Improve documentation of api v3

The documentation is improved to reflect the new version.

Tune the options

Change-Id: I894c3db3bc0c10e89db66a9a51a9ad049bb8c0c4
Signed-off-by: José Bollo <jose.bollo@iot.bzh>

1 files changed, 835 insertions, 0 deletions

diff --git a/docs/reference-v3/func-req.md b/docs/reference-v3/func-req.md
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+Functions of class afb_req_t
+============================
+
+## General function
+
+### afb_req_is_valid
+
+```C
+/**
+ * Checks whether the request 'req' is valid or not.
+ *
+ * @param req the request to check
+ *
+ * @return 0 if not valid or 1 if valid.
+ */
+int afb_req_is_valid(
+			afb_req_t*req);
+```
+
+### afb_req_get_api
+
+```C
+/**
+ * Retrieves the api that serves the request
+ *
+ * @param req the request whose serving api is queried
+ *
+ * @return the api serving the request
+ */
+afb_api_t afb_req_get_api(
+			afb_req_t*req);
+```
+
+### afb_req_get_vcbdata
+
+```C
+/**
+ * Retrieves the callback data of the verb. This callback data is set
+ * when the verb is created.
+ *
+ * @param req whose verb vcbdata is queried
+ *
+ * @return the callback data attached to the verb description
+ */
+void *afb_req_get_vcbdata(
+			afb_req_t*req);
+```
+
+### afb_req_get_called_api
+
+```C
+/**
+ * Retrieve the name of the called api.
+ *
+ * @param req the request
+ *
+ * @return the name of the called api
+ *
+ * @see afb_api_new_api
+ * @see afb_api_add_alias
+ */
+const char *afb_req_get_called_api(
+			afb_req_t*req);
+```
+
+### afb_req_get_called_verb
+
+```C
+/**
+ * Retrieve the name of the called verb
+ *
+ * @param req the request
+ *
+ * @return the name of the called verb
+ */
+const char *afb_req_get_called_verb(
+			afb_req_t*req);
+```
+
+### afb_req_addref
+
+```C
+/**
+ * Increments the count of references of 'req'.
+ *
+ * @param req the request
+ *
+ * @return returns the request req
+ */
+afb_req_t*afb_req_addref(
+			afb_req_t*req);
+```
+
+### afb_req_unref
+
+```C
+/**
+ * Decrement the count of references of 'req'.
+ *
+ * @param req the request
+ */
+void afb_req_unref(
+			afb_req_t*req);
+```
+
+
+## Logging functions
+
+### afb_req_wants_log_level
+
+```C
+/**
+ * Is the log message of 'level (as defined for syslog) required for the
+ * request 'req'?
+ *
+ * @param req the request
+ * @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_req_wants_log_level(
+			afb_req_t*req,
+			int level);
+```
+
+### afb_req_vverbose
+
+```C
+/**
+ * Send associated to 'req' a message described by 'fmt' and its 'args'
+ * to the journal for the verbosity 'level'.
+ *
+ * '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 req the request
+ * @param level the level of the message
+ * @param file the source filename that emits the message or NULL
+ * @param line the line number in the source filename that emits the message
+ * @param func the name of the function that emits the message or NULL
+ * @param fmt the message format as for printf
+ * @param args the arguments to the format
+ *
+ * @see printf
+ * @see afb_req_verbose
+ */
+void afb_req_vverbose(
+			afb_req_t*req,
+			int level, const char *file,
+			int line,
+			const char * func,
+			const char *fmt,
+			va_list args);
+```
+
+### afb_req_verbose
+
+```C
+/**
+ * Send associated to 'req' a message described by 'fmt' and following parameters
+ * to the journal for the verbosity 'level'.
+ *
+ * '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 req the request
+ * @param level the level of the message
+ * @param file the source filename that emits the message or NULL
+ * @param line the line number in the source filename that emits the message
+ * @param func the name of the function that emits the message or NULL
+ * @param fmt the message format as for printf
+ * @param ... the arguments of the format 'fmt'
+ *
+ * @see printf
+ */
+void afb_req_verbose(
+			afb_req_t*req,
+			int level, const char *file,
+			int line,
+			const char * func,
+			const char *fmt,
+			...);
+```
+
+## Arguments/parameters function
+
+### afb_req_get
+
+```C
+/**
+ * Gets from the request 'req' the argument of 'name'.
+ *
+ * Returns a PLAIN structure of type 'struct afb_arg'.
+ *
+ * When the argument of 'name' is not found, all fields of result are set to NULL.
+ *
+ * When the argument of 'name' is found, the fields are filled,
+ * in particular, the field 'result.name' is set to 'name'.
+ *
+ * There is a special name value: the empty string.
+ * The argument of name "" is defined only if the request was made using
+ * an HTTP POST of Content-Type "application/json". In that case, the
+ * argument of name "" receives the value of the body of the HTTP request.
+ *
+ * @param req the request
+ * @param name the name of the argument to get
+ *
+ * @return a structure describing the retrieved argument for the request
+ *
+ * @see afb_req_value
+ * @see afb_req_path
+ */
+struct afb_arg afb_req_get(
+			afb_req_t*req,
+			const char *name);
+```
+
+### afb_req_value
+
+```C
+/**
+ * Gets from the request 'req' the string value of the argument of 'name'.
+ * Returns NULL if when there is no argument of 'name'.
+ * Returns the value of the argument of 'name' otherwise.
+ *
+ * Shortcut for: afb_req_get(req, name).value
+ *
+ * @param req the request
+ * @param name the name of the argument's value to get
+ *
+ * @return the value as a string or NULL
+ *
+ * @see afb_req_get
+ * @see afb_req_path
+ */
+const char *afb_req_value(
+			afb_req_t*req,
+			const char *name);
+```
+
+### afb_req_path
+
+```C
+/**
+ * Gets from the request 'req' the path for file attached to the argument of 'name'.
+ * Returns NULL if when there is no argument of 'name' or when there is no file.
+ * Returns the path of the argument of 'name' otherwise.
+ *
+ * Shortcut for: afb_req_get(req, name).path
+ *
+ * @param req the request
+ * @param name the name of the argument's path to get
+ *
+ * @return the path if any or NULL
+ *
+ * @see afb_req_get
+ * @see afb_req_value
+ */
+const char *afb_req_path(
+			afb_req_t*req,
+			const char *name);
+```
+
+### afb_req_json
+
+```C
+/**
+ * Gets from the request 'req' the json object hashing the arguments.
+ *
+ * The returned object must not be released using 'json_object_put'.
+ *
+ * @param req the request
+ *
+ * @return the JSON object of the query
+ *
+ * @see afb_req_get
+ * @see afb_req_value
+ * @see afb_req_path
+ */
+struct json_object *afb_req_json(
+			afb_req_t*req);
+```
+
+## Reply functions
+
+The functions **success** and **fail** are still supported.
+These functions are now implemented as the following macros:
+
+```C
+#define afb_req_success(r,o,i)		afb_req_reply(r,o,NULL,i)
+#define afb_req_success_f(r,o,...)	afb_req_reply_f(r,o,NULL,__VA_ARGS__)
+#define afb_req_success_v(r,o,f,v)	afb_req_reply_v(r,o,NULL,f,v)
+#define afb_req_fail(r,e,i)		afb_req_reply(r,NULL,e,i)
+#define afb_req_fail_f(r,e,...)		afb_req_reply_f(r,NULL,e,__VA_ARGS__)
+#define afb_req_fail_v(r,e,f,v)		afb_req_reply_v(r,NULL,e,f,v)
+```
+
+
+### afb_req_reply
+
+```C
+/**
+ * Sends a reply to the request 'req'.
+ *
+ * The status of the reply is set to 'error' (that must be NULL on success).
+ * Its send the object 'obj' (can be NULL) with an
+ * informational comment 'info (can also be NULL).
+ *
+ * For convenience, the function calls 'json_object_put' for 'obj'.
+ * Thus, in the case where 'obj' should remain available after
+ * the function returns, the function 'json_object_get' shall be used.
+ *
+ * @param req the request
+ * @param obj the replied object or NULL
+ * @param error the error message if it is a reply error or NULL
+ * @param info an informative text or NULL
+ *
+ * @see afb_req_reply_v
+ * @see afb_req_reply_f
+ */
+void afb_req_reply(
+			afb_req_t*req,
+			struct json_object *obj,
+			const char *error,
+			const char *info);
+```
+
+### afb_req_reply_v
+
+```C
+/**
+ * Same as 'afb_req_reply_f' but the arguments to the format 'info'
+ * are given as a variable argument list instance.
+ *
+ * For convenience, the function calls 'json_object_put' for 'obj'.
+ * Thus, in the case where 'obj' should remain available after
+ * the function returns, the function 'json_object_get' shall be used.
+ *
+ * @param req the request
+ * @param obj the replied object or NULL
+ * @param error the error message if it is a reply error or NULL
+ * @param info an informative text containing a format as for vprintf
+ * @param args the va_list of arguments to the format as for vprintf
+ *
+ * @see afb_req_reply
+ * @see afb_req_reply_f
+ * @see vprintf
+ */
+void afb_req_reply_v(
+			afb_req_t*req,
+			struct json_object *obj,
+			const char *error,
+			const char *info,
+			va_list args);
+```
+
+### afb_req_reply_f
+
+```C
+/**
+ * Same as 'afb_req_reply' but the 'info' is a formatting
+ * string followed by arguments.
+ *
+ * For convenience, the function calls 'json_object_put' for 'obj'.
+ * Thus, in the case where 'obj' should remain available after
+ * the function returns, the function 'json_object_get' shall be used.
+ *
+ * @param req the request
+ * @param obj the replied object or NULL
+ * @param error the error message if it is a reply error or NULL
+ * @param info an informative text containing a format as for printf
+ * @param ... the arguments to the format as for printf
+ *
+ * @see afb_req_reply
+ * @see afb_req_reply_v
+ * @see printf
+ */
+void afb_req_reply_f(
+			afb_req_t*req,
+			struct json_object *obj,
+			const char *error,
+			const char *info,
+			...);
+```
+
+## Subcall functions
+
+
+
+### afb_req_subcall
+
+```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
+ *  4. 'info'    a string handling some info (can be NULL)
+ *  5. 'req'     the req
+ *
+ * @param req      The request
+ * @param api      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 flags    The bit field of flags for the subcall as defined by @ref afb_req_subcall_flags_t
+ * @param callback The to call on completion
+ * @param closure  The closure to pass to the callback
+ *
+ * The flags are any combination of the following values:
+ *
+ *    - afb_req_x2_subcall_catch_events = 1
+ *
+ *        the calling API wants to receive the events from subscription
+ *
+ *    - afb_req_x2_subcall_pass_events = 2
+ *
+ *        the original request will receive the events from subscription
+ *
+ *    - afb_req_x2_subcall_on_behalf = 4
+ *
+ *        the calling API wants to use the credentials of the original request
+ *
+ *    - afb_req_x2_subcall_api_session = 8
+ *
+ *        the calling API wants to use its session instead of the one of the
+ *        original request
+ *
+ * @see also 'afb_req_subcall_sync'
+ */
+void afb_req_subcall(
+			afb_req_t*req,
+			const char *api,
+			const char *verb,
+			struct json_object *args,
+			int flags,
+			void (*callback)(
+					void *closure,
+					struct json_object *object,
+					const char *error,
+					const char * info,
+					afb_req_t*req),
+			void *closure);
+```
+
+### afb_req_subcall_sync
+
+```C
+/**
+ * Makes a call to the method of name 'api' / 'verb' with the object 'args'.
+ * This call is made in the context of the request 'req'.
+ * This call is synchronous, it waits untill completion of the request.
+ * It returns 0 on success or a negative value on error answer.
+ *
+ * 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.
+ *
+ * See also:
+ *  - 'afb_req_subcall_req' that is convenient to keep request alive automatically.
+ *  - 'afb_req_subcall' that doesn't keep request alive automatically.
+ *
+ * @param req      The request
+ * @param api      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 flags    The bit field of flags for the subcall as defined by @ref afb_req_subcall_flags
+ * @param object   a pointer where the replied JSON object is stored must be freed using @ref json_object_put (can be NULL)
+ * @param error    a pointer where a copy of the replied error is stored must be freed using @ref free (can be NULL)
+ * @param info     a pointer where a copy of the replied info is stored must be freed using @ref free (can be NULL)
+ *
+ * @return 0 in case of success or -1 in case of error
+ */
+int afb_req_subcall_sync(
+			afb_req_t*req,
+			const char *api,
+			const char *verb,
+			struct json_object *args,
+			int flags,
+			struct json_object **object,
+			char **error,
+			char **info);
+```
+
+## Event functions
+
+### afb_req_subscribe
+
+```C
+/**
+ * Establishes for the client link identified by 'req' a subscription
+ * to the 'event'.
+ *
+ * @param req the request
+ * @param event the event to subscribe
+ *
+ * @return 0 in case of successful subscription or -1 in case of error.
+ */
+int afb_req_subscribe(
+			afb_req_t*req,
+			afb_event_t event);
+```
+
+### afb_req_unsubscribe
+
+```C
+/**
+ * Revokes the subscription established to the 'event' for the client
+ * link identified by 'req'.
+ * Returns 0 in case of successful subscription or -1 in case of error.
+ *
+ * @param req the request
+ * @param event the event to revoke
+ *
+ * @return 0 in case of successful subscription or -1 in case of error.
+ */
+int afb_req_unsubscribe(
+			afb_req_t*req,
+			afb_event_t event);
+```
+
+## Session functions
+
+### afb_req_context
+
+```C
+/**
+ * Manage the pointer stored by the binding for the client session of 'req'.
+ *
+ * If no previous pointer is stored or if 'replace' is not zero, a new value
+ * is generated using the function 'create_context' called with the 'closure'.
+ * If 'create_context' is NULL the generated value is 'closure'.
+ *
+ * When a value is created, the function 'free_context' is recorded and will
+ * be called (with the created value as argument) to free the created value when
+ * it is not more used.
+ *
+ * This function is atomic: it ensures that 2 threads will not race together.
+ *
+ * @param req the request
+ * @param replace if not zero an existing value is replaced
+ * @param create_context the creation function or NULL
+ * @param free_context the destroying function or NULL
+ * @param closure the closure to the creation function
+ *
+ * @return the stored value
+ */
+void *afb_req_context(
+			afb_req_t*req,
+			int replace,
+			void *(*create_context)(void *closure),
+			void (*free_context)(void*),
+			void *closure);
+```
+
+### afb_req_context_get
+
+```C
+/**
+ * Gets the pointer stored by the binding for the session of 'req'.
+ * When the binding has not yet recorded a pointer, NULL is returned.
+ *
+ * Shortcut for: afb_req_context(req, 0, NULL, NULL, NULL)
+ *
+ * @param req the request
+ *
+ * @return the previously stored value
+ */
+void *afb_req_context_get(
+			afb_req_t*req);
+```
+
+### afb_req_context_set
+
+```C
+/**
+ * Stores for the binding the pointer 'context' to the session of 'req'.
+ * The function 'free_context' will be called when the session is closed
+ * or if binding stores an other pointer.
+ *
+ * Shortcut for: afb_req_context(req, 1, NULL, free_context, context)
+ *
+ *
+ * @param req the request
+ * @param context the context value to store
+ * @param free_context the cleaning function for the stored context (can be NULL)
+ */
+void afb_req_context_set(
+			afb_req_t*req,
+			void *context,
+			void (*free_context)(void*));
+```
+
+### afb_req_context_clear
+
+```C
+/**
+ * Frees the pointer stored by the binding for the session of 'req'
+ * and sets it to NULL.
+ *
+ * Shortcut for: afb_req_context_set(req, NULL, NULL)
+ *
+ * @param req the request
+ */
+void afb_req_context_clear(
+			afb_req_t*req);
+```
+
+### afb_req_session_close
+
+```C
+/**
+ * Closes the session associated with 'req'
+ * and delete all associated contexts.
+ *
+ * @param req the request
+ */
+void afb_req_session_close(
+			afb_req_t*req);
+```
+
+### afb_req_session_set_LOA
+
+```C
+/**
+ * Sets the level of assurance of the session of 'req'
+ * to 'level'. The effect of this function is subject of
+ * security policies.
+ *
+ * @param req the request
+ * @param level of assurance from 0 to 7
+ *
+ * @return 0 on success or -1 if failed.
+ */
+int afb_req_session_set_LOA(
+			afb_req_t*req,
+			unsigned level);
+```
+
+## Credential/client functions
+
+### afb_req_has_permission
+
+```C
+/**
+ * Check whether the 'permission' is granted or not to the client
+ * identified by 'req'.
+ *
+ * @param req the request
+ * @param permission string to check
+ *
+ * @return 1 if the permission is granted or 0 otherwise.
+ */
+int afb_req_has_permission(
+			afb_req_t*req,
+			const char *permission);
+```
+
+### afb_req_get_application_id
+
+```C
+/**
+ * Get the application identifier of the client application for the
+ * request 'req'.
+ *
+ * Returns the application identifier or NULL when the application
+ * can not be identified.
+ *
+ * The returned value if not NULL must be freed by the caller
+ *
+ * @param req the request
+ *
+ * @return the string for the application id of the client MUST BE FREED
+ */
+char *afb_req_get_application_id(
+			afb_req_t*req);
+```
+
+### afb_req_get_uid
+
+```C
+/**
+ * Get the user identifier (UID) of the client for the
+ * request 'req'.
+ *
+ * @param req the request
+ *
+ * @return -1 when the application can not be identified or the unix uid.
+ *
+ */
+int afb_req_get_uid(
+			afb_req_t*req);
+```
+
+### afb_req_get_client_info
+
+```C
+/**
+ * Get informations about the client of the
+ * request 'req'.
+ *
+ * Returns an object with client informations:
+ *  {
+ *    "pid": int, "uid": int, "gid": int,
+ *    "label": string, "id": string, "user": string,
+ *    "uuid": string, "LOA": int
+ *  }
+ *
+ * If some of this information can't be computed, the field of the return
+ * object will not be set at all.
+ *
+ * @param req the request
+ *
+ * @return a JSON object that must be freed using @ref json_object_put
+ */
+struct json_object *afb_req_get_client_info(
+			afb_req_t*req);
+```
+
+## Legacy functions
+
+### afb_req_subcall_legacy
+
+```C
+/**
+ * @deprecated use @ref afb_req_subcall
+ *
+ * Makes a call to the method of name 'api' / 'verb' with the object 'args'.
+ * This call is made in the context of the request 'req'.
+ * On completion, the function 'callback' is invoked with the
+ * 'closure' given at call and two other parameters: 'iserror' and 'result'.
+ * 'status' is 0 on success or negative when on an error reply.
+ * 'result' is the json object of the reply, you must not call json_object_put
+ * on the result.
+ *
+ * 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 req the request
+ * @param api the name of the api to call
+ * @param verb the name of the verb to call
+ * @param args the arguments of the call as a JSON object
+ * @param callback the call back that will receive the reply
+ * @param closure the closure passed back to the callback
+ *
+ * @see afb_req_subcall
+ * @see afb_req_subcall_sync
+ */
+void afb_req_subcall_legacy(
+			afb_req_t*req,
+			const char *api,
+			const char *verb,
+			struct json_object *args,
+			void (*callback)(
+					void *closure,
+					int iserror,
+					struct json_object *result,
+					afb_req_t*req),
+			void *closure);
+```
+
+### afb_req_subcall_sync_legacy
+
+```C
+/**
+ * @deprecated use @ref afb_req_subcall_sync
+ *
+ * Makes a call to the method of name 'api' / 'verb' with the object 'args'.
+ * This call is made in the context of the request 'req'.
+ * This call is synchronous, it waits untill completion of the request.
+ * It returns 0 on success or a negative value on error answer.
+ * The object pointed by 'result' is filled and must be released by the caller
+ * after its use by calling 'json_object_put'.
+ *
+ * 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 req the request
+ * @param api the name of the api to call
+ * @param verb the name of the verb to call
+ * @param args the arguments of the call as a JSON object
+ * @param result the pointer to the JSON object pointer that will receive the result
+ *
+ * @return 0 on success or a negative value on error answer.
+ *
+ * @see afb_req_subcall
+ * @see afb_req_subcall_sync
+ */
+int afb_req_subcall_sync_legacy(
+			afb_req_t*req,
+			const char *api,
+			const char *verb,
+			struct json_object *args,
+			struct json_object **result);
+```
+