Provide efficient store/unstore for afb_req

Change-Id: I231e2506f58227fb8d192df042539b1551a765c5
Signed-off-by: José Bollo <jose.bollo@iot.bzh>

1 files changed, 400 insertions, 0 deletions

diff --git a/include/afb/afb-req-common.h b/include/afb/afb-req-common.h
new file mode 100644
index 00000000..8ff1b39b
--- /dev/null
+++ b/include/afb/afb-req-common.h
@@ -0,0 +1,400 @@
+/*
+ * Copyright (C) 2016, 2017 "IoT.bzh"
+ * Author: José Bollo <jose.bollo@iot.bzh>
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+#include <stdarg.h>
+
+#include "afb-event-itf.h"
+
+struct json_object;
+struct afb_stored_req;
+
+/*
+ * Describes an argument (or parameter) of a request
+ */
+struct afb_arg
+{
+	const char *name;	/* name of the argument or NULL if invalid */
+	const char *value;	/* string representation of the value of the argument */
+				/* original filename of the argument if path != NULL */
+	const char *path;	/* if not NULL, path of the received file for the argument */
+				/* when the request is finalized this file is removed */
+};
+
+/*
+ * Interface for handling requests.
+ * It records the functions to be called for the request.
+ * Don't use this structure directly.
+ * Use the helper functions documented below.
+ */
+struct afb_req_itf
+{
+	/* CAUTION: respect the order, add at the end */
+
+	struct json_object *(*json)(void *closure);
+	struct afb_arg (*get)(void *closure, const char *name);
+
+	void (*success)(void *closure, struct json_object *obj, const char *info);
+	void (*fail)(void *closure, const char *status, const char *info);
+
+	void (*vsuccess)(void *closure, struct json_object *obj, const char *fmt, va_list args);
+	void (*vfail)(void *closure, const char *status, const char *fmt, va_list args);
+
+	void *(*context_get)(void *closure);
+	void (*context_set)(void *closure, void *value, void (*free_value)(void*));
+
+	void (*addref)(void *closure);
+	void (*unref)(void *closure);
+
+	void (*session_close)(void *closure);
+	int (*session_set_LOA)(void *closure, unsigned level);
+
+	int (*subscribe)(void *closure, struct afb_event event);
+	int (*unsubscribe)(void *closure, struct afb_event event);
+
+	void (*subcall)(void *closure, const char *api, const char *verb, struct json_object *args, void (*callback)(void*, int, struct json_object*), void *cb_closure);
+	int (*subcallsync)(void *closure, const char *api, const char *verb, struct json_object *args, struct json_object **result);
+
+	void (*vverbose)(void *closure, int level, const char *file, int line, const char * func, const char *fmt, va_list args);
+	struct afb_stored_req *(*store)(void *closure);
+};
+
+/*
+ * Describes the request by bindings from afb-daemon
+ */
+struct afb_req
+{
+	const struct afb_req_itf *itf;	/* the interface to use */
+	void *closure;			/* the closure argument for functions of 'itf' */
+};
+
+/*
+ * Checks wether the request 'req' is valid or not.
+ *
+ * Returns 0 if not valid or 1 if valid.
+ */
+static inline int afb_req_is_valid(struct afb_req req)
+{
+	return req.itf != NULL;
+}
+
+/*
+ * 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.
+ */
+static inline struct afb_arg afb_req_get(struct afb_req req, const char *name)
+{
+	return req.itf->get(req.closure, name);
+}
+
+/*
+ * 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
+ */
+static inline const char *afb_req_value(struct afb_req req, const char *name)
+{
+	return afb_req_get(req, name).value;
+}
+
+/*
+ * 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
+ */
+static inline const char *afb_req_path(struct afb_req req, const char *name)
+{
+	return afb_req_get(req, name).path;
+}
+
+/*
+ * Gets from the request 'req' the json object hashing the arguments.
+ * The returned object must not be released using 'json_object_put'.
+ */
+static inline struct json_object *afb_req_json(struct afb_req req)
+{
+	return req.itf->json(req.closure);
+}
+
+/*
+ * Sends a reply of kind success to the request 'req'.
+ * The status of the reply is automatically set to "success".
+ * Its send the object 'obj' (can be NULL) with an
+ * informationnal 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.
+ */
+static inline void afb_req_success(struct afb_req req, struct json_object *obj, const char *info)
+{
+	req.itf->success(req.closure, obj, info);
+}
+
+/*
+ * Same as 'afb_req_success' 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.
+ */
+static inline void afb_req_success_f(struct afb_req req, struct json_object *obj, const char *info, ...) __attribute__((format(printf, 3, 4)));
+static inline void afb_req_success_f(struct afb_req req, struct json_object *obj, const char *info, ...)
+{
+	va_list args;
+	va_start(args, info);
+	req.itf->vsuccess(req.closure, obj, info, args);
+	va_end(args);
+}
+
+/*
+ * Same as 'afb_req_success_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.
+ */
+static inline void afb_req_success_v(struct afb_req req, struct json_object *obj, const char *info, va_list args)
+{
+	req.itf->vsuccess(req.closure, obj, info, args);
+}
+
+/*
+ * Sends a reply of kind failure to the request 'req'.
+ * The status of the reply is set to 'status' and an
+ * informationnal comment 'info' (can also be NULL) can be added.
+ *
+ * Note that calling afb_req_fail("success", info) is equivalent
+ * to call afb_req_success(NULL, info). Thus even if possible it
+ * is strongly recommanded to NEVER use "success" for status.
+ */
+static inline void afb_req_fail(struct afb_req req, const char *status, const char *info)
+{
+	req.itf->fail(req.closure, status, info);
+}
+
+/*
+ * Same as 'afb_req_fail' but the 'info' is a formatting
+ * string followed by arguments.
+ */
+static inline void afb_req_fail_f(struct afb_req req, const char *status, const char *info, ...) __attribute__((format(printf, 3, 4)));
+static inline void afb_req_fail_f(struct afb_req req, const char *status, const char *info, ...)
+{
+	va_list args;
+	va_start(args, info);
+	req.itf->vfail(req.closure, status, info, args);
+	va_end(args);
+}
+
+/*
+ * Same as 'afb_req_fail_f' but the arguments to the format 'info'
+ * are given as a variable argument list instance.
+ */
+static inline void afb_req_fail_v(struct afb_req req, const char *status, const char *info, va_list args)
+{
+	req.itf->vfail(req.closure, status, info, args);
+}
+
+/*
+ * Gets the pointer stored by the binding for the session of 'req'.
+ * When the binding has not yet recorded a pointer, NULL is returned.
+ */
+static inline void *afb_req_context_get(struct afb_req req)
+{
+	return req.itf->context_get(req.closure);
+}
+
+/*
+ * 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.
+ */
+static inline void afb_req_context_set(struct afb_req req, void *context, void (*free_context)(void*))
+{
+	req.itf->context_set(req.closure, context, free_context);
+}
+
+/*
+ * Gets the pointer stored by the binding for the session of 'req'.
+ * If the stored pointer is NULL, indicating that no pointer was
+ * already stored, afb_req_context creates a new context by calling
+ * the function 'create_context' and stores it with the freeing function
+ * 'free_context'.
+ */
+static inline void *afb_req_context(struct afb_req req, void *(*create_context)(), void (*free_context)(void*))
+{
+	void *result = afb_req_context_get(req);
+	if (result == NULL) {
+		result = create_context();
+		afb_req_context_set(req, result, free_context);
+	}
+	return result;
+}
+
+/*
+ * 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)
+ */
+static inline void afb_req_context_clear(struct afb_req req)
+{
+	afb_req_context_set(req, NULL, NULL);
+}
+
+/*
+ * Adds one to the count of references of 'req'.
+ * This function MUST be called by asynchronous implementations
+ * of verbs if no reply was sent before returning.
+ */
+static inline void afb_req_addref(struct afb_req req)
+{
+	req.itf->addref(req.closure);
+}
+
+/*
+ * Substracts one to the count of references of 'req'.
+ * This function MUST be called by asynchronous implementations
+ * of verbs after sending the asynchronous reply.
+ */
+static inline void afb_req_unref(struct afb_req req)
+{
+	req.itf->unref(req.closure);
+}
+
+/*
+ * Closes the session associated with 'req'
+ * and delete all associated contexts.
+ */
+static inline void afb_req_session_close(struct afb_req req)
+{
+	req.itf->session_close(req.closure);
+}
+
+/*
+ * Sets the level of assurance of the session of 'req'
+ * to 'level'. The effect of this function is subject of
+ * security policies.
+ * Returns 1 on success or 0 if failed.
+ */
+static inline int afb_req_session_set_LOA(struct afb_req req, unsigned level)
+{
+	return req.itf->session_set_LOA(req.closure, level);
+}
+
+/*
+ * Establishes for the client link identified by 'req' a subscription
+ * to the 'event'.
+ * Returns 0 in case of successful subscription or -1 in case of error.
+ */
+static inline int afb_req_subscribe(struct afb_req req, struct afb_event event)
+{
+	return req.itf->subscribe(req.closure, event);
+}
+
+/*
+ * 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.
+ */
+static inline int afb_req_unsubscribe(struct afb_req req, struct afb_event event)
+{
+	return req.itf->unsubscribe(req.closure, event);
+}
+
+/*
+ * 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'.
+ * 'iserror' is a boolean that indicates if the reply is 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.
+ */
+static inline void afb_req_subcall(struct afb_req req, const char *api, const char *verb, struct json_object *args, void (*callback)(void *closure, int iserror, struct json_object *result), void *closure)
+{
+	req.itf->subcall(req.closure, api, verb, args, callback, closure);
+}
+
+/*
+ * 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 an error answer and returns 1 when no error was detected.
+ * 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.
+ */
+static inline int afb_req_subcall_sync(struct afb_req req, const char *api, const char *verb, struct json_object *args, struct json_object **result)
+{
+	return req.itf->subcallsync(req.closure, api, verb, args, result);
+}
+
+/*
+ * 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
+ */
+static inline void afb_req_verbose(struct afb_req req, int level, const char *file, int line, const char * func, const char *fmt, ...) __attribute__((format(printf, 6, 7)));
+static inline void afb_req_verbose(struct afb_req req, int level, const char *file, int line, const char * func, const char *fmt, ...)
+{
+	va_list args;
+	va_start(args, fmt);
+	req.itf->vverbose(req.closure, level, file, line, func, fmt, args);
+	va_end(args);
+}
+
+/* macro for setting file, line and function automatically */
+# if !defined(AFB_BINDING_PRAGMA_NO_VERBOSE_DETAILS)
+#define AFB_REQ_VERBOSE(req,level,...) afb_req_verbose(req,level,__FILE__,__LINE__,__func__,__VA_ARGS__)
+#else
+#define AFB_REQ_VERBOSE(req,level,...) afb_req_verbose(req,level,NULL,0,NULL,__VA_ARGS__)
+#endif