hooking: Add hook at global scope

Actually the global scope only allows to trace
log messages.

Change-Id: Ib73edf2e3168311b2ad694d857e6647e34884313
Signed-off-by: José Bollo <jose.bollo@iot.bzh>

9 files changed, 271 insertions, 12 deletions

diff --git a/src/afb-hook.c b/src/afb-hook.c
index a07d8426..14076281 100644
--- a/src/afb-hook.c
+++ b/src/afb-hook.c
@@ -90,6 +90,17 @@ struct afb_hook_evt {
 	void *closure; /**< closure for callbacks */
 };
 
+/**
+ * Definition of a hook for global
+ */
+struct afb_hook_global {
+	struct afb_hook_global *next; /**< next hook */
+	unsigned refcount; /**< reference count */
+	unsigned flags; /**< hook flags */
+	struct afb_hook_global_itf *itf; /**< interface of hook */
+	void *closure; /**< closure for callbacks */
+};
+
 /* synchronisation across threads */
 static pthread_rwlock_t rwlock = PTHREAD_RWLOCK_INITIALIZER;
 
@@ -105,6 +116,9 @@ static struct afb_hook_svc *list_of_svc_hooks = NULL;
 /* list of hooks for evt */
 static struct afb_hook_evt *list_of_evt_hooks = NULL;
 
+/* list of hooks for global */
+static struct afb_hook_global *list_of_global_hooks = NULL;
+
 /* hook id */
 static unsigned next_hookid = 0;
 
@@ -1159,7 +1173,7 @@ static struct afb_hook_evt_itf hook_evt_default_itf = {
 };
 
 /******************************************************************************
- * section: hooks for tracing service interface (evt)
+ * section: hooks for tracing events interface (evt)
  *****************************************************************************/
 
 #define _HOOK_EVT_(what,...)   \
@@ -1300,3 +1314,144 @@ void afb_hook_unref_evt(struct afb_hook_evt *hook)
 		}
 	}
 }
+
+/******************************************************************************
+ * section: default callbacks for globals (global)
+ *****************************************************************************/
+
+static void _hook_global_(const char *format, ...)
+{
+	va_list ap;
+	va_start(ap, format);
+	_hook_("global", format, ap);
+	va_end(ap);
+}
+
+static void hook_global_vverbose_default_cb(void *closure, const struct afb_hookid *hookid, int level, const char *file, int line, const char *func, const char *fmt, va_list args)
+{
+	int len;
+	char *msg;
+	va_list ap;
+
+	va_copy(ap, args);
+	len = vasprintf(&msg, fmt, ap);
+	va_end(ap);
+
+	if (len < 0)
+		_hook_global_("vverbose(%d, %s, %d, %s) -> %s ? ? ?", level, file, line, func, fmt);
+	else {
+		_hook_global_("vverbose(%d, %s, %d, %s) -> %s", level, file, line, func, msg);
+		free(msg);
+	}
+}
+
+static struct afb_hook_global_itf hook_global_default_itf = {
+	.hook_global_vverbose = hook_global_vverbose_default_cb
+};
+
+/******************************************************************************
+ * section: hooks for tracing globals (global)
+ *****************************************************************************/
+
+#define _HOOK_GLOBAL_(what,...)   \
+	struct afb_hook_global *hook; \
+	struct afb_hookid hookid; \
+	pthread_rwlock_rdlock(&rwlock); \
+	init_hookid(&hookid); \
+	hook = list_of_global_hooks; \
+	while (hook) { \
+		if (hook->itf->hook_global_##what \
+		 && (hook->flags & afb_hook_flag_global_##what) != 0) { \
+			hook->itf->hook_global_##what(hook->closure, &hookid, __VA_ARGS__); \
+		} \
+		hook = hook->next; \
+	} \
+	pthread_rwlock_unlock(&rwlock);
+
+static void afb_hook_global_vverbose(int level, const char *file, int line, const char *func, const char *fmt, va_list args)
+{
+	_HOOK_GLOBAL_(vverbose, level, file ?: "?", line, func ?: "?", fmt, args);
+}
+
+/******************************************************************************
+ * section: hooking globals (global)
+ *****************************************************************************/
+
+static void update_global()
+{
+	struct afb_hook_global *hook;
+	int flags = 0;
+
+	pthread_rwlock_rdlock(&rwlock);
+	hook = list_of_global_hooks;
+	while (hook) {
+		flags = hook->flags;
+		hook = hook->next;
+	}
+	verbose_observer = (flags & afb_hook_flag_global_vverbose) ? afb_hook_global_vverbose : NULL;
+	pthread_rwlock_unlock(&rwlock);
+}
+
+struct afb_hook_global *afb_hook_create_global(int flags, struct afb_hook_global_itf *itf, void *closure)
+{
+	struct afb_hook_global *hook;
+
+	/* alloc the result */
+	hook = calloc(1, sizeof *hook);
+	if (hook == NULL)
+		return NULL;
+
+	/* initialise the rest */
+	hook->refcount = 1;
+	hook->flags = flags;
+	hook->itf = itf ? itf : &hook_global_default_itf;
+	hook->closure = closure;
+
+	/* record the hook */
+	pthread_rwlock_wrlock(&rwlock);
+	hook->next = list_of_global_hooks;
+	list_of_global_hooks = hook;
+	pthread_rwlock_unlock(&rwlock);
+
+	/* update hooking */
+	update_global();
+
+	/* returns it */
+	return hook;
+}
+
+struct afb_hook_global *afb_hook_addref_global(struct afb_hook_global *hook)
+{
+	pthread_rwlock_wrlock(&rwlock);
+	hook->refcount++;
+	pthread_rwlock_unlock(&rwlock);
+	return hook;
+}
+
+void afb_hook_unref_global(struct afb_hook_global *hook)
+{
+	struct afb_hook_global **prv;
+
+	if (hook) {
+		pthread_rwlock_wrlock(&rwlock);
+		if (--hook->refcount)
+			hook = NULL;
+		else {
+			/* unlink */
+			prv = &list_of_global_hooks;
+			while (*prv && *prv != hook)
+				prv = &(*prv)->next;
+			if(*prv)
+				*prv = hook->next;
+		}
+		pthread_rwlock_unlock(&rwlock);
+		if (hook) {
+			/* free */
+			free(hook);
+
+			/* update hooking */
+			update_global();
+		}
+	}
+}
+
diff --git a/src/afb-hook.h b/src/afb-hook.h
index 8f7f61d1..43341242 100644
--- a/src/afb-hook.h
+++ b/src/afb-hook.h
@@ -32,6 +32,11 @@ struct afb_svc;
 struct afb_stored_req;
 struct sd_bus;
 struct sd_event;
+struct afb_hook_xreq;
+struct afb_hook_ditf;
+struct afb_hook_svc;
+struct afb_hook_evt;
+struct afb_hook_global;
 
 /*********************************************************
 * section hookid
@@ -45,7 +50,6 @@ struct afb_hookid
 /*********************************************************
 * section hooking xreq
 *********************************************************/
-struct afb_hook_xreq;
 
 /* individual flags */
 #define afb_hook_flag_req_begin			0x000001
@@ -301,7 +305,23 @@ extern void afb_hook_evt_name(const char *evt, int id);
 extern void afb_hook_evt_drop(const char *evt, int id);
 
 extern int afb_hook_flags_evt(const char *name);
-extern struct afb_hook_evt *afb_hook_create_evt(const char *name, int flags, struct afb_hook_evt_itf *itf, void *closure);
+extern struct afb_hook_evt *afb_hook_create_evt(const char *pattern, int flags, struct afb_hook_evt_itf *itf, void *closure);
 extern struct afb_hook_evt *afb_hook_addref_evt(struct afb_hook_evt *hook);
 extern void afb_hook_unref_evt(struct afb_hook_evt *hook);
 
+/*********************************************************
+* section hooking global (global interface)
+*********************************************************/
+
+#define afb_hook_flag_global_vverbose			0x000001
+
+#define afb_hook_flags_global_all	(afb_hook_flag_global_vverbose)
+
+struct afb_hook_global_itf {
+	void (*hook_global_vverbose)(void *closure, const struct afb_hookid *hookid, int level, const char *file, int line, const char *function, const char *fmt, va_list args);
+};
+
+extern struct afb_hook_global *afb_hook_create_global(int flags, struct afb_hook_global_itf *itf, void *closure);
+extern struct afb_hook_global *afb_hook_addref_global(struct afb_hook_global *hook);
+extern void afb_hook_unref_global(struct afb_hook_global *hook);
+
diff --git a/src/afb-trace.c b/src/afb-trace.c
index bc2de6d2..2d098407 100644
--- a/src/afb-trace.c
+++ b/src/afb-trace.c
@@ -98,6 +98,7 @@ enum trace_type
 	Trace_Type_Ditf,	/* ditf hooks */
 	Trace_Type_Svc,		/* svc hooks */
 	Trace_Type_Evt,		/* evt hooks */
+	Trace_Type_Global,	/* global hooks */
 	Trace_Type_Count	/* count of types of hooks */
 };
 
@@ -821,6 +822,60 @@ static struct afb_hook_evt_itf hook_evt_itf = {
 };
 
 /*******************************************************************************/
+/*****  trace the globals                                                  *****/
+/*******************************************************************************/
+
+static struct flag global_flags[] = { /* must be sorted by names */
+		{ "all",		afb_hook_flags_global_all },
+		{ "vverbose",		afb_hook_flag_global_vverbose },
+};
+
+/* get the global value for flag of 'name' */
+static int get_global_flag(const char *name)
+{
+	return get_flag(name, global_flags, (int)(sizeof global_flags / sizeof *global_flags));
+}
+
+static void hook_global(void *closure, const struct afb_hookid *hookid, const char *action, const char *format, ...)
+{
+	va_list ap;
+
+	va_start(ap, format);
+	emit(closure, hookid, "global", "{ss}", format, ap, "action", action);
+	va_end(ap);
+}
+
+static void hook_global_vverbose(void *closure, const struct afb_hookid *hookid, int level, const char *file, int line, const char *function, const char *fmt, va_list args)
+{
+	struct json_object *pos;
+	int len;
+	char *msg;
+	va_list ap;
+
+	pos = NULL;
+	msg = NULL;
+
+	va_copy(ap, args);
+	len = vasprintf(&msg, fmt, ap);
+	va_end(ap);
+
+	if (file)
+		wrap_json_pack(&pos, "{ss si ss*}", "file", file, "line", line, "function", function);
+
+	hook_global(closure, hookid, "vverbose", "{si ss* ss? so*}",
+					"level", level,
+ 					"type", verbosity_level_name(level),
+					len < 0 ? "format" : "message", len < 0 ? fmt : msg,
+					"position", pos);
+
+	free(msg);
+}
+
+static struct afb_hook_global_itf hook_global_itf = {
+	.hook_global_vverbose = hook_global_vverbose,
+};
+
+/*******************************************************************************/
 /*****  abstract types                                                     *****/
 /*******************************************************************************/
 
@@ -856,7 +911,13 @@ abstracting[Trace_Type_Count] =
 		.name = "event",
 		.unref =  (void(*)(void*))afb_hook_unref_evt,
 		.get_flag = get_evt_flag
-	}
+	},
+	[Trace_Type_Global] =
+	{
+		.name = "global",
+		.unref =  (void(*)(void*))afb_hook_unref_global,
+		.get_flag = get_global_flag
+	},
 };
 
 /*******************************************************************************/
@@ -1149,6 +1210,9 @@ static void addhook(struct desc *desc, enum trace_type type)
 	case Trace_Type_Evt:
 		hook->handler = afb_hook_create_evt(desc->pattern, desc->flags[type], &hook_evt_itf, hook);
 		break;
+	case Trace_Type_Global:
+		hook->handler = afb_hook_create_global(desc->flags[type], &hook_global_itf, hook);
+		break;
 	default:
 		break;
 	}
@@ -1214,17 +1278,22 @@ static void add_evt_flags(void *closure, struct json_object *object)
 	add_flags(closure, object, Trace_Type_Evt);
 }
 
+static void add_global_flags(void *closure, struct json_object *object)
+{
+	add_flags(closure, object, Trace_Type_Global);
+}
+
 /* add hooks */
 static void add(void *closure, struct json_object *object)
 {
 	int rc;
 	struct desc desc;
-	struct json_object *request, *event, *daemon, *service, *sub;
+	struct json_object *request, *event, *daemon, *service, *sub, *global;
 
 	memcpy (&desc, closure, sizeof desc);
-	request = event = daemon = service = sub = NULL;
+	request = event = daemon = service = sub = global = NULL;
 
-	rc = wrap_json_unpack(object, "{s?s s?s s?s s?s s?s s?s s?o s?o s?o s?o s?o}",
+	rc = wrap_json_unpack(object, "{s?s s?s s?s s?s s?s s?s s?o s?o s?o s?o s?o s?o}",
 			"name", &desc.name,
 			"tag", &desc.tag,
 			"api", &desc.api,
@@ -1235,6 +1304,7 @@ static void add(void *closure, struct json_object *object)
 			"daemon", &daemon,
 			"service", &service,
 			"event", &event,
+			"global", &global,
 			"for", &sub);
 
 	if (!rc) {
@@ -1261,6 +1331,9 @@ static void add(void *closure, struct json_object *object)
 		if (event)
 			wrap_json_optarray_for_all(event, add_evt_flags, &desc);
 
+		if (global)
+			wrap_json_optarray_for_all(global, add_global_flags, &desc);
+
 		/* apply */
 		if (sub)
 			wrap_json_optarray_for_all(sub, add, &desc);
diff --git a/src/verbose.c b/src/verbose.c
index 2d60dfca..e0e38248 100644
--- a/src/verbose.c
+++ b/src/verbose.c
@@ -132,12 +132,16 @@ void verbose(int loglevel, const char *file, int line, const char *function, con
 
 void vverbose(int loglevel, const char *file, int line, const char *function, const char *fmt, va_list args)
 {
-	if (verbose_observer) {
+	void (*observer)(int loglevel, const char *file, int line, const char *function, const char *fmt, va_list args) = verbose_observer;
+
+	if (!observer)
+		_vverbose_(loglevel, file, line, function, fmt, args);
+	else {
 		va_list ap;
 		va_copy(ap, args);
-		verbose_observer(loglevel, file, line, function, fmt, ap);
+		_vverbose_(loglevel, file, line, function, fmt, args);
+		observer(loglevel, file, line, function, fmt, ap);
 		va_end(ap);
 	}
-	_vverbose_(loglevel, file, line, function, fmt, args);
 }
 
diff --git a/test/monitoring/monitor-base.css b/test/monitoring/monitor-base.css
index f2de1d92..ff761ae7 100644
--- a/test/monitoring/monitor-base.css
+++ b/test/monitoring/monitor-base.css
@@ -88,8 +88,7 @@ body.on #params, body.on #connect, body.off #disconnect { display: none; }
 /*******************************************************************/
 /* setting for traces */
 
-#apis .trace-evt {
-	visibility: hidden;
+#apis .event, #apis .global {
 	display: none;
 }
 
diff --git a/test/monitoring/monitor-demo.css b/test/monitoring/monitor-demo.css
index 87cf0a0e..1025b120 100644
--- a/test/monitoring/monitor-demo.css
+++ b/test/monitoring/monitor-demo.css
@@ -244,6 +244,7 @@ html {
 .traceevent.daemon, .trace-box.daemon { color: #5af; }
 .traceevent.service, .trace-box.service { color: #0f0; }
 .traceevent.event, .trace-box.event { color: #f52; }
+.traceevent.global, .trace-box.global { color: white; }
 
 .traceevent.closed {
 	max-height: 16px;
diff --git a/test/monitoring/monitor-pastel.css b/test/monitoring/monitor-pastel.css
index 0264bf52..d5cf3f6f 100644
--- a/test/monitoring/monitor-pastel.css
+++ b/test/monitoring/monitor-pastel.css
@@ -224,6 +224,7 @@ body {
 .traceevent.daemon, .trace-box.daemon { background: #fdf; }
 .traceevent.service, .trace-box.service { background: #ddf; }
 .traceevent.event, .trace-box.event { background: #dfd; }
+.traceevent.global, .trace-box.global { background: #eee; }
 
 .traceevent.closed {
 	max-height: 16px;
diff --git a/test/monitoring/monitor.html b/test/monitoring/monitor.html
index f22a62b2..e9572ba8 100644
--- a/test/monitoring/monitor.html
+++ b/test/monitoring/monitor.html
@@ -171,6 +171,11 @@
         <div class="trace-item"><input type="radio" value="extra">extra</input></div>
         <div class="trace-item"><input type="radio" value="all">all</input></div>
       </div>
+      <div class="trace-box global" data-trace="global">
+        <div class="trace-title">trace globals:</div>
+        <div class="trace-item"><input type="radio" value="no" checked>no</input></div>
+        <div class="trace-item"><input type="radio" value="all">all</input></div>
+      </div>
     </div>
   </template>
 
diff --git a/test/monitoring/monitor.js b/test/monitoring/monitor.js
index e1d4be5b..bee87e4b 100644
--- a/test/monitoring/monitor.js
+++ b/test/monitoring/monitor.js
@@ -445,6 +445,7 @@ function gottraceevent(obj) {
 		service: function(r) { return r.api + "@" + r.action; },
 		daemon: function(r) { return r.api + ":" + r.action; },
 		event: function(r) { return r.name + "!" + r.action; },
+		global: function(r) { return "$" + r.action; },
 		})[type](desc);
 	var tab = makeobj(desc, 4);
 	if ("data" in data)