error but NULL on success * 4. 'info' a string handling some info (can be NULL) * 5. 'api' the api * * @param api The api that makes the call * @param apiname The api name of the method to call * @param verb The verb name of the method to call * @param args The arguments to pass to the method * @param callback The to call on completion * @param closure The closure to pass to the callback * * * @see afb_req_subcall * @see afb_req_subcall_sync * @see afb_api_call_sync */ void afb_api_call( afb_api_t api, const char *apiname, const char *verb, struct json_object *args, void (*callback)( void *closure, struct json_object *object, const char *error, const char * info, afb_api_t api), void *closure); ``` ### afb_api_call_sync ```C /** * Calls the 'verb' of the 'api' with the arguments 'args' and 'verb' in the name of the binding. * 'result' will receive the response. * * For convenience, the function calls 'json_object_put' for 'args'. * Thus, in the case where 'args' should remain available after * the function returns, the function 'json_object_get' shall be used. * * @param api The api that makes the call * @param apiname The api name of the method to call * @param verb The verb name of the method to call * @param args The arguments to pass to the method * @param object Where to store the returned object - should call json_object_put on it - can be NULL * @param error Where to store the copied returned error - should call free on it - can be NULL * @param info Where to store the copied returned info - should call free on it - can be NULL * * @returns 0 in case of success or a negative value in case of error. * * @see afb_req_subcall * @see afb_req_subcall_sync * @see afb_api_call */ int afb_api_call_sync( afb_api_t api, const char *apiname, const char *verb, struct json_object *args, struct json_object **object, char **error, char **info); ``` ### afb_api_queue_job ```C /** * Queue the job defined by 'callback' and 'argument' for being executed asynchronously * in this thread (later) or in an other thread. * * If 'group' is not NULL, the jobs queued with a same value (as the pointer value 'group') * are executed in sequence in the order of there submission. * * If 'timeout' is not 0, it represent the maximum execution time for the job in seconds. * At first, the job is called with 0 as signum and the given argument. * * The job is executed with the monitoring of its time and some signals like SIGSEGV and * SIGFPE. When a such signal is catched, the job is terminated and reexecuted but with * signum being the signal number (SIGALRM when timeout expired). * * When executed, the callback function receives 2 arguments: * * - int signum: the signal catched if any or zero at the beginning * - void *arg: the parameter 'argument' * * A typical implementation of the job callback is: * * void my_job_cb(int signum, void *arg) * { * struct myarg_t *myarg = arg; * if (signum) * AFB_API_ERROR(myarg->api, "job interrupted with signal %s", strsignal(signum)); * else * really_do_my_job(myarg); * } * * @param api the api that queue the job * @param callback the job as a callback function * @param argument the argument to pass to the queued job * @param group the group of the job, NULL if no group * @param timeout the timeout of execution of the job * * @return 0 in case of success or -1 in case of error with errno set appropriately. */ int afb_api_queue_job( afb_api_t api, void (*callback)(int signum, void *arg), void *argument, void *group, int timeout); ``` ## Event functions ### afb_api_broadcast_event ```C /** * Broadcasts widely the event of 'name' with the data 'object'. * 'object' can be NULL. * * For convenience, the function calls 'json_object_put' for 'object'. * Thus, in the case where 'object' should remain available after * the function returns, the function 'json_object_get' shall be used. * * Calling this function is only forbidden during preinit. * * The event sent as the name API/name where API is the name of the * api. * * @param api the api that broadcast the event * @param name the event name suffix * @param object the object that comes with the event * * @return the count of clients that received the event. */ int afb_api_broadcast_event( afb_api_t api, const char *name, struct json_object *object); ``` ### afb_api_make_event ```C /** * Creates an event of 'name' and returns it. * * Calling this function is only forbidden during preinit. * * See afb_event_is_valid to check if there is an error. * * The event created as the name API/name where API is the name of the * api. * * @param api the api that creates the event * @param name the event name suffix * * @return the created event. Use the function afb_event_is_valid to check * whether the event is valid (created) or not (error as reported by errno). * * @see afb_event_is_valid */ afb_event_t afb_api_make_event( afb_api_t api, const char *name); ``` ### afb_api_event_handler_add ```C /** * Add a specific event handler for the api * * The handler callback is called when an event matching the given pattern * is received (it is received if broadcasted or after subscription through * a call or a subcall). * * The handler callback receive 4 arguments: * * - the closure given here * - the event full name * - the companion JSON object of the event * - the api that subscribed the event * * @param api the api that creates the handler * @param pattern the global pattern of the event to handle * @param callback the handler callback function * @param closure the closure of the handler * * @return 0 in case of success or -1 on failure with errno set * * @see afb_api_on_event * @see afb_api_event_handler_del */ int afb_api_event_handler_add( afb_api_t api, const char *pattern, void (*callback)( void *, const char*, struct json_object*, afb_api_t), void *closure); ``` ### afb_api_event_handler_del ```C /** * Delete a specific event handler for the api * * @param api the api that the handler belongs to * @param pattern the global pattern of the handler to remove * @param closure if not NULL it will receive the closure set to the handler * * @return 0 in case of success or -1 on failure with errno set * * @see afb_api_on_event * @see afb_api_event_handler_add */ int afb_api_event_handler_del( afb_api_t api, const char *pattern, void **closure); ``` ## Systemd functions ### afb_api_get_event_loop ```C /** * Retrieves the common systemd's event loop of AFB * * @param api the api that uses the event loop * * @return the systemd event loop if active, NULL otherwise * * @see afb_api_get_user_bus * @see afb_api_get_system_bus */ struct sd_event *afb_api_get_event_loop( afb_api_t api); ``` ### afb_api_get_user_bus ```C /** * Retrieves the common systemd's user/session d-bus of AFB * * @param api the api that uses the user dbus * * @return the systemd user connection to dbus if active, NULL otherwise * * @see afb_api_get_event_loop * @see afb_api_get_system_bus */ struct sd_bus *afb_api_get_user_bus( afb_api_t api); ``` ### afb_api_get_system_bus ```C /** * Retrieves the common systemd's system d-bus of AFB * * @param api the api that uses the system dbus * * @return the systemd system connection to dbus if active, NULL otherwise * * @see afb_api_get_event_loop * @see afb_api_get_user_bus */ struct sd_bus *afb_api_get_system_bus( afb_api_t api); ``` ## Dynamic api functions ### afb_api_new_api ```C /** * Creates a new api of name 'apiname' briefly described by 'info' (that can * be NULL). * * When the pre-initialization function is given, it is a function that * receives 2 parameters: * * - the closure as given in the call * - the created api that can be initialised * * This pre-initialization function must return a negative value to abort * the creation of the api. Otherwise, it returns a non-negative value to * continue. * * @param api the api that creates the other one * @param apiname the name of the new api * @param info the brief description of the new api (can be NULL) * @param noconcurrency zero or not zero whether the new api is reentrant or not * @param preinit the pre-initialization function if any (can be NULL) * @param closure the closure for the pre-initialization \ref preinit * * @return 0 in case of success or -1 on failure with errno set * * @see afb_api_delete_api */ afb_api_t afb_api_new_api( afb_api_t api, const char *apiname, const char *info, int noconcurrency, int (*preinit)(void*, afb_api_t ), void *closure); ``` ### afb_api_set_verbs_v2 ```C /** * @deprecated use @ref afb_api_set_verbs_v3 instead * * Set the verbs of the 'api' using description of verbs of the api v2 * * @param api the api that will get the verbs * @param verbs the array of verbs to add terminated with an item with name=NULL * * @return 0 in case of success or -1 on failure with errno set * * @see afb_verb_v2 * @see afb_api_add_verb * @see afb_api_set_verbs_v3 */ int afb_api_set_verbs_v2( afb_api_t api, const struct afb_verb_v2 *verbs); ``` ### afb_api_set_verbs_v3 ```C /** * Set the verbs of the 'api' using description of verbs of the api v2 * * @param api the api that will get the verbs * @param verbs the array of verbs to add terminated with an item with name=NULL * * @return 0 in case of success or -1 on failure with errno set * * @see afb_verb_v3 * @see afb_api_add_verb * @see afb_api_del_verb */ int afb_api_set_verbs_v3( afb_api_t api, const struct afb_verb_v3 *verbs); ``` ### afb_api_add_verb ```C /** * Add one verb to the dynamic set of the api * * @param api the api to change * @param verb name of the verb * @param info brief description of the verb, can be NULL * @param callback callback function implementing the verb * @param vcbdata data for the verb callback, available through req * @param auth required authorization, can be NULL * @param session authorization and session requirements of the verb * @param glob is the verb glob name * * @return 0 in case of success or -1 on failure with errno set * * @see afb_verb_v3 * @see afb_api_del_verb * @see afb_api_set_verbs_v3 * @see fnmatch for matching names using glob */ int afb_api_add_verb( afb_api_t api, const char *verb, const char *info, void (*callback)(struct afb_req_x2 *req), void *vcbdata, const struct afb_auth *auth, uint32_t session, int glob); ``` ### afb_api_del_verb ```C /** * Delete one verb from the dynamic set of the api * * @param api the api to change * @param verb name of the verb to delete * @param vcbdata if not NULL will receive the vcbdata of the deleted verb * * @return 0 in case of success or -1 on failure with errno set * * @see afb_api_add_verb */ int afb_api_del_verb( afb_api_t api, const char *verb, void **vcbdata); ``` ### afb_api_on_event ```C /** * Set the callback 'onevent' to process events in the name of the 'api'. * * This setting can be done statically using the global variable * @ref afbBindingV3. * * This function replace any previously global event callback set. * * When an event is received, the callback 'onevent' is called with 3 parameters * * - the api that recorded the event handler * - the full name of the event * - the companion JSON object of the event * * @param api the api that wants to process events * @param onevent the callback function that will process events (can be NULL * to remove event callback) * * @return 0 in case of success or -1 on failure with errno set * * @see afbBindingV3 * @see afb_binding_v3 * @see afb_api_event_handler_add * @see afb_api_event_handler_del */ int afb_api_on_event( afb_api_t api, void (*onevent)( afb_api_t api, const char *event, struct json_object *object)); ``` ### afb_api_on_init ```C /** * Set the callback 'oninit' to process initialization of the 'api'. * * This setting can be done statically using the global variable * @ref afbBindingV3 * * This function replace any previously initialization callback set. * * This function is only valid during the pre-initialization stage. * * The callback initialization function will receive one argument: the api * to initialize. * * @param api the api that wants to process events * @param oninit the callback function that initialize the api * * @return 0 in case of success or -1 on failure with errno set * * @see afbBindingV3 * @see afb_binding_v3 */ int afb_api_on_init( afb_api_t api, int (*oninit)(afb_api_t api)); ``` ### afb_api_provide_class ```C /** * Tells that the api provides a class of features. Classes are intended to * allow ordering of initializations: apis that provides a given class are * initialized before apis requiring it. * * This function is only valid during the pre-initialization stage. * * @param api the api that provides the classes * @param name a space separated list of the names of the provided classes * * @returns 0 in case of success or a negative value in case of error. * * @see afb_api_require_class */ int afb_api_provide_class( afb_api_t api, const char *name); ``` ### afb_api_require_class ```C /** * Tells that the api requires a set of class features. Classes are intended to * allow ordering of initializations: apis that provides a given class are * initialized before apis requiring it. * * This function is only valid during the pre-initialization stage. * * @param api the api that requires the classes * @param name a space separated list of the names of the required classes * * @returns 0 in case of success or a negative value in case of error. * * @see afb_api_provide_class */ int afb_api_require_class( afb_api_t api, const char *name); ``` ### afb_api_seal ```C /** * Seal the api. After a call to this function the api can not be modified * anymore. * * @param api the api to be sealed */ void afb_api_seal( afb_api_t api); ``` ### afb_api_delete_api ```C /** * Delete the given api. * * It is of the responsibility of the caller to don't used the deleted api * anymore after this function returned. * * @param api the api to delete * * @returns 0 in case of success or a negative value in case of error. * * @see afb_api_new_api */ int afb_api_delete_api( afb_api_t api); ``` ### afb_api_add_alias ```C /** * Create an aliased name 'as_name' for the api 'name'. * Calling this function is only allowed within preinit. * * @param api the api that requires the aliasing * @param name the api to alias * @param as_name the aliased name of the aliased api * * @return 0 in case of success or -1 in case of error with errno set appropriately. */ int afb_api_add_alias( afb_api_t api, const char *name, const char *as_name); ``` ## Legacy functions The function for legacy calls are still provided for some time because adaptation of existing code to the new call functions require a small amount of work. ### afb_api_call_legacy ```C /** * @deprecated try to use @ref afb_api_call instead * * * Calls the 'verb' of the 'api' with the arguments 'args' and 'verb' in the name of the binding. * The result of the call is delivered to the 'callback' function with the 'callback_closure'. * * For convenience, the function calls 'json_object_put' for 'args'. * Thus, in the case where 'args' should remain available after * the function returns, the function 'json_object_get' shall be used. * * The 'callback' receives 3 arguments: * 1. 'closure' the user defined closure pointer 'closure', * 2. 'status' a status being 0 on success or negative when an error occurred, * 2. 'result' the resulting data as a JSON object. * * @param api The api * @param apiname The api name of the method to call * @param verb The verb name of the method to call * @param args The arguments to pass to the method * @param callback The to call on completion * @param closure The closure to pass to the callback * * @see also 'afb_api_call' * @see also 'afb_api_call_sync' * @see also 'afb_api_call_sync_legacy' * @see also 'afb_req_subcall' * @see also 'afb_req_subcall_sync' */ void afb_api_call_legacy( afb_api_t api, const char *apiname, const char *verb, struct json_object *args, void (*callback)( void *closure, int status, struct json_object *result, afb_api_t api), void *closure); ``` ### afb_api_call_sync_legacy ```C /** * @deprecated try to use @ref afb_api_call_sync instead * * Calls the 'verb' of the 'api' with the arguments 'args' and 'verb' in the name of the binding. * 'result' will receive the response. * * For convenience, the function calls 'json_object_put' for 'args'. * Thus, in the case where 'args' should remain available after * the function returns, the function 'json_object_get' shall be used. * * @param api The api * @param apiname The api name of the method to call * @param verb The verb name of the method to call * @param args The arguments to pass to the method * @param result Where to store the result - should call json_object_put on it - * * @returns 0 in case of success or a negative value in case of error. * * @see also 'afb_api_call' * @see also 'afb_api_call_sync' * @see also 'afb_api_call_legacy' * @see also 'afb_req_subcall' * @see also 'afb_req_subcall_sync' */ int afb_api_call_sync_legacy( afb_api_t api, const char *apiname, const char *verb, struct json_object *args, struct json_object **result); ```