afb-stub-ws: Enforce asynchronous describe

Because remote apis describe themselves asynchronousely,
it is better to have asynchronous describe api.

Bug-AGL: SPEC-2968

Change-Id: I52b4dab697f229ad01ea2b73d6b8dee22d507912
Signed-off-by: Jose Bollo <jose.bollo@iot.bzh>

6 files changed, 164 insertions, 128 deletions

diff --git a/src/afb-api.h b/src/afb-api.h
index d55970c9..1f2a4a98 100644
--- a/src/afb-api.h
+++ b/src/afb-api.h
@@ -30,7 +30,7 @@ struct afb_api_itf
 #endif
 	int (*get_logmask)(void *closure);
 	void (*set_logmask)(void *closure, int level);
-	struct json_object *(*describe)(void *closure);
+	void (*describe)(void *closure, void (*describecb)(void *, struct json_object *), void *clocb);
 	void (*unref)(void *closure);
 };
 
diff --git a/src/afb-apiset.c b/src/afb-apiset.c
index 0a8b3390..9fddd46c 100644
--- a/src/afb-apiset.c
+++ b/src/afb-apiset.c
@@ -28,6 +28,7 @@
 #include "afb-apiset.h"
 #include "afb-context.h"
 #include "afb-xreq.h"
+#include "jobs.h"
 
 #define INCR 8		/* CAUTION: must be a power of 2 */
 
@@ -941,20 +942,25 @@ int afb_apiset_get_logmask(struct afb_apiset *set, const char *name)
 	return i->api.itf->get_logmask(i->api.closure);
 }
 
-/**
- * Get the description of the API of 'name'
- * @param set the api set
- * @param name the api whose description is required
- * @return the description or NULL
- */
-struct json_object *afb_apiset_describe(struct afb_apiset *set, const char *name)
+void afb_apiset_describe(struct afb_apiset *set, const char *name, void (*describecb)(void *, struct json_object *), void *closure)
 {
 	const struct api_desc *i;
-
-	i = name ? searchrec(set, name) : NULL;
-	return i && i->api.itf->describe ? i->api.itf->describe(i->api.closure) : NULL;
+	struct json_object *r;
+
+	r = NULL;
+	if (name) {
+		i = searchrec(set, name);
+		if (i) {
+			if (i->api.itf->describe) {
+				i->api.itf->describe(i->api.closure, describecb, closure);
+				return;
+			}
+		}
+	}
+	describecb(closure, r);
 }
 
+
 struct get_names {
 	union  {
 		struct {
diff --git a/src/afb-apiset.h b/src/afb-apiset.h
index d1f968b7..f21277a5 100644
--- a/src/afb-apiset.h
+++ b/src/afb-apiset.h
@@ -60,7 +60,7 @@ extern void afb_apiset_update_hooks(struct afb_apiset *set, const char *name);
 extern void afb_apiset_set_logmask(struct afb_apiset *set, const char *name, int mask);
 extern int afb_apiset_get_logmask(struct afb_apiset *set, const char *name);
 
-extern struct json_object *afb_apiset_describe(struct afb_apiset *set, const char *name);
+extern void afb_apiset_describe(struct afb_apiset *set, const char *name, void (*describecb)(void *, struct json_object *), void *closure);
 
 extern const char **afb_apiset_get_names(struct afb_apiset *set, int rec, int type);
 extern void afb_apiset_enum(
diff --git a/src/afb-export.c b/src/afb-export.c
index a9643f54..f96f8f81 100644
--- a/src/afb-export.c
+++ b/src/afb-export.c
@@ -1823,7 +1823,7 @@ static void api_call_cb(void *closure, struct afb_xreq *xreq)
 	}
 }
 
-static struct json_object *api_describe_cb(void *closure)
+static void api_describe_cb(void *closure, void (*describecb)(void *, struct json_object *), void *clocb)
 {
 	struct afb_export *export = closure;
 	struct json_object *result;
@@ -1846,7 +1846,7 @@ static struct json_object *api_describe_cb(void *closure)
 		result = NULL;
 		break;
 	}
-	return result;
+	describecb(clocb, result);
 }
 
 static int api_service_start_cb(void *closure)
diff --git a/src/afb-monitor.c b/src/afb-monitor.c
index e32c85ac..a53f75a3 100644
--- a/src/afb-monitor.c
+++ b/src/afb-monitor.c
@@ -36,6 +36,17 @@
 
 #include "monitor-api.inc"
 
+
+static const char _verbosity_[] = "verbosity";
+static const char _apis_[] = "apis";
+
+static const char _debug_[] = "debug";
+static const char _info_[] = "info";
+static const char _notice_[] = "notice";
+static const char _warning_[] = "warning";
+static const char _error_[] = "error";
+
+
 static struct afb_apiset *target_set;
 
 int afb_monitor_init(struct afb_apiset *declare_set, struct afb_apiset *call_set)
@@ -48,12 +59,6 @@ int afb_monitor_init(struct afb_apiset *declare_set, struct afb_apiset *call_set
 **** Monitoring verbosity
 ******************************************************************************/
 
-static const char _debug_[] = "debug";
-static const char _info_[] = "info";
-static const char _notice_[] = "notice";
-static const char _warning_[] = "warning";
-static const char _error_[] = "error";
-
 /**
  * Translate verbosity indication to an integer value.
  * @param v the verbosity indication
@@ -231,72 +236,141 @@ static struct json_object *get_verbosity(struct json_object *spec)
 }
 
 /******************************************************************************
-**** Monitoring apis
+**** Manage namelist of api names
 ******************************************************************************/
 
-/**
- * get apis accordling to specification in 'spec'
- * @param resu the json object to build
- * @param spec specification of the verbosity to set
- */
-static void get_one_api(struct json_object *resu, const char *name, struct json_object *spec)
+struct namelist {
+	struct namelist *next;
+	json_object *data;
+	char name[];
+};
+
+static struct namelist *reverse_namelist(struct namelist *head)
 {
-	struct json_object *o;
+	struct namelist *previous, *next;
+
+	previous = NULL;
+	while(head) {
+		next = head->next;
+		head->next = previous;
+		previous = head;
+		head = next;
+	}
+	return previous;
+}
 
-	o = afb_apiset_describe(target_set, name);
-	if (o || afb_apiset_lookup(target_set, name, 1))
-		json_object_object_add(resu, name, o);
+static void add_one_name_to_namelist(struct namelist **head, const char *name, struct json_object *data)
+{
+	size_t length = strlen(name) + 1;
+	struct namelist *item = malloc(length + sizeof *item);
+	if (!item)
+		ERROR("out of memory");
+	else {
+		item->next = *head;
+		item->data = data;
+		memcpy(item->name, name, length);
+		*head = item;
+	}
 }
 
-/**
- * callback for getting verbosity of all apis
- * @param set the apiset
- * @param the name of the api to set
- * @param closure the json object to build
- */
-static void get_apis_of_all_cb(void *closure, struct afb_apiset *set, const char *name, int isalias)
+static void get_apis_namelist_of_all_cb(void *closure, struct afb_apiset *set, const char *name, int isalias)
 {
-	struct json_object *resu = closure;
-	get_one_api(resu, name, NULL);
+	struct namelist **head = closure;
+	add_one_name_to_namelist(head, name, NULL);
 }
 
 /**
- * get apis accordling to specification in 'spec'
- * @param resu the json object to build
- * @param spec specification of the verbosity to set
+ * get apis names as a list accordling to specification in 'spec'
+ * @param spec specification of the apis to get
  */
-static struct json_object *get_apis(struct json_object *spec)
+static struct namelist *get_apis_namelist(struct json_object *spec)
 {
 	int i, n;
-	struct json_object *resu;
 	struct json_object_iterator it, end;
+	struct namelist *head;
 
-	resu = json_object_new_object();
+	head = NULL;
 	if (json_object_is_type(spec, json_type_object)) {
 		it = json_object_iter_begin(spec);
 		end = json_object_iter_end(spec);
 		while (!json_object_iter_equal(&it, &end)) {
-			get_one_api(resu, json_object_iter_peek_name(&it), json_object_iter_peek_value(&it));
+			add_one_name_to_namelist(&head,
+						 json_object_iter_peek_name(&it),
+						 json_object_iter_peek_value(&it));
 			json_object_iter_next(&it);
 		}
 	} else if (json_object_is_type(spec, json_type_array)) {
 		n = (int)json_object_array_length(spec);
 		for (i = 0 ; i < n ; i++)
-			get_one_api(resu, json_object_get_string(json_object_array_get_idx(spec, i)), NULL);
+			add_one_name_to_namelist(&head,
+						 json_object_get_string(
+							 json_object_array_get_idx(spec, i)),
+						 NULL);
 	} else if (json_object_is_type(spec, json_type_string)) {
-		get_one_api(resu, json_object_get_string(spec), NULL);
+		add_one_name_to_namelist(&head, json_object_get_string(spec), NULL);
 	} else if (json_object_get_boolean(spec)) {
-		afb_apiset_enum(target_set, 1, get_apis_of_all_cb, resu);
+		afb_apiset_enum(target_set, 1, get_apis_namelist_of_all_cb, &head);
 	}
-	return resu;
+	return reverse_namelist(head);
 }
 
 /******************************************************************************
-**** Implementation monitoring verbs
+**** Monitoring apis
 ******************************************************************************/
 
-static const char _verbosity_[] = "verbosity";
-static const char _apis_[] = "apis";
+struct desc_apis {
+	struct namelist *names;
+	struct json_object *resu;
+	struct json_object *apis;
+	afb_req_t req;
+};
+
+static void describe_first_api(struct desc_apis *desc);
+
+static void on_api_description(void *closure, struct json_object *apidesc)
+{
+	struct desc_apis *desc = closure;
+	struct namelist *head = desc->names;
+
+	if (apidesc || afb_apiset_lookup(target_set, head->name, 1))
+		json_object_object_add(desc->apis, head->name, apidesc);
+	desc->names = head->next;
+	free(head);
+	describe_first_api(desc);
+}
+
+static void describe_first_api(struct desc_apis *desc)
+{
+	struct namelist *head = desc->names;
+	if (head)
+		afb_apiset_describe(target_set, head->name, on_api_description, desc);
+	else {
+		afb_req_success(desc->req, desc->resu, NULL);
+		afb_req_unref(desc->req);
+		free(desc);
+	}
+}
+
+static void describe_apis(afb_req_t req, struct json_object *resu, struct json_object *spec)
+{
+	struct desc_apis *desc;
+
+	desc = malloc(sizeof *desc);
+	if (!desc)
+		afb_req_fail(req, "out-of-memory", NULL);
+	else {
+		desc->req = afb_req_addref(req);
+		desc->resu = resu;
+		desc->apis = json_object_new_object();
+		json_object_object_add(desc->resu, _apis_, desc->apis);
+		desc->names = get_apis_namelist(spec);
+		describe_first_api(desc);
+	}
+}
+
+/******************************************************************************
+**** Implementation monitoring verbs
+******************************************************************************/
 
 static void f_get(afb_req_t req)
 {
@@ -305,13 +379,23 @@ static void f_get(afb_req_t req)
 	struct json_object *verbosity = NULL;
 
 	wrap_json_unpack(afb_req_json(req), "{s?:o,s?:o}", _verbosity_, &verbosity, _apis_, &apis);
-	if (verbosity)
-		verbosity = get_verbosity(verbosity);
-	if (apis)
-		apis = get_apis(apis);
-
-	wrap_json_pack(&r, "{s:o*,s:o*}", _verbosity_, verbosity, _apis_, apis);
-	afb_req_success(req, r, NULL);
+	if (!verbosity && !apis)
+		afb_req_success(req, NULL, NULL);
+	else {
+		r = json_object_new_object();
+		if (!r)
+			afb_req_fail(req, "out-of-memory", NULL);
+		else {
+			if (verbosity) {
+				verbosity = get_verbosity(verbosity);
+				json_object_object_add(r, _verbosity_, verbosity);
+			}
+			if (!apis)
+				afb_req_success(req, r, NULL);
+			else
+				describe_apis(req, r, apis);
+		}
+	}
 }
 
 static void f_set(afb_req_t req)
diff --git a/src/afb-stub-ws.c b/src/afb-stub-ws.c
index 2a48745b..9bd8ed63 100644
--- a/src/afb-stub-ws.c
+++ b/src/afb-stub-ws.c
@@ -71,16 +71,6 @@ struct client_event
 };
 
 /**
- * structure for recording describe requests on the client side
- */
-struct client_describe
-{
-	struct afb_stub_ws *stubws;	/**< the stub */
-	struct jobloop *jobloop;	/**< the jobloop to leave */
-	struct json_object *result;	/**< result */
-};
-
-/**
  * structure for jobs of describing
  */
 struct server_describe
@@ -280,38 +270,17 @@ static void client_api_call_cb(void * closure, struct afb_xreq *xreq)
 	}
 }
 
-static void client_on_description_cb(void *closure, struct json_object *data)
-{
-	struct client_describe *desc = closure;
-
-	desc->result = data;
-	jobs_leave(desc->jobloop);
-}
-
-static void client_send_describe_cb(int signum, void *closure, struct jobloop *jobloop)
-{
-	struct client_describe *desc = closure;
-	struct afb_proto_ws *proto;
-
-	proto = client_get_proto(desc->stubws);
-	if (signum || proto == NULL)
-		jobs_leave(jobloop);
-	else {
-		desc->jobloop = jobloop;
-		afb_proto_ws_client_describe(proto, client_on_description_cb, desc);
-	}
-}
-
 /* get the description */
-static struct json_object *client_api_describe_cb(void * closure)
+static void client_api_describe_cb(void * closure, void (*describecb)(void *, struct json_object *), void *clocb)
 {
-	struct client_describe desc;
+	struct afb_stub_ws *stubws = closure;
+	struct afb_proto_ws *proto;
 
-	/* synchronous job: send the request and wait its result */
-	desc.stubws = closure;
-	desc.result = NULL;
-	jobs_enter(NULL, 0, client_send_describe_cb, &desc);
-	return desc.result;
+	proto = client_get_proto(stubws);
+	if (proto)
+		afb_proto_ws_client_describe(proto, describecb, clocb);
+	else
+		describecb(clocb, NULL);
 }
 
 /******************* server part: manage events **********************************/
@@ -546,42 +515,19 @@ out_of_memory:
 	afb_proto_ws_call_unref(call);
 }
 
-static void server_describe_cb(int signum, void *closure)
+static void server_on_description_cb(void *closure, struct json_object *description)
 {
-	struct json_object *obj;
-	struct server_describe *desc = closure;
-
-	/* get the description if possible */
-	obj = !signum ? afb_apiset_describe(desc->stubws->apiset, desc->stubws->apiname) : NULL;
-
-	/* send it */
-	afb_proto_ws_describe_put(desc->describe, obj);
-	json_object_put(obj);
-	afb_stub_ws_unref(desc->stubws);
+	struct afb_proto_ws_describe *describe = closure;
+	afb_proto_ws_describe_put(describe, description);
+	json_object_put(description);
 }
 
-static void server_describe_job(int signum, void *closure)
-{
-	server_describe_cb(signum, closure);
-	free(closure);
-}
 
 static void server_on_describe_cb(void *closure, struct afb_proto_ws_describe *describe)
 {
-	struct server_describe *desc, sdesc;
 	struct afb_stub_ws *stubws = closure;
 
-	/* allocate (if possible) and init */
-	desc = malloc(sizeof *desc);
-	if (desc == NULL)
-		desc = &sdesc;
-	desc->stubws = stubws;
-	desc->describe = describe;
-	afb_stub_ws_addref(stubws);
-
-	/* process */
-	if (desc == &sdesc || jobs_queue(NULL, 0, server_describe_job, desc) < 0)
-		jobs_call(NULL, 0, server_describe_cb, desc);
+	afb_apiset_describe(stubws->apiset, stubws->apiname, server_on_description_cb, describe);
 }
 
 /*****************************************************/